paper: Simple Motor Calculator

[Ether]

Originally Posted by bmlarson12

WOW!!! How did you do this? I have been looking for a graph of the information so I could get the general values, but this is far better!

If you assume that the speed vs torque and the current vs torque "curves" are straight lines (which is the standard assumption for almost all the motors used in FRC), then most of the equations are fairly straightforward to solve explicitly.

For example, at the rated voltage and for a given torque tau, you can find the speed as follows:

speed = free_speed*(1-tau/stall_tau)

some of the other calculations, for example solving for efficiency or finding voltage when given rpm and torque, are a bit trickier, but not too bad.

I'm glad you discovered it and hope you find it helpful.