1.4 Implementation

Fabrication

We fabricated every part of our robot except for our electronics and bearings. We laser cut all of our links, gears, and plates. The gears and plates were cut using 6mm acrylic while the links were cut using 6mm plywood . We chose to use acrylic for the gears because they would produce less friction and provide more strength than the plywood. Acrylic was used for the plates because they were transparent which allowed for the entire robot to be seen. We chose plywood for the links so they wood stand out against the acrylic. Laser cutting the majority of our parts had the advantage of quick fabrication. We saved hours of manufacturing time by laser cutting instead of 3D printing most of our parts. The only parts we did 3D print were parts that were to complex to be easily laser cut. These parts included our battery holder, switch enclosure, and motor mount.

Figure 1: Fully Fabricated and Partially Assembled Design

Assembly

Once fabrication was complete, we started assembling our robot plate by plate. We started by inserting bearings into our plates and links. We then press fit wooden dowels into the bearings of the links as well as into the gears  by hammering the dowels. For the gear plate, it was necessary to line up each set of gears to ensure that they were in sync with one another. After these gears were in place, we staggered each gear set by 20 teeth, or 120 degrees, before positioning the non-link connecting gears on the plate. Once each plate had all of the necessary bearings, gears, and links, we press fit each plate together using the wood dowels and secured the plates using screws and standoffs. Next, we inserted the three plates into the battery mount and used screws to secure them. The final step of the assembly was connecting the battery, motor, and switch to power and control our robot.

Figure 2: Fully Assembled Design

Electronics and Circuitry

Our robot was purposefully designed to require very simple electronics and circuitry. We used an open-loop system where the output of our system had no influence on our input. We used a brushed DC motor, a 11.1V Lipo Battery, and a power switch. The motor supplies the torque to move our entire robot. The battery power goes straight to the motor, and the switch is located in between them in the circuit so the motor can be easily turn on and off. The design of our robot allows for this simple electronic and circuit setup with no need for any software development.

Figure 3: Top View of Electronics