Hi Guys,
I noticed on the 4 Tensionbelt bearings in the back of the printer (4 of them) having black smudge on them. I guess this will lead to problems. Any idea how to remove the smudge and what to use ISO?
Thanks for the help!
Kinda looks like delrin spacers between two bearing sleeves, I’d double check first
I had the same issue. Except mine built up a lot more before I noticed it. It appears to be just belt residue. I cleaned mine off with IPA and q-tips and it has not returned yet
Negative. Bambu does not use a two piece design for their pulleys. See the part in the link.
Thanks,
How did you moved the bearings so you can clean all sides. Guess you can’t clean it while operating
Al
You can either
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Loosen the automatic tensioner screws at the back and gently move the XY rod assembly, which will move the belts, which will in turn move the idler bearing.
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Or you can power up the machine, and use the screen to move the XY rod assembly as needed to rotate the idler bearing.
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For future reference for those who may have this problem, here is what my pulley looked like after 515 hours
I had those smudges as well. I think it’s partly whatever junk stuff like ASA and ABS deposits on the belts which then gets rubbed off there, partly belts themselves (like when you touch them with your oily hands or you drop oil on them when oiling the rods, or particulates from wear). Some idlers had lots of this gunk, some had none, I think once some is deposited on the surface the rest gets attracted there
I used cotton swabs, IPA, and a piece of plastic to scrape it off, the removal is mostly mechanical. The only tedious part is getting in there and getting a good look at them.
I don’t think it’s going to cause any problems by itself in regards to print quality, but it could shorten the belt lifespan, so I recommend cleaning it from time to time, but I wouldn’t worry about it in general. I had deposits on my idlers for hundreds, perhaps thousands of print hours before I noticed, and some of them I only really cleaned when I was changing the belts (~4500 print hours or so).
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Thanks! I feel more at ease now.
Cleaning job ahead!
That is a great point about the filament residue. I didnt even think about that
I know this is an old thread, but I wanted to provide some additional info for anyone else in a similar situation as I found myself.
I found ringing/ghosting on certain types of prints, which were oriented at a 45 degree angle on the plate and spanned the length of the build area.
I trammed/leveled the bed, cleaned the carbon rods, cleaned and lubed the lead screws, Ran the full calibration routine, dried my filament for 24 hours, calibrated the filament using Orca slicers temp, flow, retraction, VFA, etc, and could not reproduce the issue on a small scale. Only on these larger prints which had big surface areas.
I decided to just watch the printer when it was hitting those spots to look for anything that might be out of place. In the top left corner, tucked away where you can only see a small portion of it is one of the bearings, and as the toolhead traveled across the print, i could see what looked like a small bump of buildup. The belt was not on the bump 100% of the time, only after it had traveled in one direction under tension did it slide over the bump. And where the belt hit the bump, the surface of the print bulged.
I used a q-tip soaked in alcohol to press up against the bearing while the print continued. It was a bit risky reaching in while the toolhead was moving, but the print pattern was predictable and I could get the q-tip in position for a few seconds at a time.
The change was immediate. You can see where the ringing is happening, and then it stops.
Moral of the story is, when cleaning the rods, clean the bearings.
These caused the belts to travel up and down on the bearings and in some areas would hit the accumulation of crud.
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