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How does running a large motor at a low torque affect accuracy

How does running a large motor at a low torque affect accuracy

How does running a large motor at a low torque affect accuracy

(OP)
Hello,

I am designing a test rig that uses a brushless servo motor for load testing. There is a large range of tests that need to be performed, and I am trying to find a motor that does it all. My question is, if I am using a motor that is rated for a nominal torque of 2000lbf-in, and want to use it for a test where the required input torque is 200lbf-in, will the motor accuracy deteriorate significantly from doing this?

RE: How does running a large motor at a low torque affect accuracy

Accuracy? Do you mean efficiency?

RE: How does running a large motor at a low torque affect accuracy

(OP)
I mean accuracy. Will the motor be able to accurately apply a torque much lower than its nominal rating. aka, can a motor rated for 2000lbf-in accurately provide a torque of 200lbf-in.

RE: How does running a large motor at a low torque affect accuracy

Yes, and depending on what you have for a drive on it it could be very accurate.

Keith Cress
kcress - http://www.flaminsystems.com

RE: How does running a large motor at a low torque affect accuracy

Define "accurate". What type of motor? What speed? You are not going to find a brushless servo motor that will deliver 2,000lb-ft of torque. At 1800RPM you are looking at almost 700HP. (Edit, never mind... I see my mistake. lb-in. Sheesh.)

A servo motor can have it's torque CONTROLLED by virtue of servo amplifier, which can limit the output torque from 2,000 lb-in to 200 lb-in, and in doing do it can probably hold it there at +-2%, maybe a little better.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: How does running a large motor at a low torque affect accuracy

"You are not going to find a brushless servo motor that will deliver 2,000lb-ft of torque."

I believe the OP stated 2000 lbf-inches.

Walt

RE: How does running a large motor at a low torque affect accuracy

The torque output of the motor, up to the motor's maximum, is entirely dependent on the load. Provided your load is accurate, the motor will be too.

Or are you trying to limit the torque?

RE: How does running a large motor at a low torque affect accuracy

Jeff, Is that 2% of 2000 in-lbs or 2% of 200 in-lbs?

Bill
--------------------
"Why not the best?"
Jimmy Carter

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