High Torque motor

Hi All

im trying to find out if the ODrive can power a torque motor?
this is a brushless 3 phase motor that has very low RPM but high Torque.

im working with a company to custom make the motors for a small 5 axis trunnion and I will machine the rest of the frame.

but I would love to use the Odrives but im not understanding some are saying they are low torque?

as far as I know the voltage and amps input into a particular KV BLDC is what determines the holding torque?

look forward to hearing from you all

thank you

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Provided you have a high resolution encoder (something like this, although this form factor may be a little annoying to mount to a large motor), and the motor does not need more than 90 Amps, I see no reason why it wouldn’t work. You may have to tweak the PID values to get steady control at low RPM, as the default ones seem a little mushy, but it should be doable. You will also probably want forced-air cooling on the MOSFETs if your motor pulls above 30A, and you’ll likely want to get a better thermal interface beyond 70A.

I would wait for a second opinion though, because I could be wrong.

Should work just fine. Everything @John_Little said. Check voltage & current limits, avoid overheating, and use a high-res encoder.

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Hi John

I was thinking more on the lines of a 20bit absolute encoder.

I should be able to machine either water and air cooled heat sinks or just blow air on.

talking to motor manufacturer now to get lowest kv possible. if I had 60rpm top speed with 48v I hope the torque is higher.

thank you


Torque in brushless motors is dependent on the current goin’ through it. I have the calculations here: Full torque calculation
If you have any questions about the calculations or if it’s still not clear, let me know.


In addition, the following blog post should be enlightening regarding torque production and motor Kv:

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I have a good amount of experience building and repairing cnc routers. I like your question, I need to accomplish the same thing.

Thing is, if you still have the servo drive, my servo drive can crank out 3.2kw peak from a +/-10v, 100 ma analog input. I am curious if the Odrive can push a low current signal, and I can let the bigger drives function.