combined free speed of 3 motors

[James Kuszmaul]

Originally Posted by Ether

The derivation I provided in the original post applies if the same voltage is applied to all the motors, and the individual motor stall torque and free speed values are all at the same spec voltage. The resulting "combined" Free Speed (together with the simple-to-calculate Stall Current and Stall Torque) allow you to view the combination as equivalent to a single motor with those characteristics. Treating the combination as equivalent to a single motor allows you to use all the single-motor math you are already familiar with.

However, using all that single motor math will cause you to result in suboptimal results (if you attempt to optimize in any way, beyond just modelling the system). Also, has anyone gone through the proof that you can validly treat the two motors as one, given that you input the same voltage?