backlash mack3

[Jonathan]

I almost always use it. If, for instance, you're drilling an array of holes it will clearly make a difference to the accuracy - unless you're careful with the Gcode.
I've found in some instances it is of limited value since the backlash wont be a constant value.

Be careful with the velocity and 'shuttle accelaration' settings. The motors will loose steps with too low a setting for the latter, however to high a value will make the motion less smooth.

I don't use it as I have ballscrews so I don't have to.

Have you got two ballnuts preloaded on each screw then? Or just sufficiently low backlash to ignore it with one?