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Y Axis Bearing Alternative

Discussion in 'Mods and Upgrades' started by WheresWaldo, Nov 28, 2015.

  1. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    At least with Prime if they don't work they eat getting it back (but you loose the time).
     
  2. tonycstech

    tonycstech Active Member

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  3. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    Cheap is okay but they only have 4 in stock and usually the stock is ZERO. Doesn't matter what the price is if they never have any. That is why I never suggest SDP/SI.
     
  4. tonycstech

    tonycstech Active Member

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  5. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    If you print the holders listed at the beginning they just press in, otherwise you have to drill out the existing bearing holders a bit bigger, since these are 15.9 mm O.D. and not 15 mm O.D.
     
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  6. tonycstech

    tonycstech Active Member

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    Thats interesting since i am looking at the official ROBO3D R1 STL files and they seem to be exactly 16mm in diameter.
    Yet the actual carriage i have does measures 15mm.

    I must be missing something.
     
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Not sure which STLs you are looking at, but ... The STL files on thingiverse are old. From the Beta machine actually, not even the R1 so ... it is possible the actual hardware now differs from what they did for kickstarter in 2013 :)
     
  8. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    The bearings on the OEM block do not extend all the way to the outside of the block, there is a lip on both sides. That is why the openings are only 15 mm. Just print the ones outlines and your good to go. Make sure you use something that can hold up to a bit of heat since the bed heater is so close.

    Do not overthink the upgrade, it is completely outlined in the first few posts in this thread.
     
  9. tonycstech

    tonycstech Active Member

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    I dont like to modify the stock injection molded carriage (any more then i already have) to get those bearings in, so i guess my last question is (on the bearing subject): Have you tried or know anyone who has igus bearings ? Are they worth the price ?
    Clearly stock LM8UU's are crap and will wear out your rods long before any plastic will (or bronze since it is also softer).
     
  10. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    IGUS work, they are a clean no lube bearing, just a bit of stiction that has to be overcome by initial moves. But in reality if you have a Beta, you might as well do everything you can to bring it up current. It is not like the Beta has any more intrinsic value than any of the other R1's, probably less since it really needs upgrades to bring current. Ask @mark tomlinson about using the beta, I still think he has one in 'beta' condition.
     
  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Well, it is about 50% beta still :) All of it has been modded except of the ancient bed and drawer slides (because [1] they still work and [2] I'm busy with other stuff)

    If you ever get to the point the rods are worn enough to matter you have a lot of disassembly work to do and you may as well upgrade all of the bits you can.
     
  12. Wesley Knapp

    Wesley Knapp Member

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    I got the bushings in the mail yesterday and installed them last night. I had previously printed the blocks. All went well until I tried to move the bed. The last couple of inches at either end bind up. Since nothing ever gets printed that far out no big deal except that the limit switch can't be reached. I've tried about everything to get it going smoothly to no avail. I can't tell which direction the blocks need to move in order to resolve this. I don't have any screws tightened down but as we all know that have done this there is virtually no movement allowed by the 8 screws even without nuts on them. I didn't want to do the break-in until this was resolved because it's not just a smooth/break--in issue.
    Any help greatly appreciated.[​IMG]

    Sent via PixelXL3 using Tapatalk.
     
  13. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    I think I would start with trying the bearings on the rods without the blocks.
    1) see if they free slide all the way both directions. This will eliminate a bad/misaligned bearing

    if that works as expected:

    2) with the bearing block open (uncovered) try sliding each one full stop end-to-end. This will make sure the bearings are properly aligned in the block

    adjust as needed to get #2 working.
     
  14. Wesley Knapp

    Wesley Knapp Member

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    I did slide the rods through and through the blocks with no binding issues. Maybe you missed it... These are sintered bushings not bearings and the blocks are solid with the bushings pressed in.

    Sent via PixelXL3 using Tapatalk.
     
  15. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Well, if the rods move through the bearings and not through the blocks w/bearings installed -- something is misaligned.
    I can imagine that the blocks are... they may expect a certain amount of play in the bearings (which is silly, but you never know what tolerances they were designed for) -- someone who has switched from LM8UU bearings may be able to assist.
     
  16. Wesley Knapp

    Wesley Knapp Member

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    I just measured the distance between the rods at the bearing blocks and at the rod end with the bed carriage in place and there is a .9mm difference in the width. It's wider at the block. So as the ends get closer to the blocks it tries to spread the ends causing binding. Not sure what to do. Maybe drill the screws holes through the block slightly (very slightly) so that there is some adjustable movement until secured.

    Sent via PixelXL3 using Tapatalk.
     
  17. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    If you make the screw holes bigger in the blocks you can move them a bit, another thing to do is make sure the bearings are broken in with the rails you plan on using. You can do this out of the printer, insert one end of the rod in a drill and as the drill spins move the bearing bracket back and forth to help the bearings 'break-in'. These particular bearings are very tolerant of off axis placement as the bronze bearing 'floats' within its housing. If the rods at the end are spread then since that is the fixed end it actually means they are compressed in the middle. Those two steps should get everything seated properly so you get full travel with little to no resistance.
     
  18. tonycstech

    tonycstech Active Member

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    Yep.
    Problem is where those blocks mount.
    Either make holes bigger or move the holes in a 3d modeling program and re-print.
    I suggest to take a small round file and not make the hole bigger but file toward the direction you need on the platform, not on the printed part.
     
  19. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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  20. tonycstech

    tonycstech Active Member

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    That uses different bearing.
     

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