How do Stepper Motor Drivers Overcome the Speed Restrictions Due to a Charging Coil?

[mattnedgus]

History is against you. The problem is that some bod in America decided that all stepper motors should be 2 phase, 200 full steps/rev regardless of the frame diameter, and that holding torque was actually something worth printing on the spec. sheet. The Chinese shrugged collectively and said, "Whatever" and set about making them.

Unfortunately as motors get bigger the inverse square law is not on their side so they lose power. Holding torque can be enormous but it is the pull in torque that moves you to the next next step. Pointing this out to people who have already spent money on enormous motors and unsuitable toroidal transformers, is not going to win you any friends on places like this.

You may think you can overcome this by putting in loads of microsteps but then things become springy and your tolerances quickly become slack.

You obviously appreciate the problem or you would not have asked. If you have not already blown your budget, go to the Oriental Motor Company web page and look up some speed/torque graphs for their 5 phase motors.

Thanks Robin, I'll take a look them - my options are still open.

Ah, it wasn't my intention to offend anyone - I couldn't find the information in a way that I could understand and hoped that maybe by sharing what I'd found it might help someone else later down the line.

To be honest I think I fell lucky on my current machine. It was my 2nd build (after trying V rollers on L alu-extrusion with ACME and T6-something drivers - it was hopeless!) and I had some excellent advice from Gary at Zapp regarding the motor and driver combination. I'd just hoped to increase my performance on this new build and didn't want to risk the outlay before I had a slightly better understanding, especially when I've read more than once about NEMA34's not necesarily providing the hoped increase.