Help with motor/arduino selection

Hello everyone,

It is the first time that I am working οn the field of robotics and I really need your help. I am trying to design a simple version of a device whose main purpose is to help/enhance human joints motion. For this, I need to find a motor (probably torque motor) that will be able to do the following functions:

  • Work in combination with an external torque in order to complete the required angular motion when the external torque cannot complete (by its own).
  • According to the first requirement the toque motor must be able to rotate even when it is OFF without causing any side effect.
  • CW and CCW motion.

If you are familiar with this field and can help me in any of the functions above, your help will be much appreciated! You can also reach me at

Thank you all!!!

Long before thinking about motors, you need to design and test how you are going to measure angles, how you are going to measure torque, and how you are going to ensure nothing will ever move beyond limits you set.

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Helpers need facts, data, numbers. Word sallad takes a lot of posting to make the question clear.

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I'm not sure how familiar you are with motors, because nearly all brushless motors should be able to fit the criteria you provided... depending on the torque and speeds you actually need, of course. Please do a little more research, or provide more information so people can help you here.

That said, I think your main issue is looking for a motor driver board. In that case, look at odrive and mjbots which provide very high-quality driver modules (possibly overkill, but it sounds like you're making an exoskeleton type-thing... which would be awesome :wink:). The odrive discord also has lots of knowledgeable people, so I encourage you to also ask around there.

Hope that helps!

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Sounds like the first thing to establish is the maximum safe torque for the application - its really important to not create something capable of injury.

Unfortunately torque depends on motor size (if gearing isn't involved), and the more gearing you have the less the chance of back-drivability which is a requirement. This suggests a multipole DC brushless motor, pancake shaped gives the best torque/weight ratio typically.

And to provide torque assist you need to measure the torque to be assisted, without being confused by the extra torque you provide - this may be very problematic (its not like power steering) unless there's some other control input.

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