Hi all
I am good at electronics bad at mechanics 
I want to upgrade a CNC machine to servos, but wondering what is needed to have comparable torque. Any recommendation on what motors to use that give comparable torque to the stepper NEMA23 that come with the machine? Any gearing required?
The torque the original motors give is 140 oz/in
140 oz-in is ~ 0.98 N-m of torque. These motors from the ODrive shop come with NEMA23 mounts, and are capable of 1.99N-m of torque with no gearing at up to 6000rpm
You can also get aluminum faceplates for the motors if you prefer that over the plastic 3D-printed ones
I will note, however, that you might WANT gearing or a large pulley ratio so that you can spin your motor faster. These motors can have some cogging torque that creates position control difficulties at slow speeds. Adding the gearing reduces how much that torque affects your final precision.
Thank you!
Any gearing suggestions?
Hmm, well we talked about it on here a long time ago. See this thread NEMA 23 Case & Gearbox for N5065 Motors
Not sure what development has happened since then.