Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM
 
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prusayo
(@prusayo)
Reputable Member
Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

For anyone interested in how various bearings/bushings sound with and without pressure (to simulate being held by zipties), I made a video:
http://sendvid.com/5knwjugs

The first part of each demonstration is without pressure, the second part is with slight pressure. I used a Misumi linear shaft but got the same results with the standard Prusa MK2 rod.

Results:
No pressure:
Standard Prusa Bearings same as Misumi LMU-N8
Misumi LMU-N8 igus RJ4JP same as igus RJZM - quiet

With pressure (simulating zip tie):
Standard Prusa Bearings similar to Misumi LMU-N8
igus RJ4JP - unusable
igus RJZM - quiet

Based on the results I would use igus RJZM for Y-axis ( and X-axis if it fits). I used igus RJ4JP on Y-axis loosely held by zip ties with superglue and it's fine.

Posted : 23/11/2016 5:32 am
Scyanix liked
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

Hi,
thank a lot for the video, I saw that the first 2 are quite loud, the third one seemed to stuck a bit, which on a printer would be worse than noise, but the last one makes a really good impression.
Any other options?
Btw which one of the Igus RJZM was it there are several versions:
https://www.amazon.com/Igus-RJZM-02-08-Standard-Clearance-Bearing/dp/B00QZ7YGFW
https://www.amazon.com/Igus-RJZM-03-08-DryLin-Self-Aligning-Bearing/dp/B00QZ7YJ7C/ref=pd_sbs_328_3?_encoding=UTF8&psc=1&refRID=7XSM4KF24SYACG6EPFG4
https://www.amazon.com/Igus-RJZM-01-08-DryLin-Straight-Bearing/dp/B00QZ7YJ54/ref=pd_sbs_328_4?_encoding=UTF8&psc=1&refRID=RRD4HXQAC9PFTE8VFTQ9

the last one is even 21 USD 😮

Posted : 26/11/2016 3:16 pm
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

Adding Thomas's video for reference he goes a bit more into detail

would be interested in knowing how to align them properly

Posted : 26/11/2016 4:12 pm
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

PS one additional point: s far I'm informed and Prusayo please correct me, the diameter on the bearings of the MkII kit is 15mm, while the Igus RJZM-01-08 outer diameter is 16mm. that is below 10% difference, can you still swap them, as you will do the change pls let us know

Posted : 26/11/2016 4:41 pm
StephanK
(@stephank)
Reputable Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

PS one additional point: s far I'm informed and Prusayo please correct me, the diameter on the bearings of the MkII kit is 15mm, while the Igus RJZM-01-08 outer diameter is 16mm. that is below 10% difference, can you still swap them, as you will do the change pls let us know

That's correct, RJZM-01-08 (or actually RJUM-01-08 as Igus Germany called them) are 16mm outer diameter whereas standard prusa bearings are 15mm. I so far only installed them on the heated bed (y-axis) . The spare zip ties are a bit short, but it's doable. I am using them for about a month now, no problems at all.

Posted : 26/11/2016 5:40 pm
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

ultimately if its 1mm diameter than it will be just a 0.5mm impact, right, the autoleveling shoud handle that, still I would like to get information here from Prusa team if this can be adjusted on SW level with a custom patch, and how deep the programming can mitigate such customization, since on the other hand 0.5 on a print it self is quite a lot.
I will order them, while I'm waiting for my Kit to arrive I saw you installed them on Y axis which seems to be the least problematic for a install, do you think the printed pieces for the other axis would be flexible enough to accept the 1mm biger bearings as well?
I would like to have them for sue on the extruder axis, as I expect there to be the most noise, but that is just guessing...

Posted : 26/11/2016 6:07 pm
prusayo
(@prusayo)
Reputable Member
Topic starter answered:
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

I saw that the first 2 are quite loud, the third one seemed to stuck a bit, which on a printer would be worse than noise, but the last one makes a really good impression.

The third one is stuck only when I applied pressure simulating ziptie. Since I didn't have RJZM-01-08 available I used igus RJ4JP for y-axis but didn't ziptie tightly and used superglue and it's working great:
http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/igus-rj4jp-01-08-misumi-linear-shaft-replacement-f-t2313.html


Any other options?
Btw which one of the Igus RJZM was it there are several versions:
https://www.amazon.com/Igus-RJZM-02-08-Standard-Clearance-Bearing/dp/B00QZ7YGFW
https://www.amazon.com/Igus-RJZM-03-08-DryLin-Self-Aligning-Bearing/dp/B00QZ7YJ7C/ref=pd_sbs_328_3?_encoding=UTF8&psc=1&refRID=7XSM4KF24SYACG6EPFG4
https://www.amazon.com/Igus-RJZM-01-08-DryLin-Straight-Bearing/dp/B00QZ7YJ54/ref=pd_sbs_328_4?_encoding=UTF8&psc=1&refRID=RRD4HXQAC9PFTE8VFTQ9

I ordered a sample of "RJZM-01-08 drylin® R - bearings , closed, standard design" which was sent free (1 only).

Originally my plan was to use the Misumi bearings but while waiting for the order on a whim I decided to order the igus RJ4JP since they were so cheap. Then when I tried it the difference in sound was so big I decided to use the igus in the end. Later I found out about the igus RJZM-01-08 which I will order eventually.

Posted : 26/11/2016 6:55 pm
Scyanix liked
StephanK
(@stephank)
Reputable Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

I will order them, while I'm waiting for my Kit to arrive I saw you installed them on Y axis which seems to be the least problematic for a install, do you think the printed pieces for the other axis would be flexible enough to accept the 1mm biger bearings as well?
I would like to have them for sue on the extruder axis, as I expect there to be the most noise, but that is just guessing...

I don't know, I never tried. Strangely enough, i never had any issues with noise from my extruder x-axis. The bed was horrible, however.
I've read both: some say they fit just fine, others say they had to print the replacement part.

I did put RJ4JP-01-08 on the X-axis just because i had them sitting on my desk as well and no other use for them. Those went in easily enough, but I cant say if that would stretch to 16mm outer diameter as well. In the end, swapping x-axis didn't make much of a difference at all. I guess my stock X bearings and some magna-lube i had left from my other printer were good enough.

If you're ordering from Igus, mabe check out their rods as well: AWMP-08. They aren't terribly expensive even cut to size and that should settle some other argument floating around that Igus dont't like "normal" rods. If nothing else, they look nice being all black 😉

Posted : 26/11/2016 7:16 pm
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

Well just ordering the pieces seems to be a problem here in EU, wrote today directly to Igus, waiting for information on price and availability.
Might in the end do the same you did, since I dont have a printer to print the parts, and once I assemble it I might not find the time for redo. I will thou order more pieces, and should they fit I insert them at least to the extruder, if not I safe them for some time later.

Posted : 26/11/2016 8:32 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

Isn't AWMP-08 Aluminium?

Don't we need something like SWM-08

Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 26/11/2016 9:11 pm
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

btw was looking around on options and the guy here :

as well as here
http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/igus-rj4jp-01-08-misumi-linear-shaft-replacement-f-t2313.html
uses the Igus RJ4JP-01-08
they have the outer diameter 15mm, but are not closed, which they are designed to be in, but looking at the video he don't seems to have issues with them being stuck or not fluid.

Posted : 26/11/2016 10:35 pm
StephanK
(@stephank)
Reputable Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

@David,
When I was talking to Igus they told me with RJ4JP (grey) zip tie mount is acceptable, with RJMP (tan) it isn't.
RJZM being aluminium cased are supposed to be fine as well.

That's why I ended up ordering 3x RJ4P and 3x RJZM
(... and a couple of Misumi LMU-8 just to see which ones i like most. )

@Joan,
With respect to the rods, yes AWMP-08 is anodized aluminium. Do we need (stainless) steel rods? I don't know. Igus website calls AWMP "ideal for Igildur J/Igildur 200" based linear bearings, RJZM is using Igildur J and since they weren't terribly expensive, i ordered them and stuck them in there.

I guess i'll find out in a couple of months if they hold up or if i am starting to have issues.

Posted : 27/11/2016 8:57 am
daniel.l9
(@daniel-l9)
Eminent Member
Re: Standard Prusa Bearings vs Misumi LMU-N8 vs igus RJ4JP vs igus RJZM

I was checking the comments section on Thomas's channel and he says there on the standard bearings:"Thomas Sanladererpřed 5 monts ago
As soon as you add lubrication, the material of the mates mostly stops mattering. My desktop milling machine uses cast iron slides and the run beautifully since they are packed with the heaviest grease i could find. The original Prusa Mendel even used printed PLA bushings - which, at the time, were considered good enough when oiled."
any one added grease, I saw him in another video adding it and it was quite a lot he used, can any one tell who tried as well?

Posted : 27/11/2016 11:49 pm
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