Portfolio
Marc Abalos
Engineering Product Design Graduate abalos.mthony@gmail.com
Portfolio Content
Surface modelling
FEA simulation
Group projec
ct: airship concept proposal
Lighting
Major project
1. Pad4CAD Mouse A mouse for CAD projects. The product prevents wrist fatigue by incorporating a side pad in the shell to elevate partially the palm from the desk surface and relieve pressure. Includes a grip ergonomically designed for short pointer movements.
Click for Assembly Animation Link (red and white product version)
Pad CAD The optical mouse for CAD projects. Designed for wrist fatigue prevention and accurate pointer movements.
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Development Process A Styrofoam sketch model was 3D scanned for surface modelling reference. The electronic components were taken from an existing mouse and their overall dimensions measured to fit the design.
CAD Model A general view of the CAD model with different shell transparencies, and different sections for detail views of the product assembly.
7 Top surface
Middle shell
LED indicator lens Side buttons PCB Top screw Scroll wheel Side buttons
Main PCB Infrared sensor lens Battery contacts
Bottom shell
Bottom screw USB receiver Battery Battery lid
Non-slip pads
2. Bicycle Crank Weight reduction proposal of a bicycle crank part of a project on beating the speed record in the World Human Powered Speed Challenge. The design process employed FEA simulation software to match or improve the benchmarks taken from the analysis of the initial crank.
Click for FEA Animation Link
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Boundary Conditions Bottom bracket hole diameter
From the initial crank design the indicated dimensions had to be kept unchanged and the thickness had to be not exceeded. The material used was aluminium 6061.
Pedal axle hole diameter Axial crank length
Bolt-hole position and diameter
Maximum thickness
For FEA simulation, the five bolt-holes highlighted were fixed constrained in all directions.
50cm
Load case 1
Load case 2
Load case 3
Load case 4
A remote load was applied in each analysis to simulate the pedal force. The value applied was 1200N throughout.
The stress analysis is performed in four load positions. They represent half of a pedal rotation.
Iteration History
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Design Proposal FEA SIMULATION SETTINGS AND SUMMARY Analysis Summary Physical Material
Aluminium 6061
Structural Analysis Type
Static stress analysis
Adaptive Mesh Refinement Control
High
Element Order
Parabolic
Yield Criterion
Von Mises stress Comparison of Results Initial Crank
Load case 1 FEA stress illustration Proposed Design
Mass (g)
245.607
Mass (g)
195.468
Thickness (mm)
12
Thickness (mm)
12
Max. Stress Max. Stress Safety Factor Safety Factor Result (MPa) Result (MPa) Load Case 1
178.0
1.545
164.3
1.674
Load Case 2
164.2
1.675
158.3
1.737
Load Case 3
160.9
1.709
158.3
1.737
Load Case 4
177.9
1.546
164.3
1.674
Load case 3 FEA stress illustration
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Load case 2 FEA stress illustration
Load case 4 FEA stress illustration
3. Airmedic Group project of four students for an Airlander concept proposal. Airmedic airship navigates with an autonomous warehouse to deliver medical supplies in remote and hard to access locations. The system deploys delivery drones while loitering in strategic areas. Project divided in four areas: target area and packaging, drone design and specifications, business strategy and branding, and airship and extension module distribution (personal work).
Cick for Airship Animation Link
Airmedic’s lo module. Unm with an auton system for m
ong-endurance airship manned and integrated nomous warehouse medical parcel delivery.
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Airship Module Distribution Development
17
18
Extension Module Distribution Development
19
20
Extension Module Attachment
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Group Presentation Summary: Introduction
Problems with access to vaccinations and medical resources occur worldwide due to remote locations and lack of infrastructure. Airmedic makes use of the long endurance flight of the Airlander to provide refrigerated shipping service to areas struggling with cold chain distribution. The airship reduces supply issues by loitering at strategic locations and deploying delivery drones containing stock to clinics and hospitals in collaboration with other organisations.
Group Presentation Summary: Target Area
The map indicates West African countries with some of the lowest percentages of measles vaccination coverage, and demonstrates possible routes for Airmedic.
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Group Presentation Summary: Packaging
Content examples are vaccines and medicines that require refrigeration. Pre-packaged with 50 doses and weighing an average of 0.4kg. All necessary information is printed on the biodegradable boxes for waste reduction.
100mm
100mm
150mm
Group Presentation Summary: Drone Design and Specifications
3kg
25
3kg max. load capacity.
Equiped with 4 obstacle sensors for parcel damage prevention.
30 minutes flying time.
GPS
Equiped with GPS navigation to locate the destination.
1 hour wireless charging time.
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Group Presentation Summary: Business Strategy and Branding
Login
Categories
Tracking
Contact
Registered medical professionals place orders through the app.
Wide range of products and services, with an intuitive interface design to renew, confirm or begin an order.
Real-time tracking order.
24 hour customer service availability for enquiries or issues.
Group Presentation Summary: Airship and Extension Module Distribution
Container (1.5x2.4x2.2m external dimensions with 0.9m aisle)
Airship Module (1.2m aisle with 2.2m min. height) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Automated airship control systems. Sensored drone landing platforms. Drone entry gate. Door access. Airship machinery. Drone shelving control systems. Automated drone shelving units with incorporated charging plates. Railed robotic arm drone and package assembler. Drone exit gate. Parcel conveyor belt and hull access ramp (25 degree slope). Main module extendable conveyor belt connector to the container.
12. 13. 14. 15. 16. 17.
4 1
2
5 3
6
9 8
Accordion-like seal. Railed and secured rack shelving units. Railed robotic arm parcel distributor (one each side). PVC strip curtains. T-shaped decking. Refrigeration system. 14 13
11 10
7
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12
15
16
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4. ELA Lamp A product for assisting deaf people with the use of light. The Edge Lighting Alarm Lamp employs two light sources: one array of RGB LEDs to notify the end user about their surroundings at home and another array of white LEDs for ambient lighting.
Click for Prototype Video Link
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How It Works Different sensors are placed around the house to detect noise, movement or smoke.
Power ON. Normal use as an ambient lamp.
Somebody is ringing the bell?
The baby just woke up or is crying?
Somebody arrived home?
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Smoke in the kitchen? (for complementary use with regulated smoke detectors).
The acrylic edge light of ELA dims up and down or flashes intermittently at different rates according to the signal received. Different light colours can be used accordingly.
The light diffuser rotates and opens up to emit sharp and intermittent light for smoke alerts.
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Proof of Principle Development From experimentation, it was concluded that the surface of the material must have a smooth surface to direct light efficiently. Acrylic Edge Lighting Visualisation
Clear acrylic cross section
Textured acrylic cross section
Incident light
Incident light
Experimentation with edge lighting using different acrylic thickness, edge shapes and surface textures.
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Acrylic Tube Profile Cut Reference
1.7m
b
a
0.7m
3m
a = 108.4Ëš (plane angle reference for good edge light visibility) b = 105 Ëš (acrylic tube cut reference)
Sketch model development. An acrylic tube was cut and curved with a heat gun following the sketched design. The initial round array of LEDs was soldered to fit the tube diameter.
Finished initial model.
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Developed Design
The light diffuser consists of two parts: one static and another rotating. The maximum rotation is 45Ëš
The lamp base was conceived for injection moulding.
The clear acrylic tube was maintained straight to simplify the manufacturing process, and the profile cut made symmetrical to obtain two identical parts, which lead to increase the diameter for better visibility.
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Acrylic shell
DC power socket
Static diffuser
Lamp base
RGB LED SMD board Rotating diffuser
Self-tapping screws White LED SMD board
LED ring support
Self-tapping screws
Servo arm Servo motor
Arduino-based circuit board
Lamp base lid
A section view of the luminaire assembly showing the components and wire arrangement.
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Prototyping Strategy
PCB layout diagrams
White LED array
RGB LED array
The PCBs were printed with one layer of copper traces. Both circuits consist of four blocks of LEDs in parallel. The input voltage was set to 12V DC.
The edge entry of light was polish after the cut.
hed
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The light diffusers were cut from a frosted polycarbonate tube and individually assembled with laser cut acrylic parts using MDF supports.
The base was built from laser cut acrylic parts following the structure of the design.
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The Prototype
Internal base assembly.
Finished base and diffusers. Prototype demonstration.
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Assembly demonstration of the lamp from the packaging for the end user.
5. LoopSync Final year project. A portable and compact induction loop system to reduce background noise experienced by hearing aid wearers in noisy or crowded environments. The product makes use of the telecoil installed in most modern hearing aids, discarding the need of extra adapters or receivers for its usage, and its short field range makes it less prone to interference.
Click for Proof of Principle Video Link
A portable and compact hearing loop. Discreet and easy to use whenever, and wherever.
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Usage Scenario and How It Works
Crowded and noisy event or restaurant? Can’t hear the conversation because of the background noise?
Use your portable induction loop!
M T MT
Switch your hearing aid to T-coil setting and turn ON LoopSync.
Adjust the coil for reception.
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Induced electromagnetic field in the telecoil results into speech reception.
Near speech is captured by the LoopSync microphone.
The signal is emitted through electromagnetic field dispersion.
Enjoy a conversation with reduced background noise.
Electromagnetic Field Range Tests
Metal cored test samples and an LM386 amplification module. Coil Tests Arrangement Diagram 9V Induced current reading every 1cm displacement
0.1μF
A 1kHz sound frequency input
Parallel coils throughout the process
LM386 1kΩ
100nF
220Ω
0.1μF Displacement direction
Signal Transmission Module (fixed position)
Signal Reception Module
The experiment consisted of pairs of coils of the same diameter and length, the transmitter having different winding layers and the receiver having one.
800
1000
400
Electromagnetic Field Strength (mA/m)
Coil 8/W1 Coil 8/W4 Coil 8/w1 Coil 6/W1 Coil 5/W1 Coil 3/W1 Coil 3/W4 Coil 3/w1
600
200
0
Induced current measurement set-up.
Contrast of Curve Results
Field Strength Dissipation Graph
Electromagnetic Field Strength (mA/m)
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0
40
80 Distance (mm)
120
160
Coil 8/W1 Coil 5/W1 Inverse Square Inverse Cube Inverse Square Inverse Cube
100
Flat coil samples. Long and Flat Coil Field Dispersion Diagram
10
1
0
40
80 Distance (mm)
120
160
Plotted results. Curves are labelled according to the coil core diameter (3-8mm), number of winding layers (1-4) and wire diameter (0.2 and 0.1mm).
Results show the field dispersion weakens rapidly. However, flat shaped coils can improve the range.
Initial Shape Iteration
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The coil tests allowed to have an estimate of the overall product dimensions. The initial shape iteration considered the use of rectangular coils, and it explored different proportions and side profiles to avoid a geometric appearance.
Field Emission Diagram for Circular and Rectangular Coil
Magnetic field reception shape
Rectangular flat coils can provide better field reception due to having straight edges.
A hearing loop with four directional microphones and one omnidirectional was an initial concept sketch modelled. The microphones would be used interchangeably within group talks and focused conversations depending on the side.
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Volume and Components Definition The final shape employed only one microphone. From rectangular foam blocks, the longest edges were rounded to have enough slim appearance but still have enough volume to encase the batteries and electronics. Moreover, coil inclination adjustment was incorporated to improve field reception of the hearing aid.
The batteries of the hearing loop are rechargeable LithiumIon cells. Rechargeable types reduce the overall volume of the design and are more economical in long term. Battery packs are discarded to have an even weight distribution. The charge controller uses two TP4056 IC modules. They charge single cells allowing the use of any micro USB adapter. The battery power level indicator consists of two LEDs in parallel and the circuit employs a Zener diode.
Hearing loop batteries: 2xLG HG2 18650, 3000mAh each. Two TP4056 modules in parallel are used. Coil test considering the height difference between the hearing loop and the hearing aid. Inclining the coil towards the aid improves reception. Vacuum formed sketch model with possible components layout. On the left, the Styrofoam block represent a 7.4V battery pack. Vacuum formed shell dimensions are 100x85x25mm. Below is a matt finish test.
Test of the battery power level indicator using a Zener diode with a 4.7V breakdown voltage. Low brightness indicates low in charge. The cells would be fully drained when at 5.5V in series.
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The sound amplification for prototyping operates an LM386M-1 (0.25W) and an LM386N-4 (1W). The transducer used is a noise cancelling electret microphone with a pre-amplification module based on a MAX9812L IC. Final coil prototype. Noise Cancelling Electret Microphone Dimensions 5
Term.1(+) Ă˜9.7 Term.2(-)
Audio amplifier module tests set-up with a loop listener.
Typicial Frequency Response Curve of Electret Microphones Noise Cancelling Omnidirectional
+20 L=1cm
+10 0 -10
Initial PCB of the audio amplification. From left to right: microphone preamplification, LM386 with bass boost and LM386 with Gain=20.
L=50cm
-20 -30
20
50
100
1k
10k
20k
Graph comparison based on datasheets of the frequency response of an omnidirectional and a noise cancelling microphone. For the noise cancelling type, speech or sound frequencies present in a crowded environment have less effect from 50cm away from the microphone.
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Circuit Assembly Hearing Loop Circuit Block Diagram Charging Module
Microphone
Batteries
Pre-Amplification Module
Amplification Module
Power Indicator Module
Current consumption reading of the audio amplifiers with a 1kHz input sound frequency. The voltage input is 7.5V, and the reading is 0.167A.
Circuit iteration for the connection of the charging modules and the audio amplifier with the batteries while being charged or drained.
Star ground connection to prevent signal interference when connecting the circuits together.
Coil
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The circuit assembly uses a 4PDT slide switch to connect the batteries in series for use and to completely disconnect the batteries from the audio amplifier module while in charging mode.
LM386N-4 with bass boost Star ground connection
Microphone signal pre-amplifier LM386M-1 with Gain=20
LED power indicators 4PDT slide switch TP4056 Li-Ion charge controllers
Electret microphone Coil Li-Ion batteries (7.4V)
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PCB Design LED power indicators
The PCB design considers how the end user would interact with the hearing loop. Two LEDs surround the microphone for power level indication, being visible and part of the aesthetics of the design. The LEDs from the charging modules are placed in the right edge of the PCB (Green LEDs on top of red LEDs). Sliding the switch away from the user to power ON was considered to be more intuitive for the user. The front of the device is considered the side where the coil is lifting. The micro USB connector is located below the LED charge indicators, and also under the coil casing.
Wiring side
A separate PCB was made for the SMD microphone as it required to be close to the top surface. The wire connections for the batteries and the coil had are located on the opposite side of the slide switch and the USB connector for space organisation. Wire to PCB connections considered are JST-NSH connectors (6 x 5 x 7mm, 1.25mm pitch). To achieve a compact PCB, the electronic components are SMD electronic components. The dimensions of the finished PCB are 90x35mm, double sided print.
Micro USB connector
LEDs charge indicators
Mic
HSN-TSJ rotcennoC
HSN-TSJ r otc e n n oC
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R16
R15
JST-NSH Connector
MAX9812 C7 MAX9812-LEX-T
LED3 R6
Mic
R10
LED5
JST-NSH
LED6
4PDT
R4
R11
C1
LM386N-4
R14
C8
JST-NSH
Microphone PCB
C5
JST-NSH Connector
Connector ConnectorJST-NSH JST-NSH
LED4
JST-NSH
JST-NSH
Slide switch
LED1 R9
C9
LED2 91R
B-orciM 3C 4C
A4724VCN
2C
A4724VCN
01C
7R
2R 5R
22R
1D
12R
1R
42R
31C
41C
1-M683ML
8R
6C
21R
81R
71R
31R 11C 1-M683ML
21C
32R
61C
PCB top layer
51C
Front
3R 02R 6504APT
6504PT
6504APT
6504PT
PCB bottom layer Microphone board
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CAD Development The CAD development of the hearing loop is based on injection moulded ABS. Wall thickness, parting lines and critical draft angles are considered.
The section view shows tight clearance in the top front edge as a coil case locking system.
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The coil case uses a ball snap joint to assemble into the hearing loop case, with a tight clearance so it maintains its position when unfolded. Tolerances were compared with a plastic mobile holder using a similar system for reference. The coil core is designed to be injection moulded with ABS. Enamelled copper wire would be wound in the core to be later cast moulded with resin, similar to how inductors are manufactured.
Ball snap joint clearance measurement for contrast with calculated estimations and reference.
Light travel analysis for the design of the LED lenses of the charge indicators. Material: injection moulded acrylic.
The LED lenses (red highlight) are pressure fitted into the top half of the main body.
Parts List
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Overall hearing loop dimensions 112x87x28mm 1
Top shell
2
Slide switch actuator
3
Slide switch extension
4
Microphone PCB
5
Microphone PCB connector
6
2 self tapping screws (2.5Dx5)
7
2 LED power indicator lenses
8
LED charge indicator lense
9
Bottom shell
10 Audio Amplification PCB 11
2
1 13 3 4
14
2 Li-Ion batteries (3.7V, 3000mAh)
12 Side wall (USB side) 13 Side wall (coil entry) 14 Coil 15 2 self tapping screws (2.5Dx10) 16 4 non-slip silicon pads
12
5 6 8
11
7
10
9
16 15
Prototyping Process
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The LoopSync PCBs were 3D printed for the 1:1 scale prototype. For proof of principle, the circuit layout was modified for one layer of coil traces and through hole electronic components. The circuitry was also adapted for being able to change from batteries to mains connection as a backup for prolonged demonstrations. The shell was also 3D printed with ABS. Two batches were made: one for the assembly prototype and the other was only the top shell and the coil casing for the proof of principle.
The LED lenses were cut from an acrylic tube and laser cut from a sheet.
Printed test of the ball snap joint and a printed coil winding support for turning the enamelled wire.
Spray paint tests on glossy and matt surfaces and trial of colour combinations. 1:1 scale assembly prototype and the university degree show presentation.