combined free speed of 3 motors

[James Kuszmaul]

Originally Posted by Ether

My interest was in finding the equivalent torque vs speed curve for the motor combination.

If you want the equivalent R and Kt, they would be given by:

R = 1/(1/R1 + 1/R2 + 1/R3) ... and ... Kt = (T1s + T2s + T3s)/(I1s + I2s + I3s)

Yes; those are what those constants should be (and what the resistance is). But as for Kt, it makes sense for it to be that (I say as much in the attachment to my previous post). Prove it. I may be sounding a bit picky, but I really dislike taking anything or granted that I can't see the derivation of. And I can't see how you derived that Kt other than to say it is combined motors' stall torque divided by their combined stall current. But why is it valid to say that? Why do Torque and Current still relate linearly? Intuitively, it makes sense. However, I have not been able to figure it out with actual equations.