We are building a shooter design, and were looking for a 12:1 gearbox. The motor we plan on using is the RS775 18v from BaneBots, and we can find a 16:1 gearbox, but what would be ideal is a 12:1. Has anyone ever bought/built one?

What if you took the 16:1 gear box and then did a 3:4 pulley reduction?

We are think about making a custom gearbox with 32dp gears, but we are not looking for such an extreme reduction.

You could mount the RS-775 onto a 4:1 Banebots gearbox and then use AndyMark gears or belts to complete the reduction. It’s theoretically more efficient to slow things down once than to slow down and then speed up.

Why specifically 16:1? Are you going for a particular free speed, or do you need a particular amount of torque?

This may be more work to adapt to your uses than you want, but the Dewalt gearboxes have 12:1, 15:1, and 47:1 ratios (12:1 is 3rd gear). Like Sh1ine and Chris is me said, its probably easier to just use the gearbox you have and perfect the ratio using a belt or chain, but the Dewalts are an option if you have to direct drive. There is a whitepaper somewhere that deals with how to adapt the Dewalts to typical uses in FIRST, but it does not deal with the Banebots motors (since it was written close to 8 years ago and we weren’t able to use the RS775 until last year)

CIM-U-LATOR into a CIMple Box gives you 12.609:1