Bubba, thanks for the PDF, very illustrative (I know almost nothing about gcode and fixtures, since I'm used to CAM and woodworking). I think it can also be done by using only the left and down fences and setting the zero accordingly, but then you'll need to generate your code based on the the exact Y size of the material so it "fits" the reference space.
BTW, I think the quadrants II and IV on the PDF are swapped. |