Random Y axis resistance makes bed unmovable
As you can see in the video above, my Y axis suddenly started exhibiting an issue where the bed encounters heavy resistance. It is sudden, and it is random. There is never consistency to where the resistance occurs. Just before the video above, I was able to move the bed from the back of the printer to the front without issue (once). And then it went back to behaving the way it behaves in the video.
The really odd thing is, 100% of the time I can move the bed backwards without resistance. I want to repeat that: I never encounter resistance moving the bed towards the back of the printer. Only forwards, and again, never in the same place.
As you can see, I don't think (though I am inexperienced), that there is anything that seems off in terms of parts. The bearings do not rub, and the u bolts don't touch anythign as they move. There are no blocking wires; there is no contact with anything whatsoever. The printer was working great for about a year and a half and had zero issues. I am not sure what this is. Any help would be amazing.
Thanks a lot.
Try to release completely the belt and check if the issue is still there.
we try by exclusion
Sounds like a bearing problem. What you describe is common when they arent lubricated, they seize up, often in one direction and its semi random as the balls inside jam up. You need to lubricate them.
The only way to do that properly is to remove them, clean them out and re-apply proper lubricant then refit. There are dust seals that will keep in/out grease otherwise but as a stop gap measure you can apply a thin machine oil onto the rods and move them back and forth to work the thin oil past the seals.
I would agree with Neophyte, looks like the linear bearings are offering resistance.
While removing the belt, I would check the teeth on the drive and idler pulley for Y belt, can get a build up on some teeth and this can cause the same symptoms, tight in places.
If the bearings are dry, and the mc oil makes a difference, this won't last long... get some SuperLube grease with PTFE and remove the bearings from the Y axis, clean rods and bearings with ipa and put a good thick coat of grease in the bearings before reassembly.
Also, did you notice if you lost any balls out of linear bearings on assembly, can lose a few but any more than that and I would get new bearings.
Check them if removing, and be careful when cleaning and assembling, really easy to pop them out of place without noticing.