Issues with first layer calibration- NOT like the others
I have used my MK2s for a couple of months and it's a fantastic machine. I decided it was time to finish the build with the MMU2s. I've got it assembled with just a couple of filaments loaded. I tried to run the first layer calibration and I'm having issues before it even extrudes. The x and y axes are hitting end stops during bed level check. I reset and ran the full guided setup and everything passed. Tried to run the FLC, and it happened again. The bed was all the way to the front, and as it ran the 7x7 point check, it began at the very back of the board - skipping teeth and making a racket. What gives? I plan to update the firmware tonight to 3.8.1 hoping it will be solved. Any other insights?
So, I have more information. First, I updated the printer to the latest firmware. Then, it became clear to me that the printer didn't seem to know where the axes are. Previously when I run FLC, it always starts at the front left. For some reason it wants to start about 2/3 of the way back on the bed. With the printer off, I reset the X axis to the far left, and the Y platform pushed to the back. Turning the printer back on, I go to Settings > move axis and I'm able to run the full length of both X and Y with no motor step skipping (I couldn't do that before). When I try to run the FLC, it does exactly as before, testing the first point at the back left instead of the front left of the bed. I considered that I might have a stepper plugged in backwards for Y, but it ran the FLC correctly a few days ago with the wires the way they are now.
probably a friction issue, have you lubed the bearings?
are your belts too tight. is movement notchy?
could your u bolts be too tight?
Everything worked beautifully before the upgrade. It doesn't have enough hours on it (about 100) to have any friction issues. The machine is clearly confused. It seems to know where all the motion systems are when I boot it up, but then forgets for FLC.
Today I started it up, ran a "home" from the calibration menu and then the FLC. Now it's doing fine. Hope it keeps going that way.