I volunteer at the free public makerspace Hatch run by the Watertown Library. I mostly help people learn how to use our 3D printers, laser cutter, and to do basic Arduino code. I wanted to develop a project to help people learn and develop all 3 skills. I competed in a local sumo bot tournament and spent $80 on my base kit and another $30 on additional sensors and modifications. The experience made me think that a cheaper kit that used the 3d printer and laser cutter to make parts would be a good project for beginners.
The design has undergone several iterations to make it more user friendly. Below is version 2 (left) and version 3 (right) of the chassis. Making the wire hole pass throughs made it easier to feed wires through, and gave more options for routing wires around sensors. Notches in the side of the body make it easier to fit and attach the top half.
In addition to the custom body, I designed a custom pcb board (left image) to drive the motors with a small microcontroller. However, there were some mistakes such as tying a sensor input to the same pin as the microcontroller’s led pin which caused strange and inconsistent behavior. Also the motor connections were not in the best place for routing wires, and it was very hard to debug. Based on my feedback, another volunteer did a new iteration of the board design (right image) that changed the routing and added leds that can be controlled via the code to act like “print statements” to indicate the internal state of the code so that the user can debug code without tethering the robot to a computer.
The design is currently still under iterative design and I’m working to improve the code to make it easy for beginners to read the code, understand it, and modify it.
