We built up six 20:1 Planetary gearboxes, and found one of them to be slightly noisy. Upon disassembly and inspection, we discovered that the 11-tooth pinion gear was cracked through. It’s difficult to see on the picture, but it can be seen fairly clearly if you’re looking for it.
It’s because the BaneBots pinion gears are bored for a tight interference fit on the the BaneBots motor shaft. The FP (and the new AndyMark 500 series) has a knurled shaft which is just big enough to crack the gear.