Thread: back-driveable vs. not
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Unread 06-02-2004, 08:42
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Paul Copioli Paul Copioli is offline
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Re: back-driveable vs. not
I will try to put this to bed so everyone is comfortable about the window motor and its ability to resist back driving. Two pieces of info:

1. Torque at breaker limit for window motor (torque when breaker starts to trip) ~ 5 N-m

2. Speed at which this occurs ~ 50 RPM

The max torque the window can put out is MUCH lower (at least 10 times) than the backdriving torque required to destroy the worm or break free. From experience, I can tell you that the worm breaks before the motor breaks free.

In theory, you could put a large enough diameter spool so that the 130 lbs of robot weight would break the motor, but then you would not be able to even lift yourself up. If you design the spool and motor combination to actually lift the robot up, then you are nowhere near back driving the motor.

-Paul