I initially posted this issue back in May under a related troubleshooting thread, but I ran out of suggestions (and stepped away from the Maslow for a few months in frustration) and now I’m ready to try again…
The problem - during the initial calibration pattern test cut (starting at sled centered), the Z-axis motor initially raises the bit about a quarter inch as expected. However, when the sled motors engage to move sled to upper left corner, it also turns on the Z-axis motor to raise the bit further (and further, and further) until it shears the orange tab.
If I turn off the Z-axis feature everything works fine (sled centers, initial calibration cut as expected). During the initial calibration with Z-axis motor enabled, the Z-axis seems to work fine when raised or lowered and define zero appears to work. However during the calibration pattern test cut, the Z-axis motor runs whenever the sled is moving. As sled goes from center to upper left during initial calibration test run, it continuously runs Z-axis motor until the orange tab stop “tops out” (and get’s chewed up). In other words, when the sled motors engage to move sled to upper left corner, it also turns on the Z-axis motor to raise the bit. So while sled moves up to left diagonally, the bit just keeps raising until it “tops out” the worm screw after about 15 seconds. It’s like the Z motor is somehow being turned on by GC turning on the sled chain motors.
I’ve run through the calibration process multiple times (replacing 3 chewed up orange tabs so far) and everything seems great until initial calibration run. Other than the brass bushing to extend the worm shaft, it’s a stock Z setup and I’m using 1.26 GC. I’ve also tried previous suggestions from Gero and Diang. I’ve isolated the Z access control cable to avoid any potential of cross talk. I’ve also tried removing log files, in fact I tried removing everything on PC (factory reset) and Ardino and starting over. The fact that it still happens with a complete software re-installation from scratch has me thinking it’s hardware, not software. Any suggestions?