Nigel
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Re: Replacement bearings recommendation

Sat Jan 21, 2017 3:15 am

Kiss works well with the zip ties. I can vouch for that, Across the MK1 and MK2 builds. Bearings will wear, I would replace with the same. They are cheap and work well and in my experience last as long as you lubricate them every 6 months or so.:)
Nigel

A follower of the open source Prusa I3

torsten.c
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Re: Replacement bearings recommendation

Sat Jan 21, 2017 10:51 am

Ancientwolf wrote:I must have got lucky- I picked up both the RJZM-02-08 and the companion rods IGUS carries for them and cannot detect any slop at all. Perhaps thats the key. Dont do it half way.
I also have the rods from igus and there definitely is slop - but (also according to the rep) there must be some slop by design. So I am not sure what's up with your bearings and rods :)

torsten.c
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Re: Replacement bearings recommendation

Sat Jan 21, 2017 10:52 am

Nigel wrote:Kiss works well with the zip ties. I can vouch for that, Across the MK1 and MK2 builds. Bearings will wear, I would replace with the same. They are cheap and work well and in my experience last as long as you lubricate them every 6 months or so.:)
You mean the original bearing that come with it?
Sure they work, but I guess we are all hear to reduce the noise.

ceryen.t
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Re: Replacement bearings recommendation

Sat Jan 21, 2017 8:22 pm

Ancientwolf wrote:I must have got lucky- I picked up both the RJZM-02-08 and the companion rods IGUS carries for them and cannot detect any slop at all. Perhaps thats the key. Dont do it half way.
With calipers, I can confirm that the ID of my bearings are 8.07, which is the 70 microns allowed by the specs. The specs do allow for manufacturing variations in the bearings, so it's possible that you received bearings with tighter tolerances due to manufacturing variations.

With your bearings, can you wiggle them at all when they're on rods? For comparison, my Misumi bearings do not wiggle at all when put on Misumi rods.

patrizio.b
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Re: Replacement bearings recommendation

Sun Jan 22, 2017 9:04 am

From the specs, it seems that the all-Igus solution (RJZM-x-08 / AWMP-08) fit is about D9/h8, a free running clearance fit (there is slop). The all-Misumi solution is about K6/g6, an interference fit (there is no slop). This is confirmed by experience reports. I think that they should be both valid fits for their materials and applications, since they're manufactured from top notch companies. Probably the Misumi solution is better overall, if you don't consider the noise reduction of the Igus solution. Since there are no clear reports of quality difference, I would simply say to go Misumi if you don't mind the noise, and Igus otherwise. They are both decent upgrades to stock bearings - and neither will solve the problems of a cheap zip-tie based printer assembly.

http://www.misumi-europe.com/en/catalog ... F04_EN.pdf
http://theoreticalmachinist.com/IsoTolZoneCalc
http://www.amesweb.info/FitTolerance/FitTolerance.aspx

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Ancientwolf
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Re: Replacement bearings recommendation

Sun Jan 22, 2017 6:53 pm

ceryen.t wrote:
Ancientwolf wrote:I must have got lucky- I picked up both the RJZM-02-08 and the companion rods IGUS carries for them and cannot detect any slop at all. Perhaps thats the key. Dont do it half way.
With calipers, I can confirm that the ID of my bearings are 8.07, which is the 70 microns allowed by the specs. The specs do allow for manufacturing variations in the bearings, so it's possible that you received bearings with tighter tolerances due to manufacturing variations.

With your bearings, can you wiggle them at all when they're on rods? For comparison, my Misumi bearings do not wiggle at all when put on Misumi rods.
I can also confirm the ID of the batch I got is averaging 8.015 to 8.022+- 0.010, except for the last 2 of 8 that are closer to 8.036 and 8.042. There is a small amount in the last two thats noticeable. I'm not complaining since it was just the Y carriage I was working with.

Nigel
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Re: Replacement bearings recommendation

Mon Jan 23, 2017 1:47 am

@torsten.c I get very little noise. I always print in quiet mode. No issues with prints. From day one. Just my kit build experience.
Nigel

A follower of the open source Prusa I3

ceryen.t
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Re: Replacement bearings recommendation

Mon Jan 23, 2017 11:57 pm

ceryen.t wrote:EDIT2: I note that the RJ4JP-01-08 bearings might actually have a tighter tolerance than the RJZM-02-08 bearings according to the specs. The RJ4JP-01-08 bearings supposedly allow up to 40 microns of slop, while RJZM-02-08 bearings allow up to 70 microns of slop.
I received an RJ4JP-01-08 bearing today. With calipers, I can see that the ID for the RJ4JP-01-08 bearing is 8.04mm, while the ID for my RJZM-01-08 bearings is 8.07mm. Both measurements agree with the specifications laid out on the IGUS website.

When placed on rods, the RJ4JP-01-08 bearing wiggles significantly less than my RJZM-01-08 bearings (though there is a non-zero amount of wiggle).

So in my experience, the RJ4JP-01-08 bearing does have a tighter tolerance than the RJZM-01-08/RJZM-02-08 bearings.

dustin.s
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Re: Replacement bearings recommendation

Tue Jan 24, 2017 6:16 pm

I finished assembling my printer today. I used the stock bearings, and luckily it is very quiet. I also have a Lulzbot Taz 5 and the Prusa is much quieter than it. I think I will hold off on any kind of bearing upgrades.

julien.k
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Re: Replacement bearings recommendation

Tue Jan 31, 2017 9:13 pm

I'm using RJ4JP on my kit (ordered the bushings before receiving the kit, so I did not used the default ones at all), so far it's working well, the noise is now coming from the fan and the steppers. Tolerances look quite good as well.

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