Hi Brett,
Thank you for responding.
I am not setting a particular depth other than cutting to the surface of my model. I import an STL of my model in Desk Proto, and generate the tool paths there. I'm using bits in the .015 to .003 range, with 0 "skin" on the model, one tool cutting the entire model.
The developer of Desk Proto has checked the code and it looks good. Zero for the part is zero for all axis' of the mill. The part is centered (half above, half below) the intersection.
I'm zeroing with an electrical widgit and a special gauge for setting Z. From those settings I can cut test models to within .0003". Which is fine for my jewelry pieces.
I just recently started using the Z gauge. I zeroed it, cut two models in a piece of wax. Both were fine, except for the step over. Changed the step over of the second part, ran it a third time. It was 1.2mm too thick. This had happened time and time again. But not until I got the Z gauge did I have proof the tool was not moving. Z position of the tool was identical after the third part, as it was when I set it prior to running the first part. All indications while I am in Desk Proto is that the model is set up properly. Needless to say, I've checked this many times since having this problem, which is over two months when I started milling.
My wax is put in the rotary axis with tail stock holding the other end. I am performing a two sided milling proceedure with an auto flip between sides. This is set up in Desk Protos N-Sided Wizard. I then load the G Code into my milling computer, open in Mach3 and run it.
Any ideas of what to check are appreciated.
By the way does anybody else have Mach lock up with G Codes approaching 5 million lines? Thats another problem I have had.