Manufacturing
Basics
The device mainly is built from laser-cut 3/16" clear acrylic sheet. This material creates very rigid upright structure, is strong enough to be used for links and gears, and is slippery enough to make bearings unnecessary (in most cases). A few parts, such as the input and output plates, were created using 3D printing. All of the parts were built in the ASME wood shop and the Longhorn Maker Studio, both in ETC.
Some of the acrylic parts on the passive mechanism had to be bent at a 90 degree angle to satisfy the design. We put the straight part in a vice, used a heat gun to heat the acrylic above its glass transition temperature (about 30s of heating on high), then carefully bent the piece into shape using pliers.
When doing this, keep the backing paper on the acrylic or cover the pliers' jaws with tape. This ensures that the pliers' teeth will not scratch or deform the acrylic.
Full BOM
Quantity | Part | Material |
1 | Motor Tee-mount plate | 1/4" Acrylic |
2 | Horizontal Driving Link | 1/4" Acrylic |
2 | Horizontal Coupler | 1/4" Acrylic |
2 | Tower Wall | 1/4" Acrylic |
4 | Parallelogram Link | 1/4" Acrylic |
2 | Vertical Driving Gear | 1/4" Acrylic |
2 | Vertical Driven Gear/Link | 1/4" Acrylic |
1 | Vertical Coupler | 1/4" Acrylic |
2 | Vertical Output L-bracket | 1/4" Acrylic |
4 | Claw Mount | 1/4" Acrylic (bent) |
2 | Passive Claw Gate | 1/4" Acrylic (bent) |
4 | Passive Claw Bumper Holder |
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2 | 3/16x5" Bumper Rod | Aluminum round stock |
1 | Claw Platform | ABS (3D printed) |
1 | Input Platform | ABS (3d printed) |
1 | Output Platform | Pine |
1 | Output Platform Support | Pine |
1 | Input Platform Support | Pine |
2 | 3/8x6" D-Shaft | Hardened steel |
2 | 3/8" Miter Gear | Nylon |
2 | 3/8" Horizontal Rotation Pin | Aluminum round stock |
6 | 3/8" Bearing | Nylon |
10 | 1/4" Bearing | Nylon |
16 | #10 Lock Nut | Steel |
16 | #10 1" Machine Screw | Steel |
8 | #10 Nut | Steel |
4 | #10-32x4" Hex Standoff | Steel |
8 | #10 Washer | Steel |
8 | #10x5/16" Machine Screw | Steel |
1 | 4x4x1/4" Tower Turntable support | Pine |
1 | 4" Ball-bearing Turntable | Steel |
14 | #8x1/2" Wood Screw | Steel |
1 | Tower Base | Pine |
8 | 3/8" Shaft Collar | Steel |
4 | 3/16" Shaft Collar | Steel |
18 | 3/16" Bushing | Nylon |
3 | 3/8x2.5" Machine Screw | Steel |
3 | 3/8 T-nut | Steel |
3 | 3/8 T-nut | Steel |
6 | 3/8 Washer | Steel |
1 | Arduino Uno |
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1 | SaberTooth 1 Motor Driver |
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1 | 12V Power supply |
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1 | Pololu 131:1 Gearmotor |
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1 | 120V Power switch |
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1 | 10-Kohm Potentiometer |
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1 | Power cord |
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| Hookup wire |
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