Dynamo Magazine

6 Sparkfun

14 CNC

9 LASA Robotics

EZine 2012

Summer 2012 :: Table of Contents

A

04 The LASA

Robotics Team A good idea?

History, more

06 Sparkfun

Behind the scenes

16 End of the

Manual Era

What’s next with CNC machining

20 Cardboard.

Like you wouldn’t believe!

22 New CAD on

the Block

We compare SketchUp, others

while ago, in my robotics team, we had this metal arm that needed to be able to stay up without power.

It was driven by a simple transmission from the motor; and it looked fine - but didn’t work. When work on the robot started that day, we started off talking about what we should do. It was very irritating. See, there was this plan to solve the problem. We were going to change the geartrain. However, the other group members wouldn’t let me replace it. Their reason: “We don’t have enough time.” First of all, that made no sense. We had time. Second: once, finally, they let me fix it, I finished in time, and it worked perfectly! The outrageous part- without my urging, we would never had done this, and the robot would not work.

When I tell you about this, it seems amusing. The unfortunate part is that it’s happening everywhere. In some way, some form, no task is completely immune to this mis-planning; it could be called a form of entropy; that is, nothing can be one hundred percent efficient. The classic example is chores; everyone needs to do them, but no one wants to. Why not? And then I could go on to include everyday tasks and jobs that are not chores; then it gets interesting. Start that home improvement project; plant that garden; try that recipe! Draw out that idea; build that contraption; program that robot!

Everyone needs to move.

But people say that planning is good. Simple as that. And it’s a powerful point. But... that’s not what I’m pointing out. I’m not saying that you should jump into things as soon as you can. I’m not saying that building according to a design, or even attending a meeting, is bad (in fact, it’s one of the best things ever invented). What I am trying to say is that, when you have something that you will absolutely need to do, do it. If other people (or even yourself: laziness) are opposing you, ignore them. No, it will not be insubordination; according to the prerequisites stated, they are mistaken. Go do it!

This is an afterword. They don’t usually appear in articles, but it’s necessary. I believe that the best thing to call this piece is a “rant.” I am telling you all that I think about this, as much as I can, and as quickly as I can. I am writing to incur in you that emotion, that feeling of impatience, that need to improve things I have; that feeling is what this magazine is about. I hope you don’t take offense to anything I have said. Still, you’ll get my point, eventually. It’s logical. Is it really good to do such a thing, to just sit around?

Now, before I end the spiel... I don’t want to get into this, but... here it is. Is there a purpose to life? If, as the philosopher Friedrich Heinrich Jacobi said, there is none, my opinion may be considered, as they say, “null and void.” But please, don’t just sit there. Move.

Daniel Teal

To DO, or not to do.

The final, working robot: just for purposes of illustration.

“

[But] without my urging ... the robot would not [have] worked.

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2D enthusiast and programmer :: Jonas Wechsler Robot engineer :: Miles James Programmer and 3D enthusiast :: Daniel Teal

EDITORS

Ms. Richey LASA High School

ADVISER

MagCloud Publications LETTER FROM THE EDITORS We are the design team for the Dynamo magazine: directed at those who enjoy making things; think along the lines of Instructables, but with our own ideas. It’s a semester project for LASA High in Austin, TX- this will be the only published issue.

Though this may be a school project, feel free to read through and enjoy; perhaps you like this sort of thing. Despite our attempt at a good presentation, we hope you’ll find kindred spirits in us. We’ve had fun with it. Thank you.

PUBLISHER PHOTOGRAPHY CREDITS Front cover: Sparkfun’s electronics.

In the Shop: Photo courtesy LASA Robotics Spark of Life: Photos courtesy Sparkfun Road to Robots: Photos courtesy LASA Robotics Rise of the CNC: Photo courtesy Trinity Racing Cardboard: Credit is given with images All other photos taken by the editors.

CONTRIBUTORS

Jonas Wechsler

Miles James

Programmer. Hair.

Electro Swing. Gaming.

Manual construction.

Electronics.

Enjoys building robots and hanging out with friends. Attends the Liberal Arts and Science Academy.

Daniel Teal Does useful stuff.

Builds 3D printers, cleans the workshop, and creates CAD programs.

In The Shop

T

he air is filled with the sounds of power tools, programmers yelling about code in the next room, and the friendly joking of comrades working on shaping a piece of metal into part of a chassis. It’s a Robotics Club build day. I’m here because robotics is something I love and I feel it’s an amazing activity.

I have heard complaints about how some kids in the teams seem to treat the newer ones. For instance, one complaint that I have heard was from someone who was not new to shop equipment and power tools and already knew how to do most of the things they were being told to do. Even after this person explained what they knew the older kids still showed them what to do. I can understand where that might get annoying, but it’s more of a safety measure. They have to explain how to do these things the first time the first time, then when the person has shown they can do this task, everything is good. I have also heard the opinion, from someone who can do a lot of the stuff done in their team, at home, that they just don’t really see the point of them going to the club since they did a lot of the same things at home.

This being said there are a lot of things that I have found to be really great about the robotics club that I am in. I always have a sense that someone will willingly help me if I don’t know how to do something, and there is almost always something for me to work on. Even when there is not something to work on, there is a large sense of familiarity and friendliness that makes it easy to hang out with other teammates who don’t have anything to work on. These times of sitting around waiting for something to do, though, are very infrequent.

I have found the club very easy to fit into. There are parts of the competitions for just about everyone. There’s the actual

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building of the robot and there’s the coming up with the designs - which is where the engineers, mathematicians, and physicists really shine through. That doesn’t mean they, however, are the only people who will contribute good ideas. You could have no interest in engineering and end up having an idea that becomes an integral part of the robot. But once the design is done there is a plethora of jobs that need accomplishing. The robot has to be built, a program has to be made, and you have to make a model of the field to practice on. Someone needs to write papers and make presentations about the club, you generally want to have someone working on spirit stuff for competitions (there is actually a most spirited team award that can affect how you place overall), and you want to have people thinking about fundraising and outreach. I have found myself a part of most of these activities and have enjoyed almost all of them, even the ones I don’t like normally.. The robotics teams are great for anyone who wants to be involved in a team or are interested in any of the activities that I mentioned previously. I find the competition challenges to be quite entertaining and fun.

Miles James

BEST certainly centers around robotics- but does it contribute to eductation?

A Bug in the System

I

entered the bottom floor “dungeon” of LASA High in order to attend a meeting for the BEST robotics competition. Today was “D4,” or Drop Dead Design Day, after which we would have a design for the final robot. My spirits were high as I came in, expecting to indulge in the intelligence of others while having an interesting and mutually rewarding discussion with the robotics team.

Unfortunately, this was not the case. The ideas that I hoped to share and discuss were avidly rejected because they were too divergent, something I strive for when brainstorming.

I proposed some alternative design, say, using a drivetrain rather than having the robot use the standard tank-like chassis (This design would provide more speed, which was a discussed problem with the previous makeup). My idea was rejected. Ideas of this sort were thrown about for around four hours until we settled on a design that looked exactly like the previous years’ designs except with minor adjustments to fit the challenge.

The explanation was that it was too risky to try something that wasn’t tried and true; if the team put all their effort into a robot that didn’t work, they wouldn’t have anything for the competition. Besides, the team had repeatedly done quite well at competitions, often achieving first place at capitol and state, as illustrated by their website. They had no reason to change and all members of the entire team, especially those running it, were quite recalcitrant to any impetus of change.

The actual construction of the robot was not particularly captivating. I have done plenty of things of this sort on my own, and, naturally, I am much more interested in the projects that I develop at home than the robots assigned by the competition.

During middle school I took a robotics class in my first year and I quickly became a teacher assistant for the class. Throughout my three years of robotics I became extremely tired of RC cars and this sort of project. Seeing as all bases of the competition’s robots are huge RC cars, one can see how the robot itself was not something I found inspiring.

Of course, I’m not here to rub my problems in the reader’s face; I actually have a solution to propose. The competitions always revolve around the placement and movement of objects on a field, with certain restraining parameters. Although the restraints vary quite a bit from year to year, the competitions still end up resulting in very similar robots, i.e., a chassis similar to that of a tank with a claw with various attachments. After a brief overview of their website, this belief is quickly confirmed and illustratrated. Instead, the competition should vary more with challenges that are conducive to alternate designs. This wouldn’t

“

The ideas that I hoped to share and improve were avidly rejected.

be too hard; The robot could simply have restraints put in place to force the designs to not conform to the standard. Consider a robot that has to work in cooperation with a human operator to accomplish tasks that would clearly be impossible alone.

The competition is not conducive to learning, the success of the team quite clearly takes priority over the education of the students. This is illustrated in that the team is resistant to any designs that deviate from the tried and true. If a student does not know how to construct or program a part of the robot, they are not educated on how to do it, rather they are simply told not to do it. This is not entirely true; students can be educated on how to use certain tools and machines in the shop, though this problem holds its ground when it comes to electronics and coding. I myself learned more about electronics in one week of solo research than I did during two months of robotics. This flaw is mostly because the team simply does not have the time to develop a good robot. According to their website, they are given a mere 10 weeks to build a robot, a field, train drivers, and prepare a proper presentation. The solution to this is simple: given more time, the team would be able to educate their members.

While I understand the appeal of a club of those that have similar interests to you, the robotics competition itself is executed in a way that relies on this appeal as a draw, rather than having the challenges themselves attract members.

Jonas Wechsler

5

The Spark of Life

When one thinks of an electronics distributor, one think of a concrete building full of concrete people testing products in a room full of cubicles. However, Sparkfun electronics is composed of a team of friendly, relaxed engineers. The office was strewn with creativity and innovation, from a 5 foot N64 controller to a model terminator arm composed of spare electronics components.

Normally hardware distributors are relatively faceless companies, with very little emphasis on public relations. One need only to look at the McMaster-Carr website; the amount of emotion able to be attached to it is very similar to the loving connection between a person and a pile of recycled cardboard. (The website is essentially a digital catalog; that is, it’s a list of item names and numbers.) However, Sparkfun strives to maintain a healthy relationship with their customers, consistently reading their forums and paying attention to customer feedback.

When Dia Campbell, an employee at Sparkfun who specializes in wearable electronics, was asked about the company’s philosophy with their customers, she explained that, “SparkFun can’t really help nurturing our relationship with that community, because we’re still part of it.” Sparkfun consists of hobbyists and makers themselves, so they’ll know and feel guilty if they’re not serving their customers well.

Likewise, Dia explained that the audience consists to a large degree of very experienced makers: “We try hard to be very responsive to the needs of our community. We listen carefully to product suggestions by phone, email, and forum, and we keep comments open on all of our products for feedback. We’re lucky to have customers who are talented, hands-on people themselves. If a product has flaws or needs

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and hardware are made outside of Sparkfun, almost all of the boards are made in house. Dia said that she is, “responsible for keeping an eye out for new e-textile products that we should be carrying, evaluating them for sale, writing tutorials to teach people how to use them, and occasionally speaking directly with customers or media about e-textile,” and went on to state, “New products are being developed quite literally ALL the time. Designing these boards is a critical function within the engineering department, and all of the engineers usually have multiple boards in the works at all times.”

Sparkfun is truly a busy building, though this doesn’t obstruct their ability to maintain a casual atmosphere, and these liberal rules contribute hugely to their creative output.

Because the workers are given the freedom to work on their own projects, they can ensure the quality of their own products.

Jonas Weschler

improvement, they’ll let us know!”

The amity of the company wasn’t merely outward; Dia went on to explain that self expression was avidly encouraged within the company. She stated that, “You only have to walk into one or two hackerspaces to get the message loud and clear that discipline and formality aren’t necessary to get a lot of really cool stuff done, so we really keep those to a minimum.

Love what you do, work hard to see projects through, and document your work, but don’t worry too much about dress codes and restrictive or demeaning policies. ” Of course, this doesn’t mean there isn’t any work to be done at Sparkfun - the company has the normal jobs- tech support, customer service, marketing and communications, human resources, finance, and IT, as well as an education department teaching people about the products and an engineering department that designs the future products.

The production team in particular is huge, although a lot of work is done by the company’s pick and place machines, there are still some things that are done manually.

There is also a team of kitters who assemble various components and repackage them for the storefront. Since the machines work off of reels of parts, if they aren’t sure how well a product will sell they make a smaller quantity of them and construct the board by hand. Although the tools

THE

Road to Robots 30 years ago, LASA had no robotics team, no robotics class, and a class that was only adapted to include engineering. Today Lasa has a robotics club, class, and a class specifically made to teach engineering, all of which were started by Tony Bertucci. Bertucci (also known as Bert by robotics students) has started and conceptualized some of the most well-known parts of LASA. LASA’s Robotics team is known as an example for other schools on how teams should act, and the signature course Sci Tech, which Bertucci and Mr. Pace started 25 years ago, is one of the first classes LASA students are required to take.

The road to a robotics club started when, in the mid-1970s, Bertucci took over class called Advanced Tech. Before Mr. Bertucci took over the class it was run by a man named Jet Avalos, but robotics wasn’t the main focus. “He did some robotics stuff in it, but it was mainly an excuse to do electronics” Mr. Bertucci said. Not long after Bertucci started teaching at LBJ, and right before he made the switch to the science Academy Jet Avalos left teaching and Bert filled the position, “I guess I was the natural choice to take his place”. Bert’s first degree had been in industrial arts and before taking over the Advanced Tech class he had taught various other technological classes. After taking over the Advanced Tech class Bert geared it solely towards robotics. “[I] put a big manufacturing slant on it, since that was more my strength” Bert said. That is definitely something Bert carried over into the robotics class, and initially, the club.

Above: LASA Robotics demobot triumphantly lifting innertube during its demonstration.

The robotics club was started in the early 90s by Bertucci and a group of his students. The concepts in robotics and even some of the doing of it were not new to Bert and his students. Bert had been teaching the Advanced Tech class

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LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Rob

and classes very similar to it for over ten years and he at least had some idea of what to do. Bert and his students were certainly happy to have an outlet to do robotics.

“When we first started the club, back in the 90s, robotics was pretty new, and to some extent we were just glad to have something to do…since nobody really knew what they were doing, any kind of contest was new.”

positive. One of these came about during competition were the robot had to stack plastic pyramids, “we were one of the only teams at the competition that was actually able to perform it autonomous”. The competitions evolved about as much as the robots did. The large competitions went from being little things that nobody really knew how to work out to being huge competitions that people tend to understand pretty well by the end.

“The thing you have to remember when you’re looking at competitions is that essentially they are very large complex things being run by volunteers” Bert said, “That being said I think they do a great job.”

“We were one of the only Even though the contests were new, Bert and the robotics club did their teams at the competition best. In their second year of existence and competing they made it all the that was actually able to way to national championships.

When asked about which robots that perform it autonomous” he has seen were the most memorable, one comes to his mind pretty quick, and it probably wasn’t because it was his favorite. “The first robot that we did for FIRST was memorable, not because it was an especially good robot, but because it did require me to get seven stitches and give me a concussion”. FIRST is one of the largest robotics competitions in the U.S. and has several different levels of competition two of which the LASA robotics team participates in every year. There were other robots that he remembered that were infinitely more

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In the last couple years, two new robotics related activities have sprung up at LASA. The first is the Robotics class.

This is something that Bert had been trying to get at LASA for good little while. “it took a little bit of effort over an extended period of time” Bert stated when asked about getting the class started. You can tell its something that he

botics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LASA Robotics - LA

“The purpose of robotics is to teach how to think and how to apply”.

FAR LEFT: A LASA Robotics student making repairs to a demobot during a demonstration. Drivers and programmers behind him.

TOP RIGHT: Two Robotics students, Daniel and Jade, working with team mentor Danny.

BOTTOM RIGHT: Robot constructed by the FTC for competition.

CENTER: Image of a LASA Robotics polo shirt.

is glad that he got started. He only teaches robotics and its evident that that is enough for him. The other robotics activity that has sprung up, in the past year, is another club. This club was not one started by Bert but by one of the Robotics seniors, Harris. “The concern was that there wasn’t enough time in the weeks that we have during competition to really keep on developing engineering and things like that, and while I didn’t see it as a major problem other people did.” Bert didn’t feel the spin off club was completely necessary but he understood why Harris might think that. “During the six week build, its crazy”. The new part of Robotics has a very free setup, the people who go talk and try and think of what they might want to build, someone will bring in something they want to talk about, or mention something they might be interested in talking about next time.

The LASA robotics club has been around for a long time and has had a rather interesting history. LASA Robotics is very well established in the high school robotics scene, being one of the older teams. Mr. Bertucci is often told how well behaved his students are and how other team’s coaches use his students and his team as a model for what a team should look like.

This wheel chair robot was created by the LASA Robotics team on contract for a California citizen.

“I would say that one of the really good things about having a program like this is that it provides an outlet for kids that they wouldn’t have in a purely academic 100% academic lecture type school”. Bertucci, the man who started it, is always willing to have more people join him and thinks that robotics a great activity for everyone. Bert feels that “The purpose of robotics is to teach how to think and how to apply”.

Miles James

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L A S A

R o b o t i c s

2 0 1 2

FTC 4290 :: “PHobia”

Power tools aplenty...

ROBOTICS:

A Guide to Shop Equipment

1

Plasma Cutter: The Plasma Cutter works just like CNC mill, Utilizing CAD software to cut shapes of metal to use in whatever project you are working on. The main difference is that, like its name suggests, it uses plasma to cut. This means it can cut through very durable materials much fast. The CNC Mill is more precise though.

CNC Mill: The CNC Mill utilizes CAD programs and various sized drill bits to cut through metal automatically. You can tell it how deep to cut and in what shape to cut. It is generally used when someone needs a lot of precision on a durable material or when someone is just feeling lazy.

2 3

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Lathe: The Lathe is medium sized machine that is used to manipulate the shape of rods. The rod is clamped in to the machine and spun at very high speeds. You can spin small wheels on the machine to move the various parts of the machine to where you need them to be. One of the parts can be moved toward the rod and drill a hole into the middle of the rod. One of the other parts is used to shave of the end or shave into the rod.

4

Drill Press: The Drill Press is a machine that is used to drill holes in materials. It can be used to drill holes quickly.

5

6

Sanders: There are a few types of sanders that may be in a shop, all of which sand things and are characterized by how they move. One of these would be the circular sander. This sander is a large wheel that spins and you place the wood against the sander where it goes down against the table of the machine. Another type of sander is the belt sander. As its name suggests this sander has a large belt of sand paper that is moved at high speeds and accomplishes the same thing as the circular sander. The third type is a spindle sander. This sander is used to sand down curves or holes made inside of something.

Band Saw: The Band Saw is a machine that is used to cut wood and thin metal. It has large bladed band that spins around two large wheels.

The band saw is the most versatile of the non-handsaws. Wood can be very easy to maneuver on the saw, at least when it is smaller. The band saws main purpose though, is to cut long strips off of wood. How wide a piece you can cut tends to depend on quite a few factors. The larger the piece of wood the more you might want to consider a table saw.

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Miter/chop saw: The Miter saw is mainly used to cut through thicker pieces of wood like 2x4s. It has a secondary purpose of being able cut small angles, but really only out of that isn’t that wide. It tends to not be used that often because there is no maneuverability within the cut, you have to cut straight and you have to cut straight through.

8. Table saw: The table saw has a variety of uses. It is normally used to cut pieces of wood that are to big for a band saw. Its main purpose is cutting of very large pieces of wood. It can also be used to cut gouges into wood. You can get special blades for the saw that stack on to each other.

If you need to cut, say, a half inch deep by half inch wide gouge down the length of the wood you could do that pretty easily. Changing out the blades can take a few minutes and can be somewhat dangerous but it is really the best option for gouges in large pieces of wood.

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RISE

of the CNC Downstairs at our high school, in the shop hangs a sign: [ClichĂŠ picture of sunset] M O T I VA T I O N .

If a pretty poster and a cute saying are all it takes to motivate you, you probably have a very easy job.

The kind robots will be doing soon.

With the advent of the CNC, this is coming true.

See, I often browse the internet for new ideas and innovations; that is, avant-garde technology. And every so often, I come across a custom mechanism, sometimes metal, sometimes wood, sometimes bought, sometimes salvaged, that brings the digital into real life. I’ve seen plotters, routers, three-dimensional printers, and laser cutters; all sorts of computer- numerically controlled devices (CNCs). But they’ve been coming up more and more often. It’s the beginning of a revolution.

Hobbyists especially, everyone wants to be able to create whatever they want. But what does one do if he is bad with his hands, or can’t find time?

Machines, they say, are never bored.

And they can make things.

Ergo, the rise of the automated tool.

At its heart, it is, well, a tool. But be it saw, lathe, metal former, or welder, it is controlled by a computer. Multiple motors drive the movement of cutting edges or what-have-you; in turn, electronics control these. Specialized software interfaces with such contrivances in order to translate a digitized design into hardware.

Carlos Jones, a senior at the Liberal Arts and Science Academy, terms the CNC mill a “shortcut between a CAD (computer aided design) and a finished part.” His workflow: start with a model created in a design program such as SolidWorks, import it to SprutCAM to generate machinereadable code, and finally, send it off to Mach3, which interfaces with the CNC hardware.

According to Carlos, however, “The mill doesn’t actually allow anything we couldn’t do with manual tools; it just lets us do it faster.” That is, it’s not the all-in-all.

Enter the RepRap. Stylized as a “rapid replicator,” it’s an original 3D printer with the goal of copying itself. According to the project’s home page, “RepRap is about making self-replicating machines, and making them freely available for the benefit of everyone.”

It can print in abs plastic, that durable material that most commercial products are formed of. More importantly, it’s an open source design; all plans and ideas are shared with the community. Because users create and reshare parts with improvements, many “reprappers” have very advanced machines; even to the point where, unattended, a device can print in not only

How a CNC Works 1

An engineer designs a 3D file with a Computer Aided Design program, such as SolidWorks or AutoCAD, and saves it in a .stl file as a mesh of triangles.

2

The .stl file is run through a short script that converts it to g-code, a sequence of instructions. A typical instruction might go “G01 X1 Y2 F7.5” in order to move one inch on the x-axis and 2 on the y-axis at a rate of 7.5 inches per minute.

3

The gcode is loaded into one final program that controls the CNC itself. Signals are sent according to the g-code to move the motors.

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4

The most common type of motor for a CNC is a stepper motor, so named because it moves in “steps” of a few degrees according to a certain pattern sent by a microcontroller or computer controlling the machinery.

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One by one, these motors often drive leadscrews which slowly and powerfully inch the cutting head and work together.

6

Finally, a rotating bit (its rotating mounting is called a spindle) mills away unwanted parts of the material, or, in the case of a 3D printer, adds to it to create the final product.

multiple colors but multiple materials, including electric conductors.

already had, for a total of only about ten dollars.

In the near future, complete circuits could be reproduced, which, with sophisticated software, could both achieve the RepRap’s goal completelyand automate machinery.

Here’s what my plan was: I hit the enter key. Pulses go flying through silicon at billions of cycles per second. It streams to an Arduino microcontroller, which, through an ULN2003 chip composed of eight transistors, sends reciprocating signals to the multiple coils in a stepper motor. Leadscrews turn, and a geared down mechanism turns thermoplastic against a modified commercial extruder.

Now, really curious about the subject, I started to build one of these 3D printers. After a bit of research, it was easy to determine that it would take hundreds of dollars to buy pieces one by one; since I didn’t have that much money, I tried to cobble one together a different way. First, the motors; Stepper motors, probably the easiest and most accurate type to use, were salvaged from old printers. I ordered some chips on eBay to control them from an Arduino; I now had working electronics, not counting materials I

But- they work. Moral? If I can get this far, anyone can. The future is here.

Daniel Teal

I should tell you that I’m still working on this. I’m not done. Most of all, I need to build a plastic extruder: conveniently, hot glue guns can be bought cheaply nowadays, and, while not optimal, they work. Additionally, while building the mechanics, I found it hard to build fifteen dollar leadscrews.

Want to make a CNC? Here’s a simple wiring diagram for controlling a stepper motor.

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The ULN2003 chip, which can be purchased very cheaply on eBay, contains transistors to provide the motor with high enough voltage to effectively drive it. Pins 1-4 are hooked up to a microcontroller in order to be activated one at a time. For a more detailed description and discussion, see http://en.wikipedia.org/wiki/Stepper_motor.

Coil 2

ULN2003 D1 D2 D3 D4

1 2 3 4 5 6 7 8

16 15 14 13 12 11 10 9

Coil 1

Stepper Motor

Coil 3

Coil 4

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ROBOTICS:

Cardboard “Nothing” - Joost Van Bleiswijk

“Cellulose” Paul Coudamy

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Assorted pieces by Chris Gilmour

Elsa Pagis Effets Pourpets ppatches24 (Instructables) Patricia Dessoulles Leo Kempf Design Piotr Pacalowski

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DESIGN:

New Names

in CAD Manufacturing

3D Modeling

Google SketchUp First release: 2000 Cost: free Developer: Google The traditional approach to 3D modelling is to drag solid figures around on a grid. SketchUp, instead, lets you (aptly named) sketch 2D shapes with one of several tools and then push or pull it out into the next dimension. Mainly marketed towards architectural, civil, and mechanical engineers, according to Wikipedia, it was designed as “3D for everyone” and seems to live up to it. To test it out, we built this Klein bottle (an object with only one side, related to the Möbius strip). It took roughly one hour. Bear in mind, however, that we’re not experts. If the program suits you, it could be the fastest way to a three-dimensinal representation of your project.

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Klein Bottle

It’s always nice to know what you’re building before you make it. And it’s also nice to be able to share plans with the world: therefore, you need a good computer aided design (CAD) program. Ideally, your goal is to be able to precisely describe the exact shape and size of a project. Unfortunately, this can sometimes be hard to describe to the computer, but many software packages make a very good attempt to let you. Here are our opinions on two of the newest, most recent, and most innovative programs out there: Google SketchUp and Tinkercad.

Tinkercad Location: online Cost: free Purpose: 3D printing I had never heard of WebGL before. But I have now.

Tinkercad is an online app (WebGL is a 3D library for javascript) with uses Costructive Solid Geometry; that is, you place simple objects on a plane and then add and subtract them. Originally developed in order to 3D print quickly and easiy, I would go as far as to say that it’s even easier to use than SketchUp. The only downside is that any very complex object is slow to build; some are impossible (think screw).

Still, giving it a try, on our first attempt we were able to build a pair of scissors. Although, due to only basic design skills, they might not work, the neat thing is that we can just hit that button labled “Print 3D” - and we can order a real life copy. No physical effort needed.

Final Thoughts We’ve used other CAD programs before, but it’s always nice to see new ones.

Both these were free; other common programs, like AutoCad, are commercial; but there’s a reason for their price.

They are perfect for complex engineering applications.

Solidworks, another costly piece of software, is amazing if you know what you’re doing. If you need to make a cube, 60 mm on a side, with rounded edges, you can do it very easily. It gets even better as you assemble these tiny building blocks.

On the other hand, programs like these,

SolidWorks

that is, SketchUp and Tinkercad, are more for small models.

We believe that Sketchup is good for precisely that: sketching. It’s quick and can do quite a lot; unfortunately, it’s hard to give objects dimensions. Tinkercad is for 3D printing. If you need a small object, you can build one in about five minutes. As far as free programs go, though, these are some of the best.

Daniel Teal

SolidWorks

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