Bearing concerns - missing 688ZZ and tiny ball bearing in box

Discussion in 'Build Help' started by Alex Stevenson, Mar 19, 2016.

  1. Alex Stevenson

    Alex Stevenson Well-Known Member

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    I'm working my way through the page:
    http://wiki.e3d-online.com/wiki/BigBox_Parts_Preparation#Single_.26_Dual_Extruder_Filament_Idlers

    I've got to the point in the sub-assembly of the spool carrier clamp, and realise that I don't have any of the 688ZZ bearings left (I used the two I had on the y-axis rear brackets).

    I also have nine of the 634Z bearings left and there's no mention of them on this first page.

    More worryingly, I also just noticed that there's a tiny ball bearing (about 1mm in diameter) that was stuck to the outside of one of the LM8LUU bearings. I have no idea where it's come from, but I'm worried that it's come out of one of those bearings, and in which case, could any / all of them be damaged?

    * Could anyone please advise what I should do regarding the ball bearing - am I right to be concerned?
    * Did anyone else have any missing bearings from their kit?
    * Will the nine remaining 634Z bearings be used on subsequent pages?

    Just another note, regarding the manual - it's really hard to check part numbers as the parts' text is in images so I just can't search the contents of the page. Also, I've been reviewing Shao's post on their construction, as it clearly labels the bearings - I would have had no idea how to tell them apart without it.

    Incidentally, I'm attaching images of build progress so far (sorry, they are not in order):

    IMG_20160312_223321.jpg IMG_20160312_181722(1).jpg IMG_20160312_184245.jpg IMG_20160312_195726.jpg IMG_20160310_212129.jpg IMG_20160313_094142.jpg IMG_20160319_173148.jpg IMG_20160313_112706.jpg IMG_20160319_170858.jpg IMG_20160313_171326.jpg
     
  2. Trevor

    Trevor Well-Known Member

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    Just simply slide the linear bearings through the rods and you will be able to tell which are good or not.
     
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  3. Henry feldman

    Henry feldman Well-Known Member

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    Many of us had failed linear bearings (I just bought some third party ones from ServoCity rather than wait for international fedex (bought a bunch of spares, since they seem "tweaky"). There were multiple containers of the other bearings (some were in a bag in the motion box and some were in a plastic tube). Look around. I thought I was missing one, and it was in yet another bag...
     
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  4. Alex Stevenson

    Alex Stevenson Well-Known Member

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    Thanks both.

    I tried sliding the bearings along the rods, and they _seem_ okay. I'm not entirely convinced that if there's a missing bearing from inside one of them, that it will remain stable, but at least they seem like they should work, I guess...

    I've checked through the bags a few times and not yet found the missing bearing, but I'll keep checking through until team BB start work again next week.
     
  5. Trevor

    Trevor Well-Known Member

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    If they slide ok without rattles, scratches, or seize, they should be ok. Just the nature of cheap linear bearings. One loose bearing out of the dozens that are in there won't compromise anything. They'll never be perfect. Like Henry said, you can always buy a bunch as spares.
     
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  6. Greg Harker

    Greg Harker Member

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    I am building the dual and I am also missing the 688ZZ bearings and I have the sleeve of 634Z. on the plus side the bearings I have seem to be in good shape. I noticed it at the same stage you did.
     
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  7. Alex9779

    Alex9779 Moderator
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    I remember having issue finding them too. I had a stack of 634ZZ in the extruder box while the 688ZZ were in another box. Can't remember exactly...
     
  8. Pierce

    Pierce Well-Known Member

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    Building a dual had same issue, check your extruder box for a white looking semi transparent tube it contains the ten bearings your are looking for which covers the rear spool holders as well. The extruder box is packed full so you might need to take everything out to find it :) I employed the option of asking someone else to check all the boxes for missing parts in case I was being stupid... I was for bearings, but was still missing a few bolts and a gear.
     
  9. Old_Tafr

    Old_Tafr Well-Known Member

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    I too found a tube full of bearings in either the stretch or extruder box. Looking through every single box of bits before starting, just like reading through all the steps before building a specific part is good practice. Time spent on this is then saved during the build.
     
  10. Alex Stevenson

    Alex Stevenson Well-Known Member

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    It's great that you guys found yours, but it's not in any tube, and certainly not in the extruder or stretch boxes (incidentally, I got the Pro rather than the dual).

    I agree it's good practive to sort through everything and organise before starting, which is precisely what I did. I rebagged the corrected parts bags from the stretch box (which are now in numbered sections of an organiser box, separated by type), and a few of the parts used so far were indeed in the extruder box (as described in the diagrams in the manual).

    However, I've checked several times now, and no sign of the bearing anywhere.
     
  11. cez

    cez Well-Known Member

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    The 688ZZ bearing listed in drawing number 37 (17) Spool Carrier Clamp is an error, it should be a 634ZZ, you only need two 688ZZ bearings for the rear 532mm bar.
     
    #11 cez, Jul 12, 2016
    Last edited: Jul 13, 2016
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  12. kevclarx

    kevclarx Active Member

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    I've read that it is helpful to lube them up with a little white lithium grease as well. I just bought a handful of extra linear bearings when one of my LM8UU's exploded little ball bearings all over the room as I was sliding it on the rod.
     
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