This week I made much more progress on building the launcher mechanism after the new parts arrived due to complications mentioned in the last status report. Specifically, the parts are the 3D printed wheel attachments, 45º angle connectors and screws, PVC pipe, and putty. The 3D printed wheel attachments fit perfectly in the middle of the wheel, with very high friction such that the wheel does not slide up and down, and attaches smoothly onto the shaft/teeth of the bike motor axis. Since the bike motor has a rounded bolt that extends beyond the teeth, the wheel would wobble a little. I inserted putty into the 3d printed attachment to fix this issue and ensure the wheel spins stably. I connected the bike motor base to four 45º angle connectors with corresponding screws and separately them to the distance of a tennis ball diameter to make sure it can launch it. The PVC sheet that will be used as the lid of the base has not arrived yet, so I stationed the motors on a cardboard box/plastic container lid temporarily for interim demo. I also helped Miles work on the motor control of the launcher. The motor control board borrowed from the ECE department is not working properly and possibly broken, so a new temporary one that has a potentiometer speed control with an on off switch was bought and I helped Miles incorporate it into our project. I would say the launcher mechanism, even though it is not perfect and a few parts are temporary solutions, it is ready for interim demo. In the next few weeks, I am confident that we can easily replace the temporary parts with better and permanent ones that work similarly.
I would say my progress is now back on schedule. After the compilations mentioned last week about 3D printing the structure, I found that buying parts like PVC pipes/sheets and 45º angle connectors instead of 3D printing them made the process more straightforward. The structure is much more stable, something I worried about with 3D printing. My focus can now be more on how to improve the launch of the tennis ball and integrate the different major parts of the project, rather than if physical parts are going to break or not.
Next week, I hope to get started on the base rotation (x-axis) by purchasing gears to attach to the inside of the PVC pipe. I want to help Miles with controlling the stepper motor to rotate the base since the launcher can shoot a tennis ball now, while John works on the CV. Finally, I am going to try to replace the temporary parts with permanent ones and try to maintain or improve the launch of the tennis ball.