Looking a replacing the LM8UU's on my i3 X & Y axis as I

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(The Hozza) #1

Looking a replacing the LM8UU’s on my i3 X & Y axis as I want something that is quieter during travel, I’ve found these and considering giving them a try.

Igus Drylin RJ4JP-01-08

Before I purchase them can anyone offer an alternative? or I reason why I shouldn’t try these?

http://www.igus.eu/wpck/12157/Motek14_N14_6_3_Vollkunststofflager?L=en

(Keith Applegarth) #2

How does the cost compare with the LM8UU?

(The Hozza) #3

About 4 times the price here in the UK

(Step Cia) #4

Was just browing alternative to bring the noise down this morning. Thought Id share what I found. http://www.mcmaster.com/#standard-linear-bearings/=xvsfhn

(Niclas Öberg) #5

I printed some from thingiverse. No rattle and great fit.

(Steve Wood (Gyrobot)) #6

I agree with @Dave_Benson ​, the plastic bushes are made to be press fitted into correctly toleranced holes otherwise they will be loose. I use the rigid sleeve versions too.

(The Hozza) #7

@Steve_Wood_Gyrobot
Well it does state in the literature for the RJ4JP for use with 3D printers, but wouldn’t be able to tell what fit would be like until I have them.

The other option I have considered and a cheaper one is this http://www.thingiverse.com/thing:878675

(Øystein Krog) #8

I rewrote my Prusa i3 to use the bronze bushings with graphite inlays (from robotdigg) and it’s been working well.
You have to take a lot of care with alignment to avoid binding, and event now it is far from as smooth as ball bearings, but it is very silent.
In combination with TMC2100 stepper drivers, the only noticable noise is from my PSU fan.

(matthew bennett) #9

I’ve been a fan of oiled pla bushings for years. But now my Series 1 can simply print IGUS 170 and 180, I need to try printed IGUS lm8uus.

(Joe Spanier) #10

Remember that these bearings must be pressed into a housing of the specified diameter to be the correct size. They will be oversize if you just zip tie them on like most of the prusas have you do.

(dstevens lv) #11

@Joe_Spanier That particular part is meant to be a direct replacement for an LM8UU.

(Michael Scholtz) #12

I just posted one on thingyverse and youmagine look for lm8uu. I printed them as place holders for ball bearing till i got some. But they seem to work quite well.


https://www.youmagine.com/designs/lm8uu-bearing-bush

(The Hozza) #13

Right I tried these on my i3 X & Y axis, they are terrible just way too loose on the rods, print quality dropped so have gone back to good old LM8UU…

(Joe Spanier) #14

That’s because they have to be press fit

(The Hozza) #15

These one’s don’t

(Øystein Krog) #16

I use these now (the RJ4JP) and for me they work really well, I still use TMC2100 stepper drivers and my machine is now extremely silent. I have to work on reducing fan noise now as it is by far the biggest source of noise.
One thing to note is that smooth rods can vary a bit in size/fit type, so that might be why it is loose for you? Try to measure your rods with a micrometer and see if they match the IGUS specs, maybe they are too small.

(The Hozza) #17

@Oystein_Krog
They are indeed too small IGUS however do rod to match, I have already emailed asking a price.

(Michael Scholtz) #18

I found some extended lm8uu bearings that are 45mm long. So I use 1 bearing instead of 2 of the 25mm ones and it’s very nice with 2 bearings I’ve had to always be carefull with not clamping to tight as they seem to misalign the long one it’s not a problem

(Øystein Krog) #19

@Michael_Scholtz The “long” LM8UU is actually called LM8LUU, and indeed I think it will be better to use one long ball bearing rather than 2, I’ve seen some bots do this.