How to choose a motor for our application

Hello there,

We would like to make some test to a mechanical drive system (gear box).

So will make a loop system like this ( → motor – mechanical drive system (gear box) – mechanical drive system (gear box) – motor ← ).

We will need 2 motors for this application. And we will need to control the speed and the direction of the motor. (clockwise and counterclockwise)

We have an Odrive the power supply and we don’t have the motors.

We have the 24V Odrive 3.6v version and a power supply 24V - 1000W in our labratory.

What motor you suggest to buy for this application with high RPM and high torque?

Thank you!

What RPM and torque do you need?

Or, if you only know the RPM, you can calculate the max torque that you could get at that speed with 1000W, and choose a motor based around that.

Also, given you have the 24V board, can you adjust your power supply to slightly below 24V?
I normally recommend the 56V board for 24V applications - the 24V is a maximum limit - you can destroy the board with about 26V, so you don’t have much headroom for control and braking.

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Hello towen,

I’m trying to find the best option with these components. With as much speed and torque as possible; to avoid buying more components.

Our goal is speed ~about~ 8000 - 10000rpm and torque ~about~ 1-1,5 Nm. If there is no motor with these options, we could use a lower spec motor.

Yes, we can set the power supply to below 24V.

Is there a motor you can recommend with these components?

Thank you very much for your time.


So at 10k rpm and 1Nm that happens to be almost exactly 1kW of mechanical power (1047W)
To make the most of your power supply, you’ll want something that produces about 20V back-EMF at 10k RPM i.e. Kv ~= 500.

e.g. you can buy a version of the ODrive standard 5065 motor wound for kv500 instead of 270.
APS 5065 Outrunner brushless motor 500KV 2200W (note that this is NOT a dual-shaft motor, so you’ll need some way of attaching your encoder)

Any motor with EMF constant approx Kv500 and a power rating of >1kW should work for you.
It’s also possible to convert Kv from rpm/V to Nm/A - it depends if you are using industrial motors or hobby motors. Industrial motors tend to be specified in Nm/A, whereas hobby motors are specified in no-load rpm/V

With 20V at 1kW you’ll be using 50A. Make sure you have considered cooling of the odrives and motor. It might be worth jumping up your voltage.