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  1. #1
    Join Date
    Jul 2019
    Posts
    24

    Linear Bearing Worn Out?

    I noticed I had been getting some weird finishes and a bit of play when pushing/pulling on my spindle ~0.1mm.

    Disassembling the machine, the cars on the x and y axis had less preload compared to the z axis and would slide down the rail when held vertically.

    So I decided to pull some cars apart and measure the balls..

    measuring approx 20 balls
    z axis car - balls were 3.974mm maybe a couple 3.973mm
    x axis car - 3.967mm-3.972mm (mostly closer to 3.970mm)
    y axis car - 3.959mm-3.970mm (average 3.965mm)

    I have attached some photos on inside one of the y axis bearings, there seems to be some wear. looking at an x axis block only one of the bearing rows inside the block has some wear all the others are very shiny. The balls in both the x and y seem to be dull compared to the z axis.

    The bearings were purchased from AliExpress which claim they are genuine but for the price...

    Has anyone seen this before?

    I'm guessing this is cause by misalignment maybe some dirt/chips in it? Should I throw them in the bin?

    Unfortunately I've been burned pretty bad by everything I've bought from AliExpress (ball screws off centre, replacement ball screws bent, BK/BF bearings failing, faulty spindle etc..) I guess you pay for what you get.

    Ritzy

    Attachment 453606
    Attachment 453608
    Attachment 453610

  2. #2
    Join Date
    Jul 2019
    Posts
    24

    Re: Linear Bearing Worn Out?

    Anyone?? What am I doing wrong???...

  3. #3
    Join Date
    Jan 2005
    Posts
    15362

    Re: Linear Bearing Worn Out?

    Quote Originally Posted by Ritzy321 View Post
    Anyone?? What am I doing wrong???...
    Bad linear rail alignment and surface mounting will wear everything out quite quickly

    Linear Rails have to be precisely mounted and have very tight tolerances especially if they are preloaded
    Mactec54

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