TL;DR I got only a 4mm cut when I was trying to get a 5mm deep cut.
I am cutting some plywood stock. I measured it with my micrometer and it was about 5mm (4.9-5.05 measurements). I set the depth of cut in estlcam to 5.1mm to make sure I make it through. Looking at the gcode, it doesn’t look like a CAM problem. The Z-5.1000 is in there a bunch.
Before the print, I moved the Z axis down onto the 0,0 location, and used a piece of paper to make sure it was just above the surface of the wood.
After finishing the program (everything looked great, the downcut bit is awesome) it became obvious that it did not cut the entire 5mm. I cut one piece out with a knife, and measured the thickness again, and got 5mm. I measured the depth of cut, and I got 4.0-4.1mm.
So I moved the bit down to 0,0,-1 mm and reset the home position, and ran the program again. This time, it just kissed the spoil board.
What did I do wrong? How am I off my 1mm in the Z?