I've been plugging away on this M2 for 80-90 hours or better since I got it last week. Used Rev D. Been pretty happy with it. Went to set up a print from my room over octoprint, then went to check on it after it began printing. Saw it wasn't extruding anything and noticed it was pushing the glass build plate down. Sure enough, somehow the bed raised. Or the screw lowered. Or the z-endstop dropped? Everything seems tight as tight can get and it's solid. It didn't seem out of level other than the bed was now much closer to the nozzle. Tightening the leveling screws all the way will allow the nut to engage the endstop without crashing into the bed, but is very very close. I've never been able to adjust the z-endstop screw since I haven't had the tools to loosen it (it was pre-set as well).
What could have caused it? I've got a BLtouch coming in and this coincidentally happened the day before it arrives. I've got a second printer I can print the mount for the BLTouch no problem, I'd just like to figure out what may have happened so that I don't ruin the printer by not tending to the bed properly. In my head, since it's replacing the Z-endstop I might be able to leave the z-stop nut and not worry about it. I feel this is where buying and assembling a kit would have been beneficial
I searched a few different strings, but could not find anything so I do apologize if it's somewhere on this forum.
Edit: Have begun proceeding with the installation of the BLtouch. I've realized my dupont crimping skills need work. Grabbed a very nice at work and will try again. I really enjoyed printing out a peice that replaced a core part of the M2. This 3D printing stuff is just too cool.
Edit 2: Put things back together, found Z-min endstop was actually a little loose and slid down a little. This specific problem is solved.