Are the Zapp 3NM steppers good with their PM-752 drivers?

[Jonathan]

(although Mariss of Gecko fame did show the maths once) its 66%!

Thanks for the clarification. Do you by any chance have a link to the 'maths' behind this? I'd be interested to see..

Strange... if you haven't already, try swapping driver channels to validate its not a driver issue, then motors (assuming they are the same) to validate its not a motor issue

(I quoted the feeds in mm/s since personally I think it's better to work with smaller numbers and easier to visualize, but I'll endeavor to stick with the convention from now on)

I've only wired up one driver so far, so that can't be the issue. I'll try swapping the motors though. All the motors are the 3N-M ones.
The handle for the Y axis (before I removed it) did seem a little harder to turn than the X-axis so I may try loosening the nut. I tightened it to reduce the backlash. Annoyingly to get to the nut you have to take the bed off the machine and all sorts...takes ages :(