1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Solved Y axis rods. Binding at one end, or the other.

Discussion in 'Troubleshooting' started by joea, Apr 11, 2020.

Thread Status:
Not open for further replies.
  1. joea

    joea Active Member

    Joined:
    Nov 12, 2019
    Messages:
    351
    Likes Received:
    51
    While investigating apparent Y axis issue, swapped the "teflon bearings" I had installed with some tape around them (to tighten seeming loose fit) with fresh ones with no tape. Turns out, when properly tightened, with all 6 screws installed, there was no "play". to speak of. There were only holes in the bed for 4 screws one at each corner, as mentioned in another post.

    So, I increased the diameter of all the holes to allow a bit of slop, thinking I could let the position "self adjust" while tightening the screws and nuts. Great idea, but seems if I adjust with the bed centered, it is tight at the extreme end of travel. Adjusting with the carriage at one end or the other makes it too tight at the other end.

    While checking the rods for trueness, I found one of them with a rough "streak" along the length. I tried a bit of smoothing but seems the chrome is worn though in on spot.

    Gotta replace that before anything else, so wondering if there are recommended suppliers and/or any "avoid at all cost" suppliers.

    Beyond that, any known issues with end pieces being faulty? These do not look like printed parts, too smooth all around.
     
    #1 joea, Apr 11, 2020
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    You can print the rail arms if you like. I have a printed set that works fine.

    If the bearings get worn they will wear the smooth rods (you will get grooves/mars along the length).
    So ideally you want to replace the bearings before that happens or at least keep them lubricated (lithium grease is my lubricant of choice)

    At any rate you can just buy 8 mm steel rods (chrome coated if you like) to replace them if you want. Cut them to length once you get them if you can't find rods of that matching length

    It is likely the factory rail end arms were injection molded, not printed.
     
    #2 mark tomlinson, Apr 11, 2020
  3. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    It is a closed loop :) If the bearings wear they will wear the rods which then makes the bearings wear worse/faster.
    If you catch it before the rods wear you can just swap bearings otherwise you are going to be swapping the rods too.
     
    #3 mark tomlinson, Apr 11, 2020
  4. joea

    joea Active Member

    Joined:
    Nov 12, 2019
    Messages:
    351
    Likes Received:
    51
    Am I reading too much into your reply? You say "if you want" a few times. Do you doubt those steps will amount to anything?
     
    #4 joea, Apr 11, 2020
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    I am saying there are options.

    Yours probably are not printed, but they can be and if so, they work fine (I have two printed sets myself)

    Clearly you have not, b ut in the future ... you can :)

    Just summarizing that if you do decide to replace them, you do not need to get them from Robo Or partsbuilt.com (feel free to see if partsbuilt has them). You can get 8mm steel rods or 8mm steel, chrome plated rods to replace your existing ones and cut them to size.
     
    #5 mark tomlinson, Apr 11, 2020
  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    The existing rods can be removed from the bearings and rail arms and new ones put in place.
     
    #6 mark tomlinson, Apr 11, 2020
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    One of my original Robo Beta printers from 2013 had the old drawer slide rails and wooden bed. I replaced it with the same rail system on the R1/R1+ -- bought rods, printed the base mounts, added the LM8UU bearings and printed the rail arms. Got the bed and heater from PartsBuilt and it now looks (and works) exactly like the R1+ base
     
    #7 mark tomlinson, Apr 11, 2020
  8. joea

    joea Active Member

    Joined:
    Nov 12, 2019
    Messages:
    351
    Likes Received:
    51
    Waiting to hear from PartsBuilt now on the length of their rods as it is not specified. None of what I have found offered matches what I have now.

    The rods in there now appear to have "factory finished" ends. But I guess there is no guarantee that these were stock items anyway.

    I hesitate to buy longer ones and cut to fit due to concerns about bed the magnet alignment. But I guess I can fudge that a bit by how I position the end pieces.
     
    #8 joea, Apr 12, 2020
  9. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    I have cut my own before and while you will not get the nice polished end, they are buried in the cross-pieces that hides that :) As long as you get a relatively clean cut (with an angle grinder/cutter/whatever) you can make it work.
     
    #9 mark tomlinson, Apr 12, 2020
  10. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    If you really want to do the work you can just make the bed longer :) We did that with one (used a 3 foot long aluminum plate) I did have to swap the Y motor to one with more gearing (the plate was heavier).
    Not saying it was a brilliant idea (we have never really needed an extra long Y axis very much) but it is doable :)
     
    #10 mark tomlinson, Apr 12, 2020
  11. joea

    joea Active Member

    Joined:
    Nov 12, 2019
    Messages:
    351
    Likes Received:
    51
    Just marking this a resolved. I replaced the rods and bearings and all is well.
     
    #11 joea, May 14, 2020
Thread Status:
Not open for further replies.

Share This Page