[Mike Betts]

Originally Posted by Al Skierkiewicz

...I think if you throw in a fudge factor for efficiency of each of the motors (I am guessing between 90 and 95%)...

Al,

The efficiency of DC motors is dependent on speed and is usually much less. Take the CIM for example:

Stall Current = 114A
Stall Torque = 2.45 N*m
Free speed = 5342 RPM = 559 radians/sec

Efficiency at Max Power = (1.23 N*m * 280 rad/sec) / (12V * 57A) = 50%

Therefore, the mechanical power at the spindle will be 343W and I would expect the power dissipated in the generator’s brake resistor to be about 172W or so…

Mike