The lower chassis was our main focus and for this we started with a sketch design. Each part is accurately measured and the slots are customized according to their shape to ensure that each part can be perfectly placed into the groove and fixed. Additionally, we also need to consider how the lower chassis connects to the wheels. For this purpose we have designed a connection point reserved for possible future components.
Another thing we need to consider is how to connect the upper and lower chassis. Since we plan to use 3D printing to manufacture the chassis. Its plastic material makes it difficult for us to drill screw holes into it. After our testing, the 3D printer was not accurate enough to print threads. Therefore, after many debuggings, we finally decided to make an unthreaded hole with a hole diameter slightly larger than the screw. Then we designed a vertical column to support and connect the upper and lower chassis, and fixed it with screws and nuts. The final results are as follows.
