Progress

My primary accomplishment this week was designing the gearbox that will be used for the motor-based energy harvesting scheme. The gear ratio and general structure was based on the design by Cai, Liao, et. al, but I had to determine the exact dimensions, optimal gear profile, mounting strategy, etc. myself.

I printed using the “Extra Fine” slicer settings and standard print speed on the Robotics Club Bambu X1 Carbon printer in PLA. The result worked astonishingly well, spinning smoothly enough to keep going off of inertia alone for about a second. Even with the small amount of weight provided by three M6 nuts and minimal balancing, the gearbox would spin in my hand as I swung my arm. We were unfortunately unable to attach the motor for real power measurements, as we discovered that we needed M1.6 size screws, but even so this is very promising.

Pacing

Working on the gearbox put me somewhat behind on the PCB design; I will need to work on that some more next week. Fortunately, the gearbox testing is doing much better than expected, so I should be able to catch up.

Planning

Next week, I will:

• Attach the gearbox to the motor and get real numbers on power output
• Do the layout for the PCB so it can be ordered over Spring Break