I'm not sure why this code is skipping depth passes after the stops at the beginning. I'm trying to run the same contour code over and over and incrementing the depth by 0.02" each pass. For whatever reason, it goes from -0.02, to 0.06 to 0.10, to 0.14. It's skipping 4, 8, 12 etc. Did I do something wrong or is this a limitation of the demo?