Calibration Failed after a long time turned off
I'm attempting to boot my MK3s back up after a few weeks offline and I am having an issue that I first noticed when trying to run a print. During the mesh bed leveling step before the print begins the Y axis would stall and create a loud noise as if it was trying to push through something. I made sure there was nothing in the way and tried to do mesh bed leveling again separately from the print. Same issue. So I reset all calibration and started from scratch. The x and y axes can both home just fine with no noise or issue, then the Z calibration starts and it moves up and asks to clean the nozzle/take off metal plate/etc. and then it moves down and just stops when it hits the carriage. Shows an error "Calibration failed. Check the axes and run again." Every time I've tried, this happens. The nozzle is touching the carriage and shows this message. What do I need to do to overcome this? I've never seen this before.
Afew weeks offline? OK we're talking dust, spiders, and who knows what else...
Time to clean and lubricate all the smooth rods. To clean the fan blades, and to evict anyhing that crawled into small spaces.
Then check both axes move smoothly when pushed, slowly, by hand.
I made sure it was clean before booting it up. I wiped everything down and used compressed air. All axes move fine during the calibration and by hand when powered off. That doesn't seem to be the issue.
So I worked a bit on it, did a factory reset and installed the latest firmware. Lubed all the rods. Adjusted the level sensor. Moved the Z threaded rods to matched height. After all this and a few tries it made it past the Z calibration and was successful with a first layer calibration run. While inspecting each part during the various moves, I noticed one of my bearings in right hand Z rod is loose enough to slide up and down within the printed body. Is there anything I can do to tighten that up to remove the slop? Would a printed spacer help? Or should this not even be a concern?
Can you provide a video, with sound, of the failure process?
one of my bearings in right hand Z rod is loose enough to slide up and down within the printed body.
Do you mean the X end idler carrier?
That suggests the part is distorting. That could easily be enough to fail calibration. Has it been under excess tension, possibly in bright sunshine?
IMO the part should be replaced. If you are still within warranty log into your Prusa shop account and raise a chat with support. If not then you can either buy a replacement, attempt to print one, or find someone nearby who will print one for you (World tab above.) Although you could theoretically re-use the existing bearings they are tricky to remove and replace so order two new bearings.