Z-axis stepper motor problem

[techasist]

I have a Exlas 1280 with a motorized Z-axis. It has four lead-screws on each corner and two separate stepper motors driving the screws.

I am now having a problem where the work-table is not going up or down when there is any weight on the slats. Even the honeycomb table is too heavy. It used to work about alright before except for when there was too much weight on the work-table.

I checked the belts and there are no missing tooth. The motors don't turn at all, so it's not a mechanical problem. They are magnetized, but the field is not strong enough to make the motor turn.

The stepper driver is a QJ8060. The settings are maxed out at 6amps (which is divided between the two stepper motor connected in parallel).

Any help/advise would be appreciated. Any way to get rid of these crappy lead-screws? Any ideas?

Thanks.

Edit: Is it possible to change the microstep settings (1/32 at the moment) and choose a smaller step so that the motor has more torque on a smaller angular motion?

[Tweakie]

Edit: Is it possible to change the microstep settings (1/32 at the moment) and choose a smaller step so that the motor has more torque on a smaller angular motion?

Not much help solving your problem but from my experience, the greater torque is obtained from using less microsteps rather than more.

Tweakie.

[Ken_Shea]

techasist,
Why not contact Exlas, my experience with their replies is that they are prompt.

i am guessing the QJ8060 drive, is their loose wire sufficient to swap a drive for a test?

[techasist]

Thanks all for your prompt replies.

I tried to reduce the microstepping and it did increase the starting torque.
I also played a bit with the tension on the belt and made it as loose as possible and the next thing I knew the motor way running as if nothing happened to it.
Lucky outcome this time. The motor is a bit noisier but as it is on the z-axis, I don't really care.

Thanks.