bumping holding current - how it affects torque?

[dsc]

Ok, I can see where the max power calculation kicks in, the only issue is that running at 600RPM, the ratio stepdown would be massive, with 6.66 you are looking at huge pulleys or simply a 6.67:1 planetary gearbox, which wouldn't fit due to the size of the motor. I will try and look at less powereful motors, maybe some Nema 23s or shorter Nema 34 and match a gearbox to those.

Where did the 37.1Nm figure come from? at 600RPM, you only have 2.7Nm torque delivered by the motor, so over a 6.66:1 ratio, there's 18Nm on the output. Or am I missing something?

Regards,
T.

[Jonathan]

Yes, the optimum ratio is a bit unwieldy. Not difficult with two belt reduction, if you've got the space. You imply that the requirement is 188W, plus a bit to account for the inefficiency of the gearing. If that's a planetry gearbox then you'll need to add quite a lot, but if it's timing belts then 200W is probably sufficient. You're probably not going to get that much power from a smaller stepper motor, but by all means check.

Where did the 37.1Nm figure come from? at 600RPM, you only have 2.7Nm torque delivered by the motor, so over a 6.66:1 ratio, there's 18Nm on the output. Or am I missing something?

No, you're correct. I made silly mistake and corrected it but you were too quick!