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Z Axis Ball Bearings  

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jack
 jack
(@jack-15)
Member
Z Axis Ball Bearings

Hello,

I made a mistake when assembling my Prusa XL and accidentally let the Z Axis slide off too much and lost a few of the ball bearings in the rod.

Could anyone tell me what size ball bearings I should buy to drop into the rod to replace them? I was able to recover most of the balls and was able to re-insert them but when comparing it to the other side am still missing a few (and there is at least 1 ball that I am unable to recover).

I hear that Misumi bearings are the best ones to get, if anyone has suggestions on where to purchase them that would also be fantastic. On Misumi's site I mostly see ball bearing assemblies, not just the tiny balls themselves.

Posted : 25/01/2024 2:31 am
j
 j
(@j-5)
New Member
RE:

Did you ever figure this out? I just had 4 come out and I'm not sure how to put them back

This post was modified 4 months ago 2 times by j
Posted : 04/03/2024 4:17 pm
ThreeDeeByRusty
(@threedeebyrusty)
Member
RE: Z Axis Ball Bearings

Same exact problem. Except the only reason my ball bearings were past the limit is because I was trying to straighten out a crooked heat bed. Reason for crooked heat bed was due to the extreme misalignment between bearing bed bracket threaded holes and the heat bed mounting holes. 

Posted : 06/03/2024 1:13 am
Erik D.
(@erik-d-2)
New Member
RE: Z Axis Ball Bearings

@jack-15 @j-7 @threedeebyrusty I did worse, all the ball bearings fell on both sides. I had to remove the bed to show Prusa support the sag and forgot these had to be removed. Did you find out what size bearings they are and how many are on each side? Did you figure out a technique to put them back safely? I am really upset and see no way to re-assemble it correclty.

Posted : 13/03/2024 2:58 pm
Evan Sandler
(@evan-sandler)
Member
RE: Z Axis Ball Bearings

STAND BACK

For the first time in my life, I'm actually going to contribute to the technical forum. I don't know what size ball bearings to use, and I'm still combing through my carpet trying to find the last 3 balls I'm missing, bit I know how to reassemble the bearings. The bearing assembly has two tracks that the balls roll through, one on either side. These tracks are circular loops that the balls actually travel around, which is why they so efficiently propel themselves out of the assembly when the linear rail is removed. The trick I figured out is to use the linear rail to hold most of the balls in place during reassembly.

First, I pressed a few balls into the tracks on both sides of the bearing assembly, then reinserted the rail. Then, I slid the rail forward until just enough of the track was exposed to let a single ball in on either side. I then took a set of tweezers and started packing the remaining balls into either side of the assembly, using the point of the tweezers to push the balls towards the rail, deeper into the ball tracks.

Posted : 16/04/2024 3:44 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Z Axis Ball Bearings

if you are only missing three balls, leave one out of one side of the linear rail truck and two out of the other side, and the bearings should function well. 
they are not highly stressed

regards 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 : 16/04/2024 4:05 pm
JARIAS
(@jarias)
Member
RE: Z Axis Ball Bearings

Any luck with the size/type of the bearing balls? I'll miss like 4.

Posted : 13/05/2024 4:51 am
kenryan
(@kenryan)
Eminent Member
RE: Z Axis Ball Bearings

If you have decent calipers to measure one, McMaster-Carr sells loose bearing balls (look under steel stock).

Posted : 22/06/2024 3:45 am
JARIAS
(@jarias)
Member
RE: Z Axis Ball Bearings

Yup, I need to buy a good caliper and disassemble the block. I'll take a look there. Thanks, man!

Posted : 22/06/2024 4:16 am
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