Quote Originally Posted by Ross77 View Post
I'm sure that I can improve on the 3mm depth with a bit more tuning... now its cutting clean edges It appears to be 0.3mm out, not sure if this is a step unit error ( had to round up to whole no.) or backlash.

3mm deep sounds about right for a 6mm tool, so does 1420 rpm suggest you experiment with feed rates.

Measure the backlash, find out how much of the 0.3mm is accounted for. Perhaps a man has to ask himself, is Delrin better suited to free rolling gantry style machines?

I spent a lot of time and money removing the backlash from my machine, if I could have done the same with a plastic nut it would appear somewhat futile :whistling:

Robin