Loud noise on Y-movement - bearnings?
 

Loud noise on Y-movement - bearnings?  

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bastian.m
(@bastian-m)
Trusted Member

Hey there,

i think, i've also a problem with the Y-axis-bearings.
Here's a video:

Is there any other option than to replace the bearings? I tried to grease them with WD40, but with no hearable difference :-/
I haven't printed alot since i have the MK2 (maybe 2 full 1kg filament-rolls?).

Thanks!

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Posted : 12/11/2016 2:26 pm
roman.t
(@roman-t)
Honorable Member

Y axis can be little loud but IMHO that resonating sound is caused by inner plastic cover in the PSU.

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Posted : 12/11/2016 2:32 pm
bastian.m
(@bastian-m)
Trusted Member

Are you sure?
The noise appears not constantly - only on y-axis-movements with "more speed".
I will check that plasticcover on the psu - i already wanted to place the psu outside of my enclosure, .. now i have to 😀

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Posted : 12/11/2016 2:48 pm
roman.t
(@roman-t)
Honorable Member

I am not sure :-). But removing it helped me with this kind of resonating sound.

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Posted : 12/11/2016 2:57 pm
PJR
 pjr
(@pjr)
Antient Member Moderator

I tried to grease them with WD40

Now, why would a Water Dispersant (yes, that's what "WD" stands for...) "grease" the bearings. If anything, it would have the effect of removing any traces of oil. If you do want to grease the bearings, then you should use something more suitable. You could try grease (preferably silicone, copper or graphite based).

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 12/11/2016 3:03 pm
JohnnyricoMC
(@johnnyricomc)
Estimable Member

Never use WD40 in 3D-printing. Instead, look for a high viscosity synthetic oil. Something suitable for usage on bearings and threaded rods.
Additionally, keep your printer in a clean dust-free environment.

I'm using a Super Lube 51010 pen to lubricate the threaded and smooth rods.

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Posted : 12/11/2016 3:56 pm
bastian.m
(@bastian-m)
Trusted Member

I tried to grease them with WD40

Now, why would a Water Dispersant (yes, that's what "WD" stands for...) "grease" the bearings. If anything, it would have the effect of removing any traces of oil. If you do want to grease the bearings, then you should use something more suitable. You could try grease (preferably silicone, copper or graphite based).

Peter

Had to read it twice to understand your sarcasm, than i had to laugh:-D Of course, i've read the wikipedia-article, and you are right. Damn. I read about, how bearings had to been greased - it had to be "thin" grease, so the .. bearing-balls dont stick together, so i tought WD40 would be right ( ... ).

I've ordered the correct oil.. will post, if the noise disappears after i've greased the bearings (...).

(Self-)Made my day 🙂 Sorry, no native english speaker.. 🙂

Edit: Would be engine-oil okay too? It's synthetic, and i got 5L in my garage.. 🙂

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Posted : 12/11/2016 4:14 pm
PJR
 pjr
(@pjr)
Antient Member Moderator

Bastian

Apologies; didn't mean to be sarcastic.

Personally, I prefer to run the bearings dry because I have a dusty environment. But for some parts, I use light machine oil, silicon/PTFE grease and occasionally copper grease.

Then again, my (dry) bearings are not noisy.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 12/11/2016 5:18 pm
Omikron
(@omikron)
Estimable Member

WD-40 is quite good for flushing out contaminants and old grease from a mechanical part, but you MUST remember to re-oil/grease afterwards.

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Posted : 13/11/2016 5:43 am
george.o
(@george-o)
Active Member

It could be the bearings. I recently replaced a warped heat bed and decided to check the Y-axis bearings while I had it off. They had a lot of play in them. I replaced the bearings and the noise level dropped by a large amount.

I used light machine oil on the original ones.

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Posted : 13/11/2016 8:17 am
pieter.b
(@pieter-b)
Eminent Member

Also check that the distance between the smooth rods of the y-axis is exactly the same at both ends (<0.1mm), and check the tightness of your y-axis belt. Improving that significantly reduced rattling noise for me. But it was never as extreme as yours.

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Posted : 13/11/2016 12:27 pm
mavu
 mavu
(@mavu)
Estimable Member

If you should decide to replace the bearings, I can tell you that its pretty easy, and quickly done.

Snip 4 cable binders on the rods, and snap them out.
disconnect one side of the belt. That should be enough to flip the bed in place without disconnecting any cables.

Slide rods out, snip the cable ties on the bearings, and replace with new ones.

Then its just relacing all cable ties, and rods, and you're done.

For bearings, I used LMU8 named brand linear bearings, and the datasheet said to use Lithiumsoap based grease which I got from amazon. There is a nice video on youtube on how you pack the bearings with grease and remove the transport oil.

Its done in 30 minutes.

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Posted : 13/11/2016 2:02 pm
bastian.m
(@bastian-m)
Trusted Member

Hi there,

i've removed the PSU from the MK2-Frame (and the plastic cap, because i will place it outside of my enclosure) and checked the y-rounded-belts: One end: 16,3cm, the other 16,2cm. I corrected that to 2x 16,2.

As soon as the grease/oil is delivered, i will grease the rods.
Actually, i print some testobject (long y-rectangle) to check, if the noise still appears.

I will post a answer after i got something new 🙂

Edit: God damnit.. it's not the psu. The noise is generated by the headbed, which is resonating to the y-axis-movements. I have to check the screws, but i think, they are fixed. So i think, the problem are the bearings...
I will wait for the grease - maybe, it will fix the noise (or reduce it to a acceptable level). If not, i have to buy new bearings.
My problem is, that i life in europe - i searched ebay for some LM8U-bearings, but they are all delivered from china (bad quality?). The "good ones" (that are named in another post here) are very expensive (10-25 € per bearing), and thats a little bit to much for my budget.
Has anyone a tip, where i could buy some "better" bearings than the original from prusa, where the delivery to germany is cheap?

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Posted : 16/11/2016 12:15 pm
PJR
 pjr
(@pjr)
Antient Member Moderator

Bastian

When I search eBay.de, the first item that comes up is the IGUS bearing: http://www.ebay.de/itm/12x-DryLin-Igus-RJ4JP-01-08-Gleitlager-anstelle-LM8UU-RepRap-Mendel-Linearlager-/272279116093?hash=item3f6519993d:g:K98AAOSwxvxW78eU

Very good price for that (less than €1 each).

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 16/11/2016 1:03 pm
bastian.m
(@bastian-m)
Trusted Member

Hey Peter,

I will give them a try and ordered 12 bearings - thanks, that you spend time to search/give me that link, Peter.
Would it be recommended to replace all bearings? Or should i wait until im getting problems with the x-axis-bearings?

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Posted : 16/11/2016 2:56 pm
PJR
 pjr
(@pjr)
Antient Member Moderator

Bastian

Personally I would simply swap out the Y axis bearings to start with only because it is the quickest and easiest to do. It is unlikely that you will need to change the Z bearings. Change the X bearings only if you think you need to.

I played about with the bearings on my Mk1, but only the Y axis. I think I bought the same set of 12 from the same supplier. I only changed the Y bearings, and have kept the rest as spares.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 16/11/2016 3:34 pm
dejan.s
(@dejan-s)
Active Member

Bad news. I got my MK2 this week and already built it with drylin bearings. I ordered these. It sounds exactly the same as yours, so i am afraid the problem lies elsewhere.

I also get the impression that the sound comes from the heated bed resonating. The question is what produces the vibrations.

I will have to measure the distance between the rods in the evening, but i am pretty sure that i double checked the whole Y axis frame at least 3-4 times before I continued building. I layed it on a flat surface and made sure every corner is touching it.

What i found strange is, that i had to put the Y axis frame out of alignment into the XZ frame. That means that distances of the M10 counter nuts are is "off" by 4mm (left side from behind has 104mm distance, right side 100mm as described in the assembly instructions), but that's how my heated bed lines and the X axis smooth rods are parallel.

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Posted : 17/11/2016 8:29 am
bastian.m
(@bastian-m)
Trusted Member

Hey,

i think, i know what the cause of this noise is - the y-axis-bearings.
I haven't changed them yet, but.. check the following...

It appears ONLY, if the Y-Bed is in the middle of the rods. If the bed is near one of the endstops, it doesnt happen.
If it's "in the middle", i tap with my finger onto some places on the bed. I recognize, that it gives on the left and right side, in middle of the bed, a little feedback. The screws, that fix the bed on the y-axis-frame are tight; but it seems, that the rod inside the y-axis-bearings has some play (maybe 0,3-0,5mm). You can hear it (it makes a quiet noise), but as i said, only, if the bed is not near the endstops. I can't explain it for myself, and i'm sorry that i'm having trouble to describe it in english :/

This would explain, why the noise is only generated sometimes - mainly, if i print objects that are centered in the middle of the bed. I never heard the noise on objects, that are near the borders of the bed. So of course, i tought, that the problem resolves itself, after i replace the bearings.

"Maybe": The bearings that you replaced - could you check, if they have play too?

Edit: If the noise is generated as the printer runs, you could tap with your finger to the bed - in my case, the noise dissapears.

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Posted : 17/11/2016 3:51 pm
dejan.s
(@dejan-s)
Active Member

Thats 100% what I am experiencing (but i already thought that was clear when you described the bed as "resonating" in one of your prior replies).

I disassembled the whole Y axis and added the bearing brackets to the drylin bearings instead of the zip ties. You really have to pay attention to not overthighten them (if using zip ties and also the brackets...). I also realigned the whole y axis frame and hotglued the lid in the PSU.
Yes there is a little bit of play between the rods and the breaings and when you move the bed (without the belt attached) you can easily "provoke" that vibration/resonation. I am asking myself if it would have been better if i had used the stock bearings. But on the other hand so many MK2 users are using the drylin bearings without issues...
I am using the printer placed on an old large gaming mouse pad in silent mode. The noise level is okay, but i really want it to be perfect and be able to use both modes without the fear that the printer will disassemble itself because of the vibrations 😛

If there are any further suggestions, please tell me =)

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Posted : 18/11/2016 8:32 pm
bastian.m
(@bastian-m)
Trusted Member

Hmpf. Don't know whats going wrong... got the new bearings today and started to replace the original 2 hours ago.
Then i got the problem, that the y-axis-frame (alu) scratches over one of the screws, that fixes the headbed to the y-frame. Had to correct the two frames, so there were in 90° angles...
After i replaced the bearings and checked that all is correct, i lowered the PINDA a bit (had to set live-adjust to -0,5 so i thought it would be a good idea to minimize that value); than i started to calibrate XYZ again.
Than i had 5-6 noozle-crashes into the headbed (god damnit). The last times, it crashes at cal. point 4 (middle, right) - had to correct the frame again (i removed the felt-foots (?!),... now i lowered the PINDA-Probe again; the calibration runs at this moment.

Grml.

The positive: Maybe, i found the thing that's resonating. I had to disassemble the Y-Belt-Holder (the orange part under the y-frame) - and i noticed, that one screw was 2mm to short; so i can't tighten it up. I replaced it with the correct screw...

Hopefully, this running XYZ-calibration not ending up in nozzle-crash #7...

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Posted : 18/11/2016 10:43 pm
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