Thread: Motor rpm and Torque
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Unread 11-01-2003, 10:50
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Paul Copioli Paul Copioli is offline
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Fudge Factor
It is a total fudge factor accounting for the loss of speed due to drive friction.

If you notice, only the torque is effected by efficiency. So, in theory, you could achieve the free speed of the motor. In reality, the drive friction will also slow you down to something less than free speed.

The actual equation that this comes from is:

F= ma + Ffdrive

You can derive top speed from this equation. Ffdrive is the friction losses in the drivetrain. What we do is disconnect the motors and pull on our robot with a spring scale at constant (approx.) speed.

Historically, we see 10% losses in the calculated free speed.

-Paul