Contents:
- Bill of Materials
- Fabrication and Assembly
- Electronics and Circuitry
- Software Development
Bill of Materials
All components used may be obtained via the TIW, excluding the buttons which can be replaced with available joystick components and the cup. The quantity of rubber bands will depend on elastic strength.
| Component | Quantity |
|---|---|
| 12x24 .25in acrylic | 1 |
| M3 25mm Screws | 2 |
| M3 20mm Screws | 10 |
| M3 16mm Screws | 8 |
| M3 Lock Nuts | 14 |
| M3 Nuts | 14 |
| M3 Washers | 10 |
| 6mm Axles 3in | 4 |
| 6mm Ball Bearings | 8 |
| Small Cup | 1 |
| Rubber Bands | 2 |
| ELEGOO UNO R3 | 1 |
| 9V DC Batteries | 2 |
| 9V Battery Connectors | 2 |
| Buttons | 2 |
| L 298N Motor Controller | 1 |
| Assorted Breadboard Wires | ~25 |
| 1kOhm Resistor | 1 |
| 2kOhm Resistor | 1 |
| 12V Geared DC Motor - 100 RPM | 1 |
| PLA Filament |
Table 1: Materials list for full mechanism
Note that the 12V Geared DC Motor can be replaced with 10 RPM rather than 100 RPM. Doing so removes the necessity of the rubber bands.
Fabrication and Assembly
Linkage Mechanism Assembly
We laser cut the majority of the mechanism out of 0.25" acrylic. Note that the DXFs are not to scale. We also 3D printed one part to assist the laser cut parts in securing the motor.
Provided below are the DXFs of our linkages:
Figure 22: Linkage DXF's. Note: not all linkages are to scale. Each linkage is 0.5" wide and have been scaled down for ease of visibility.
These are the DXFs for our base:
Figure 22: Base DXF's. Note: not all figures to scale.
For the motor mount, we laser cut a vertical holder and 3D printed a base to rest the motor on.
Figure 23: Motor mount DXF and 3D printed support.
Figure 24: Linkage DXF that connects the motor to the full mechanism.
Figure 24: Cup holder DXFs.
We used 6 mm rods to connect our cup holder to the joints of the links of the 4 bar to allow it to rotate with the mechanism. We used M3 screws to assemble the holder. We used 6mm ID bearings to allow for rotation and reduce friction.
Figure 25: Close shot of the final assembly of the cup holder mechanism.
We assembled the four-bar by connecting the joints using 3M screws and lock nuts. We also had two rubber bands to help the lifting mechanism operate with limited torque. We press fit bearings into the rotating arm. We cut a special slot into the input link so that our motor shaft can rotate the link.
Figure 26: Image of the full final assembly.
Electronics and Circuitry
Below is an image of the finalized electronics elements of the design.
Figure 27: Close up image of the electronics configuration.
We utilized the provided motor drivers to control our 12V DC motor. Rather than using a bulky 12V power source, we fed two rechargeable 9V batteries in series through a voltage divider to output 12V to the motor controller. To enable better control of the system, two buttons were used. The red button reversed the polarity outputted by the motor driver, changing the direction of the motor, while the blue button activated the motor to move the mechanism up/down. An ELEGOO UNO R3 was used to control the system.