Gearing down RS550 motors
Howdy, it's been a couple of years since I was last here and recently I have found myself in the position to finally (after nearly 20 years of interest in this stuff!) build my first featherweight and have found a couple of friends who would like to join me. Having now finished university for a month, I've been doing a lot of research for this over the past few days with the hope of starting to build in the next couple of weeks. The main stumbling block I have right now is that I want to use the (seemingly common) RS550 motors, but have no idea whatsoever what the best route to connect them to the wheels would be.
I'll be using 4" wheels and have decided that roughly 16:1 seems to be about the best reduction between the motor and the wheels. So far, I've found the Banebots P60 gearbox which seems to do everything but is also around £53 each side - £106 is quite a significant part of our budget. I also have some reservations about using a gearbox that, if damaged, would need to be replaced as a whole unit and that I couldn't slightly tweek the ratio on if I wanted to speed up/slow down the drive.
My other option is in using sprockets and chains - 4:1 from the motor to a shaft, 4:1 from that shaft to the wheels. The problem I'm mostly finding here is that sprockets for the RS550's 3.175mm shaft seem impossible to come by. I have found a coupler to connect the shaft to a 5mm one and a sprocket for that size, but I don't know if that could be trusted. On the plus side, damage here could be repaired on each individual component and I could chance sprockets to slightly smaller or larger ones if I wanted to change the speed. It would cost roughly £40 each side at most which, although still a decent amount of the budget, isn't quite so bad.
Is there anything else I am missing that could simplify the process?
