Calculating Power Output

Pls give details.

Is the shaft hor or vetical?

Where exactly the load is mounted, over the length of the shaft?

What is the matl of shaft?

You'll need to know the torque. Since there are many other variables (allowable deflection, allowance for keyway, resistance to side loads, friction losses etc) it might be best to look up an existing electric motor manufacturers shaft sizes eg 1400RPM motor with 60Nm torque shaft available in shaft size Xmm. ffeJ

Much more information is required.

Length of the shaft is very important, if we take it to a ridiculous length of 100 miles, the diameter, plus material, and type/size of bearings are going to be a major influence.

It depend on the load/torque at the output. It also depends on how fast the motor start and stop. We're missing a lot to get to a solution.

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