y-axis belt rubs against belt-idler side
I bought a used MINI and found out that the y-axis makes some squeaky noises, when the table is close to the front. Apparently the belt rubs against one of the sides of the belt-idler. I already loosened the belt in the front and tried to re-align it, but if I move the y-axis one time from back to front, the belt is again in that position:
Is there any problem with that, other than being annoying?
I think the best would be to do this step again: https://help.prusa3d.com/guide/2-yz-axis-assembly_196824#197994 and align everything again? Or is there something else I could do?
Best Answer by Diem:
It's possible that the idler bearing housing has distorted or worn in use; print a replacement and try that.
https://www.printables.com/model/57214-mini-printable-parts
Cheerio,
RE: y-axis belt rubs against belt-idler side
Maybe I went a bit over the top, but I ordered new bearings and replaced all of them on the X and Y axis. By doing that I also had to adjust the belts and the printer is now as silent as a new one 😉
RE:
The silence was only for a few hours... Afterwards, the squeaky sound returned.
I re-assembled the whole belt stuff again but it keeps squeaking.
I believe that it is not the belt rubbing against the idler, but rather the idler rubbing against the plastic (it can rotate easily and move slightly left and right) or the screw moving inside?
Is there anything I can do against it? Would some grease help on the screw that holds the idler?
Here is also a video where you can hear the noises:
RE: y-axis belt rubs against belt-idler side
AFAIR when you buy Prusa Mini it comes with a little grease tube, you could use it between the outer plastic and the idler.
Otherwise any grease/silicone designed for plastic parts should be good enough (like for RC/cassette players/printers etc).
See my GitHub and printables.com for some 3d stuff that you may like.
It's possible that the idler bearing housing has distorted or worn in use; print a replacement and try that.
https://www.printables.com/model/57214-mini-printable-parts
Cheerio,
RE: y-axis belt rubs against belt-idler side
But how should it distort? This is a rather sturdy part. The printer isn't that old and wasn't used too much... But okay, I cannot rule out that somebody abused the printer before I got it and printing a new one is cheap. I'll try some grease on the screw as well.
If it's been running off centre, perhaps over-tensioned with varying heat just above it then it can't hurt to change it.
Cheerio,
RE: y-axis belt rubs against belt-idler side
I checked on another MINI we have at work, which came pre-assembled and there also the belt runs a bit off-center. I believe that is not a big issue, as long as it does not rub?
Any ways - print has already finished and I'll replace the part this evening...
RE: y-axis belt rubs against belt-idler side
Fwiw my only remaining MK3S+ runs off center too. It doesn't seem to hurt anything and it's got thousands of hours.
On some older MK3 machines that I no longer have I was able to fix it by printing a different motor mount that shifted the motor mount over slightly. I'm not familiar with the mini, but on the MK3 I think this was not an uncommon occurrence since there were a number of fixes on printables. I know I'm my case there was no way to get it to run in the center with the original motor mount. My suspect was variations in the frames and how they were assembled was the culprit.
RE: y-axis belt rubs against belt-idler side
Okay, so I replaced the part and put some grease on the bolt to be on the safe side 😉 So far, it is pretty silent! There is some resonance in the y-axis though, not sure if that is from an incorrect installation of the bearings...
Also interesting, my old part has F2 on the bottom, the new one is R6 - is that the revision number?
RE: y-axis belt rubs against belt-idler side
Well - what do you know... Squeaky noise is back! Around 2h of silence and then it started again.
The only thing that I haven't changed yet are the belt and bearings itself. However, the bearings themselves seem to be fine - I checked that they run smooth and silent outside the printer. Could it be that the belts start to squeak?
RE: y-axis belt rubs against belt-idler side
I think I fixed it. I also printed the y-axis front, back and the belt holder. The noise is completely gone and the y-axis is now super silent.
Not sure though if really the new parts were the missing link or if I just had to re-assemble everything... In any case, now I have almost a MINI+ and not a MINI 😀