Servo magazine 2015 07 by Kap Dimitris

07.2015 VOL. 13

NO. 7

Columns 08 Robytes by Jeff & Jenn Eckert

Stimulating Robot Tidbits • Germbot Senses Humidity • Brickbot: Fast but Pricey • Thumbs Up! • Slip-On Robotic Feet

10 GeerHead by David Geer

The TigerBot Evolution Continues See where the design, testing, and construction of RIT’s TigerBot V have evolved to now.

76 Then and Now by Tom Carroll

The Robot Hut When it comes to robot collections, this unique museum is absolutely out of this world.

PAGE 76

Departments 06 Mind/Iron Can Your Robot Handle the Heat?

13 Events Calendar 14 New Products 37 Showcase 64 SERVO Webstore

16 Bots in Brief • Leap of Faith • Jeff and Lily Get All Swarmy • No Skills Required • You Better Sit Down for This • Let the Sunshine In • Nitty GRIT-y Control

82 Robo-Links 82 Advertiser’s Index SERVO Magazine (ISSN 1546-0592/CDN Pub Agree#40702530) is published monthly for $24.95 per year by T & L Publications, Inc., 430 Princeland Court, Corona, CA 92879. PERIODICALS POSTAGE PAID AT CORONA, CA AND AT ADDITIONAL ENTRY MAILING OFFICES. POSTMASTER: Send address changes to SERVO Magazine, P.O. Box 15277, North Hollywood, CA 91615 or Station A, P.O. Box 54, Windsor ON N9A 6J5; cpcreturns@servomagazine.com

SERVO 07.2015

In This Issue ... 38 CNC Part Creation Workflow

PAGE 58

by Michael Simpson The process of part design is covered this month.

43 Animatronics for the Do-It-Yourselfer by Steve Koci In this second installment, we’ll get back to the basics of animatronics discussing things like vocabulary, tools and materials, resources, and the physical construction process.

50 BattleBots is Back, Baby! by Michael “Fuzzy” Mauldin The classic fighting robot tournament is back on the air waves, and is bigger and better than ever!

58 The Robots of Maker Faire by Camp Peavy After 10 years, this annual event continues to showcase some very cool automatons.

PAGE 43

68 Analog Servos for Robotics by Eric Ostendorff In some ways, analog servos are the “unsophisticated brutes” of the robotics world.Thoroughly understanding their strengths and limitations can help you identify which things are better handled in hardware vs. software.

The Combat Zone 20 BattleBots is Back. Now What Do I Do? 23 Building Better Bots: The Power of the Watt Meter 26 Small Bot Masters — Peter Waller 30 BUILD REPORT Renewing Old Iron 34 BUILD REPORT Battle Hardening the Inside of Your Bot

07 MaxRoboTech Comics Moving & Robot Survival SERVO 07.2015

Mind / Iron by Bryan Bergeron, Editor ª

Can Your Robot Handle the Heat? I’m working with a team of engineers on a DOD-sponsored project to develop a physiologically accurate robot the size and shape of an adult male. As you might expect, there are a number of challenges such as how to pump fluid “blood” from the torso to the arms and legs while maintaining a physiologically accurate pulse, as well as how to provide a realistic sucking wound in a scenario where the chest is penetrated with a piece of shrapnel from an IED. There are dozens of servos, solenoids, microcontrollers, pumps, and hundreds of sensors in the design. One of the many things that this project has taught me is to appreciate the difficulty of dissipating heat in a close space. On a drone, you have the luxury of air flowing over heatsinks on a microcontroller board to provide convection cooling. On a submersible, there’s typically the heatsink of flowing water on the thermally conductive hull. I’m not sure exactly how NASA engineers deal with heat buildup in closed airless satellite systems, but I’m impressed that they’ve found a way to dissipate the heat generated by all those components. So, picture a human sized chassis, covered with thermally insulating “skin,” with the batteries typically supplying 12 VDC in excess of 20A. That’s about twice the power required by an Easy Bake Oven. Now, I’ll concede that a 120W light bulb is less efficient than a microcontroller or a solenoid, but there is still a great deal of heat to deal with. Poking a few holes in the chest wall and inserting a fan isn’t an option because the fan noise would interfere with normal breath and heart sounds (as heard by a stethoscope). Using the blood system is potentially problematic in that failure of the circulatory system could result in a spike in heat buildup and catastrophic failure of the robot. If you’re familiar with the Hondo Asimo, you’ve seen one answer to the heat problem: simply install a backpack air conditioner on the robot. That’s not a option in our case, as we’re limited to anatomically correct design. We haven’t licked the problem yet, but we’re getting there. The point of this editorial is to suggest that you think about the scalability of your robot designs — especially when it comes to heat dissipation. I never considered heat with small carpet roamers or even larger crawlers, where the servos are exposed to the elements. However, when you start hardening a design, protecting it from the elements, you’re also probably interrupting the routes of heat dissipation. Because catastrophic thermal runaway can be expensive, heat dissipation is worth considering in your next large-scale robot design. SV

FOR THE ROBOT INNOVATOR

ERVO

Published Monthly By T & L Publications, Inc. 430 Princeland Ct., Corona, CA 92879-1300 (951) 371-8497 FAX (951) 371-3052 Webstore Only 1-800-783-4624 www.servomagazine.com Subscriptions Toll Free 1-877-525-2539 Outside US 1-818-487-4545 P.O. Box 15277, N. Hollywood, CA 91615 PUBLISHER Larry Lemieux publisher@servomagazine.com ASSOCIATE PUBLISHER/ ADVERTISING SALES Robin Lemieux robin@servomagazine.com EDITOR Bryan Bergeron techedit-servo@yahoo.com VP of OPERATIONS Vern Graner vern@servomagazine.com CONTRIBUTING EDITORS Tom Carroll Kevin Berry David Geer R. Steven Rainwater Jenn Eckert Jeff Eckert Eric Ostendorff Michael Mauldin Steve Koci Camp Peavy Michael Simpson Russ Barrow Brandon Davis Matt Spurk Mike Jeffries CIRCULATION DEPARTMENT subscribe@servomagazine.com WEB CONTENT Michael Kaudze website@servomagazine.com WEBSTORE MARKETING Brian Kirkpatrick sales@servomagazine.com WEBSTORE MANAGER Sean Lemieux ADMINISTRATIVE STAFF Debbie Stauffacher Re Gandara Copyright 2015 by T & L Publications, Inc. All Rights Reserved All advertising is subject to publisher’s approval. We are not responsible for mistakes, misprints, or typographical errors. SERVO Magazine assumes no responsibility for the availability or condition of advertised items or for the honesty of the advertiser. The publisher makes no claims for the legality of any item advertised in SERVO. This is the sole responsibility of the advertiser. Advertisers and their agencies agree to indemnify and protect the publisher from any and all claims, action, or expense arising from advertising placed in SERVO. Please send all editorial correspondence, UPS, overnight mail, and artwork to: 430 Princeland Court, Corona, CA 92879. Printed in the USA on SFI & FSC stock.

SERVO 07.2015

Robytes by Jeff and Jenn Eckert Germbot Senses Humidity A recent development at the University of Illinois at Chicago (www.uic.edu) doesn't appear to be all that robotic, but creator Vikas Berry has officially dubbed it the NanoElectro-Robotic Device (yes, NERD), so we won't argue the point. Besides, it is interesting in several ways. For one thing, it is a bioelectronic device created by depositing two graphene quantum dots at opposite ends of a sporulating bacterium, thus creating a "robotic germ." When researchers attach electrodes to the quantum dots, the result is a bacterial humidity sensor. When the humidity level drops, the spore expels water and shrinks. As the dots become closer to each other, their conductivity increases and can be measured at the electrodes. According to Berry, NERD reacts ten times faster than polymer-based devices and provides better sensitivity in low pressure/low humidity situations. "We can go all the way down to a vacuum and see a response," he noted, which is useful in preventing corrosion or food spoilage and "is also important in space applications, where any change in humidity could signal a leak." No specific applications were cited, but the project was backed by the Terry C. Johnson Center for Basic Cancer Research, the National Science Foundation, and the Office of Naval Research, which may give us a hint.

Sporesâ&#x20AC;&#x2122; response to humidity is translated to an electronic response at graphene quantum dots.

Slip-On Robotic Feet This month's venture into robotic ridiculosity brings us to the Giant Robot Slippers with Sound, available from ThinkGeek. At least from the ankles down, they allow you to look and sound exactly (well, sort of) like a real robot. They are designed to fit any foot up to a men's size 12 (ladies' size 14). Best of all, as you walk, they exude a "vrrrrrr-clank" sound that is sure to annoy family, friends, and (if you dare) coworkers. The slippers will run you a somewhat hefty $29.95, but they are guaranteed to comply with Asimov's Three Laws. The required four AA batteries, of course, are not included. Details and a video can be found at www.thinkgeek.com/product/153b.

ThinkGeek's Giant Robot Slippers with Sound.

SERVO 07.2015

Go to www.servomagazine.com/index.php/magazine/article/july2015_Robytes to comment on these topics.

Brickbot: Fast but Pricey There's a good chance you missed the 2015 World of Concrete trade show, which drew nearly 56,000 attendees and 1,500 exhibitors to the Las Vegas Convention Center. If you had made the trip, you might have caught a demonstration of the show's Most Innovative Product Award winner: the SAM100 (Semi-Automated Mason) robotic bricklayer. Apparently, there is a serious shortage of skilled masons in the US, so Construction Robotics (construction-robotics.com) developed SAM to help fill the gap. It turns out that SAM is pretty darn good at it and is able to lay about 230 bricks per hour, compared to the 300 to 500 per day placed by the average brick mason. The company insists that the system isn't going to put anyone out of work, though. A representative noted that masons who work with the device will be able "to focus on tooling joints, monitoring wall quality, and performing tasks such as installing insulation, wall ties, and lintels ... SAM SAM100 lays approximately 230 modular definitely improves the health aspects of through utility sized bricks per hour. masonry, particularly the impact of the work on mason’s backs. Currently, masons lift the equivalent of two to three pickup trucks each week." With a price tag of $650,000, SAM will be out of reach for small masonry firms, so most workers will still need to keep a bottle of Advil handy.

Thumbs Up! Your mom was adamant that you should never pick up hitchhikers, but even she might have made an exception for hitchBOT: a robot from Port Credit, Ontario. The creation of Drs. David Smith (McMaster University) and Frauke Zeller (Ryerson University), hitchBOT is — in his own words — "a free-spirited robot who wants to explore the world and meet new friends along the way. I am an avid Instagrammer and tweeter. On my downtime, I can appreciate a good game of trivia and would never pass up any opportunities to bake desserts." In 2014, he hitchhiked more than 6,000 km (3,700 mi) from Halifax, Nova Scotia, to Victoria, British Columbia. The 26 day trip included 19 rides. Then, in February 2015, hitchBOT set off on a trek through Germany, with stops at Neuschwanstein Castle, Brandenburg Gate, and Cologne Cathedral. The trip included rides in a sports car, a bus, and even a bicycle. hitchBOT is said to be relatively talkative, employing the Cleverscript AI speech technology (details at www.cleverscript.com). It can answer questions about itself, astrophysics, philosophy, and other subjects. Its language skills are still developing, though, so responses may not always make a lot of sense. hitchBOT is also unable to move around on its own, so it is entirely dependent on the good will of people who help him along the way. Future destinations have not been announced, but you can follow his activities at www.hitchbot.me, www.facebook.com/hitchbot, twitter.com/hitchbot, or instagram.com/hitchbot. If you happen to see him thumbing a ride, just pull over, tip hitchBOT catches a ride in an your tuque at him, and ask, "How's she bootin'er?" Maybe even offer him a ride. It SUV on his way to Victoria, BC. might be fun, eh? SV

SERVO 07.2015

GEERHEAD

by David Geer geercom@neo.rr.com

The TigerBot Evolution Continues: TigerBot V The TigerBot humanoid will ultimately serve as a tour guide for visiting pupils considering Rochester Institute of Technology (RIT) as the next step in their educational experience. The very first TigerBot.

TigerBot V.

SERVO 07.2015

Monthly coverage of commercial, unique, and military robotics.

Post comments on this article at www.servomagazine.com/index.php/magazine/article/july2015_GeerHead.

The TigerBot project will continue to span many years as students enter and leave, bringing the robot from its current state of development to the next stage, and finally to the completed robot that will guide prospective students visiting the RIT campus through its halls, introducing them to this educational institute. Design, testing, and construction of TigerBot V are currently underway. This robot will rise to new heights (literally, around five feet/five inches) and will gain new capabilities on its way to maturity — just as RIT students accomplish new goals every year. he crux of the news about the latest partnership between Teknic, Inc., and the RIT electrical engineering department in developing this advanced autonomous humanoid robot called TigerBot lies in the challenges in building the robot to the newest size specifications. “When the size of the robot reaches above four feet — now growing to 5’5” — the torque requirements change dramatically because of the size and added material weight,” says Ferat Sahin, Associate Professor, Electrical and Microelectronics Engineering Department at RIT. Since the force times the distance is the torque at a given joint, when the robot is taller and the arms and legs are longer, the torque requirements for the arms, legs, and torso increase. To determine torque, RIT students working on TigerBot implement it in SolidWorks and simulate it in Gazebo, attaching the weights of the links and parts, and calculating the necessary torque at each joint. “We also put probes on the links and took outputs for certain motions to determine torque requirements,” commented Sahin. So, the knee, for example, now requires 250 Newton meters of torque. As the size of the robot increases, the torque increases in a non-linear fashion. “It is hard to do that with reasonable gear ratios. We plan to use 1-to-50 and 1-to-100 gear ratios,” said Sahin. That means using higher quality motors and servos with greater strength than is available among high-end hobby servos. “The main limitation of high-end hobby servos is their low torque rating. With higher quality motors, you can come up with and use control profiles based on human motion, as well,” Sahin explained. RIT chose the ClearPath servo motors because they meet the torque requirements without adding too much additional weight themselves, plus are easy to use and control thanks to ClearPath’s control algorithms. “They come with a controller that is right next to the motor. The embedded controller/control mechanism is better than that of hobby servos because you can set up profiles, controlling the motor with incremental changes or full angles. This all happens internally. You simply have to send the proper control signals to the controller,” Sahin pointed out. Further, the new TigerBot requires high performance

gears so the robot can achieve the necessary torque. RIT is looking at a couple of different kinds of gears: harmonic and cycloidal. “We use harmonic gears from Harmonic Drive. Their gears are ten times lighter than the cycloidal gears, but you need to incorporate them and embed them into the joints. This gives us freedom when designing the joints. The torque is very close to that of the cycloidal gears, but the backlash is greater,” Sahin said. The cycloidal gears can handle very large torques, but they weigh in at four kilograms so are heavy. “We are only SERVO 07.2015

Resources

Media Release www.rit.edu/news/athenaeum_story.php?id=49918 Next TigerBot http://edge.rit.edu/edge/P15201/public/Problem%20Definition

using two of the cycloidal gears on the hips, and two on the knees,” noted Sahin. RIT is looking for sponsorship from the Harmonic Drive gear manufacturer. The school already has a sponsorship from a cycloidal gear maker. “However, we have purchased sample gears from each type of company and will be testing them soon,” commented Sahin. RIT students are testing the gears on one leg, knowing that what will work on one leg, will work on the other. All four of the previous TigerBot designs range in size from 2.5 to above four feet, each with functional walking gaits that RIT developed using inverse kinematics algorithms. Using these algorithms enables RIT students to build increasingly larger robots without changing more than a few inputs to the calculations. By simply changing the size of the links in the algorithm, the algorithm can produce calculations for correct joint angles for the given humanoid robot motion the roboticists desire. “TigerBot II had an ROS (Robot Operating System) based inverse kinematics algorithm with successful operation,” said Sahin. RIT students searched for servo products and found the ClearPath: an all-in-one product that incorporates a threephase permanent magnet brushless servo motor; a high resolution optical encoder; a DSP-based, all-digital vector servo drive; and a motion controller. “The size, performance, and overall power capacity of these servos were very attractive as space is at a premium inside the robot. With ClearPath, we don’t have a servo drive to install and there’s no motor cable between the drive and motor in this servo product,” Sahin explained. The all-in-one servo for OEM applications offers the highest commercially available power density in the fractional horsepower class. “It uses a servo compensator with advanced feed forward gains and numerous proprietary heuristics, and adaptive gains as well as nonlinear extensions. Its three-phase vector torque control provides fast torque response, independent of rotational speeds,” commented Sahin. The folks at Teknic responded to RIT’s request for corporate sponsorship and because they are a local company, they were able to send out two engineers to visit the campus to do design reviews and trainings. “They also recommended a couple of vendors for gearbox technology,” said Sahin. RIT expects both the hardware and the software in the new human scale TigerBot to turn out uniquely different from those of the previous TigerBot iterations. The TigerBot will have higher quality motors, stronger gearboxes, and minimal backlash — no backlash will really spread to the rest of the robotic system thanks to using these motors and gearboxes. The TigerBot already has an ROS software implementation for everything, including the test joints. So,

SERVO 07.2015

the control of everything — including all the robot’s joints — will be possible using the ROS software and adding these joint ROS models to the overall system. “In addition, the main controller of the robot has more computational power for additional sensor interface and future behavioral algorithms,” Sahin stated. To have tour guide capabilities, the RIT TigerBot will eventually have to be able to walk safely and smoothly throughout the halls for the area covered. “It will also have to have smooth interaction with visitors when they ask a question,” remarked Sahin. “We are in the middle phase of the multi-year TigerBot development project. We have designed humanoids with 22 joints and have explored several manufacturing techniques and motor-to-gear pairs,” commented Sahin. Now comes the third and final phase where the robot grows to human scale, and proposes new opportunities and new challenges for expansion as a platform. “I believe once the physical implementation of the robot is completed, we will be able to complete the algorithms for safe navigation and human interaction (using recordings of the lab info, voice recognition, and speakers for one word interactions),” said Sahin. RIT must explore, test, and achieve the right balance of structural materials, gears, and motors for a stable predictable robot that will be safe in a human environment. For that, more work must be done in the balancing, walking, navigation, and guide aspects of the robot. TigerBot will ultimately house and use a number of different advanced sensor technologies for navigating in and interacting with its environment. “We are exploring sensors including accelerometers, gyros, force sensors, current sensors, IR distance sensors, and ultrasonic distance sensors. We are considering Microsoft Kinect for 3D mapping and localization,” disclosed Sahin. The robot will also use a touch screen interface, voice recognition technology, and voice-to-text sensors. The inverse kinematics algorithm uses an ROS library which RIT has modified to suit the TigerBot’s dimensions. RIT replicated the robot in a simulation tool with a physical world engine that is entirely compatible with ROS. Further, RIT developed an algorithm for TigerBot II that balances the robot using accelerometers, gyros, and current sensors for the servomotors. “We will be expanding upon this successful approach,” concluded Sahin.

Last Word Named after the RIT Tigers men’s ice hockey team at the Institute, TigerBot will instill pride in the school with its unique capabilities and offerings. SV

EVENTS Know of any robot competitions Iâ&#x20AC;&#x2122;ve missed? Is your local school or robot group planning a contest? Send an email to steve@ncc.com and tell me about it. Be sure to include the date and location of your contest. If you have a website with contest info, send along the URL as well, so we can tell everyone else about it. For last-minute updates and changes, you can always find the most recent version of the Robot Competition FAQ at Robots.net: http://robots.net/rcfaq.html. â&#x20AC;&#x201D; R. Steven Rainwater

JULY 26-29 4

RoboBombeiro San Miguel Sports Hall, Guarda, Portugal Autonomous fire fighting robots. http://robobombeiro.ipg.pt

7-11

Botball National Tournament Albuquerque, NM Student teams build autonomous robots that compete on a game board by moving black and white balls. www.botball.org

10-11

International Autonomous Robot Racing Competition University of Waterloo Waterloo, Ontario, Canada Student-built autonomous robots must navigate a course, avoiding fixed obstacles. http://robotracing.wordpress.com

13-17

K*bot World Championships Las Vegas, NV Events include autonomous two-wheel drive K*bots and four-wheel drive K*bots, as well as remote controlled Cyber K*bots. www.kbotworld.com

17-23

RoboCup Robot Soccer World Cup Hefei, China Events include small-size robot soccer, mid-size robot soccer, Sony legged robot soccer, humanoid robot soccer, Robocup Junior robot soccer, and Rescue Robots. www.robocup.org

20-26

International RoboSub Competition SSC Pacific TRANSDEC, San Diego, CA University teams build autonomous underwater robots that must complete a different task each year. www.robosub.org

ASABE Robotics Competition New Orleans, LA University teams build robots to complete a different agricultural task each year. http://abe-research.illinois.edu/ ASABERobotics

SERVO 07.2015

NEW PRODUCTS Gooseneck Robot Kit from Actobotics

These boards simply slide over the motor terminals and solder in place. The pre-installed .100” spacing row pins allow plug-and-play connectivity to several different plug styles (JST, Rx battery connector, male servo connector). The plug-in makes switching polarity, swapping motors, and reconfiguring a robot without firing up the soldering iron quick and easy. Each board has multiple holes which can be utilized to run additional wires to the motor or to daisychain multiple motors. It is sold with 90 degree header pins pre-soldered to the board. Prices start at $0.69/each.

he Gooseneck™ now available from ServoCity is a little trail-wheel robot kit that glides effortlessly across the floor. The 2.975” orange skate wheels are each driven by a 195 RPM 3V-12V precision planetary gearmotor. The “truck-bed” style chassis is ideal for battery storage, electronics, or for hauling things around. The chassis is almost entirely snap-together, requiring only a 7/64” hex key for assembly. The chassis plates incorporate the 0.770” Actobotics hub pattern, allowing for easy attachment and customization using other Actobotics components. The protruding “Gooseneck” piece provides a base for a robotic arm, gripper kit, scoop, or other custom attachment. Price is $89.99.

Actobotics Gearmotor Power Input Boards

he gearmotor power connector boards also now available from ServoCity add versatility to any gearmotor.

MIPS-based Microcomputer

magination Technologies announces an updated version of their MIPS-based microcomputer called Creator CI20. Launched in December 2014, the Creator CI20 is an affordable microcomputer that runs Linux and Android, and enables open source developers, the maker community, system integrators, and others to implement a wide array of applications quickly. It is ideal for projects such as home automation, gaming, wireless multimedia streaming, and others that require a high performance Linux or Android platform with GPU and video capabilities, and provides excellent connectivity. This new version includes an improved board layout that optimizes Wi-Fi performance, and is easier to mount in cases. They’ve also designed a new 3D printable enclosure. Builders can use the source files available on Imagination Technologies’

SERVO 07.2015

For further information, please contact:

ServoCity

www.servocity.com

website to build their own versions. On the software side, they are adding out-of-the-box FlowCloud support, and also bringing new features to Linux and Android: • FlowCloud is an IoT (Internet of Things) API designed by Imagination to connect devices to the cloud; it already runs on other MIPS-based dev boards, including the chipKIT Wi-FIRE from Digilent. FlowCloud gives users comprehensive deviceto-cloud infrastructure and services, enabling IoT innovators to rapidly create new applications based on the CI20 such as home automation, robotics, industrial monitoring and control, and many others. • For Android 4.4, several improvements have been made, including audio over HDMI and Bluetooth; new built-in Ethernet settings; audio jack auto-

detection (easily switch audio output from HDMI to headphones, and vice versa); and audio recording. Support for USB storage is coming soon. • For Linux, Imagination is working on updating to kernel version 3.18 which will offer a boost in vital performance areas such as memory speed and graphics.

The new MIPS Creator CI20 incorporates an Ingenic JZ4780 SoC which includes a 1.2 GHz dual-core MIPS32 processor and PowerVR SGX540 GPU. Retail price is $65. For further information, please contact:

High-Definition Action Cameras

The S60 is priced at $299.99. It includes: a waterproof housing, quick release mount, body clip mount, waterproof body clip mount, two flat adhesive mounts, two curved adhesive mounts, quick release mount, carrying pouch, USB cable, wrist strap, manual, and CD.

itec and AEE have combined forces to deliver two new action cameras (the MD10 and S60) designed to capture images in high definition precision. With lens and ultra resolution, users can video action and showcase their hobby talents with ease. The MD10 version is priced at $209.99. The camera includes: a waterproof housing, quick release mount, body clip mount, waterproof body clip mount, two flat adhesive mounts, two curved adhesive mounts, quick release mount, carrying pouch, USB cable, wrist strap, manual, and CD.

FEATURES: • 1080p30 / 720p60 WVGA 120fps • 8 Megapixel Shooting • 180° Image Flip Feature • 8 MP / 8fps Burst • Intelligent Voice Control • 4X Digital Zoom while Recording • Wi-Fi Connection with 328 ft Range • IP-68 Waterproof Housing with 20 meters Diving Depth (Included in Full Package Only) TECHNICAL SPECIFICATIONS: Recording Time Video - About 210 Min. (Max.) Audio - About 240 Min. (Max.) Dimensions: 1.34 x 1.10 x 2.05 in. Weight: 1.76 oz. There is also an MD10 Lite Package priced at $179.99. It includes: body clip mount, USB cable, manual, and CD.

Imagination Technologies

www.imgtec.com

FEATURES: • 1080p / 60fps and 16MP Image Shots • Two inch LCD Back for Viewing Footage • High Capacity 1500 mAh Lithium Battery • Heavy Duty Camera Attachment • Pushbutton Start Design

• • • • •

IP-68 Waterproof Housing with 10 meters Diving Depth 180° Image Flip Feature Wi-Fi Connection with 328 ft Range 4X Digital Zoom while Recording Handsfree Recording with G-Force Sensor

TECHNICAL SPECIFICATIONS: Recording Time Video - About 180 Min. (Max.) Audio - About 210 Min. (Max.) Dimensions: 2.32 x 1.69 x 1.38 in. Weight: 1.92 oz. For further information, please contact:

Hitec

www.hitecrcd.com SERVO 07.2015

bots

IN BRIEF LEAP OF FAITH

n a leap for robot development, the MIT researchers who built a robotic cheetah have now trained it to see and jump over hurdles as it runs — making this the first four-legged robot to run and jump over

obstacles autonomously. To get a running jump, the robot plans out its path much like a human runner: As it detects an approaching obstacle, it estimates that object’s height and distance. The robot gauges the best position from which to jump, and adjusts its stride to land just short of the obstacle before exerting enough force to push up and over. Based on the obstacle’s height, the robot then applies a certain amount of force to land safely before resuming its initial pace. In experiments on a treadmill and an indoor track, the cheetah robot successfully cleared obstacles up to 18 inches tall — more than half of the robot’s own height — while maintaining an average running speed of five miles per hour. “A running jump is a truly dynamic behavior,” said Sangbae Kim, an assistant professor of mechanical engineering at MIT in a recent interview with Jennifer Chu from the MIT News Office. “You have to manage balance and energy, and be able to handle impact after landing. Our robot is specifically designed for those highly dynamic behaviors.” Kim and his colleagues — including research scientist Hae won Park and postdoc Patrick Wensing — planned to demonstrate their cheetah’s running jump at the DARPA Robotics Challenge in June and present a paper detailing the autonomous system in July at the conference, Robotics: Science and Systems. Last September, the group demonstrated that the

SERVO 07.2015

robotic cheetah was able to run untethered — a feat that Kim notes the robot performed “blind,” without the use of cameras or other vision systems. Now, the robot can “see,” with the use of onboard LIDAR — a visual system that uses reflections from a laser to map terrain. The team developed a three-part algorithm to plan out the robot’s path based on LIDAR data. Both the vision and path-planning system are onboard the robot, giving it complete autonomous control. The algorithm’s first component enables the robot to detect an obstacle and estimate its size and distance. The researchers devised a formula to simplify a visual scene, representing the ground as a straight line and any obstacles as deviations from that line. With this formula, the robot can estimate an obstacle’s height and distance from itself. Once the robot has detected an obstacle, the second component of the algorithm kicks in, allowing the robot to adjust its approach while nearing the obstacle. Based on the obstacle’s distance, the algorithm predicts the best position from which to jump in order to safely clear it, then backtracks from there to space out the robot’s remaining strides, speeding up or slowing down in order to reach the optimal jumping-off point. This “approach adjustment algorithm” runs on-the-fly, optimizing the robot’s stride with every step. The optimization process takes about 100 milliseconds to complete — about half the time of a single stride. When the robot reaches the jumping-off point, the third component of the algorithm takes over to determine its jumping trajectory. Based on an obstacle’s height and the robot’s speed, the researchers came up with a formula to determine the amount of force the robot’s electric motors should exert to safely launch the robot over the obstacle. The formula essentially cranks up the force applied in the robot’s normal bounding gait, which Kim notes is essentially “sequential executions of small jumps.” To see it in action, go to http://newsoffice.mit.edu/2014/mit-cheetah-robotruns-jumps-0915.

bots

IN BRIEF JEFF AND LILY GET ALL SWARMY

orty one tiny robot submarines is a lot of tiny robot submarines. It’s so many, in fact, that controlling them individually doesn’t make sense. The only way to go then is to give them levels of swarm intelligence, so that each individual robot can take care of itself while the swarm as a whole completes an objective. The CoCoRo (Collective Cognitive Robotics) Project sponsored by the European Commission has been working with a heterogeneous swarm of Image courtesy of CoCoRo Project. autonomous underwater vehicles (AUVs) since 2011. However, the most important thing to know about these robots is that 20 of them are named Jeff. Jeffs are powerful; they’re able to swim upstream against a current of 1 m/s. The other AUVs — the Lily robots — aren’t quite as burly, so in the swarm they stay higher in the water to provide a communications link between the Jeff robots, the base station, and the rest of the world. Each AUV is capable of operating on its own and small groups share data between themselves. Then, the entire swarm makes decisions based on the collective data. The advantages here are the same as with any robot swarm: It’s versatile, adaptable, and very robust against failures of individual members. You could lose a handful of Lilys or Jeffs — and, of course, it would be very sad — but the mission could continue. The specific swarm behaviors that the robots employ are modeled on swarming experts; namely, fish, birds, social insects, and even slime molds. A group of Lily robots can achieve a coherent shoaling or flocking configuration by emitting and receiving pulsed light signals. Similar to slime mold or fireflies, such pulsed signals are relayed from one agent to the next, forming signal waves that move through the whole swarm. These waves are used to keep the swarm of Lily robots together as a group, to coordinate the swarm, and to move it in a desired direction. In terms of practical applications, one possible scenario could be an underwater search, where Jeff robots spread out to locate a target, signal each other when it’s found, and then call Lily robots over for help communicating with the surface.

SERVO 07.2015

NO SKILLS REQUIRED

uribot is an affordable compact robot kit, designed to make coding and robotics easily accessible to people of all ages and skill levels. It packs in quality hardware — usually seen only at universities — and is intended to grow with the ability of the user. This makes Muribot significantly different from robotic platforms that are created for a specific skill level. By bridging the gap to a high quality learning experience, Muribot aims to be a major competitor in the STEM market and began crowdfunding to achieve that goal back in May. The robot is pre-loaded with a remote control demo, which means it’s possible to play with it right away. Code is written in C using MPLab IDE, and the Muribot API (application program interface) makes it simple and easy to get started. No previous experience is necessary. More advanced users can begin to control the hardware right away, forgoing the API. Images courtesy of Mid-Ohio Area Robotics. Muribot can be used to explore concepts at different levels, from simple line following and odometry to the more advanced design of neural networks and swarm robotics. The platform is fitted with 25 sensors, including eight infrared proximity and ambient light sensors, three-axis accelerometer and magnetometer, yaw-rate gyroscope, and much more. The internal 900 mAh battery takes about 1-2 hours to charge, and provides 6-8 hours of running time per charge. Muribot is part of the FOSS (Free Open Source Software) and Free Education movement, so is fully open source and hacker friendly.

YOU BETTER SIT DOWN FOR THIS

ecently, Swiss startup, noonee completed the first round of testing for their Chairless Chair with German car manufacturer, Audi. The Chairless Chair is a wearable sitting exoskeleton for people working on construction lines that is designed to allow movement while still providing enough support to prevent the repetitive stress and health problems that are so common in this kind of work. Rather than just providing a chair to sit in, noonee avoids the issue of muscle wastage by designing the exoskeleton to support the wearer in such a way that they continue to use their muscles. The version of the Chairless Chair tested at Audi is called TITAN, which is made out of titanium. The next stage of development will be to create a version manufactured from carbon.

Image courtesy of Audi.

SERVO 07.2015

LET THE SUNSHINE IN

coppia — a 2013 Israeli based startup — is providing a robotic solar panel cleaning system to power companies with solar farms in the desert. Ecoppia recently installed and retrofitted five solar panel sites totaling more than 35 MW. Their systems are cleaning about five million dusty panels every month.

NITTY GRIT-Y CONTROL

s robots get smaller, cheaper, and more capable, it often makes sense to rely on swarms of little bots instead of one big one. As swarms grow in size and complexity, intuitive methods of real time control become critical. Georgia Tech’s GRITS (Georgia Robotics and Intelligent Systems) Lab has developed a way to dynamically control large swarms of robots using just a tablet and a finger (or two). While robots are typically pretty good at determining efficient ways of completing tasks, they’re not so great at adapting to change and figuring out which tasks need to be done — especially if they need to change priorities on-the-fly. This is where the humans come in.

With Georgia Tech’s system, a novice user can assign goals just by poking at a tablet, and a swarm of robots will coordinate with each other to achieve those goals. The scenario that this system was designed for is the obligatory disaster search-and-rescue mission, where you have a large amount of rugged terrain that needs to be covered optimally — something robots are good at. They have no trouble cooperating to search an area. Meanwhile, a human can identify areas of interest, and set those areas as goals for the robot swarm. Once a new goal is assigned, the robots redeploy themselves based on an algorithm that guarantees optimal coverage, without the human having to get any more involved.

Image courtesy of Georgia Tech.

SERVO 07.2015

Post comments on this section and find any associated files and/or downloads at www. servomagazine.com/index.php /magazine/article/july2015 _CombatZone.

Featured This Month: 20 BattleBots is Back.

BattleBots is Back. Now What Do I Do? ● by Kevin Berry

Now What Do I Do? by Kevin Berry

23 Building Better Bots: The Power of the Watt Meter by Russ Barrow

26 Small Bot Masters — Peter Waller by Brandon Davis

29 Cartoon 30 BUILD REPORT: Renewing Old Iron by Matt Spurk

34 BUILD REPORT: Battle Hardening the Inside of Your Bot by Michael Jeffries

SERVO 07.2015

ith the resurrection of the show BattleBots™, many of you who’ve been skipping the Combat Zone section or maybe weren’t that interested in building a bot just to have it destroyed, might be thinking about joining in. This article is meant to help ease you into the sport with some tips, clues, and warnings. First and most important: TV shows like BattleBots and Robot Wars may have ended back in the early 2000s, but the sport didn’t die along with media coverage. In fact, there are more events worldwide than there ever were during the “glory days.” Every continent has events. Now, this is important. The term is “combat robot.” The TV show — great as it is to have it back — doesn’t hold a monopoly on the sport. To fit in with the veterans — many of whom have been participating for 15 years — do yourself a favor and call it the right name. Second — and nearly as

important — do your homework. The absolute worst way to approach a club, builder, or FaceBook group is like this: “Hi. I want to build a BattleBot. How do I do that?” (Ed. Note: For my own sanity, I used correct grammar, spelling, and sentence structure. Most of these posts aren’t nearly this neatly stated.) The links included here, plus any search engine will get you to hundreds of fight videos, build reports, and articles. (Blatent Advertisement: Combat Zone has published articles on building and fighting bots for nearly 10 years. There’s an article for almost anything you can think of somewhere in your dusty stacks of old issues.) In fact, the February issue had a specific parts list in the article “Today’s Beetle” by yours truly. The June issue had a great overview called “The Influence of Combat Robot Kits” by Nate Franklin. So, you can do a lot of work

yourself before you start asking for help. There is no “one design” or “standard” combat robot. The creativity and uniqueness of each bot is part of the fun. There is a nearly infinite combination of components and philosophies on fighting styles, so it’s truly a design task, not a cookbook. Here are two “best practice” first posts:

RoboGames 2009. Photo courtesy Dave Schumaker and RoboGames.

An informed question showing you’ve done your homework will be answered with lots of advice — much of it good. Of course, a humble friendly tone is always welcome. If you’re into theory, the RioBotz tutorial is an exhaustive guide and well worth reading.

Many of the links here have forums, builder’s guides, or other resources as well. Third: Remember that this is a volunteer sport, with no true central organization. So, while the rules are generally similar from event to event, there are always local variations.

1. “Hi, I’m interested in getting involved in the sport. I see you’re holding an event next month. I’d like to volunteer to help out there any way I can.”

Thrifty Throttle Th

This will make you instantly popular, and you’ll learn so much in a short time, you’ll be building for your second event. 2. “I’ve designed my first Beetleweight. For my ESC, I’m down to either the BaneBots BB-3-9 or the FingerTech tinyESC. I’m using BaneBots 24 mm 25:1 motors. Will one of the ESCs be better than the other, or am I on the wrong track?”

Run motor controllers or servos with And AndyMark’s easy and affordable PWM signal generator. sign • PWM PW Generation Standard servo range - 1000ms-2000ms Arduino extended range - ~540ms-2300ms • Co Comfortable one-hand operation • 9V Battery Operation (battery not included)

Visit AndyMark.com and view our wide selection of robot parts! Use coupon code

“SERVO5” for 5% off your next order

Kokomo, Indiana • www.AndyMark.com • 877-868-4770 SERVO 07.2015

Clubs and Events

Facebook Groups

Northeast Robotics Club www.nerc.us

(Note: Some of these are closed groups, and you'll have to request to be added.)

Robot Battles www.robotbattles.com Saskatoon Combat Robotics Club http://kilobots.com Carolina Combat Robots www.carolinacombat.com Western Allied Robotics www.westernalliedrobotics.com Ohio Robotics Club www.ohiorobotclub.com Bot Blast http://botblast.webs.com United States Alliance for Technical Literacy www.usatl.org Central Illinois Robotics Club www.circpeoria.org RoboWars Australia www.robowars.org

• BOtsIQSWPA (SW Pennsylvania BotsIQ) • Sonoma Ant Wars • Florida Combat Robot Builders • Queensland Robotics Sports Club • Atlanta Robot Fight Club • Robotics Community (covers all kinds of robotics including combat) • Combat Robotics (for serious builders) RioBotz Combots Tutorial www.riobotz.com.br/riobotz_combot_tutorial.pdf

Rules and Event Listings RoboGames www.robogames.net Builder’s Database www.buildersdb.com/events.asp Standardized Procedures for the Advancement of Robotic Combat http://sparc.tools

tell you they started with a mega weapon bot and fielded either a piece of junk, or had Atlanta Combat Robots to leave the weapon off and http://johnmccusker4.wix.com/atlantacombatrobots run a boxbot. No one will give you a bad comment if you National Robotics League bring a pretty good wedge or http://gonrl.org box for your first attempt. Fighting Robots Association We all have a series of www.fightingrobots.co.uk spectacular failures in our past, so keeping something going Brazilian Events for three or four fights is a www.robocore.net huge accomplishment. Fifth: Rules. There are two Central Florida Events sets in the US. One — the http://southeastcombots.com heritage of the Robot Fighting League — is on the Each Event Organizer (the poor RoboGames site. (WARNING: The old schmuck who puts their money, time, RFL web URL has been taken over by and sanity on the line to hold an spammers and is virus laden. Go event) will have specific do’s and straight to the RoboGames site for don’ts; for example, how an event is rules.) judged and scored. Or, whether The second — a new and slightly “unsticks” are allowed. Some limit the different take on the old RFL rules — is energy in weapons due to arena or on the SPARC site. Build to the rules venue safety requirements. for your event. Don’t argue; don’t ask Fourth: KISS. Build a box or for safety waivers. There is a reason for every one — usually connected to wedge first. Every single builder will

SERVO 07.2015

safety. Make sure you are 100% compliant with the rule set — both in general and specific to the event. Sixth (and last): Not every club or competition listed here is holding regular events. Some haven’t had one in a while; some are more ad hoc. Still, if there’s a club or event in your area, let them know you’re interested. It often doesn’t take much of a push to re-energize an event. If you possibly can, go to RoboGames in the spring in northern CA. It’s the granddaddy event of our sport and an amazing experience. Just remember, the garage and backyard events are just as fun, and may be closer to home. I listed only North America, South America, Australia, and U.K. events, and probably missed some. There is an event in India, has been one in Korea, and some are held on the European continent which I didn’t list here. Now, go forth and get involved. SV

Building Better Bots: The Power of the Watt Meter ● by Russ Barrow

o, you’ve mastered the calipers (even if you can’t quite seem to keep it turned off), figured out how to use the voltage and continuity dials on the digital multimeter, and are pretty sure you have the scale figured out (except for that awkward triple beam balance thing). So, what about that watt meter that all the cool builders are using? Should you spend the money and energy into this black box that fits between your batteries and the robot? The short answer: Yes, you should. Watt meters have dramatically reduced in price over the years, and include all kinds of features that not only can be used to observe operational conditions of your robot, but can help you design a machine that will work more efficiently and eliminate many headaches that will cost you time and money later. Let’s see “whatt” all we can do with this new tool.

What is a Watt Meter? A watt meter is an instrument used to measure the power a system consumes as a factor of time. They typically consist of an insulated sensor with a display, with source and load wiring on each end. The meter is placed between your power supply or battery, and the system or robot that is consuming the power. Ohm’s Law tells us power is equal to voltage (potential energy) multiplied by current (flow of electrons), represented by P = I x R.

and perhaps even logging functions. Figure 1 is an example of a simple high current watt meter.

Baseline and Inspection Some of the new online hobby stores and web products have revolutionized robot building. The perfect motor or battery is merely a click away and as far as pricing, bargains are to be had everywhere. As far as quality, well, there is always room for improvement. Whether a product is going to work as advertised often depends on the first test. Unfortunately, too many of us are confirming successful operation by listening to a sound it makes, how hot it gets, or if smoke comes pouring out.

Figure 1.

So, a watt meter will provide a summary of current draw and voltage as consumed by the load over time, measured in watts. So, at a minimum, a watt meter will provide a real time measurement of voltage and current. However, most also include peak rating capture, amps or watts per hour,

Personal CNC Mills Shown here with optional stand and accessories.

Shown below is an articulated humanoid robot leg, built by researchers at the Drexel Autonomous System Lab (DASL) with a Tormach PCNC 1100 milling machine. DASL researcher Roy Gross estimates that somewhere between 300 and 400 components for “HUBO+” has been machined on their PCNC 1100.

PCNC 1100 Series 3 starting at:

$8480 (plus shipping)

www.tormach.com/servo SERVO 07.2015

that is contacting the stator wires of a motor or interfering with the rotation of a rotor. You can also see the direct effect of wiring loses and mechanical drag.

Motor Optimization and Gear Reduction Figure 2.

The first thing you should do with any new product is to connect it to a watt meter to see if the parameters listed for the product match what you have. Consider this a baseline or initial performance behavior before you start to assemble or modify parts. Any battery (source) or motor and electronic speed controller (load) should generally match the vendor’s specifications. If your battery’s voltage it too low or the motor pulls far too much current, then you might have a quality issue and should not proceed with using the product. Beyond the initial test, you can continue to evaluate the performance of the system as you build. This can be especially helpful in mounting motors or supporting drive shafts. A much higher than expected current or wattage can indicate a binding or excessive drag from a bearing or non-parallel/ perpendicular mount. You might also see a large current draw from a mounting bolt Figure 3.

SERVO 07.2015

Both brushless and brushed permanent magnet motors have a linear operation specification. Many will have a functional chart that provides operation as a result of voltage, current (in amps), torque, and efficiency — each as measured by RPM or speed. See Figure 2 as an example. Don’t get lost in the details of the motor curves; the key is to understand certain relationships. First, a motor will have a no load speed with a current (in amps) based on a voltage — often a factor of its KV (RPM is the KV multiplied by the voltage). As the load is applied, the motor will require more torque, slow, then current will rise. All this happens linearly. So, even if you do not have a chart for a motor, you will have the no-load and stall current for a given voltage, and you can plot it as a linear line between the two points over RPM. Another item to note is that the peak efficiency of the motor is typically in the 75%-90% RPM range. This is the point where the motor can generate optimal output power without creating excess heat and reduced run time (duty cycle). As an example, if while using your watt meter, you note a steady or normal operation motor current that is midway between your no-load current and stall current for a given voltage, you know that the motor is

operating at 50% RPM. This is also well outside of the maximum efficiency zone. If you added additional drive reduction — such as a higher gearbox ratio or a larger output pulley — you will drop the necessary torque and current to the motor and increase motor speed. This may also indicate you need a motor with more torque and/or a higher RPM. So, your watt meter can help you find the optimal output speed per given power required. The advantage of this work is increased run times from a battery, longer life for the motor and battery, and a reduced chance for a catastrophic failure.

Battery Selection Unless your robot is tethered, you will have a finite amount of power from a battery. All batteries have three main parameters we need to understand. One is voltage. This is the potential energy of a given cell type multiplied by the number of cells. For the longevity of the cell, we need to keep the voltage between its maximum and minimum cell voltage. As an example, Lithium Polymer cells — or LiPos — have a maximum voltage of 4.2 VDC and a minimum voltage of 3 VDC. Typical voltage is 3.7 VDC. Run these cells above or below these voltages once or potentially many times, and they will swell or explode (worst case) and reduce capacity (best case). The second parameter to understand is the capacity of the cell given in amp hours (Ah). If a battery is rated for one amp hour capacity, it can provide one amp of current over an entire hour’s time. The third parameter is the battery’s internal resistance, often referred to as its “C” rating. The C rating is shorthand for the capacity of the battery or cell. If the 1 Ah battery has a 30C rating, its internal resistance is low enough to deliver a maximum of 30 amps (1 Ah x 30) until its voltage drops below the

minimal voltage and the battery is depleted. Higher currents can damage the battery similar to voltages outside the minimum and maximum range. Figure 3 is a common battery with these parameters clearly identified. Using your watt meter, if you observed a robot consuming an average of 30 amps and had to run it for three minutes, you would not be able to use that 1 Ah 30C battery because you would run out of capacity. By matching units, a 1 Ah battery can provide 60 amp minutes (1 hour = 60 minutes), but understand that you cannot provide more than 30 amps at any time. So, running a 1 Ah/60 amp battery at 30 amps yields only two minutes of run time on the battery. Most likely, you will not be running a motor with an average current close to the C rating, as motors typically will have a higher starting current

(peak current) that while momentary, should be used within the C rating of the battery. In this way, the watt meter can provide you start-up and running currents that will define the needed batteryâ&#x20AC;&#x2122;s capacity and C rating.

Voltage Drop, Brownout, and Worst Case Testing Much of the testing so far has focused on running and peak currents, but remember voltage and current combine to create power. Since the battery is a defined finite power source, large current spikes create large voltage drops. Between the batteries and motors reside controllers, drives, and other electronics. Most of these electronics have a minimal operating voltage. If you momentarily go below these values, the microcontroller,

power regulator, or other component can enter an unknown or unpredictable region and stop functioning. This is commonly referred to as a brownout. Disconnecting and reconnecting power can solve this, but if you are competing, have a robot out of reach, or in air, bad things can happen. Therefore, it is important to watch your battery or power supply voltage during all test conditions to make sure you have a safety margin on voltage. Finally, after spending so much time designing and making our bots, be prepared to test beyond average conditions. It may be difficult to abuse something you have put so much time into, but it is always better to find problems when you can correct or replace them easily. During these tests, use your watt meter to find the limits, and know what to expect when you need it. SV

SERVO 07.2015

Small Bot Masters — Peter Waller ● by Brandon Davis

he places I fight bots have four weight classes: 30, 12, 3, and 1 pound. I am especially fond of the 1 lb. That’s 16 ounces to my nextdoor neighbor, but to Peter Waller that is 453.59 grams. It is also, to him, overweight by more than 300 grams, or two whole robots. Peter is a master of the Bonsai Tree branch of fighting robots. The United Kingdom — that portion of the green and blue wobbly he calls home — has popular, well-attended fights for bots at far less than a pound. The arena for these fights is a bit different to most American boxes: a minimum of 30x30 inches and at least half of the edge of the arena must be un-walled to allow robots to drop directly into the ditch that surrounds the arena (a loss). There is an encompassing Lexan box around the whole thing to contain the more energetic competitors. This contracts pretty starkly with my own 72x72 inches of flat to the wall box with a single 16x16 inch push-out on one side. With all of that as prologue, I’m going to get out of the way of a master telling his own story. Peter Waller begins: I am a 68 year old retired electronics engineer with a love for all things engineering. I have been Antweight

150 grams

Fleaweight

75 grams

Nanoweight

25 grams

SERVO 07.2015

Fit in a four inch cube Fit in a three inch cube Fit in a 50 mm cube

Anticyclone.

married for 47 years to a very understanding wife who — although has no interest in robotics — is quite happy for me to spend my money and time on them. Work lost much of its interest as I got older as I seemed to be dealing with more of the European legislation such as WEEE and ROHS and less engineering, so I took early retirement on my 59th birthday and never looked back. I first got into robots after watching Robot Wars on TV, and spent the best part of two years making a heavy. It took a long time because I tried to make everything from scratch — from the 150A speed controllers to the caterpillar tracks. It had a pneumatic spike which was supplemented by several bungee ropes, but by the time it was finished it was out of date and the ability to punch through 1 mm steel plate which I thought was good was useless against 3 mm steel or 5 mm aluminum that was then the standard. Needless to say, it didn’t get through the trials for Robot Wars and was consigned to the back of the

garage. That winter, having seen the Ants on the Internet, I decided to build one as I could do that indoors and the garage was cold. The first event I ever went to was Antweight World Series 3 in the year 2000 at Guildford University with a total of 15 Antweight robots competing. I was lucky enough to win with my spinner, Combatant. When you compare that with last month, when at AWS46 (we have three per year) we had 101 Ants, you can see the class is getting very popular. Having won my first event, I was completely hooked and have been building small robots ever since. Although I had some success for a few years culminating in 1st and 2nd at AWS 27, I now find that my reaction times are not quite up to those of the younger roboteers and I haven’t won since. [BD: I think a bit of modesty is on view here. He might not have swept a series since AWS 27 in November 2008, but by the 2010 AWS37, he had five AWS trophies.] Peter: I don’t tend to be too formal in my design approach; in fact, it is sometimes a little haphazard. For many years, I have used a package called Design Cad to produce drawings in 2D, and a package called Contour Cam to produce files for a small CNC mill I have. Although this mill is capable of milling aluminum, I have tended to use it mostly on fiberglass, carbon fiber, polycarbonate, and Delron [a.k.a., Delrin – acetal polyoxymethylene resin].

Current Nanos.

More recently, I have got into 3D printing my parts. Initially, I was getting the parts made by the agency Shapeways in the Netherlands, but for the last two years, I’ve been using my own printer. I have mainly used an UP Plus 3D printer with ABS, but recently I have bought one of the Prusa i3 kits so I can experiment with more advanced materials. Virtually all my current combat robots are 3D printed with a few parts armored in polycarbonate or titanium. I produce the 3D CAD drawings using the free version of Google SketchUp, which seems to be quite adequate for the task. The main advantage in printing your own parts is that you can try out parts of the design in stages without having to design every detail in one go. Also, at home, prints can take up to a couple of hours compared to a two week turn around at an agency. It is very fast and a lot cheaper once you have paid for the printer. British Antweights are about a third of the weight of US ones and we have a size restriction, as well. As it has become easier to get the robots within size and weight, what with the use of LiPo batteries and smaller and lighter controllers, receivers, and servos, we have introduced smaller classes to maintain the challenge. At these weights and in our arenas, the most important factors to a competitive robot are: good grip, a very good scoop for getting under the

Current Fleas.

opposition, the ability to self-right or run inverted, and the ability to withstand hits from the spinners. To improve the grip, I have started molding my own tires in a very soft silicone rubber material from Bentley Advanced Materials (www.benam.co.uk/products/silico ne). I started using a material called Dragonskin, which was 10A hardness. I have since moved on to an even softer material called Ecoflex, which is 00-30 hardness (10A is about 00-55). I first 3D print a wheel and a separate mold that fits round it, then pour in the rubber and then remove the mold when set. This has almost doubled the pushing power of my robots. [BD: He built a keen little spring scale test rig that he videos sometimes to demonstrate the push of his tiny brawlers; www.antweightwars.co.uk/TyreTra ction.pdf has the results of experiments he did with it in 2012 before he started to roll his own wheels out of Bentley Goo.]

Current Ant Fleet.

Here is Peter’s stable of bots: • Current Ants. Eight Antweights: two horizontal spinners, one full body ring spinner, two flippers, one grabber/lifter, and two pushers — one of which is tracked and clustered with a second 20 gm pusher. • Current Fleas. Four Fleaweights: one horizontal spinner, one walker with horizontal spinner, one flipper, and one pusher. • Current Nanos. Five Nanoweights: one horizontal spinner, one flipper, one walkerpusher, and two wheeled pushers. [BD: Allow me to make a few minor points here. First up, the man has a multibot for a 150 gram. Next, the Fleaweight shuffler, Shuffleaction, gets a weight bonus and can top the scales at 113 grams; he uses the extra weight on a horizontal spinner. Add it to the Nanoweight shuffler and together they don’t weigh 150 grams! He molded feet onto 3D printed legs to give a sixfooted shuffler better traction! Bow down ye fans of small bots, you walk in the presence of the mighty. You have to check out his website listed at the end of the article. Peter Waller’s game is tight.] Peter: Besides the radio controlled combat robots, I SERVO 07.2015

Shuffler feet.

His game is tight.

have dabbled in some autonomous robots. Namely, a micromouse wall follower and three mini Sumos — all of which have enjoyed some success. About five years ago, I developed a range of small robot controllers as the commercial ones were too big and heavy. After building one for a friend, I ended up making them unofficially for many other roboteers. I built just over 100 for other people before I was able to retire them when one of the other roboteers from Reading University started making smaller and cheaper ones. Probably the most fun robots I have built have been Antweights with suction to give more grip. The idea wasn’t mine but from a chap from Sweden, and we actually had a fight on the underside of the arena polycarbonate lid. The main problem with these types of robots is that they are reliant on a really good smooth arena surface and even if it starts like that, after a few spinners have chewed it up you lose all suction. One or two people are now having more success using ducted fans to produce down force, although they take a lot of power. My worst disaster was attempting to build a full body spinner with suction. I had several attempts at building

SERVO 07.2015

full body spinners but where the spinning mass is a high proportion of the total robot, they seem to become unstable at high revs and leap into the air. I decided to add suction to keep it on the ground, but when testing it drove over a damaged part of the arena where suction was lost and it leapt into the air and exploded (www.youtube.com/watch?v=Pj_Nl eCYeq8). [BD: This is one of the over 100 videos on Peter’s Antweightwars YouTube channel. Suckspin (steady, exhale quietly, okay — no really, it’s the name) starts to whine mightily, the vacuum pump sucking the 150 gram bot to the floor of the arena.

Suckspin.

Add in the shriek of the weapon motor — spinning steel impact blades. The thing is VERY stable as the top mounted blade spins up past seeing and begins to move. A turn, no wobble in the motion at all, a quick dart forward, and it grenades in fine fashion, parts in all directions.] Peter explains: My robot design philosophy is to build a robot that is competitive, easily

Resources Peter's Website http://antweightwars.co.uk Peter's topic pages on the Robot Wars Forum [this is fascinating reading]: Antweight http://robotwars101.org/forum/viewtopic.php?f=1&t=1933 Fleaweight http://robotwars101.org/forum/viewtopic.php?f=7&t=2268 Nanoweight http://robotwars101.org/forum/viewtopic.php?f=24&t=2210 Peter's YouTube Channel www.youtube.com/channel/UCeJQVzAOehGjc0w5GS5d2CQ

controlled, novel, good looking, and well engineered. My best bot is Anticyclone. It is not always the most successful, but I do love spinners. By placing the spinner at the exact center of the drive axis, the robot turns around the spinning axis and therefore does not

suffer from gyro related problems. The addition of a thin layer of polycarbonate around the body has made it much more resilient to impacts, and the 2 mm titanium blade does some real damage against vertical spinners. Probably the one robot I would

most like to be able to build would be a micromouse maze solver, but I am not sure my programming skills are really up to it, so I keep finding reasons for putting it off. Growing up, my Meccano set was my favorite and most played with toy. SV

SERVO 07.2015

BUILD REPORT: Renewing Old Iron ● by Matt Spurk

built my first robot back in 2001. It was an Antweight (one pound) robot called 3-letter-word. After I finished the Ant, I decided to start on a simpler project and built my heavyweight (220 pound) robot named 4-letter-word. It started life as a tough steel box with what we thought was an indestructible thresher. It was cool, but the thresher was promptly thrashed in the first event. It then fought the next event as a simple pushy box. That was neither cool nor successful. For the third event, we added an aluminum disk with steel blocks on the end. That was both cool and mildly successful. In the fourth event, I forgot the belt for the disk at home, and the weapon was damaged in our first fight before we could get a new belt. Without the disk, we were back to being a pushy box and not cool or successful. It was a good ride and I learned a ton about robots, and used that knowledge to build dozens more in the Insect weight classes, but I retired the heavyweight. It spent the next 810 years lying in a slumber. When the folks at USF announced Southeast Combot Championships in Tampa, I knew it was time to pull the old bot out from under the workbench and put it back together. The first task to be completed was a damage assessment. I surveyed the mechanics and it was in pretty rough shape. The wheelchair motors had been removed and were sitting in a box; two of the four tires were cut up; and the batteries had long ago given up their sealed-lead acid (SLA) souls to the recycling center in the sky.

SERVO 07.2015

Figure 1.

I decided most of the robot would remain the same, but with technology updates here and there, and some modifications to make the design more robust. The first major modification was to change the drivetrain from fourwheel drive (4WD) to two-wheel drive (2WD). This seems counter-intuitive, because the 4WD gave the bot additional traction when pushing, but that additional traction negatively affected turning. Being able to face your opponent is important. The next major change was going from 24 volts’ worth of SLA batteries to 30+ volts of lithium polymer (LiPo) batteries. The battery upgrade should improve the speed, and offers about a 40 pound weight savings over the previous version. The last planned upgrade is the addition of a pneumatic hammer. With only five weeks remaining until the event and

many repairs left to make, the hammers ultimately ended up getting sacked. It was a shame because they were mechanically complete. They just needed to be plumbed, but I simply didn’t have time to finish. Some of the systems that I had 10 years ago remained in the robot. They’ve earned the right to stay as far as I see it. The wheelchair motors have seen plenty of abuse, but they provide good torque and the price is right. The wheelchair motors are controlled by an RSGSS speed controller, which went obsolete back in like 2003. I really don’t know why it isn’t still

Old Iron vs. BearTooth.

sold. It was a nice little speed controller and came in an aluminum enclosure which kept debris out of the sensitive electronics. I really like mine and put it back into this robot. The frame will be kept, but modified. Also, the one thing that has held up and I think deserves a mention is the flexible coupler in this robot. This was an ingenious moneysaving coupler my dad built back in 2002. It is a rubber steering coupler (a.k.a., a rag coupler) from a car. The hubs are made of shaft collars, two large washers, and two bolts that were welded in place and then cut shorter (see Figure 1).

The Rebuild Progress started slowly at first, but picked up steam quickly once I got the drive mounted. The old bearings were removed from their housings. Some were still in good shape, some were a little gritty, and the remaining were frozen solid. I salvaged enough bearings for the 2WD version and reinstalled them in their mounts. I revised the interior bearing from the cheap flange bearing to a larger roller bearing. These bearings worked very well. To make room for the pneumatic ram, I cut the wheelchair motor’s shaft down about 1.5.” I also cut about 0.5” off the wheel shafts, so I could slide each motor out about 2”. This gave me plenty of room for the pneumatic cylinder to fit between the drive motors. Somewhere along the moves and various attempts to put the robot back together, I lost the gearbox covers. This wasn’t a huge problem, but the covers are necessary to hold the gear oil in the gearbox with the way they are mounted. I fabricated some new

Old Iron vs. The Big Cheese.

covers out of polycarbonate. I like them because you can see the internals of the gearbox and watch the gearbox turn, which is cool. Perhaps not the best-suited material for the job, but I like it. Plus, if (read when) the plastic fails, the red brown grease will leak out and it will look like the robot is bleeding — which is cool too.

The Event The event in Tampa featured four

heavyweights: Gruff, The Big Cheese, BearTooth, and my bot, which I called Old Iron. When we got to the event, we had pretty much everything ready, so we got through safety pretty quickly and helped to finish the last of the arena assembly. We had the very first fight of the day. We were fighting The Big Cheese which is a 2WD wedge with large 14” pneumatic tires driven by wheelchair motors. The fight started off well for Old Iron. We were able to get under The Big Cheese, and we were able to

Old Iron vs. Gruff.

SERVO 07.2015

Rumble 1.

Rumble 2.

Rumble 3.

SERVO 07.2015

get a few pins in. Without the hammer, I had to be content to just hold the Big Cheese there. The fight went back and forth for a few minutes and then disaster struck. The front wedge spikes on Old Iron got stuck in the wood kick-plate. The rule allowed one free unstick. After the restart, I noticed that one side of the drive was starting to fade. As I tried to loop around to face The Big Cheese, Old Iron took a slow stroll right into the wall on the opposite side of the arena and got stuck again. The first fight went to The Big Cheese by TKO. When I pulled the robot back to the pits, I noticed that one motor was really hot and the other motor was quite cool. Coincidentally enough, the motor that wasn’t really doing anything during the match was the cold one. Imagine that. Upon further review, the drivetrain was loose at various locations and the wheel was slipping on the shaft. We retightened all the hardware in the drivetrain, charged the batteries, and got ready for our next fight. We also hit the front wedge teeth with the angle grinder to make them a little less sharp. This appeared to work as Old Iron didn’t get stuck in the wall for the rest of the tournament. The next match was against BearTooth, which had a vertically spinning disk. It was a brand new team and a brand new bot built as a college senior project. The two bots started the match with a full length box rush and smashed together right in the middle of the arena. Old Iron immediately had the opposite drive starting to fade. I managed to get a nice box push and got a few pins. BearTooth got a couple nice hits in, but it didn’t seem to do any significant damage. The drive on Old Iron was getting worse as the fight wore on, and I only had one drive really functioning well. At about the mid-point in the match, Old Iron just suddenly stopped moving. The fight ended with BearTooth winning by KO.

Chuck Butler (a fellow competitor) came up to me after the match and mentioned he saw some sparks coming from one of the drive motors on Old Iron during the match. We pulled the cover off the back of the motor and noticed that one of the power wires to the brushes was loose. We retightened the wire screw and assumed that the KO was due to the speed controller faulting out due to over-current or over-temp. We put Old Iron back in the box for a fight against Gruff, but it was still dead. We lugged Old Iron back into the pits and found that there was something wrong with the speed controller. We started wiggling components and found that two of the three large capacitors had bad solder joints. We also found that the voltage regulator had a bad solder joint. We repaired those joints and tried Old Iron again. This time it worked like a champ. We put Old Iron back in the arena for her match against Gruff. Gruff is a low wedge with a powerful lifting arm. Gruff is also much faster than Old Iron. The match started with Gruff zooming across the arena and slamming into Old Iron. Gruff was under Old Iron and quickly tossed Old Iron upside down and up against the wall. Gruff could have left us there and won the match in about three seconds, but decided to flip us back down. During that flip, the bottom base plate (er, plywood cover) fell off and pulled out the receiver and receiver battery with it. The match ended in about 12 seconds with a win for Gruff by Tap-Out/KO. We took Old Iron back to the pits to charge the batteries and prepare for a rumble. We bolted the bottom plate back more securely. After the heavyweight brackets were complete, we put Old Iron back in the arena. This time, we did a tag team rumble with The Big Cheese and Old Iron taking on the heavyweight winner, Gruff. Gruff put on a clinic and threw

Rumble 5.

Rumble 6.

Old Iron and The Big Cheese around the arena. Old Iron spent most of the match either upside down or airborne, but the real key was it was still driving at the end. So, even though Gruff won by kicking everyone else’s butt, I’m claiming victory.

The Good, the Bad, and the Ugly Well, what was good? The frame was very strong, we sustained only superficial damage, and could put the bot back in the arena today if necessary. We got to catch up with old friends and make some new ones, which is always awesome. There is a new heavyweight event which will likely take place at a similar time each year. What was bad? The drivetrain was a weak spot. We couldn’t keep

the robot running consistently. I still haven’t taken the drive apart to see the current state of things, but that definitely needs some work. The bot is also too slow. We were the slowest bot in the field and it really showed. The old wheelchair motors just don’t cut it against today’s modern bots. What was just plain ugly? The lack of the hammer was really bad. It’s okay to be slow, it’s okay to be unreliable, but it’s not okay to be boring, and Old Iron was boring. I think with the addition of the hammer and a little more work making the drive more reliable, it could have been a fun robot and a crowd favorite. As it was, it was just plain boring. That is unacceptable and that will be the first thing we fix for next time. Well, that, and a coat of paint. At least I’ll brush some of the rust off. It is old, after all. SV SERVO 07.2015

BUILD REPORT: Battle Hardening the Inside of Your Bot ● by Michael Jeffries

ith robot combat, often the first things you’ll think about are the big parts — typically, the armor, weapon, and drive system. Getting these elements right is a good start when building a bot. However, the little details can make the difference between winning and losing. Often, you’ll see a robot get knocked out with no externally visible cause. Something failed internally. While that’s not always preventable, there are a lot of losses like this that can be avoided with “battle hardening.”

Wrap Your Connectors

While it may feel like the connections in your bot are nice and secure, it’s often not enough to deal with the sudden shocks they’ll experience in a match. It’s not all the time, but every once in a while you’ll have an impact that’s Exposed plugs pose a risk in combat and can leave a just right and it’ll jostle your perfectly functional robot sitting dead in the arena. connectors apart. Luckily, this sort of issue is easy to prevent. Again, a quick wrap of electrical tape around the connector is typically enough to absorb the shock and keep the connector together. Back before I knew about this, I had a 60 lb robot with a massive spinning bar, and it was fighting a fairly tough opponent. After a Many of the commonly The forces a small plug can experience in combat particularly hard hit, their used 2.4 GHz receivers use can be surprising. power switch was destroyed a bind plug to create the and they were dead. At the same connection to the transmitter. This your transmitter. The receiver won’t time, both of the battery packs I was plug connects the signal and negative do anything but sit there until it’s leads on the batt/bind port of the either powered off or re-bound. using came unplugged just from the receiver. If you power cycle the robot, it’ll energy coming back through the For receivers with exposed start working again as normal. Or, if robot. I won the fight, but if they prongs, it is possible for the same you realize what has happened quickly hadn’t been knocked out by the hit it leads to bump into conductive enough, you may be able to re-bind would have been a very easily materials in your robot and force the before getting counted out — but preventable loss. receiver into bind mode mid fight. that’s unlikely. When the receiver enters bind A quick wrap of electrical tape mode, your robot will stop moving as around the exposed prongs is typically the receiver will stop responding to enough to prevent the issue entirely. Whenever wires and moving parts

Cover Your Exposed Receiver Plugs

Restrain Your Wires

SERVO 07.2015

are in the same area, there’s a chance the two can become entangled. When that happens, you’ll have a mess on your hands. Maybe you’ll get lucky and it’ll just rub the insulation off. Maybe you won’t, and you’ll end up shredding your electrical system. Taking a bit of time to make sure all of your wires are secured and well away from moving parts will save you headaches in the long run. Once you think they’re secure enough, give them a good pull toward the parts that could grab them and make sure they’re really not going anywhere.

This is the first step to avoiding surprise shorts in a match.

Tape or Shrink Wrap Your Exposed Connectors A bit of tape or shrink wrap over your connectors may not seem like much, but it’s one more step to ensure that as the bot jostles around in combat and/or the occasional metal shaving finds a path through your machine, that there’s one less spot that can turn into a short. It’s not a lot of time or weight invested for another boost to reliability.

A bit of effort here can avoid robotic disembowelment.

Pad Your Batteries Batteries are another element of your robot that doesn’t deal with shock well. There aren’t any chemistries out right now that like getting beaten on, but the worst of the bunch when it comes to handling damage are LiPo packs. These packs can swell a bit under heavy load and when damaged badly enough, will occasionally catch fire. While you might think of damage to a pack being something like a saw blade cutting into it or a spike puncturing it, that’s not always the case. Extreme shock and a rigid enclosure can be enough to cause serious issues. Whatever enclosure you use, make sure to have some sort of padding between your battery and the rigid elements of it. This padding

will allow the pack to swell unimpeded, and gives it time to both accelerate and decelerate when dealing with a sudden impact.

Use Threadlocker — Seriously, Use It! You likely have bolts somewhere in your machine, and if they’re not going into a material that reacts poorly to threadlocking compounds (for example, polycarbonate becomes extremely brittle when exposed to threadlocker), then you should use threadlocker. Loctite is the most well-known brand of threadlocker and is easy to get a hold of. If you have a fastener you never want to get out again, use red Loctite or an equivalent. If you’ve

got something you may want to get out in the future, use blue Loctite or an equivalent. If you’re removing the fasteners after each fight for maintenance, then you can probably skip the threadlocker, but it’s still worth considering. If you’re skipping the threadlocker, make sure the fasteners are nice and snug before each fight, and consider the use of lock washers to help keep things together.

Use Connectors on Parts You'll Potentially Need to Replace It will add a bit of weight and a little cost to your build, but designing SERVO 07.2015

Shock can kill batteries; anything you can do to reduce this effect helps.

It saves time and makes it that much easier to swap in spares when you should, rather than when you need to.

your systems so they can be fasteners (the most popular replaced without needing a brand being Velcro™), 3M Dual soldering iron can not only Lock Reclosable Fasteners save time making repairs, but (similar to hook and loop, can allow you the time to somewhat more rigid), or replace worn or suspect vibration isolation mounts. components before they fail in (These are essentially nuts or the arena. bolts connected together via a For most systems, you chunk of rubber). should use polarized There are certainly more connectors (Deans connectors, approaches as well, but the for example) as they ensure core goal is the same: You you won’t hook things up want to give the electronics backwards while swapping more time to accelerate when parts. Bullet connectors are your robot gets hit. It may not useful as well, however, they’re seem like much, but that extra It doesn't take much to keep the shock away from best suited to brushless motors fraction of a second to get to the most fragile part of your robot. and drive motors where you speed can be the difference may need to quickly reverse the between something breaking polarity to get things working right. connections heading out from that and it being good to go for another point. This arrangement combined match. with the use of polarized connectors wherever you’re able will result in a very simple to work on system, which makes it easier to avoid mistakes while Soldering will play a part in most For both the positive and negative preparing for or repairing after a bots to at least some degree. Getting leads in your robot, you should have a match. good at creating strong solder common power distribution point. connections is a critical skill to ensure Ideally, this will be located very close that your electrical system doesn’t fall to the battery as that will allow you to apart in the arena. use smaller wires throughout the rest The critical elements of a strong of the robot since they’re not required There are a wide range of solder connection are the right solder, to carry as much current. methods for attaching electronics to the right iron, good solder flow, and Typically, you’ll have the positive your chassis that can help isolate them the correct application of heat and distribution point either directly at the from shocks. If you don’t need airflow solder to get good coverage. Opinions power switch or located closely to it. for cooling, you can entomb them in vary on exactly what is “right,” so I’ll For the negative lead, I generally bolt foam and glue, tape, or even cable tie stick with what I’ve found to work on several high current connectors them to the chassis. If you need robots ranging from 150 g to 30 lbs. together with the battery side lead airflow, then you’ve got to look more coming in and all of the other towards things like hook and loop • Solder: I use 60/40 rosin flux

Have a Common Power Distribution Point

Practice Soldering

Shock Mount Your Electronics

SERVO 07.2015

cored solder. I picked up a roll from McMaster-Carr (part number 7659A3) in 2010 and have been using it ever since. • Soldering Iron: I use a Weller W60P 60 watt soldering iron with a CT5D8 tip. For larger wires, the wide tip is critical for heat transfer. Tiny tips won’t transmit much heat, which dramatically limits the size of wire your iron will handle. • Acid Flux: I use Lucky Bob’s Acid Flux and have been using it regularly for going on a decade now. It’s a bit nasty and you need to ensure you burn it all off when you’re using it (as it could corrode wires over time), but I’ve yet to find a better way to tin my wires. The process I use is: Brush acid flux on the bare wire; coat the tip of the iron in rosin-cored 60/40 solder; and touch-coat the iron tip to the wire on all sides. This results in a good deal of solder soaking into the strands of the wire. Then, when you do connect it to something else, the connection is that much stronger. • Helping Hands: These things are a good way to avoid charred fingers when you’re doing a lot of soldering. I tend not to use them, but they can be quite “handy.”

GREAT DEALS!

Stock Drive Products Setting Ideas Into Motion

One-Stop Shop for Mechatronic Components Explore | Design | Buy Online

Battle Harden Your Motors Pete Smith wrote up a fantastic guide to battle hardening his Kitbots 1,000 RPM motors. The same techniques demonstrated in his guide can be applied to a wide range of gearmotors to get a bit more life out of them for what amounts to very little effort. Be sure to check this guide out at www.teamrollingthunder.com/Kit bots/Battle_Harden/body_battle_ harden.html. SV

Over 100,000 small mechanical parts

www.sdp-si.com

no minimum requirement

SERVO 07.2015

CNC Part Creation Workflow Part Design

By Michael Simpson Post comments on this section and find any associated files and/or downloads at www.servomagazine.com /index.php/magazine/article/ july2015_Simpson.

Idea

In this article, I will

I start with an idea. It can be as simple as a small rectangle spacer, or as complicated as a carriage for a 3D printer. For this article, I want to create a tiny box made from two dominos; much like the one shown in Figure 1.

show you how I take an idea for a simple

Modeling If the part is simple enough, I often forgo the modeling stage and move directly to drafting. In order to help you visualize the part, I modeled the parts in this article. How you model your idea can vary from extremely sophisticated software such as Autodesk Inventor, to a simple sketch drawn on a napkin. The box will consist of two parts. The bottom part (Figure 2) is made by machining a small pocket in the center of a domino. The top part (Figure 3) is made by machining two pockets into a domino. These two pockets form a lip that will slip into the pocket on the bottom domino.

object, then work through the design and tool path creation. I break my part creation down into

Figure 1.

the following stages: • Idea • Modeling • Drafting • Tool Path Creation • Part Creation 38

SERVO 07.2015

Figure 2.

Drafting In the drafting stage, I create basic shapes with boxes and circles. The shapes will be used in the Tool Path Creation stage to create the tool paths. For most of my basic part making, I use a 2D CAD program called CorelDraw. While I will be using CorelDraw in the next few examples, you can easily use other software packages. Most of the concepts I use will have counterparts in your software. Adobe Illustrator is another software package that is suited to this process. The most important consideration in choosing your drafting software is its ability to export an accurate file format your CAM software can understand.

Drafting — Step A I start by adding the shape that represents the stock I am going to use. In this case, it is the blank side of a 1” x 2” domino shown in Figure 4. I used calipers to get the exact width and height of the domino. The closer your drawing values are to the actual size of the stock, the more

Figure 4.

Figure 3.

accurate your pockets and holes will be in reference to its edges. This is especially important if you are mating two parts and want the edges to line up. Note that I have included the dimensions in the figures shown here. This is only for illustration purposes. I would normally not include dimensions in the drawings to be exported to my CAM software. The dimensions would be interpreted as part of the drawing and could make it difficult to line up the stock later.

Drafting — Step B Next, I add the pockets to the stock. Here, I have added the place where I want the main pocket in the bottom domino. To do this, I added a rectangle of 1.75” x .75” to the center of the stock as shown in Figure 5. I also added a 1/8” fillet to each corner. It is important that your inside cuts are not any sharper than the radius of your bit. If they are too sharp, your drafting representation will not match what is machined. The ability to center one object inside another will

Figure 5.

SERVO 07.2015

Figure 7.

Figure 6.

make your job much easier. Look for this feature when selecting your drafting software. Continuing, I add a rectangle inside the one just created. This can be done manually or — as shown in Figure 6 — by using the contour tool. This extra rectangle is where I will mill a pocket into the box top. Stay with me here; you will see the method to my madness in the next stage. The contour tool is one that I use in many of my drafting sessions. This is another feature to look for when selecting your drafting software.

Drafting — Step C I use the export feature, and export the drawing into a format my CAM software can use. In this case, it is the EPS file “dominobox.eps” shown in Figure 7. I have found that the Encapsulated PostScript works best when transferring drawings from CorelDraw to Vectric CAM software. Your results will vary depending on the actual software you are using. If you get wacky results, go back and try a different format. This ends the drafting stage of my process. That said, it’s not really the end. I often have to go back to the drafting stage and make tweaks. Think of it more as the “back to the drawing board” stage.

Figure 8.

Tool Path Creation To create tool paths that your CNC can follow, you need to use a CAM package. By the way, CAM stands for “Computer Aided Manufacturing.” The CAM packages I use come from a company called Vectric. For 2D or 2.5D (as it is sometimes called), you can use Cut2D or its big brother, VCarve Pro, or its grand pappy, Aspire. The interface is the same on all of them. They are differentiated by the number of features and the amount of drafting they allow you to do. While all of them support drafting or CAD to one degree or another, I prefer using my stand-alone CorelDraw CAD software for this. Since that is its main function, it does it very well. For this article, Vcarve Pro is shown, but the Cut2D software is nearly identical — although it does have some size limitations.

Tool Path Creation — Step A To start, I load the “Domino Box.eps” file into VCarve Pro. The software starts you out in the “Job Setup” form as shown in Figure 8. Here, notice that the software has properly set our stock size. Next, I add the measured thickness of the stock. In this case, it is .3085. I uncheck the “Use origin offset” and check the “Center data in job” options. For this job, something that is very important is the XY origin position. I set it to the left rear point. This is because I will be zeroing the machine to the rear vise jaw and to the vise stop placed to the left of the vise. Note that other jobs may require other origin settings. It all depends on where you are referencing zero on your machine.

Tool Path Creation — Step B I’m going to machine the bottom domino first, so I will

SERVO 07.2015

Figure 10. Figure 9.

start with its pocket. I select the outer center box and click the “Create Pocket Toolpath” button as shown in Figure 9. The actual toolpath creation is where all the work is done. Referring to Figure 10, I set the cut depth to .15. That’s how deep I want to make the pocket. I select the tool I will use (which I will get into in a moment), then I select offset milling which follows the shape of the pocket. I select the direction of the cut and add a .25” long plunge ramp, as well. The plunge ramp — while optional — helps flat bottom bits enter the cutting depth with far less force than plunging straight down as you would do with a drill bit.

Tool Selection When you select your tool, you are taken to the Tool Selection form. It is important that you select a tool that matches what you are going to mill with. All the Vectric software packages come with a basic library of tools. They include both metric and imperial versions of end mills, Vbits, and drills. You will quickly add sizes and shapes that are not included. I have some very extensive tool libraries on some of my machines. I have sets that even include colored markers. The software makes it easy to copy or create new tools. In our case, I selected a 1/8” end mill. I set the spindle speed, machine feed, and plunge rates to match the tool and machine. The spindle speed has little importance here as it is set manually. Some machines like my KRMx02 and KRmc01 will automatically set the speed based on this setting. Figure 11 shows I have chosen a feed rate of 15, which is as fast as the KRmf70 will move. It is important to

note when you are selecting a tool that any changes made to the form will be there the next time you select this tool. There are options, however, that allow you to edit feed and speed parameters for just this session. Once I am happy with the tool path, I give it a name and click the calculate button. This will bring up the Preview form shown in Figure 12. If you hit the Preview button, you will see your tool go to work. The software will show you your part with the new tool path.

Tool Path Creation — Step C The last step in the tool creation stage is to save the

Figure 11.

SERVO 07.2015

Figure 13.

Figure 12.

The only difference is that I choose the inner box as the interior pocket. I also create a second pocket that extends from the outer box to the edge of the domino. This new pocket will only be .05” deep. It will form the lip that will fit into the bottom domino. Once the paths are created, I save the paths to a file called “Top Pockets.txt” as shown in Figure 14.

Conclusion Figure 14.

I took an idea, created a 2D drawing file, and from that created a set of tool paths that will be used to tell the CNC machine how to cut the parts. While this may seem oversimplified, it is the basic process I use to make parts for various projects. Just keep in mind that some of those projects may include hundreds of parts.

Next Month Next time, I will take you through the actual part creation stage.

tool paths. Here (Figure 13), I select the tool paths that I have created and hit the Save Tool Paths button. Since this is the bottom domino, I call it “Bottom Pocket.txt.” Later, when I actually create the parts, I will load this file. It is important to note that the Save Tool Path form also lets you select the post processor you will be using. This is because the base language that the CNC machines use is called G-code. Unfortunately, there are nuances and limitations in each machine that pretty much makes a Gcode file for one machine incompatible with another. In the case of the MF70 CNC, I will be using the Mach3 post processor.

Top Domino The top domino is done just like the bottom domino.

SERVO 07.2015

Final Thoughts If you want more information on my KRMx02, KRmc01, and/or KRmf70 CNC books, you can find them at www.kronosrobotics.com. I also have a free download for an early CNC router book that I wrote. You can download it at www.kronosrobotics.com/krmx01/index.shtml. If you have any questions, you can post them in the MF70 conversion forum located at http://forum.servomagazine.com/viewtopic.php?f=49& t=17107. SV

DIY Animatronics

From the Beginning By Steve Koci

Last month, we looked at an example of what could be accomplished using basic skills and materials that were available from your local hardware store. This month, we’re going to take a step back and discuss some of the basics of animatronics. I understand that this may be too basic for some of our advanced builders, but check it out anyways. Perhaps you'll pick up a tidbit or two. We’ll go over some vocabulary; discuss some of the options; I’ll suggest some resources to get you going in the right direction; and we’ll go over some of the tools and materials you should start to accumulate to assist you in your builds. We’re going to be discussing the physical construction process in this issue. We’ll delve into the “brains” in a later installment. So It Begins We’ll just be scratching the surface on many of the topics we’re going to cover this month. These subjects will be covered in much greater detail in future articles, but the hope is that we at least give you the confidence to take the first step. There’s nothing that mysterious about building animatronics if you break it down into individual components. I’ve always believed that the hardest part of any project is to just take that first step. Once started, the project seems to gain momentum as you complete each individual task. Then, before you know it, you’ve completed it and get to start the process all over again! There are many factors that should be considered when planning your project. Some questions you should ask yourself include the following: • Why am I building this and what do I want it to accomplish?

• How much will the prop be required to work? • Is this a holiday decoration that will only be used for a few days a year? • Is it a one time deal for a school project or is it to be used to demonstrate a project proposal? • Is it to be used in a commercial setting where it will need to run for extended periods of time? • Will it need to survive the even more rigorous life as a child’s toy? • What is my budget in both time and money? • Do I have the necessary skills already or do I need to learn any new ones? • Has someone already created something like what I envision or am I going to need to design it from the ground up on my own? Spend some time doing research by persuing the Internet to see if someone has already attempted a similar build. Oftentimes, you can find valuable information that can save you substantial time, effort, and money. I am SERVO 07.2015

DIY Animatronics Post comments on this section and find any associated files and/or downloads at www.servomagazine.com/index.php/magazine/article/july2015_Koci.

often surprised by how much information is available to assist me in my projects. Articles, forum threads, and even videos detailing the work of others can speed up your design process and keep you from having to continually recreate the wheel. When doing your research, be sure to bookmark any interesting discoveries even if they don’t directly relate to your current project. A future project may benefit from something you came across months ago. These currently unrelated tidbits may also trigger new building ideas.

Has Anyone Seen My Drill? There are many steps to complete before you ever start building. Take stock of the tools you have on hand and decide if you need to purchase or borrow any. When just starting out, this can add a substantial amount to the cost of construction. In addition to the basic hand tools, the instrument I find the most useful is my rotary tool. The wide assortments of accessories available make it an invaluable prop building partner. Whether I’m fabricating brackets for an armature, cutting aluminum, or removing material from a plastic skull, it’s my primary tool choice. I have one permanently plugged in and hanging above my bench with a flex shaft installed, and a battery powered version in its charger for when I am working outside. Sitting right next to my Dremel are my two battery powered drills. Having one for drilling and another with a screw or nut driver installed greatly speeds up my work flow. Have a good assortment of sharp bits close by, as well. Another useful addition to my toolbox is a hot glue gun. I know what you’re thinking. How can hot glue successfully stand up to the repeated stresses put on our creations? Well, you’d be correct. The primary use I have for my hot glue gun is when I am putting together the initial prototype. It provides a quick, fairly sturdy bond that allows me to test a variety of configurations before committing my build to more permanent materials. You can easily break the bond if required, or dissolve it with a shot of rubbing alcohol. Owning a soldering iron and knowing how to use it will

Parts Suppliers ServoCity — www.servocity.com/ Monster Guts — http://monsterguts.com/ Spider Hill Prop Works — www.spiderhillpropworks.com/ McMaster Carr — www.mcmaster.com/ Fright Props — www.frightprops.com/ RobotShop — www.robotshop.com/ SparkFun — www.sparkfun.com/

SERVO 07.2015

certainly be something you’ll want to be comfortable doing. Whether it’s extending the wires that provide power to your design or soldering up a circuit board that will control it, sooner or later you’re going to need to know how to solder. There are plenty of good tutorials on YouTube, and I’ve included my favorite with the other resources. (SERVO had a recent tutorial on Basic soldering techniques that wrapped up in the June 2015 issue.) When selecting your initial project, start small. It’s very tempting to try a really cool but complicated project, and then get discouraged when it doesn’t turn out as expected. Select a project that utilizes your current skill set so that you maximize your chances for a completed first project. Nothing builds confidence like success! A good assortment of different building materials also makes the process proceed smoothly. The following materials are the ones I most frequently reach for. We’ll go over the pros and cons of all of them and look at the situations where each may excel.

Time to Get Started You will need to determine what building materials you will utilize to construct the actual armature. Things to consider include strength, weight, rigidity, cost, durability, and ease of use. Safety always come first. So, if in doubt, over-build! Foam Core Foam core is a great medium for prototyping and experimenting with different designs. It’s cheap and easy to cut and work with, yet provides sufficient strength to do some light testing of your basic build concept. PVC Although plastic pipe can be used for some lightweight builds when only minimal torque is being exerted upon the structure, I primarily use it for prototyping. The pipe and fittings are inexpensive and easy to find at your neighborhood hardware store. It is very easy to work with and to make adjustments on-the-fly. However, it’s not very rigid or strong, so think long and hard before deciding to include it in your final build. Remember that your build is only as strong as its weakest link. I have used it successfully in a project using a low torque motor, and took advantage of the low rigidity to add a little extra movement. I prefer to use the gray electrical conduit versus the white plumbing pipe as it is a little cheaper and it comes with a coupler built into the end. All of the plumbing fittings will work with the electrical conduit, as well. If you are going to use plastic pipe in your final assembly, you will need to make solid connections. The traditional method is to glue the joints together but I prefer

DIY Animatronics to use self-tapping screws. This allows me to disassemble the project if required to either make changes or do repairs. I’m also able to completely take it apart if I no longer need it so that I can reuse the parts in another project. Wood Using wood in your builds can certainly be a viable option in some situations. It’s easy to work with too and most of us have had opportunities already to become familiar with its characteristics. It’s readily available from any hardware store, and many of us have a stock in the garage ready to use in our projects. I bet you already have most if not all the tools you need to convert those scraps of wood into some viable props. Even if you don’t have any handy, it’s not expensive and comes in a wide variety of sizes and grades. Using wood does have its drawbacks, however. You want to be certain to seal it from the elements thoroughly to prevent it from warping and degrading. Holes have a tendency to expand with extended use, causing the movements to get sloppy. In order to gain sufficient strength and rigidity, you often have to use bigger lumber which increases the weight. More weight often means larger motors or higher air pressure to get the desired results. Although it’s tempting to use screws, I’d suggest you use bolts with locknuts whenever possible. Especially with very active props, screws tend to work loose and the results could be a disaster. If you have to use screws, make sure they are of sufficient strength and quality. Even though drywall screws are quick and easy to use, they should only be used in the prototype stages. When constructing your final build, please replace them. I’m guilty of breaking this rule myself, and had a pneumatic prop shear three drywall screws off on a hinge. The resulting effect was impressive for about two seconds and then required an extensive repair. Never again! Aluminum This is probably the material I reach for the most often as I love its versatility. You can work it with common hand tools if that’s all you have at your disposal and still get very good results. It’s sufficiently strong for most of my designs and the light weight means I can often get the movement I’m after with a much smaller motor than if I was working with a heavier material. Aluminum and steel can both be purchased from most big box hardware stores, but I suggest you check to see if you have any retail metal shops in your area. I’m fortunate enough that we have one nearby, and I make a trip with the truck whenever I get low and stock up. The price savings can be substantial, and the selection of sizes, shapes, and thicknesses is much larger. Steel There are some times when there’s no choice but to go with steel. The majority of my projects that use pneumatics are constructed with it. Its strength is hard to beat when

Figure 1. A 1” PVC prop joint from Spider Hill Prop Works.

Figure 2. Slider rig built from wood and drawer slides.

you’re expecting a prop to stand up to the abuse pneumatics can inflict. Steel is also my material of choice when constructing especially large projects. Sometimes it’s the only way to get the required rigidity without having to add a vast amount of bracing. If steel is that great, why don’t I always use it, you ask? For one, it is heavy. Secondly, it can require some specialized tools and skills to shape it to your needs. Many times, you can drill and bolt together your creation, but being able to weld will definitely improve your results. Many community colleges and local maker spaces offer classes on learning to weld, which would certainly shorten the learning curve. Once you learn to weld, there’s no going back! Drilling steel can be challenging in itself and a benchtop drill press will be a substantial improvement over a hand drill. With either tool, make sure to use some oil on the drill site to extend your drill bit life and simplify the job. SERVO 07.2015

DIY Animatronics

Figure 3. Plastic skulls with servos installed to allow them to talk.

Figure 5. A nice wiper motor starter kit might include these items (available from www.monsterguts.com/store/ product.php?productid=17760&cat=3&page=1).

and see if we can make some sense of all this.

Figure 4. Wiper motor rocking chair mechanism.

My most recent tool addition for working with steel was a portable band saw. There are many models available to fit most budgets. It has become my “go to” tool whenever I have steel to cut. It has simplified the process and I now look forward to the cutting portion of the build process. It slices like butter!

How Do We Make It All Go? The most common methods at the disposal of the DIY builder for powering your creation are servos, motors, and pneumatics. Although there are some other options as well, we’ll save those for a future discussion. How do I choose? Let’s check out some of our choices

SERVO 07.2015

Servos Servos — especially among this magazine’s readership — are the preferred device most of us reach for when we look to add motion to a project. The ability to control the exact location of a moving part combined with the wide variety of available models make servos a builder’s dream. The new line of Actobotics parts from ServoCity is allowing us to combine servos in never-before-imagined combinations. Now, instead of spending hours in the shop designing and building all the necessary brackets and parts required, I can quickly find just what I need to complete my build. The significant time-savings is a huge benefit and has allowed me to construct just about any mechanism I can dream up. To help you compare the many different models of servos available, here are links to a couple of charts with the resources: www.servocity.com/html/hitec_servos.html Hitec comparison chart

DIY Animatronics www.servocity.com/html/futaba_servos.html Futaba comparison chart Use these to help you decide on which model fits your particular needs. My primary servo for light duty is the Hitec HS-425BB, and it’s the one I use in many of my talking and moving skull projects. For the price, it’s hard to beat and a good place to start. If it’s not up to the task, then I’ll start moving to a model with more torque. If you’re not familiar with that term, it’s simply the amount of power a servo will impart with a one inch arm and is measured in ounce/inches. No need to be overly concerned with it at this point; just use it in your comparisons. When you are comparing servos, take note of the speed which is given in seconds. The lower the number, the faster the servo operates. Motors You have a wide range of choices when selecting the proper motor. AC motors require no special electrical knowledge to use. Just plug them in. Even though I occasionally reach for one, I primarily use DC motors; most often 12V models. There’s a multitude of kinds available with different speeds and strengths. The many different motors used in cars can be especially useful. Take, for example, wiper motors. They can be workhorses for many of the larger props. They have high torque; a low and high speed, depending on how you wire them; and most will allow you to reduce the voltage to get even slower speeds. When I purchase a wiper motor, I always pick up one of the wiring harnesses as well. It comes with the appropriately sized connectors, and makes for a quick and clean connection to your power source. When shopping for the power supply, get one with sufficient amps. It’s suggested that you use one with at least five amps to avoid underpowering the motor. I’ve also found many smaller motors from surplus houses that fit the need when working with smaller armatures. Please read the spec sheets carefully — especially when looking for a motor that will operate continuously and will do so without overheating. Many motors are not designed for continuous use and require downtime between activations. Pneumatics When it comes to building something that requires lots of power and/or fast activations, it’s time to reach for the air. The flexibility of using air will solve many of the problems that can come up. You can purchase pneumatic cylinders in a wide range of lengths, as well as bore. If you need more power, you can increase the size of the bore of the cylinder or boost the air pressure. The use of flow controls on your cylinders also allows some adjustment, and lets your cylinders respond at one

Figure 6. A 110V Christmas reindeer motor which moves an arm forward and back.

Figure 7. Mechanism that uses a single vent motor to move a head side to side, as well as up and down.

SERVO 07.2015

DIY Animatronics

Figure 8. Vent motor which uses magnets to move a Ouija board planchette back and forth.

speed when they extend and another rate when they retract. When getting started using pneumatics, you may want to consider buying a kit to insure all the components will work together. I’d suggest getting one that uses a five port four-way solenoid as they are the most versatile. You can always plug up ports that aren’t needed, but it’s nice to have the option. Additionally, when purchasing cylinders, I always go with the double-acting cylinders since air pressure may be alternately applied to provide force in both directions. They do use more air than single-acting cylinders, but the added flexibility is worth the trade-off. You’ll need to select the mounting style, as well. You can get models with specific mounts, but I prefer to get them with a rear pivot version. This gives me the maximum adaptability when used in conjunction with a clevis attachment on the cylinder rod. Finally, you’ll need to decide whether to use AC or DC. As with the motors, I prefer to go with 12 VDC, but they are also available in 24 VDC or 110 VAC. When purchasing components, I try to consider not only the requirements for the current project but plan for the usefulness of my components in future builds. I’m constantly dismantling creations that I no longer use and reusing the parts, so this will save me time and money down the road. There’s no magic here, but getting all the correct pieces the first time can be intimidating. Once you assemble a kit and get comfortable working with an air system, you’ll know what to order for your next project.

That’s Not What I Want to Do! You’ve decided on a design, picked the materials to use, and chosen the proper device to make it move. You’ve labored in your shop to bring your creation to life. Congratulations! You’ve completed your first build. It’s time to power it up and enjoy your success, right? Well, maybe. Oftentimes, the resulting motion is not what you planned when you worked it out in your head. Don’t be discouraged if it takes a substantial amount of tweaking and modifying to get the result you want. I seem to spend more time on this stage than any other during the build process. It’s all part of the fun!

Wrap Up

Figure 9. Waving Santa. See him in action at www.youtube.com/watch?v=NLeOjiqUM6w.

SERVO 07.2015

The design and construction of animatronic props and characters can be a very rewarding and challenging undertaking. Hopefully, I’ve been able to convince you to give it a try. Your creations can be as simple or complex as you desire, with each completed project adding to your confidence and skill sets. So, pick a project and get moving! SV

DIY Animatronics

Figure 10. Detail of Santaâ&#x20AC;&#x2122;s arm movement mechanism.

Figure 11. Close-up of the armature used to move his head back and forth.

Figure 12. An example of the components that may come in a complete pneumatic kit (www.evilusions.com/store/kits/lid-opener-kit-detail).

LEARNING RESOURCES Stan Winston School of Character Arts www.stanwinstonschool.com/ YouTube â&#x20AC;&#x201D; Stillbeasts Studios www.youtube.com/user/StiltbeastStudios My Website and YouTube Channels www.halstaff.com/ www.youtube.com/user/halstaff?feature=mhee EEVblog Soldering Tutorial www.youtube.com/watch?v=fYz5nIHH0iY Essential Mechanism Examples www.robives.com/essentialmech Forums www.hauntforum.com/index.php http://letsmakerobots.com/ Books and Magazines Nuts & Volts www.nutsvolts.com/ DC Props Prop Building Books http://dcprops.com/store/books-dvds/ Prop Ideas http://omarshauntedtrail.com/Props/props.htm Figure 13. Simple pneumatic pop-up.

Pandemic Cemetery Prop Plans www.pandemichauntproduction.com/prop-plans.html

SERVO 07.2015

By Michael "Fuzzy" Mauldin

BattleBots is Back, Baby! Thatâ&#x20AC;&#x2122;s right! BattleBots is coming back to TV! The first episode is premiering Sunday, June 21, 2015 on your local ABC network channel (check listings for the time in your area). BattleBots will consist of six action-packed episodes airing this summer. 50

SERVO 07.2015

Post comments on this article at www.servomagazine.com/index.php/magazine/article/july2015_Mauldin.

Thanks to SERVO Magazine, BattleBots, Inc., and ABC, I was able to attend all three days of taping at the Mare Island Sports Center in Vallejo, CA this past May and document the tournament for SERVO readers. Just like the people waiting to get into the Sports Center to be part of the live audience, youâ&#x20AC;&#x2122;ll have to wait to find out who won. For now, Iâ&#x20AC;&#x2122;ll give you a preview of the glorious robotic destruction coming to a television screen near you.

The BattleBox and the main stage.

The live studio audience waits in line to enter the arena.

Happy audience members at the front of the line for the semi-finals and final match.

SERVO 07.2015

Donald Hutson and his team from San Diego, CA ready their robot for the preliminary round of fighting.

Old Teams and New Teams As mentioned, there will be six episodes of BattleBots. In order to hold a competition, film it in front of a live audience, and be ready to broadcast it this Father’s Day, ABC limited the event to just 24 robots with four alternates. These were chosen from a few dozen entries submitted by teams in the United States and the United Kingdom. Donald Hutson of San Diego, CA leads Team Mutant Robots, and drives the bot during fights. They are sponsored by QualComm, SolidWorks, Automation Direct, and CAMWorks. Donald won two past BattleBot championships with his super heavyweight robot, Diesector,

and in November 2001, won the BattleBot award for Best Driver. Donald clearly represents the veteran champion. He has competed in all four BattleBot weight classes, and has even built a 900 monster called GearCrow. There will be no super heavyweights this time at BattleBots. Motors, batteries, and builders have all gotten better since 2002. To contain all the energy of a robot fight, BattleBots upped the BattleBox’s polycarbonate walls to 1.250 inches. However, even with 25% thicker walls, they decided that 250 pounds was as much robot as they could safely contain. Because of the shortened season and limited number of bots, all robots are limited to that weight. The upshot is that for the first time on television, every robot can face every other robot in the competition. Challenging the veterans for this year’s trophy are younger, newer teams like Team JACD. JACD is a collaboration between Cambridge-based robot builders Adam Bercu, Charles Guan, Dane Kouttron, and Jamison Go. They are far from newbies, however, having built dozens of robots for other robot fighting competitions weighing between one and 120 pounds. They have a dozen championship trophies in their collection, as well. Even with all that experience, they discovered partway through that building a 250 pound robot is more that twice the work, so they brought in additional team members.

What’s Inside a BattleBot? We can’t show you any more of this robot right now, or tell you its name or builder Lucy Du (L), Jamison Go (C), and Charles Guan (R) of Team JACD working on a drive component.

SERVO 07.2015

A Drone’s Eye View

DJI provided this Inspire drone to fly inside the BattleBox, filming the action.

The dilemma of watching or televising a fight between two destructive robots is how to see what the robots are doing without being in harm’s way. The solution has always been thick sheets of polycarbonate that are mostly clear and impervious to projectiles large and small. However, even brand new polycarbonate creates reflections and warps the view. For BattleBots 2015, DJI provided two of their Inspire 4K camera drones and technical support to get a truly new perspective on each fight. Michael Shabun of DJI Technology, LLC gave me a close-up look at the carbon-fiber technology and tiny built-in camera that records 4K video on a microSD card during flight. I can’t wait to see the drone footage when BattleBots airs. The DJI Inspire drone with 4K camera.

Marc DeVidts (far left) works on his robot while Trey Roski (left), founder of BattleBots escorts some VIPs through the pits. or driver. For that, you’ll have to tune into the show. However, we can tell you that this mean machine uses multiple “short” AmpFlow A28150 24 volt neodymium magnet DC motors to drive its wheels, and a “long” AmpFlow A28400 24 volt PMDC motor to drive a wide belt that spins something at the front end. Once the tournament has been televised, we’ll be able to provide more details about which robots competed, how well they did, what parts they used, what worked, and what didn’t.

Please Show Me at Least One Robot? Since you asked nicely, we’ll show you an inside view of one of the crowd favorites from the May 2002 BattleBot competition, Warhead. SERVO 07.2015

robots the past few years, but they are still rare in the larger weight classes. Whether it works well or not this time, the new Warhead will be like a scorpion on whisper mode.

This Show Goes to Eleven! While I was interviewing Greg Munson, co-founder and president of BattleBots, I asked him what was different about the show in 2015. He quoted Peter Abrahamson, “This one goes to 11!” According to Munson: “But seriously, The new An inside close-up of a BattleBot. BattleBots TV show will be true to the sport of robot combat — gone are the schtick and silliness of the old show.” “We’re focusing on the excitement and drama of the competition, the frantic repairs in the pit, and the journey from the Prelims to the Championship.” “We think viewers will love this format, and we welcome everyone’s feedback when the show airs on June 21st.” Having been on the show in 2001 and 2002, and having watched the taping of this summer’s season, I can definitely An inside close-up of Warhead from Team Razer of Bournemouth, England. confirm that ABC has done it better than ever before. Warhead was a crowd favorite in 2002 because it used One addition is the new entry tunnel that showcases a gasoline-powered engine to rev up and control its massive the teams as they bring their creations into the arena. You just know that anything that needs a doorway that grand spinning dome. I remember being in the pits working on has got to be pretty special. my own super heavyweight BattleBot. An even bigger change is that the host and Whenever we heard the roar of a gasoline engine commentators were actually sitting at the BattleBox being started, we’d drop our tools and run to the stands to watching the fights and describing them live. see which robot was making all the racket. I am certain that the intimacy of a ring-side seat will This time will be quieter. Warhead has replaced its gas enliven their commentary — especially when 500 pounds of guzzler with a three-phase brushless motor. Brushless moving metal smacks into the wall 10 feet away. motors have come to dominate the spinners in smaller

SERVO 07.2015

Warhead stretches its wings on stage at BattleBots.

Team Leader Nola Garcia and the girls of the Carrollton School of the Sacred Heart in Miami, FL enter the arena with their robot, Sweet Revenge, driven by Sabrina Tamames. From the front going back: Sabrina Tamames, Alexis Vidaurreta, Meagan Carpintero, Sara Dwyer, Julian De Zulueta, Nola Garcia, Regina Morfin, Bill Garcia, Elisa Baena, Elizabeth De Zulueta, Nadya Ganem, Emilie Martinez, and Catalina Rincon.

I Bet I Could Build a BattleBot We bet you can, too! Thatâ&#x20AC;&#x2122;s how a lot of successful BattleBot builders got started (including me). If fortune favors the show, there will be another season of BattleBots, and a chance for new builders to enter. According to Greg Munson, the best thing to do is sign up for the BattleBots newsletter at BattleBots.com.

Greg Munson, co-founder and President of BattleBots. SERVO 07.2015

(L-R) Kenny Florian, Chris Rose, and Molly McGrath host the show.

Commentators Florian and Rose sit right next to the BattleBox while they describe the fights going on inside.

Subscribers will be the first to know about new events and new rules. Of course, subscribers to SERVO Magazine can read through back issues to learn from some of the best builders of the past.

It’s the time all of us robot builder’s have been waiting for: the return of BattleBots to TV. This year, the hazards are randomly activated by an all new computerized control panel. Pete Lambertson remains the man in charge. Behind him is Trey Roski, co-founder of BattleBots. There are also a couple of thousand screaming fans chanting to see some robot fighting action. Join them on ABC, Sunday, June 21st. You won’t regret it. SV

The Box is Locked It’s almost “Robot Fighting Time.”

An Awesome Trophy Deserves an Awesome Trophy Stand Veteran BattleBot builder, Mark Setrakian from Team Sinister is a special effects artist who builds amazing robots that are sometimes just too pretty to destroy (he can do nasty, too; he was co-champion in 1995 with his robot “The Master”). For the return of BattleBots to television, Mark once again shows his technical prowess. Axis 2 appears at first glance to be a five-fingered robot hand that slowly rotates a clear platter on which rests the coveted Giant Nut. Moving one finger at a time, the hand slowly rotates the trophy at a constant velocity while the arm underneath remains stationary. The motion is hypnotic. Mark's general gait generator After talking with him at the event, I learned that Axis 2 is program controls the hand from really a five-legged walking robot, as you can see in the photo his Apple MacBook Pro. of it walking on his workbench. When it is holding the trophy, it is really just “walking on the ceiling.” After watching the trophy rotating for the better part of an Special Effects master and hour, it occurred to me that a simple pre-programmed motion robot builder, Mark Setrakian would accumulate small errors that would eventually spill the built Axis 2 — the robotic precious object onto the floor. hand that displays and Mark explained that the Giant Nut has a small centered dot attached to the bottom. The platter is clear, and the palm of the hand rotates the Giant Nut trophy on the main stage. contains a camera looking straight up (that camera view is shown in the photo in the upper left window of the computer screen). Mark wrote a general gait generator program that runs on his Apple MacBook Pro. The gait generator allows the number of legs to be Axis 2 is really a fivea variable, along with phase angles and other subtleties. When Axis is legged robot, seen here walking on the workbench started, it just walks toward the dot. Once the dot is centered, the robot walks in circles around it, giving a self-correcting constant rotation of in Mark's shop. Photo courtesy of Mark Setrakian. the trophy. You can literally watch it for hours.

SERVO 07.2015

Author Bio Michael "Fuzzy" Mauldin and his family "Team Toad" have competed in four earlier seasons of BattleBots, reaching the quarterfinals twice. He is a graduate of Rice University and holds a PhD in Artificial Intelligence from Carnegie Mellon University. His thesis on Information Retrieval led to his creation of the Lycos search engine, which in 1996 became the fastest company ever to go public in the United States. Now severely retired, he and his wife Debbie raise beef cattle, and train horses and dogs at the Lazy Toad Ranch in Liberty Hill, TX.

Pete Lambertson at the control panel of the hazards with Trey Roski, co-founder of BattleBots behind him.

Photographer, Michael "Fuzzy" Mauldin of Team Toad.

Photos courtesy of Michael "Fuzzy" Mauldin, Kelsey Mauldin, and BattleBots, Inc.

Extreme Robot Motor Control

The T he E Easiest asiest W Way ay tto o Design Custom

Front F ront n Panels Panels & Enclosures www.robotpower.com

MEGAMOTO GT Shield New

Software and plug compatible with our MegaMoto shield

Our Highest Current motor control for Arduino™

You design it

We machine it

to your speciﬁcations using our FREE CAD software, Front Panel Designer

and ship to you a professionally ﬁnished product, no minimum quantity required

Cost effective prototypes and production runs with no setup charges Powder-coated and anodized finishes in various colors

Select from aluminum, acrylic or provide your own material

6 6 6 6 6

35A Continuous - 50A peak 6.5V - 40V Built in Voltage Reg can power the Arduino Current sensor outputs can be sent to any analog pin Over temp and over current protection

THE USA

The Hydra 6 6 6 6 6 6

7V - 28V Triple 6.5A / 8.0A Peak H-Bridges Current/Temp limiting R/C inputs w/mixing Limit switches on one channel 2.0" x 2.1" x .5"

Standard lead time in 5 days or express manufacturing in 3 or 1 days

FrontPanelExpress.com

MADE IN

The Vyper Big Bots! Big Power! Big Motors!

6 6 6 6 6 6

120A+ H-Bridge - 200A Peak! 8V - 42V Overload protected RC and Analog Pot input Supports 8 AWG wires! 2.85” x 2.25” x 1.75”

Phone: 360-515-0691 s sales@robotpower.com

SERVO 07.2015

The Robots of

Maker Faire Ten years ago, the first "Maker's Faire" happened. It just happened to happen in the San Francisco Bay area in California. Well, it didn't just happen to happen here. It happened here for a reason — the people, the culture, and the artistic infrastructure. The dot.com bubble had just burst, so we were all getting real. Linux was beginning to take off, there were no "smartphones" — just clam shells — and we were happy. No 3D printers to speak of, Wi-Fi was just getting started, and we were all learning to pronounce "Ardweeno." "PIC" and "Stamp" ruled the microcontroller universe, self-driving cars were just starting to roll, and we were happy. Yeah, there were robots. There have always been robots at Maker Faire. In fact, I think maybe Maker Faire was made for robots since robots are definitely made for Maker Faire. Heck, look at the Maker Faire mascot, "Makey" (Figure 1). He's a robot, and that speaks volumes. No Facebook, no flying cars. Oh wait! We still don't have flying cars ... but the robots are almost here! 58 SERVO 07.2015

Figure 1. Maker Faire's mascot is a robot named "Makey" ... 'nuff said.

’ve always thought of RoboGames as the best of Maker Faire. That is, Maker Faire with just the robots. I still think that way, but Maker Faire doesn’t have the competitive edge of RoboGames. It has a more artistic vibe ... a magic really — Burning Man without the playa dust. It actually fits the HomeBrew Robotics Club (HBRC) better where we can just go and bring our robots, show (and tell) them off, and talk with folks about the club. Evangelizing actually (goes along with our plans for “Total World Domination”). Competition is fun and competition is good, but Maker Faire has a more

By Camp Peavy

relaxed and easy-going atmosphere. No competition to speak of. Although, there is still the pressure to perform. I’ve participated in nine of the 10 Maker Faire happenings, most of them with the HBRC — all of them with my faithful Burning Man robot “Springy Thingy” (Figure 2). I recently had some bad luck with the Mystery Machine (my van), so my good robot building buddy, John Erickson gave me a ride to the Faire in his truck. We loaded up the robots and made a weekend out of it (Figure 3). The first order of business was to set up the HBRC booth, which took most of Friday. This is something new for Maker Faire 2015 — that is, opening on Friday. The crowds were a little lighter — “Industry Day” they call it — corporate groups, educators, school kids, and media. It was nice to have things set up and ready to go for the throngs on Saturday morning (Figure 4). Maker Faire reminds me of

Figure 5. Beer2D2 in his native environment. Instead of going for a beer, the beer comes to you.

Post comments on this article at www.servomagazine.com/index.php/magazine/article/july2015_Peavy.

Figure 2. Springy Thingy is my Burning Man robot ... she has survived six Burns (1999-2005), the goal being to leave the event with a functioning robot. Photo credit: Bill Sherman.

Burning Man with creativity so thick you can cut it with a knife. Arts, crafts, and technology merge, and a feeling that one person can actually change the world. I suspect the West Coast Computer Faire (another San Francisco Bay Area phenomenon) felt a bit like this in the ‘70s. We (the HomeBrew Robotics Club) had 12 participants and over 20 robots of all shapes, sizes, and variety. We were located between Nick Donaldson (King of the Hexapods) and Bill and Becky Sherman with their “robots in the classroom” display. The esteemed Steven Nelson was there too with his latest obsession,

Figure 3. John Erickson drives his homebrewed robot, "Charlene" to the Faire.

“Beer2D2” (Figure 5). Watch for Steven’s chronicle of Beer2D2 in the August issue of SERVO. These are a few of his favorite things. In the next booth down were the boys (ages 14 to 75) of “Ubiquity” robotics — a

Figure 4. Here comes the Saturday morning crowd! Well over 100,000 people attended the event. It's not just a Faire, it's a worldwide movement.

SERVO 07.2015

Figure 7. "Glider," the rollerblading hexapod has won numerous Gold medals at RoboGames and is a perennial favorite at Maker Faire.

Figure 6. Some of the boys of Ubiquity Robotics posing with "Magni" and the tabletop option.

Figure 10. Another superstar robot at the Faire was "Roy the Robot." Here, he is chillin' at his booth.

Figure 9. Among the superstar robots at the Faire was Robonaut — a robot by NASA designed to work alongside humans in space.

Figure 8. Rocky poses with Meccanoid "G15KS." They were mentioned in an article by Business Insider entitled "Cute and Scary Robots We Saw at San Francisco's Big Annual Gathering.“

HomeBrew Robotics Club spinoff Kickstarting a business around affordable ROS-based mobile platforms. I can still hear Dr. Bot’s

SERVO 07.2015

continuous sales pitch. I must say it’s alluring (Figure 6). Nick (the aforementioned King of the Hexapods ... you know ... the guy with the monkey on his shoulder) had some servo trouble with his rollerblading hexapod “Glider” at the start of the day, but with some ingenious engineering he was able to rebuild the servo and skated his way into IEEE Spectrum’s “Best of Maker Faire Bay Area 2015.” Another

obstacle course traversed (Figure 7)! Meccano (the Erector Set folks) introduced their new little humanoid robot named “Meccanoid“ that was mentioned in Business Insider (along with Rocky and the Black Mast Dancers) as “cute and scary robots we saw at San Francisco’s big annual gathering.“ I’ll leave it to you to guess which is which (Figure 8). Meccanoid is very animated and easy to program with LIM (Learned Intelligent Movement) where you pose the robot in different positions and then the robot memorizes the motions. This is how one programs the industrial robot, Baxter. Meccanoid also features voice recognition, voice synthesis, and Bluetooth; wheeled motors drive the feet. It’s open source code and available in two models. I predict Meccano will sell a million of these bots. Rocky, on the other hand, is one of a kind. Among the other superstar robots at Maker Faire was NASA’s Robonaut (Figure 9). The basic idea behind

Robonaut is to have a humanoid robot to work alongside the astronauts in space. The form factor is such that Robonaut can use the same tools as the human astronauts. Eventually, it will be deployed on extravehicular activities, including being used as an endeffector for the robotic arm on the International Space Station. My favorite robot Figure 11. Definitely among the cute robots from last year — “Roy are Romibo and the Mirabots. Romibo (the fury one) is a therapy robot and the Mirabots the Robot” — was are just for fun. They change colors and present in all his recognize faces. Photo Credit: Jared Peters. theatrical glory. He’s available as a laser cut plywood kit — at least his arm is currently. The big picture is to create a human sized animatronic character from only laser cut mechanics and off-the-shelf hobby servos (Figure 10). “DFRobot” had a huge presence at Maker Faire; they are actually a Goldsmith sponsor. The Chinese company makes and distributes a broad assortment of robot components and kits. What I really liked about their booth was the array of modules and bases — from simple stuff for small tabletop robots to popular boards like Arduino and Figure 13. "Pirate Dave" created Raspberry Pi and ready-to-build kits. "Petey the Parrot" as a highly They also had numerous bases: articulated shoulder puppet that tracks, wheels, walkers — large and can move even the toughest of pirates to tears… small. Ten years ago, you had to build of laughter, of course! these bases from scratch. Yeah, that’s Photo Credit: Robots-Dreams.com. fun, but it’s a huge barrier to entry. Robotics. Children with autism often Now, budding roboticists just need to prefer to communicate with simplified buy a base, choose a controller board, characters during times of high stress add sensors, and create an and anxiety. Currently, teachers are application. The business of mobile beta testing Romibo in five countries. robotics has arrived! All the parts are Their feedback is being used to guide easily available. the product toward consumer Other cute robots included introduction in 2016. Romibo and Mirabots (Figure 11). “Mira” is a curious social robot Romibo is an engaging smart designed by Alonso Martinez. It character for autism therapy and changes colors and recognizes faces. language learning from Origami

Figure 12. This is Dan Albert and his full sized humanoid, WATSON. It's funny no one paid WATSON much attention until he added that silly balloon ... just don't call him an airhead!

They are “awww-some.” Then, there’s Dan Albert (Team Walk Like a Man) with WATSON (Figure 12) — the full size humanoid. Dan hung out at one of the pillars and wasn’t getting much action until he added a balloon head. It’s funny what attracts people. Without the “head,” WATSON might as well have been just another 3D printer. However, with the silly little red balloon head, WATSON suddenly became more human. Next time, Dan’s bringing the mannequin head. “Avast Ye Scurvy Swabs!” — The very animated and piratey “Petey the Parrot” (Figure 13) was created by David Sidley. It was printed on an Afinia H479 3D printer. (Yo-Ho-Ho!) There are 31 parts in all which take about 32 hours to print. Rocky the Robot Pirate could definitely use one SERVO 07.2015

jammed (in a good way). This is a lighted robot kinetic army and part of a Kickstarter campaign (Figure 14). Each robot is a “delta robot” like those used on assembly lines — except it’s upside down and its endeffectors are bright multicolored LEDs. Figure 14. Light Play's 84 autonomous dancing The effect is delta robots danced the night (and day) away mesmerizing! in the "Dark Room" at Maker Faire. Speaking of armies, Photo Credit: Robots-Dreams.com. on the sidewall of the of these! Perhaps “Dave, the Funky building there was the “Game of Monkey” (the one on Nick’s shoulder) Drones” — a Fight Club for could use a companion. quadcopters! The rules were simple to Of course, there were dancing learn, but difficult to master: A) Two robots. Yes, dancing robots — Robot drones enter the arena; last one flying Dance Party — because robots just wins. B) If both drones crash, the first want to have fun! The robot (Chris) is one back in the air wins. available to DJ at your party, but be Meanwhile, outside in the south forewarned! The robot revolution will lot, MegaBot was waiting. “Mark II” is be armed with music. Meanwhile, the first full-sized mobile, dual-weapon inside the dark room, Light Play’s 84 paint ball cannon. MegaBot made its autonomous dancing delta robots debut on Saturday: caterpillar treads,

rising 15 feet high, swivel cockpit, and paint ball cannons. Its target was the poor defenseless Pittsburg art car. This is the first of a proposed giant robot combat league which would feature eight of these monsters battling to the death in football arenas around the country ... awesome (Figure 15)! Also lurking outside the Maker Faire buildings was the giant walking “Tin Spider” (Figure 16). Built by expert sheet metal craftsman, Scott Parenteau, this 12 legged geodesic domed spider can be seen roaming the playa at Burning Man after wowing crowds at Maker Faire. Then, under the swimming pool water, lurked OpenROV. This is an open source, low cost underwater robot for exploration and education. It’s also a passionate community of professional and amateur ocean explorers and technologists. Maker Faire doesn’t just happen ... it is a happening! And it’s been happening for 10 years. I, for one, am looking forward to the next 10 years of making things, but most specifically making robots!

Figure 15. MegaBot Mark II was a definite highlight as it blasted the poor little defenseless Pittsburg art car. Photo Credit: Ralph Hipps.

SERVO 07.2015

Online Resources Ubiquity Robotics http://ubiquityrobotics.com/ The Best of Maker Faire Bay Area 2015 http://spectrum.ieee.org/view-from-thevalley/robotics/diy/eyecatching-exhibits-atmaker-faire-bay-area-2015Meccano Maker System www.meccano.com/meccanoid/ “Cute and Scary Robots We Saw at San Francisco's Big Annual Gathering of Tech Tinkerers” www.businessinsider.com/the-very-cuteand-very-scary-robots-of-maker-faire-20155#rocky-the-pirate-is-also-known-to-jam-todeath-metal-as-part-of-the-black-mastgroup-verdict-scary-talented-dancers-14 R2: Robonaut http://robonaut.jsc.nasa.gov/ Meet Roy http://roytherobot.com/ DFRobot: Drive the Future www.dfrobot.com/ Meet Romibo http://origamirobotics.com/ Mira looking around www.youtube.com/watch?v=rfqpomYA8es I built a robot in my garage to compete in the DARPA Robotics Challenge http://makezine.com/2014/05/30/i-built-arobot-my-garage-to-compete-in-the-darparobotics-challenge/ Petey the Parrot promotional www.youtube.com/watch?v=ZV7JpwbW4ww Robot Dance Party http://robotdanceparty.org/ Robot Army Starter Kit www.kickstarter.com/projects/1984252088/ robot-army-starter-kit/description Car no match for 15 foot fighting MegaBot http://makezine.com/2015/05/17/car-nomatch-15-foot-fighting-megabot/ Tin Spider is a 13 foot rideable robot with 12 legs www.youtube.com/watch?v=5TLYFBt0mKY Welcome to OpenROV www.openrov.com/ InMoov www.inmoov.fr/

Figure 18. An InMoov arm — printed and assembled by HBRC member, Wes Thierry.

Figure 16. Creeping around outside the buildings was another giant robot called "Tin Spider." This arachnid can also be found crawling around at Burning Man.

We have reached critical mass. The exhibitors are becoming (and I don’t mean this in a bad way) more corporate; that is to say, the robots are finally where the computers were in the ‘70s — almost ready for prime time. Almost ready for real consumer applications. Almost ready for Total World Domination! Don’t just be a spectator, participate! Finally, I’d like to give a mention to my favorite robot at Maker Faire: “InMoove” (Figure 17). I saw this robot roaming around a couple of times and couldn’t help but be entranced by its fluid motion and uncanny human appearance. I believe this is the end game in robot design because ultimately, we are building a model of ourselves — our progeny, our future. One of the HomeBrew Robotics Club members (Wes Thierry) has already built the arm (Figure 18) and I notice a number of InMoov humanoids on the InMoov website. Open source and robotics are a match made in heaven as no one individual or one company master all the intricacies of diversities involved. And so it begins ... the next 10 years. SV

Photo Credit: Robots-Dreams.com.

Figure 17. My favorite robot at Maker Faire: "Inmoov" — the first life size 3D printed open source humanoid in the world.

SERVO 07.2015

The SERVO Webstore CD-ROM SPECIALS

7.2015 FEATURED

ROBOTICS Arduino Robot Bonanza by Gordon McComb Create high-tech walking, talking, and thinking robots. "McComb hasn’t missed a beat. It’s an absolute winner!" Breathe life into the robots of your dreams — without advanced electronics or programming skills. Arduino Robot Bonanza shows you how to build autonomous robots using ordinary tools and common parts. Learn how to wire things up, program your robot's brain, and add your own unique flair. $29.95

Build Your Own Quadcopter: Power Up Your Designs with the Parallax Elev-8 by Donald Norris Build a custom multirotor aircraft! Build and customize radio-controlled quadcopters that take off, land, hover, and soar. Build Your Own Quadcopter: Power Up Your Designs with the Parallax Elev-8 features step-by-step assembly plans and experiments that will have you launching fully functioning quadcopters in no time. $50.00

SERVO 07.2015

Making Things Move: DIY Mechanisms for Inventors, Hobbyists, and Artists by Dustyn Roberts

In Making Things Move: DIY Mechanisms for Inventors, Hobbyists, and Artists, you'll learn how to successfully build moving mechanisms through non-technical explanations, examples, and do-it-yourself projects — from kinetic art installations to creative toys to energy-harvesting devices. Photographs, illustrations, screenshots, and images of 3D models are included for each project. $29.95

Build Your Own Humanoid Robots by Karl Williams GREAT 'DROIDS, INDEED! This unique guide to sophisticated robotics projects brings humanoid robot construction home to the hobbyist. Written by a well-known figure in the robotics community, Build Your Own Humanoid Robots provides step-by-step directions for six exciting projects, each costing less than $300. Together, they form the essential ingredients for making your own humanoid robot. $24.95

Build Your Own Teams of Robots with LEGO® MINDSTORMS® NXT and Bluetooth® Plan, design, assemble, and program robot squads that communicate and cooperate with each other to accomplish together what they can’t do individually. Inside the authors show you how to construct a team capability matrix (TCM) and use the Bluetooth RoboticOriented Network (BRON) so your robot teams can share sensors, actuators, end effectors, motor power, and programs.$30.00

Robotics Demystified by Edwin Wise YOU DON'T NEED ARTIFICIAL INTELLIGENCE TO LEARN ROBOTICS! Now anyone with an interest in robotics can gain a deeper understanding — without formal training, unlimited time, or a genius IQ. In Robotics Demystified, expert robot builder and author Edwin Wise provides an effective and totally painless way to learn about the technologies used to build robots! $19.95 We accept VISA, MC, AMEX, and DISCOVER Prices do not include shipping and may be subject to change.

Order online http://store.servomagazine.com/home.php SPECIAL OFFERS

Forbidden LEGO by Ulrik Pilegaard / Mike Dooley Forbidden LEGO introduces you to the type of free-style building that LEGO’s master builders do for fun in the back room. Using LEGO bricks in combination with common household materials (from rubber bands and glue to plastic spoons and ping-pong balls) along with some very unorthodox building techniques, you’ll learn to create working models that LEGO would never endorse. Reg $24.95 Sale Price $19.95

The SERVO Buddy Kit

PROJECTS 3D LED Cube Kit

PS2 Servomotor Controller Kit

From the article “Build the 3D LED Matrix Cube” as seen in the August 2011 issue of Nuts & Volts Magazine. An inexpensive circuit you can build to control a servo without a microcontroller.

For more information, please check out the May 2008 issue or go to the SERVO webstore.

Includes an article reprint.

$39.55

This kit shows you how to build a really cool 3D cube with a 4 x 4 x 4 monochromatic LED matrix which has a total of 64 LEDs. The preprogrammed microcontroller that includes 29 patterns that will automatically play with a runtime of approximately 6-1/2 minutes. Colors available: Green, Red, Yellow & Blue. Jig and plastic cases also available.

This kit accompanied with your own PlayStation controller will allow you to control up to six servomotors. Includes all components and instruction manual. For more information, please see the February 2011 edition of SERVO Magazine. Assembled units available! $79.95

$57.95

SERVO 07.2015

To order call 1-800-783-4624 SERVO Magazine Bundles

Celebrate Your Independence! Build robots!

S av e $1 0. 00 O nl y $5 7. 95 ! Now you can get one year’s worth of all your favorite articles from SERVO Magazine in a convenient bundle of print copies. Available for years 04, 05, 06, 07, 08, 09, 10, 11 and 2012.

Robot Building for Dummies

Call me at my order desk! Visit my online store @ www.servomagazine.com

Linux Robotics

by Roger Arrick / Nancy Stevenson

by D. Jay Newman

Discover what robots can do and how they work. Find out how to build your own robot and program it to perform tasks. Ready to enter the robot world? This book is your passport! It walks you through building your very own little metal assistant from a kit, dressing it up, giving it a brain, programming it to do things, even making it talk. Along the way, you’ll gather some tidbits about robot history, enthusiasts groups, and more.

If you want your robot to have more brains than microcontrollers can deliver — if you want a truly intelligent, high-capability robot — everything you need is right here. Linux Robotics gives you stepby-step directions for “Zeppo,” a super-smart, single-boardpowered robot that can be built by any hobbyist. You also get complete instructions for incorporating Linux single boards into your own unique robotic designs. No programming experience is required. This book includes access to all the downloadable programs you need. $38.95

$24.95

CNC Machining Handbook: Building, Programming, and Implementation by Alan Overby The CNC Machining Handbook describes the steps involved in building a CNC machine and successfully implementing it in a real world application. Helpful photos and illustrations are featured throughout. Whether you're a student, hobbyist, or business owner looking to move from a manual manufacturing process to the accuracy and repeatability of what CNC has to offer, you'll benefit from the in-depth information in this comprehensive resource. $34.95

FOR BEGINNER BOT BUILDERS

$59.95

$49.95

$39.95

These labs from LF Components show simple and interesting experiments and lessons, all done on a solderless circuit board. As you do each experiment, you learn how basic components work in a circuit, and continue to build your arsenal of knowledge with each successive experiment. For more info and a promotional video, please visit our webstore.

SERVO 07.2015

Analog Servos for Robotics By Eric Ostendorff

Servos are motorized gearboxes which move to a certain location or speed specified by a control signal. The focus of this article is on analog servos which are the ones traditionally used in R/C cars and airplanes, and, more recently, are used in hobby robotics. Digital servos will also work, but are often more expensive and consume more power than analog servos. They do offer extra features, but we won't get into those here. Figure 1.

Figure 1 shows three different servo sizes, from a large “quarter scale” servo (left) to a small nine gram servo (right). A standard sized servo (center) measures about 40 mm L x 20 mm W x 36 mm H, and weighs 40-50 grams. The cheapest (~$5-$10) servos use plastic gears and bushings. Better ($30+) ones use metal or “karbonite” gears and ball bearings for bigger loads and longer life. Servos generally require 4.5-6 volts to operate and consume most of the electric power in a robot. While most microcontrollers require very little electrical power and could run on tiny batteries, servos require larger batteries — either alkaline or rechargeable. The minimum practical power supply to drive one or two servos is three AA alkaline cells.

SERVO 07.2015

Post comments on this article at www.servomagazine.com/index.php/magazine/ article/july2015_Ostendorff.

A servo cable has three wires going to its three-pin female connector: ground (usually black or brown); V+ (battery positive, usually red); and the control signal (usually white, yellow, or orange). Polarity is important; always doublecheck when connecting servos.

Figure 2.

SERVOS: INSIDE AND OUT Figure 2 shows an exploded view of a typical hobby servo. A variety of internal gear ratios are available, delivering different kinds of mechanical advantage. In general, a high gear ratio servo (lots of gear reduction) will deliver more torque/force at a slower speed. A low gear ratio servo (less gear reduction) will move faster but with less torque/force. Note: Forcing a servo to rotate (when off) can damage it. The particular internal gearing allows some servos to move easier than others. When in doubt, donâ&#x20AC;&#x2122;t force it! Some servos will rotate in opposite directions for a given signal. Electronic servo reversers are available for a few dollars, but are generally not needed in robotics as the rotation is easily reversed in software. Servo specs list stall torque and speed (transit time for 60 degrees) at 4.8 volts and six volts for comparison, plus which direction they

Figure 3.

rotate when a signal is applied. Electric motors in servos include brushed (standard), plus brushless and coreless (high performance). In robotics, we use both standard servos and continuous rotation servos. Both respond to standard hobby-protocol pulses, ranging from 1-2 milliseconds (ms) wide. A constant 50 Hz stream of pulses is required to keep the servo energized; one pulse wonâ&#x20AC;&#x2122;t do anything. Pulse widths of 1 ms drive the servo one direction; pulses of 2 ms drive the servo the opposite way; and 1.5 ms is the center of travel. In reality, these numbers give less than 180 degrees of travel, so the pulse range for robotics may vary from 0.50 ms - 2.50 ms to deliver full travel as shown in Figure 3. The number of splines on the output shaft varies SERVO 07.2015

Figure 4.

between brands, so servo horns and accessories are not necessarily interchangeable. Medium sized Futaba servos use 25 splines, while Hitec servos use 24 splines. Not compatible. There are also some minor differences between various brands of female connectors, but nothing that will prevent most brands from plugging into a standard threepin male connector or PCB (printed circuit board) header. Watch out for pre-1998 Airtronics servos, however, which have reversed power connections and may “release the magic smoke” if hooked up to a standard servo controller.

STANDARD SERVOS

SERVO TESTERS Electronic servo testers (Figure 4) are very handy and

Figure 5.

SERVO 07.2015

cheap — some as low as $2. Several servos can be connected at the same time. Most testers have three modes, selectable by a pushbutton switch. Mode 1 allows manual servo control: Twist the knob and the servo rotates accordingly. Mode 2 locks the servo in its center position. Mode 3 oscillates the servo back and forth. Some simple projects might not even require anything beyond a servo tester! The cheaper testers only send 1-2 ms output pulses which rotate most servos less than 180 degrees. That’s still useful for checking servo motion on a project before a programmable controller is available. A tester with a built-in display showing the pulse width is extremely valuable. To avoid damaging the tester and servos, always double-check polarity when connecting the battery (also 4.5V-6V) and servos. Connect the battery first to verify the LEDs come on properly before connecting any servos. DIYers can build the simple servo tester shown in Figure 5.

Standard servos rotate their output shaft about 180 degrees, or a half rotation. Another way to say it is they move ±90 degrees from their center position. They are used for precise rotational positioning; perhaps moving a robot arm or leg joint, steering a wheel, scanning a sensor, or aiming a laser. An internal potentiometer (rotary sensor) detects the output shaft position and provides feedback to the internal control circuit. This is called a “closed loop” control system. A servo knows its position and whether it needs to move based on the incoming control signal. It will fight and “growl” to maintain position — even up to the point of breaking or stripping its gears. Extra power is consumed to move a heavy load or to hold a fixed position when strong forces are involved. Standard servos have internal mechanical stops at each travel limit; often a tab on the output gear which hits a part of the case. On some servos, the output gear is only half a gear (a.k.a., sector) since it only rotates 180 degrees. You’ll waste power and possibly damage a servo if you send a control signal which makes the servo try to rotate beyond its mechanical stops. Every servo is slightly different, so if

you plan to drive a servo to its mechanical limits you need to test it individually and determine the custom control signals (numbers in the program) which correspond to its mechanical limits. Standard servos rotate slightly on power-up — even with no control signal applied. The rotation will consistently be either CW or CCW, depending on the servo. Usually this is not a problem, but here’s one example where it is. Sometimes I use a servo to mechanically trigger various one-shot mechanisms when rotated to different positions. It’s possible that something would unintentionally trigger on power-up when the servo moves slightly. To avoid this, I build my mechanism so that it triggers when the servo moves in the opposite direction from power-up. In fact, I like to use the mechanical limit as the start and end positions in the program, so that the servo is homed against a hard stop and can’t rotate at all when turned on. Analog servos are dumb. Take that two ways: They are not smart servos with their own microprocessor, plus they can’t talk. As in talk to their controller. They are obedient slaves — and will do their best to move where commanded just as fast as they can go. The servo has its own internal feedback — a closed-loop system that keeps trying to do as instructed. However, the micro never gets any feedback from the servo. The possibility exists that the servo may not have had the power, torque, or time to move to a commanded location. The micro won’t know this. (Bummer, huh?) Here’s an experiment I did in the course of writing this article. I added one wire to a servo, connected to the center wiper of the position-sensing potentiometer which provides position feedback to the servo’s internal electronics. The potentiometer is a voltage divider, outputting an analog voltage proportional to the output shaft position. If we allow the micro to read that voltage using an ADC (analog-to-digital converter), it can determine the servo’s position. There are numerous ways to do that, based on which microcontroller we’re using. I used a PICAXE and in an hour or so, I had a modified servo and code that would let me teach a motion sequence by manually moving the servo first, then the PICAXE could play it back. I subsequently found that LadyAda beat me to this with an Arduino. In fact, Adafruit sells hacked servos with the extra feedback wire.

MECHANICAL CONNECTORS For mechanical connection to the output shaft, servos come with one or more servo horns: plastic connectors which press onto the splined output shaft and are retained by a tiny screw (don’t lose that hard-to-find screw!). They may be circular or have 1-6 arms with many small holes, mainly intended to connect to wire push-pull linkages. Connecting wheels or other parts to servo horns can be a challenge. Servocity.com sells a wonderfully mind-numbing array

of bolt-on servo accessories: wheels, couplers, shafts, hubs, gears, sprockets, and brackets. They are well-designed and straightforward to use. Some accessories cost more than a cheap servo, but spend some time at Servocity.com. There is a wealth of parts and information there. You will surely learn and get ideas. Maybe even buy something. The robotics/DIY crowd loves to improvise, adapt, and overcome, utilizing the horns which come with the servo. Sometimes tiny nuts and bolts can be used to screw the servo horn to another part. This requires fairly accurate drilling and assembly. If you are fearless and VERY sure of your assembly skills, you can glue parts to the servo horn using only thick gap-filling CA (cyanoacylate, a.k.a., super glue). Don’t waste your time using hot melt glue, which will eventually shift or fail and undo all your careful calibration and programming. First, drill a mating hole in your part before gluing so you can access the tiny retaining screw. That way, you can still remove the horn assembly from the servo when necessary. The nylon servo horn is very difficult to glue properly. Thoroughly rough up the top and bottom of the horn to be glued with coarse sandpaper or a file. You want visible scratches and gouges all over for good adhesion. Clean off any dust; use good quality thick glue; and alternate layers with accelerator/kicker to build up material and encapsulate the servo horn. Don’t get glue in the servo, obviously, but use plenty of glue with plenty of ventilation. That’s cyanide gas burning your nose, lungs, and eyes. Many servos include mounting screws and rubber grommets. The grommets are for shock absorbing and vibration damping on model airplanes and cars. They are not used in robotics since they can deform over time, allowing creep and reducing positional accuracy. Servos have mounting flanges for screw mounting. Alternate methods of mounting servos to a flat surface include strong double-sided tape or gluing for a permanant assembly. Hot melt glue can be used, and later removed with alcohol if necessary. Thick super glue as previously discussed is obviously more permanent. As with the servo horn, rough up the outer servo case with sandpaper and clean thoroughly before using glue on the servo. Like rubber mounting grommets, servo savers are best left to the R/C car crowd and skipped in most robotics applications. These spring-loaded shock aborbers on the steering linkage “give” in a crash to avoid breaking internal gears and to save the servo. Unfortunately, they also give under steady loads and introduce positional inaccuracies that are counterproductive to the precise positioning needed in robotics.

CONTINUOUS ROTATION SERVOS Continuous rotation servos (CR servos) look like SERVO 07.2015

Figure 6a.

Figure 6b.

Figure 6c.

standard servos, but differ internally. They have no mechanical stops and rotate continuously in both directions, making them suitable for driving wheels on a robot. They have no position sensor to provide feedback to the internal control circuit, so this is an “open loop” control system. The servo will turn forward and reverse at different speeds based on the control signal, but there is no built-in way to verify rotation or distance. CR servos should stop at a specified control signal (1.5 millisecond pulse) but not all do, mainly because of manufacturing tolerances, temperature stability, etc. Some CR servos can be “nulled” (adjusted) for a precise stop by turning an internal potentiometer with a small screwdriver. Good quality servos are consistent over time; cheaper ones drift and need to be re-nulled occasionally. It’s noteworthy that when a CR servo is nulled and receiving a stop command (1.5 ms pulses), it is not simply “doing nothing.” It is applying dynamic braking and will resist turning more so than if the servo was unpowered. CR servos are not terribly fast; 40-50 RPM is typical. Not surprisingly, their top speed increases when powered by higher voltages. I coaxed 60 RPM out of a large CRmodified VS-11 servo by using 7.2 volts, but that risked servo damage. Stick with six volts max. If you need more speed or higher voltage, use an H-bridge with a gearmotor instead of a servo. Even lacking feedback and being slow and drift-prone, CR servos continue to be popular in hobby robotics. They are fairly cheap, ready to go with a built-in control circuit, and have the familiar servo form factor. Many standard servos can be modified for continuous rotation. Some are easier to modify than others, and some give better fine speed control. To modify a servo, the internal feedback potentiometer must be disconnected or replaced, and the output gear (and/or case) modified to remove the mechanical stops. Many examples of this popular “hack” can be found on the Web. Finding wheels to mount on a CR servo can be a challenge. There are some premade wheels which fit

SERVO 07.2015

directly onto a servo spline (Pololu and Solarbotics sell Futaba spline wheels). Some have the matching female spline molded into the plastic wheel; others have a servo horn attached. You can make your own wheels by attaching a servo horn to some existing wheels using either screws or glue as previously described. Accuracy is naturally required to center the horn on the wheel. Otherwise, the wheel will be eccentric and make the robot wobble. In the case of gluing servo horns to a wheel, epoxy would be a better choice than CA, since the curing time is minutes instead of seconds. As the epoxy is curing, you can spin the servo using a servo tester to verify concentricity and nudge the wheel into running true. Be sure to rough up the nylon servo horn to promote good adhesion (also described previously). If you are handy and have access to some basic shop tools, you can make your own wheels out of a flat plate of plastic, wood, or other soft material. Cut out an oversized circle with a bandsaw, then glue the servo horn firmly to the circle as described, eyeballing the center. Now, mount the wheel on the CR servo and spin it with the servo tester, using a pencil or marker to draw a circle of the right diameter. Next, use a disk or belt sander to make the wheel round — just barely oversize. Finally, spin the servo/wheel with the servo tester while CAREFULLY holding it against the sander, making it perfectly circular at the desired size. Watch that servo cable and do NOT let it get pulled into the sander! Two servos I know of come with a 1.75” diameter circular horn — a small but free and instant wheel. This diameter “wheel” gives a forward speed of 5-7 inches/second. Drive wheels need rubber tires for traction, which are often O-rings or rubber bands. A handy source for custom-width rubber band tires is to cut a loop out of a bicycle inner tube, which is what I used on that 1.75” horn. For any given servo and RPM, larger wheels will give higher speed. I have even seen peanut butter jar lids screwed to servo horns, using rubber band tires to give a good advantage on mobile robots (Figure 6). Get creative!

Figure 7a. Figure 7b. Figure 8.

It’s “wingless” (no mounting flanges) and has an integral axle opposite the output shaft for increased strength and less flexing. Sail winch servos (720 degree servos) have different internal gearing which rotates the output shaft two full rotations, stopping at each extreme. Do not confuse these with “360 degree servos” — an alternative and unfortunate term for continuous rotation servos. Linear servos are controlled by standard servo signals and come in different sizes — from the tiny Spektrum in Figure 8 to the giant Firgelli in Figure 9. EMS sells a $10 kit to convert a Futaba S3003 to linear, or you can buy the smaller VS-19 Pico linear servo for the same price. Power servos are monstrous stump-pulling affairs. If power is your primary concern, ServoCity’s $240 SPG7950A-BM offers an astounding 3,402 ounce-inches of

SPECIALTY SERVOS In addition to traditional hobby rotary servos, roboticists are fortunate to have a selection of specialty servos. Robot-specific servos have been created for the humanoid and arm market, as well as brackets and hardware to make complex linkages. At the high end are Dongbu’s Herculex and Robotis Dynamixel digital servos with amazingly high power and capability. They have encoders, dedicated programmers, and specialized communication protocols — all beyond the scope of this article. Lately, some of their mechanical features are showing up on cheaper digital “robot servos,” such as the LD2015 shown in Figure 7.

Figure 9.

SERVO 07.2015

SERVO BATTERIES/ POWER SUPPLIES

Figure 10.

torque (Figure 10). It’s a 180 degree standard servo, also available in 360 degree and continuous rotation versions.

WHERE TO BUY Servos are widely available at local hobby shops and online. Standard size analog servos are generally priced from $5-$65. ServoCity mainly sells big brands like Futaba and Hitec, along with their wide variety of servo accessories. Discounter Hobby King sells all brands, including smaller Turnigy, BMS, and Tower Pro/Hextronic brands. Hobby King has an exceptional value in its $2.69, nine gram HXT900 version. It is very popular and often on backorder. Hobby robotics sellers Adafruit, Parallax, Pololu, RobotShop, Solarbotics, and SparkFun all sell servos.

Figure 11.

Not surprisingly, a servo’s power output gets stronger and faster as the supply voltage increases, but going much above 6V risks damage as mentioned earlier. Some servos can operate down to three or four volts with correspondingly lower power and speed, and often with less accuracy and repeatability. Some of my small robots use a single 3.7V Li-Ion battery to power everything directly, including their CR servos. Some applications have very specific power requirements. A six-axis arm I built worked very well, but it required a very specific 4.0 volts for proper operation. The servos would oscillate at higher voltages and lost precision at lower voltages. As mentioned initially, servos consume most of the power on a robot. I bench tested a dozen servos of various sizes and under ideal stationary, quiet, no-load conditions, they all draw 5-10 mA. Sounds very efficient. As soon as they “growl” (still stationary with no load applied), however, current jumps up to 80-100 mA just sitting there. Try slow motion with no load and it goes up to 100-150 mA. Any loads or just accelerating an unloaded servo can pull an amp or more per servo. I have generally found that a single battery can power a robot’s servos and microcontroller if filter/decoupling caps are used. A small 0.1 µF disk cap and a 10+ µF electrolytic cap right at the microcontroller power pins works great. Of course, the battery needs to be able to maintain voltage while delivering high current. Choosing the right battery and servo combination for a robot takes experience and testing. Rechargeable lithium-ion (Li-Ion) and lithium polymer (Li-Po) batteries offer better power to weight ratios than older NiMH or NiCad batteries, and make disposable alkaline cells look ridiculous in comparison. Perhaps the most common “noob” problems discussed in Parallax’s very helpful robotics forum stem from weak alkaline batteries. Things appear to function properly until the servos move — drawing an amp or more — causing the old batteries’ voltage to drop and reset the microcontroller. New alkaline batteries almost always solve the problem. An outstanding example of servo power management is the walking "Tai Chi" robot (Figure 11) shown at www.youtube.com/watch?v=imq0HPXiQmM and discussed at www.picaxeforum.co.uk/showthread .php?27524-9g-Tai-Chi-Stepper. The builder is running 12 small 9 g servos from just four AAA alkaline batteries.

CONTROLLING SERVOS FROM A MICROPROCESSOR Hobbyists use several different microprocessors in their

SERVO 07.2015

Arduino: oscillate servo between positions 0 and 180 (approximate degrees) #include <Servo.h> Servo fred; // create servo object to // control servo named “fred” void setup() { fred.attach(9); // attach servo “fred” on pin 9 // to the servo object } void loop() { fred.write(0); // move servo to position 0 delay(1000); // pause 1 second fred.write(180); // move servo to position 180 delay(1000); // pause 1 second }

PICAXE: code oscillates servo between positions 100 and 200 (1000-2000 ms pulse) servo 1,100 ‘ initialize servo on pin 1 to center position 100 do ‘ start loop servopos 1,100 ‘ move servo to position 100 pause 1000 ‘ pause 1 second servopos 1,200 ‘ move servo to position 200 pause 1000 ‘ pause 1 second loop ‘ end loop

Code Samples. robots. Which one is “best” is a subject of spirited debate — we robo-geeks are just as passionate as sports fans. The BASIC Stamp 2 and PICAXE are easy for beginners to learn since they use the BASIC language. Arduino is everywhere, and there are libraries and tutorials for its C-like language. Parallax’s Propeller does real multitasking on its eight cogs, and can be programmed in both C and its dedicated Spin language. To keep this article of general interest, I’ve included four simple code snippets for comparison. These barebones programs generate signals to alternately “slam” a servo (no Watch these helpful online servo tutorials: www.youtube.com/watch?v=v2jpnyKPH64 www.youtube.com/watch?v=iGS_kz8hx4k Gorgeous new homemade 12-servo biped walker: www.youtube.com/watch?v=imq0HPXiQmM

BASIC Stamp 2 do for b0=1 to 50 pulsout 1,1000 pause 20 next for b0=1 to 50 pulsout 1,2000 pause 20 next

Propeller (Spin language) CON _clkmode = xtal1 + pll16x ‘ The clock frequency will be ‘ 16 times the crystal ‘ frequency. _xinfreq = 5_000_000 ‘ We are using a 5MHz crystal. OBJ Servo : “Servo32v7.spin” ‘ This object will start a cog PUB ServoDemo Servo.Start ‘ Start Servo Object repeat Servo.Set(16, 1000) ‘ Move Servo waitcnt(clkfreq + cnt) ‘ wait one second Servo.Set(16, 2000) ‘ Move Servo waitcnt(clkfreq + cnt) ‘ wait one second

acceleration or ramping) between the 1,000 ms and 2,000 ms positions once each second.

SUMMARY I hope this article gave you a little clearer view of analog servos. They have been around for a long time and will be around a good while longer. In some ways, they are the unsophisticated “brutes” of the robotics world — the final gear-grinding, current-sucking, heat-generating “dumb” output component of an otherwise sophisticated high-tech robot. In the end, robots are all about controlled mechanical motion, and servos are what allow that magic to happen. Thoroughly understanding servos’ strengths and limitations can help to identify which things are handled better in software vs. hardware. The availability and affordability of servos and microcontrollers makes robotics a hobby that can be enjoyed by everyone. SV SERVO 07.2015

a n d

g{xÇ Now

by Tom Carroll TWCarroll@aol.com

The Robot Hut I do not believe that there is a reader of this magazine who has not looked at a robot in a movie and wondered if they might also have a similar robot for their own. So, I cannot imagine a better demonstration of the ‘then and now’ of robotics than a museum dedicated to robots — from early movies to today’s blockbusters. Before delving into the Robot Hut Museum, I would like to discuss the evolution of robot action props into computer-generated images of robots for movies. We all know that the ‘robots’ shown in movies in the past were either people stuffed into uncomfortable robot suits or were remotely-controlled action props. Whether the robot was a gigantic monster like the robots in Pacific Rim, cute little roving garbage can-sized bots like R2D2 in Star Wars, or even the not so friendly police robots such as the ED-209 in Robo Cop shown in Figure 1 — we were enthralled with them all.

Figure 1 - The ED-209 police robot from the film, Robocop.

SERVO 07.2015

Living in Southern A few action props are California a few decades still used in movies, such as ago, I had the privilege of BB8 in the latest Star Wars building some robot action episode that will arrive in props for several movies. movie theaters this The prop people from one December. One of the of the films, Revenge of the film’s stars, Oscar Isaac is Nerds, needed two identical shown in Figure 3 with a remotely-controlled action working BB8. The action prop robots — one of which prop was created by is shown in Figure 2 — and utilizing Sphero’s two extra non-functional technology. but identical-looking props BB8 will be seen as a Figure 2 - One of to represent the single CGI robot throughout the four action props robot ‘built’ by the two star film, but many close-up from the film, nerds in the first of the shots will show this Revenge of the Nerds. film’s series. amazing rolling bot as a The production physical being with the company waited and robot’s head staying on waited to give me the top of the revolving ‘go ahead,’ and finally sphere. told me to start and have the robots completed in just a few weeks. With such a close deadline, I told I do miss the old them I would have to days when people hire a friend who was actually built movie Figure 3 - Oscar Isaac with the BB8 robot at the temporarily out of work props like those shown Star Wars Film Celebration to assist me, as I had a at the Robot Hut. The in Anaheim. full time job at Robot Hut is an Rockwell. amazing museum. One would think They tossed a nice amount of that such a museum would be based money my way to get them near the Los Angeles, CA film industry completed, and we met the deadline. or at least in a large metropolitan That seemed to be the way that movie area, but this unique gallery is located productions operated in those days. about 30 miles north of Spokane, WA A bit later in the film industry, in a tiny rural community called Elk. along came CGI robots such as the A friend, Ryan Smyth invited me NS-3 humanoids from the film, I, to go there this past April, and four of Robot. I loaned about a dozen his friends went with us. After driving ‘antique’ 1980’s robots to the prop almost 400 miles and eight hours people for that movie that never from the Portland, OR area (I live just made it on screen. With today’s north of Portland, in Washington), we computer graphics imaging arrived at the small country road that technology, movie robots are now a leads to the museum owner’s farm. bunch of 1s and 0s on a hard drive Upon reaching the farm, one somewhere. would never know that the new red

The Robot Hut

Advances in robots and robotics over the years.

Post comments on this article at www.servomagazine.com/index.php/magazine/article/july2015_ThenNow.

metal barn-sized building with the front facing away from the road was the actual museum. Figure 4 shows the six of us in front of the building. I do believe that the 18 foot high robot with smoke coming from its mouth and the ‘Robot Hut’ sign might have given it away, had it been facing towards the road. John Rigg, the owner and curator of the museum came out to meet us. Two wildly friendly dogs were at his side and soon were nuzzling up to us for a friendly pet or two. John reminded me of Doctor Emmett Brown — the character played by actor Christopher Lloyd in the movie, Back to the Future. The museum is open by invitation only, so that was the reason John met us upon arrival. You need to email him if you’d like to schedule a visit. His massive collection of movie and other robots was so overwhelming that he finally had to move his collection into the newly built metal building in 2000. It is not a commercial operation, but a passion of love of robots. He cannot take the time to show every casual visitor the museum who may happen upon his farm, as there are many chores and duties he must attend to daily. We entered through the white door into a small 6 by 10 foyer adorned with robot posters. Another door led us into the actual large gallery area. It was breathtaking. Wall to wall robots — from tiny robots that could fit in your hand to eight foot tall creations straight out of one of your favorite robot movies. It was hard to figure out where to start as all of us set off in different directions.

The Machine Man Band will Entertain You Right near the entrance stood two six foot tall robots that comprised the ‘Machine Man Band’ as shown in Figure 5. To the right of the robot

Figure 4 - The Robot Hut museum in Elk, WA.

band was an older small computer that controlled quite a bit of the museum’s robots and sounds. With a few deft strokes on the keyboard, John soon had the two robots playing several of over 160 tunes that he programmed into the computer. He designed and built these two robots from scratch; the music wafted throughout the museum and was quite pleasant. The actual ‘instruments’ were the pipes in the chest of the blue robot and the drums in its hands — not some separately recorded music. They are a bit loud, sounding much like a calliope in a circus midway. The Machine Man Band was built in 2002, then rebuilt in 2003. It was featured in SERVO Magazine 11 years ago when John described how the over 100 MIDI electro-mechanical devices were programmed, and how he took almost a year to build both robots, plus their 48 organ pipes and solenoid valves to control the whole works.

Robots Galore If you (as a visitor to the Robot Hut) only had a few minutes to see the exhibits, the area of the museum shown in Figure 6 would be the place to stop. B9 from the TV series, Lost in Space is on your left, built by John in the 1990s. John used to video tape his robot project’s construction progress on VHS tapes and he has those tapes in storage somewhere. Just like he did with his Robby the Robot, he said he kept “building B9

Figure 5 - Machine Man Band robots and computer control.

Figure 6 - Robots galore!

over and over again until I got it right.” The actual movie original — costing $75,000 to build in 1960 — was copied and had several versions during the TV show. They bounced around amongst owners, and supposedly one of the originals is now in Paul Allen’s Science Fiction Museum in Seattle. It seems to be one of the most copied robots for collectors who are extreme fans of the Lost in Space series. The large silver robot on your far right is Gort from The Day the Earth Stood Still, who is waiting for your command, “Klaatu barada nikto.” He is a bit shorter than the original, but every bit as perfect in form. Diminutive Huey, Dewey, and Louie from the film, Silent Running are at the bottom, and were built by John in 2004. To the far right is an excellent reproduction of the time machine from the 1960 movie of the same name. Though not a robot movie, it is one of the most noteworthy science fiction films of all time. SERVO 07.2015

Figure 8 - John Rigg re-making Tobor as a museum display with Fred Barton (in the black shirt).

Figure 9 - John Rigg standing next to Robby and his space taxi car.

‘prop shop’ on the premises in which he has made many robots. I’ll highlight that later. Figure 7 - Tobor the Great.

John told us that the seat in the time machine was actually an antique barber’s chair. He built the prop in 1997. In the middle stands Tobor, with a chest full of bent metal tubing.

Tobor the Great One of my favorite automatons is Tobor the Great (Figure 7). You can imagine where it got its name. When I first saw the movie as a kid, I had dreams of having my own robot. If I remember right, it was the kid genius in the movie who ‘saved the day’ against the bad guys when Tobor was still able to follow the radio signal when the bad guys smashed the ball point pen that hid the remote control for the robot. Though very few of the robots on display were actually used in movies, this is not to say that John was not heavily involved in making movie props. The collage of photos from his website shown in Figure 8 presents the fabrication process of several Tobor replicas with Fred Barton and himself. Our group later toured his

SERVO 07.2015

Robby from Forbidden Planet Although Tobor was the robot that first stirred my imagination about robots, it was Robby the Robot from MGM’s 1956 Forbidden Planet that captured my heart, as well as many other generations. The only other movie robot that might have generated more interest is R2D2 from Star Wars. Robby was the epitome of a friendly and safe robot that utilized Isaac Asimov’s Three Rules of Robotics. The ‘robot’ was built by the MGM Studio’s prop department at a cost of $125,000 — a huge sum in those days for a movie prop. Robby had several movie appearances after Forbidden Planet — one of which was The Invisible Boy in 1957. Robby — or parts of Robby — appeared in many TV episodes over the years, as well. The original Robby was bounced between several owners over the years, vandalized, and repaired a few times, then was finally sent to Carnegie Mellon’s Robot Hall of Fame in 2004.

Figure 10 - Another of John Rigg’s Robbys.

The several Robbys that are on display at the Robot Hut are every bit as spectacular and accurate as the original. John is shown in Figure 9 standing next to Robby, who is the driver of the unique ‘taxi’ that was used by Dr. Morbius to transport the visitors to and from his residence. John built both of the robots and the unique ‘Jeep,’ as he calls it. His first Robbys were built starting back in 1987. Again, he would decide

Figure 12 - If you do not have room for a seven foot Robby, a smaller version or a steam punk-headed Robby may be right for you.

Figure 13 Kenny Baker in R2D2 costume and Anthony Daniels in C3PO suit.

Figure 11 - An initial Robby design not used in the movie, and his friend, R2D2.

that he could do more, so he kept building “better” ones. Collectors snapped up even the ones that he did not like. Another Robby shown in Figure 10 stands in a corner with a few of his brethren, and another uniquely designed Robby built by John is shown in Figure 11. This was one of the first designs and was not used as the final prop in the movie. A series of pintsized Robby replicas shown in Figure 12 is displayed in one of many showcases in the museum. Robby is so memorable that even people who do not like science fiction readily recognize the robot. Sitting in front of Robby is his equally famous robotic friend, R2D2 from Star Wars. R2D2 squeaked and beeped his way through many scenes and stole the hearts of millions of fans. I can see why Anthony Daniels worked so well in the C3PO costume in Figure 13, but why did Kenny Baker have to be stuffed into the mobile R2D2 can when great radio control systems were available in the mid 1970s?

Figure 14 - Maria robot 'suit' from Fritz Lang's, Metropolis.

Other Great Movie Robots Roving about the museum, visitors will see Maria from Fritz Lang’s 1927 film, Metropolis. Maria was a Maschinenmensch, which is German for “machine-human.” She lived in the far future of 2026. This was one of the most expensive movies made up to that time. The ‘Maria suit’ is shown in Figure 14. John traded some Time Machine parts for her. Sitting in Robby’s cart, visitors will see the star of the 1987 movie, RoboCop shown in Figure 15. It was another robot that John did not build himself, but bought from a collector in Florida. The parts were cast from the original RoboCop’s molds. RoboCop was actually a cyborg — a mortally

Figure 15 - RobotCop.

wounded cop wearing an exoskeleton. Again, jumping back in time, the robot shown in Figure 16 is from the 1954 movie, Target Earth that depicted giant robots from Venus attacking Chicago. John built this particular one in 2004. SERVO 07.2015

Figure 16 - Robot from the 1954 film, Target Earth.

Figure 18 - C-3PO from Star Wars.

Three More WellKnown Movie Action Prop Robots

Figure 17 - Johnny Five from Short Circuit.

SERVO 07.2015

Placed in other very visible locations in the museum are three famous movie robots that are fairly recent. Number Five — or better known as Johnny Five from the 1986 movie, Short Circuit — is shown in Figure 17. As you probably already know, the film’s storyline is about when the military robot, number 5 from Nova Robotics was struck by lightning and went from being a robotic killer to a sentient — a kindhearted being who was ‘alive!’ Again, here is a robot prop that took John four years to build, finishing up in 2004. Building one part at a time, John either used stills grabbed from both the ’86 and ’88 movies, or from driving down to the LA film industry area to photograph and measure an actual prop. One cannot talk about the Star Wars movies and cute little R2D2 without mentioning the prim and proper speaking gold-colored British butler robot, C-3PO (Figure 18) that

Figure 19 - The Terminator T-800 Model 101.

accompanied his diminutive pal around in most scenes. Notice that C3PO is holding his severed leg! Can you imagine being stuffed into an extremely uncomfortable and very hot costume and standing in the blazing desert sun for hours in an outdoor set? The protocol droid appeared in all seven Star Wars movies and the prop’s designer, Ralph McQuarrie based C-3PO somewhat on the Maria costume from Metropolis. John built his C-3PO in 2000. The Terminator from the 1984 film of the same name has become even more famous. Not necessarily as a killer robot (in the first movie), but because he (it) later became the “governator” of a large western state where I used to live. Whereas most robots in movies slowly became a bit more tame and likeable as the years passed, the Terminator T-800 Model 101 from the year 2029 is a pretty nasty cyborg.

Figure 23 - A long line of WowWee robots.

Figure 21 - John Rigg and his biped robot cart.

Figure 24 - Androbot Topo and a series of Heath Hero robots on display.

Figure 20 - Side view of the Terminator.

Figure 19 shows him stomping on a pile of human skulls. Figure 20 is a great side view of the prop showing the nice details. “It was built by Sideshow,” commented John. “I traded robot parts for it many years ago. It is solid resin, cast and then chrome plated, and weighs a ton! It would have been lighter if it was made of metal, I think.”

The Prop Shop After leaving the museum building, the six of us went over to the ‘prop shop’ to see another unique robot that he built — both for his grandkids and for the town’s Elk Day’s Parade. He built the ‘biped robot cart’ shown in Figure 21 in late 2013 and early 2014 for a fun ride for the kids, but was convinced by others to feature it in their parade. The robot’s skin is actually made from tough cardboard from pallet

Figure 22 - John Rigg demonstrating how the robot steers.

skids, and the upper body is in the form of the Target Earth robot. It is powered by three 12 volt car batteries, using a PCM controller for speed and direction control. It can be steered (Figure 22) and wheels in the feet can be locked for walking or freewheeling for coasting.

Figure 25 - Just a few of the many glass display cases full of treasures.

Final Thoughts Check out all the included photos of the many long showcases that display almost any type of robot that you can imagine. The long line of WowWee robots shown in Figure 23 is a good example, as are the row of experimental robots in Figure 24, and one of the long glass cases seen in Figure 25. This was a most interesting trip and tremendously fun for all of us. If your favorite movie is or was a science fiction film and there were robots involved, you must add John’s

Figure 26 - The alien saucer from the 1953 film, War of the Worlds.

Robot Hut to your bucket list. I’ll close this article with a great shot in Figure 26 of the alien saucer from the film, War of the Worlds that is hanging from the ceiling of the museum. Definitely go to John’s website at www.robothut.robot nut.com for more info. The Hut is absolutely out of this world. SV SERVO 07.2015

- -

COMPONENT LEDs â&#x20AC;¢ LED BULBS â&#x20AC;¢ LED ACCENT LIGHTS

For the finest in robots, parts, and services, go to www.servomagazine.com and click on Robo-Links.

Need electronics? www.nutsvolts.com

Advertiser Index All Electronics Corp. ..................................................37

RobotShop, Inc ....................................................67, 82

AndyMark .............................................................21, 82

SDP/SI .........................................................................37

BattleBots .....................................................Back Cover

Servo City/Robot Zone .......................................82, 83

Firgelli ...........................................................................19 Front Panel ..................................................................57 HiTec ........................................................................2, 82 Maxbotix .....................................................................82

SuperBrightLEDs .........................................................82 Team Synergy Moon ..................................................29 The Robot Marketplace .............................................25

PanaVise ......................................................................13

Tormach .......................................................................23

Parallax .........................................................................25

VEX IQ ...........................................................................3

Robot Power ...............................................................57

Weirdstuff Warehouse ...............................................37

SERVO 07.2015

Who will build the ultimate fighting machine?

NEW SERIES JUNE 21 SUNDAYS 9|8c

#BattleBots