Did My Bearings Die?
I'm starting to think that one or multiple of my y-axis bearings have gotten worn out or warped.
Hardware: I3 MK3s
Background:
I noticed on some recent prints that unless I manually auto-homed the system (sometimes 2 or 3 times) it wouldn't make it there, like the system forgot how far away it was. Self-test checks always came back successful when trying to figure out what was going on so that was no help. Then on some occasions during mesh leveling, there would be grinding on movements and the y-axis would not actually move back far enough. This was hit or miss but my prints were still coming out fine when this didn't happen...until they weren't. Then the level shift gremlins came in full force.
Troubleshooting so far:
After reading a few posts about this, i checked the y-axis belt tension, it was a bit lose so I tightened it, ran a self-test and again passed. Moved to mesh leveling, same results as before.
I turned power off to the system and moved the bed along the y-axis and noticed it was very stiff but only when moving forwards. Moving back it was smooth without much resistance. I then removed the belt entirely just to rule out any friction but this changed nothing in it's resistance. I then loosened the u-bolts holding the bearings to see if those had some how gotten too tight and causing issues but again, no luck.
What Do I Do Now?
Based on my troubleshooting, I suspect something has gone wrong with the bearings causing the rigid y-axis movement to be the cause of the failures. So do I replace these bearings? Is there a way to check this theory out further? If they are bad, is there any good guides/advice out there for servicing them instead of a full replace? Am I even on the right track?
RE: Did My Bearings Die?
Sounds like it yes. It could be that the plastic seal is worn/damaged which is why it’s resistant in one direction only but it’s also just as likely that the balls inside the races are kaput.
In the very short term you can use a thin oil and work it back and forth trying to get it past the dust seals but that is definitely a stopgap measure for when you can’t remove them to re-lubricate properly. Next best is removal, clean them out with ipa and then re-grease them. However if they are as bad as you describe then they are possibly damaged so replacement sounds like the best bet long term.
When/if you get new ones don’t forget to clean them and repack with a suitable grease before fitting them to get maximum life out of them.
RE: Did My Bearings Die?
@neophyl
Just went ahead and bought a bunch from Amazon. Why mess with trying to fix bad ones when I can buy replacements and have extras when this inevitably happens again right?
RE: Did My Bearings Die?
Pretty much yeah. I like to keep spares around too. The oil suggestion was just so you can keep printing while waiting for them to arrive.
RE: Did My Bearings Die?
Not in that big of a hurry for that extra headache. Already been down for a week, what's 2 more days?
Thanks for the tip though.