[Ether]

Originally Posted by JesseK

Steve, I can't account for how to apply inefficiency accurately (i.e. sqrt(inefficiency) vs full inefficiency to only torque)

Let Nmotorfree be the motor free speed

Let Tmotorstall be the motor stall torque

Let G be the gear ratio

Let eff be the efficiency

Then for the combination of motor+gearbox:

Ncombofree = (Nmotorfree/G)*sqrt(eff)

Tcombostall = (Tmotorstall*G)*sqrt(eff)

... and connect a straight line between the above two points to get the speed vs torque curve for the combination motor+gearbox.

I think that's what Steve is saying, it it seems to make sense. Are there any other physics folks out there who would be willing to weigh in one this?


[edit] see this post for an alternate view of how this should be modeled [/edit]