Question Voron 2.4 Belt Noise Problems

[AlbatrossFPV]

Printer Model

Voron 2.4 R2

Extruder Type

Clockwork 1

Cooling Type

Afterburner

Hello all,
I’m having a rather specific issue with the Voron 2.4 that I built a couple of months ago from a kit by Spool 3D. As you should hopefully be able to tell from the video attached, the XY motion system is making all sorts of weird noises, such as creaking and squeaking. I am aware that the stepper motor noise is normal, but I don’t think that the creaking and squeaking noises are normal. A few more details that I have noticed in no particular order:

• It seems to be regular, as in, when the gantry passes over certain spots multiple times, similar noises are produced in the same spot every time
• The noises became gradually worse after building the printer, at first it was not at all noticeable, but now after about 300 hours of printing, it is quite pronounced
• I have rebuilt the printer completely once to replace all of the 3D printed parts with ones of my preferred color (purple!), which did not seem to improve or worsen the noises
• I have replaced nearly all of the flange bearings that the belts ride on in hopes of fixing the problem, but to no avail
• The noises do not seem to have any significant effect on print quality, although the print quality coming off of the machine is not exactly top notch either
• The A and B belts sometimes look like they will climb out of the bearings during movement, but never actually do (bottom right bearings looking from the back on B belt are especially prone)
• There seems to be a decent amount of wear on the belts since there black powder on the geared idlers and some of the belt sides are showing the internal reinforcement of the belt
• I do have a replacement set of belts, but I do not want to install them for them to simply wear away again, so ideally I’d like to find a solution before changing the belts if possible
• The XY motion system is completely stock (as described in the manual) except for the addition of the Klicky Probe mod
• The noises occur when moving diagonally as well as straight

If anybody has had this sort of problem before and found a solution, I would much appreciate your wisdom. If it would help to have more specific info, I will gladly provide. Thank you in advance!

 

[NoGuru]

That is almost certainly a bearing, Idler, or liner rail.
If you have wear on your belts you have probably destroyed some bearings.

Have you racked the gantry?
Makes sure your belts are tensioned equally.
You can loosen the grub screws on your pulleys and move the toolhead around a bunch to help settle the pully at the right height so they are nice and level.
Also what are your belts tensioned at?

 

[AlbatrossFPV]

Yes, I have unracked the to the best of my ability. It does not seem to bind when moving it around and the Z joints seem to line up fine when installing the gantry.
I'm pretty sure that the belts are tensioned equally, however I have yet to put a number on how well tensioned they are. When I get home, I'll try to measure the tension with the spectrum analyzer app thingamajig.
I did try adjusting the belt tension while moving the gantry and it didn't seem to change the noise significantly, but I suppose excessively tight belts could still wear more than usual.
I'm pretty sure that the linear rails are fine, since after un-belting the gantry to change printed parts, I moved it around a little bit and it didn't seem to make any concerning noise.

 

[NoGuru]

Based on what you are saying, I would focus on the bearing stacks and pulleys. Look for excess grease on the top or bottom of them.

 

[AlbatrossFPV]

Ok, I'll take a look around those spots when I get the chance. Is there any specific reason why I am looking for excess grease?

 

[NoGuru]

Ok, I'll take a look around those spots when I get the chance. Is there any specific reason why I am looking for excess grease?

It just sounds like broken bearings and a lot of times they pop the cap that holds the grease in.

 

[AlbatrossFPV]

Ok, so I’ve looked over the bearing stacks and everything seems alright from what I can see. I took a few pictures showing the bearing stack on the left (from the back) and some of the wear on the top of the belts that looks like the inside reinforcement of the belts to me. See below:

https://imgur.com/a/AXNMvDa

https://imgur.com/a/pQsrusF

Also, I filmed a video of the consistency of the nose (happens in the same spot multiple times over), so I’m inclined to think that it might be the belts, maybe due to the excessive wear. What is sort of bothering me now though is how they wore down so quickly. I looked at the belts as they went over the bearings/pulleys and some spots on them seem to overflow on the bearings/pulley (image link below), so now I’m wondering: is it common to need to add extra shims between the bearings?

https://imgur.com/a/PetFM9y

 

[Dave32]

I took a few pictures showing the bearing stack on the left (from the back) and some of the wear on the top of the belts that looks like the inside reinforcement of the belts to me.

That's normal. Many belts like this are either "endless" (ie: continuous loops), or produced as large loops first before being cut to strips. Belts of this type have reinforcement cords that are wound in a helical (or sometimes a balanced two-layer crisscross) pattern prior to the belt being cut to width. In belts of these types, there will naturally be spots (on both sides) where the reinforcement cords are exposed at the cut.

 

[AlbatrossFPV]

That's normal.

That's good to know, although that now makes me even more confused as to where the noise is coming from

 

[MattTheNoob]

I'm not saying it is the right/best approach, but I would disconnect the steppers (mechanically) and move the traffic around to identify the location of the noise. Also...
Linear slides have "recirculating" bearings. If one of the balls is damaged, you would get the same noise in roughly the same area for a while. It would likely migrate around after a while.
After that I'd start disconnecting one belt/component at a time until I isolated the source.
Good luck and please let us know what you find!

 

[AlbatrossFPV]

I'm not saying it is the right/best approach, but I would disconnect the steppers (mechanically) and move the traffic around to identify the location of the noise. Also...
Linear slides have "recirculating" bearings. If one of the balls is damaged, you would get the same noise in roughly the same area for a while. It would likely migrate around after a while.
After that I'd start disconnecting one belt/component at a time until I isolated the source.

That is certainly the methodical approach and as such, is likely the best way to go about things.
I'll definitely report back when/if I find the problem.

 

[sabarjp]

A good mechanics trick you can use while doing the above is to touch a long screwdriver to various components and put your ear to the handle end of the screwdriver. This amplifies sounds and makes it a lot easier to tell exactly where a noise is originating from.

 

[AlbatrossFPV]

A good mechanics trick you can use while doing the above is to touch a long screwdriver to various components and put your ear to the handle end of the screwdriver. This amplifies sounds and makes it a lot easier to tell exactly where a noise is originating from.

That sounds like a pretty cool trick. I'll definitely have to give that a try.

 

[AlbatrossFPV]

Ok, so I’ve finally got around to doing some troubleshooting. The first thing I did was remove the belts to check if the problem was the linear rails, but it was not. Everything moved smoothly and silently without the belts. Next, I installed some 0.3mm thick M5 washers between each set of flange bearings in the rear bearing stacks (6 total) and re-installed the belts. This seemed to improve the noise level a little bit, but it was most decisively not as quiet as I would have liked. If I were to hazard a guess, I would say it dropped the intensity by about ⅓. The final thing I tried was replacing the old set of belts with a new set that I bought a while back. This finally reduced the noise to nearly zero, the only thing I can hear is the monotonous whine of the stepper motors.
Now I suppose my only worry is that the noise will return after a few hundred hours on these new belts. The noise started appearing at about 200 hours on my old belts, which I think is pretty soon to require a replacement. I guess only time will tell if there are other mechanical problems. If the noise reappears, I’ll try to remember to update this thread with any new things I find.
Thanks for all of your help!

 

[NoGuru]

If it does return, maybe just rebuild the motion system.

 

[AlbatrossFPV]

If it does return, maybe just rebuild the motion system.

Yeah, that'll be what I will probably have to do if it does come back, although I also rebuilt most of the motion system when I replaced all of the printed parts about 200-250 hours in, which didn't really seem to help things so its possible that it wouldn't help.

 

[Sandman50]

I had a similar issue - it turned out to be the slot covers in the back corners of the frame. Removed those and the issue went away. Apparently the slot covers relaxed some after use so that they would hit the belt.

 

[AlbatrossFPV]

I had a similar issue - it turned out to be the slot covers in the back corners of the frame. Removed those and the issue went away. Apparently the slot covers relaxed some after use so that they would hit the belt.

I did notice that the belts were hitting the extrusion slot covers that I was using, but even after removing them, the noise did not decrease significantly. The belts on slot covers noise was much softer and sounded more like a soft sliding, whereas the other belt noises sounded more like a grinding noise.