I am designing a test rig where a uniform (but programmable) torque load is required, and moved intermittently at 60-120rpm.
Can a stepper be used as this variable torque load ?
It would be rotated by an external force 1 full rotation in 0.5-1 sec.
It would be uni-directional.
Basically acting as a brake, but retarding, not stopping the force.
It would be about 50N@r=30mm ->T=1.5Nm v=200-400mm/s P=10-20W
The load would be stationary when the external force was absent.
The duty cycle would be very high: 1s static 1s rotating 24/7. eg 2.5 million cycles a month.
I am wondering whether a feasible option is to use a somewhat oversized stepper with one way clutch (don't worry if you don't know what that is) on a simple constant uniform torque duty say at 10-20% of its normal stall torque.
That would make a very clean solution to a programmable one way torque load, and 10-20W seems a small amount to dissipate.
However, I've tried looking for torque control of steppers but everything seems angled at position not torque control and things that are available seem quite high-end eg [
www.youtube.com].
[
motion.schneider-electric.com] looks interesting and seems to imply that a "standard ?" 4Q controller should be able to handle the problem.
Any opinions gratefully received.
