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Motor Physics Question

Motor Physics Question

Motor Physics Question

(OP)
If I need to  hold and rotate a 120lb load using a motor (at the pivot point) from horizontal to vertical at a distance 10 inches from the pivot point, I would need a holding torque of 1200in-lbs right? Is it possible to increase the holding torque of a motor using gears? or do you just increase it's torque in motion? Can anyone suggest a motor for this application? Stepper or Servo?

RE: Motor Physics Question

make sure you've got your units right, but yes you need to multiply the force by the moment arm.

You can use gears to increase the torque of a motor. In this case you might find a worm drive has some advantages.
 

Cheers

Greg Locock


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RE: Motor Physics Question

Motors are not intended and generally not designed to "hold" at a fixed position.

Motors are design to spin.

 

RE: Motor Physics Question

ckb614,

   I know a stepper motor will hold its position.  Will a DC motor really do this, by some means other than exactly matching the rotating moment?  In either case, the motor is consuming power, and converting all of it to heat.

   If you select a self locking worm drive, the system can be powered into its position, and left there with the power off.  Generally, you need a ratio of something in excess of 40:1.  The analysis that will get you the correct answer to this, will be explained in your machine design textbook.  

               JHG

RE: Motor Physics Question

(OP)
Thanks for all the responses!  

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