For my midterm project, I made a skittle dispenser (figure 1). My mechanical movement was #24, a spur gear that uses a 1:4 gear ratio (figure 2).
Figure 1: Skittle Dispenser – Contract the Rainbow!
Figure 2: Mechanical Movement 24
My process was as follows:
1. 2D DRAWINGS
The main moving part of this device was the gears, which I laser cut. This involved creating 2D drawings of the gears (figure 3).
Figure 3: 2D Drawings of Gears
2. LOW FIDELITY PROTOTYPE
After printing my gears, it was clear that I needed to increase the diameter of my small gear. Originally, the diameter of the small gear was 2.5 cm, and that was too small. Learning from this, I increased the diameter of the gears from 2.5 cm and 15 cm to 5 cm and 20 cm respectively.
3. HIGH FIDELITY MODEL
The first step was laser cutting the gears again to see if the new sizes were appropriate. They were, so I continued building my high fidelity prototype by laser cutting the support structures of my skittle dispenser.
I also plasma cut the handle of the device by creating 2D drawings (figure 4).
Figure 4: Plasma Cutting 2D Drawings
I also had to 3D print some parts of the model because I wanted to the device to be food safe. Plastic is much easier to clean than wood, so I chose to 3D print any part of the model the skittles touch.
4. ASSEMBLY
The assembly done using a combination of wood glue, epoxy, and super glue. The hardest part was ensuring the axle was smooth so the gears could move smooth. It was very tight inside the walls, so ensuring everything was in the right place was difficult (figure 5).
Figure 5: Assembly
Cost estimation:
1. MATERIALS
The materials used in this model were: wood, metal, PLA, epoxy, superglue, and woodglue. These materials are all quite cheap except for PLA. The total for these materials can be estimated at $50.
2. LABOR
The entire process took about 10 hours. At $15/hour, the labor can be estimated at $150.
TOTAL COST: $200
