A10 PRINTING ISSUES !!!

[aarli]

Check heat bed roller bearings. I bet the tightening ones are the first to die. Happened to my A10 after just 3rd print. I was going mad over Y-shifts before I finally realised what the cause is.

Main hint for me was the fact that it started screwing up my prints somewhere after more than half had already printed. So I logically seduced it has to be something that's being affected by heat.

I turned out that one of the rollers started occasionally jamming. Once I identified the problematic roller I loosened the pressure on it, later ordered a large quantity of spare rollers. By the time replacements finally arrived, I had already lost 2 rollers (which I temporarily swapped out with rollers from Z axis, as it moves the least)

Oh, I also identified the root cause of the beating failure: production flaws. Each roller has 2 tiny ball bearings. The outer rings of these 2 bearings is separated by about 1mm thin wall. Due to that there is same width gap between inner rings. If the force applied is perpendicular to bearings shaft that's not an issue. That's how it should be.
But as soon as you use such bearing setup for tightening rollers then 2 different forces apply. As shafts are vertical and roller has to roll in the horizontal groove the it has to pull towards the groove while the other force is being applied which is the tightening force (essentially pulling rollers inner rings towards each other) and 1/4th of bed weight is also applied along the same bad axis. These bearings aren't meant to bear vertical loads.

And now the main point. To avoid such damage there should be a simple washer between inner rings, to eliminate the tightening force, as inner and outer ring distances from each other shpild be equal or ideally the inner rings should have a wider gap.

About 40% of my rollers were missing the inner washer between bearings. Or the washer was too thin to have any effect. So, inconsistencies and manufacturing quality issues.

The rollers that I ordered all had proper washers in place, so I instantly swapped out almost all of them (I actually got better shaped rollers too)

[Dave Winwood]

I'm having layer shift issues in the Y direction also. I tried loosening the rollers but the bed became wobbly. I've set the rollers so that clamp the runners just enough but I still get shifting. I also noted that the stiffness varies as I manually move the Y axis and I'm assuming I have some dodgy rollers. Can you tell me where you got yours? I had a search but couldn't find any. Cheers