View Single Post
  #2   Spotlight this post!  
Unread 27-01-2012, 15:28
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,040
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: paper: Simple Motor Calculator

Quote:
Originally Posted by bmlarson12 View Post
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.