Closed Loop Stepper Controller FOC or PM

[weston1968]

A HSB57 controller came with the closed loop stepper I purchased for my Electronic Lead Screw (ELS). It has an option for FOC or PM with the default set to FOC. Does anyone have any experience with which is best?

This controller shuts down if the stepper starts to miss counts. It has happened when I accidentally hit something with the cutting bit while feeding. I have to turn off the lathe for 2 minutes for the controller to reset. Is this normal?

This manual is also used for the HBS57

 

[WobblyHand]

A HSB57 controller came with the closed loop stepper I purchased for my Electronic Lead Screw (ELS). It has an option for FOC or PM with the default set to FOC. Does anyone have any experience with which is best?

This controller shuts down if the stepper starts to miss counts. It has happened when I accidentally hit something with the cutting bit while feeding. I have to turn off the lathe for 2 minutes for the controller to reset. Is this normal?

Acronym soup. Not familiar with FOC, guessing PM is permanent magnet. Total guess again, it's your motor type. HSB57 seems to be for a 3 wire motor. The two manuals I checked, neither mention any settings by that name.

2 minutes seems like a long time, but maybe there's a thermal switch inside. Might depend on how you are powering things, if there's a cascade of power supplies, might take longer.

My closed loop stepper has stuttered only when I incorrectly set the current, or when cutting 4 TPI threads on a 3/4" steel rod. It has never lost place, and I have not ever crashed it. So never experienced a stall in operation. I can however stall the motor if I grab and hold the pulley. I just shut off the power to the driver for 10 seconds and power it up again. Ready to go again.

 

[weston1968]

FOC refers to a type of current rotation sensing "field oriented controller". I assume that PM means just using the motors magnetic steps. This HSB57 (of which there are many types) is for a the standard 4 wire closed loop motor.

Here is what I have gathered so far. I get a lot more torque out of the stepper using the FOC setting. This did not happen before the closed loop stepper but it has happened a couple of times with the ELS controller: I use threading on a 0.1mm thread for cutting down the diameter any length. I just advance the cutter with each pass until I have the shaft diameter I want. The pieces I am machining now have a 20mmx1.0 thread 11.5 mm long on the end of what I need to be a 12mm shaft. I cut the thread longer than I need and when I cut the shaft to 12mm I start off with the threaded part 11.8 mm. After cutting the shaft deep enough that I can accurately measure the width of the thread I use the ELS to move the cutter over then go back to cutting the shaft with the thread set to 0.1 mm. Occasionally the ELS threading goes in the wrong direction destroying my part.

I have two types of motor controllers for the chuck. The one that came with the lathe and the potted black controller. I like the potted black controller because it gives me finer motor speed control. The problem is that it is very jerky as you adjust speed of the chuck. It may be the cause of the ELS controller getting "lost". I turn the chuck off to make measurements. I have put back in the original controller to see if the problem follows the controller.