Hi,

I have 2 Leadshine EM806 drivers running two steppers for a lathe. On the X Axis I have no problem. On the Z Axis, I can rapid at 4000 mm/min easily enough. The ballscrew pitch is 5 mm from memory and the gearing is roughly 1 : 2 (motor:ballscrew).

I did some threading testing on the lathe and noticed that I cannot thread whilst the RPM on the spindle is higher than around 200 rpm. If I run say 640 rpm, the Z stalls but only stalls feeding towards the chuck. I have no mechanical binding. I messed with acceleration rates (Centroid Acorn) but with threading it seems to ignore these.

The motor is a 12.5 NM stepper - Nema34. It's being fed by a 70V Leadshine PSU and runs at max current (8.3A). Ive run the 'auto sense' flicking the dipswitch number 4 to sense the motor. I can hear the motor pulse.

I dont have a cable or PC with serial port (old laptop somewhere) so checking the drive isnt easy. Is it possible that I can get better performance from the system by messing with the software or is that just fine-tuning?

On my other lathe, I have no problems but the ballscrew pitch on that machine is very fine, hence torque is not an issue.

Here's a quick video of it - you can see that it comes in, starts the thread, but then only goes in 1 direction but stalls in the other. Thoughts?