Max Torque For BaneBots RS550 12v Motor

I’m looking for the max torque produced by the BaneBots RS550 12v motor as a stand alone motor and also with the 64:1 and 256:1 transmission.

How many ft-lb does it take to stale out the motor in these cases?

You can find that information here

http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2013/2013MotorInformation.pdf

Given that you’re asking about 64:1 and 256:1 gearboxes, I assume you’re looking at using the RS-550 in a Banebots P60 gearbox. Don’t do this.

I can’t stress enough how bad an idea this is. The Banebots P60 gearboxes are made with unhardened gears and are thus rather weak. The RS-550 at 256:1 has enough torque to shred that gearbox. At 64:1 it’s not quite strong enough, but any sudden shocks to whatever you’re driving with the gearbox will likely shred it. P60 gearboxes with large gear ratios are guaranteed to explode and break often and at the worst times.

So, if you want to build a system that isn’t going to break after two matches, I recommend you look at the VEXPro Versaplanetary. Everything’s modular so it’s easy as heck to change gear ratios or motors. Like swap out ratios and motor in 10-15 minutes easy. And the 1/2" Hex Shaft is good for 100+ ft-lbs in simple loading. It’s much less likely to explode on you, and even if it does, it’s going to be a whole lot easier to repair.

This isn’t mandatory, of course. You can use a 256:1 or 64:1 P60 gearbox, you just can’t use one on a system you want to work for more than 2 matches.

From the Banebot website:

We recommend maximum torque not exceed 35 ft-lb for all P60 Series Gearboxes.
It is possible to mount motors that will exceed this in higher gear reductions. Higher reduction gearboxes should be utilized primarily for speed reduction. Designs utilizing a P60 gearbox / motor combination that will exceed 35 ft-lb should include a method of limiting torque to prevent damage to the gearbox.

Additionally, the RS550 will let out the magic smoke if it thinks about getting close to stall torque.

Now, with all the proper warnings in place, here is the spec. you asked for.

Stall torque = .49Nm
Stall current = 85 A

Make sure to include the transmission’s efficiency into any calculations of usable torque you might make.

So, assuming 33% efficiency: (.49X64)X.33= 10.3 Nm, 10.3Nm = 74.3 ft/Lb.
That is double the recommended torque for the Banebots, but well within the abilities of the VexPro VP.