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Unread 18-01-2011, 14:10
EricVanWyk EricVanWyk is offline
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Re: Tetrix DC Drive Motor W739083 dynamometer data

Quote:
Originally Posted by colin340 View Post
so from what I see everyone is planning on a tall gear ratio (to theoretically increase wheel diameter)

I am very uneducated on electrical motor performance but so far I thought Max performance was somewhere near the motors free speed (although I do understand you get full torque at any RPM assuming your motor does not burn up) if this was the case wouldn't you want a shorter ratio than 1:1 essentially creating a slower and higher torque drivetrain to ensure the motor was operating at peak RPM.

I'm pretty sure I'm wrong based on Richard statements
Colin -

You are likely thinking of a different type of motor. Maybe an internal combustion engine?* DC motors behave very very differently.

Take a look at the spec Greg posted, it will clear things up.

For a given voltage, a DC motor has the most Power output at about half of its free speed. Torque is highest at stall, and decreases linearly to zero torque at free speed.



* My knowledge of combustion engines is pretty close to zero, but I think wenkels have performance like you suggest: http://4wings.com.phtemp.com/crafts/a2con/torque.jpg