I just took possession of a 2016 PRSAlpha ATC, replacing my OLD (circa 2001) PRT. It's taking a bit of getting used to, unfortunately. I did find out that I have a bad connector on the Z-Zero plate, which was causing a lot of headache. I have most everything figured out, but still one nagging issue, and that is depth of cut.

The first problem: After I successfully zeroed the tool, Iput the dust skirt on and then ran my program. It was into 1/8” acrylic. I checked the program and it was to go 0.010 into the spoilboard. It probably only penetrated the material about .050”. So, I stopped the program, moved the bit to an open part of the board, turned on the spindle, moved Z to 0.00 and then ran it along the Y axis. Right on the money……barely scratched the surface. Then, I re-ran my program WITHOUT the dust skirt on and it cut fine. Is it possible that that dust skirt brush is so stiff that it prevents the Z-axis to go to full depth? There’s no other explanation for it, but it seems preposterous.

Today I ran a program and left the dust skirt off. It was programmed to cut 0.015" into the spoilboard. It did not cut through. I edited the file to 0.020" depth. It did not cut through. I then edited the file to cut 0.040" through, and it finally did, but barely. I tried to measure the depth of the cut with my calipers, but it is as good as 0.001 into the board, and 0.000" in other places.

What could be making my machine do this, do you think? Could my Z-stepper be bad?