In need of assistance with an extremely frustrating problem I am encountering. I recently expanded my Sphinx 1050 to a 1010 for more cutting area (originally started as a 55 and has expanded over time). During the last expansion, I did not mess with the z axis at all, and never has this issue in the past. I was playing around with a test cut of some text after surfacing my wasteboard and found that over the course of the carve, the text was carving deeper and deeper as it moved from left to right, despite the Openbuilds Control never exceeding the correct max carving depth from my GCODE. I originally thought it could be a tramming issue, but it doesn't appear to be, as I successfully flattened my wasteboard and did a test cut of a rectangle around the text in the image by manually jogging my machine at 0.05mm below the Z zero, and it was a consistent depth all the way around (barely visible in the image below). It seems that as the text is being cut, it is not retuning to the correct Z zero value, rather it thinks the Z zero is lower and lower, as low as 0.58mm below the correct Z zero. The image shows #1 - the first test cut that clearly shows this issue from left to right, #2 - another failed test in which I tried to reduce the carving depth but still had similar results, and #3 - where I carved each word individually and manually reprogrammed the Z zero value between each word. #3 produced the best results (ignore the "B"), where each word is carved to the correct depth, but I can't understand why when all of the words are grouped over a longer carve, the Z zero value is slipping. Any thoughts or assistance would be greatly appreciated.
Put a dial indicator on the Z axis, zero, hit cycle start, and when it's done, MDI G0 Z0 and see what the indicator says. That'll tell you for sure whether it's an axis issue, a collet slip issue, or whatever. Might be big enough you don't even need an indicator, just a line on a Post-It would work. If it's an axis issue it's either screw slip/stick, motor slip/lost steps (usually acceleration too high for the load, sometimes cable binding), or some kind of mechanical connection issue (loose wheels, loose screw mounts, loose motor shaft/screw coupler... That list is quite long)
I had this exact thing happen once it was a bad connection on one of the wires for the z-motor caused intermittent lost or gained steps. Can also be the things Rob lists. Gary
