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Thread: linear bearing orientation

  1. #1
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    linear bearing orientation

    Is there any advantage in the way that linear bearings are mounted.

    I am useing thk2r20 for my y axis and would like to know if it would be better to mount them on the top and the bottom of the axis of on the front.

    It seems to me that if they are mounted at the top and the bottom that you are then supported by the balls on each side of the bearng. Where as if you mount them on the front of the axis you are only running on the top set of balls.

    still trying to finalize my design.

    tks
    Daniel


  2. #2
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    Have you tried the THK applications engineering dept??? That's where I'd be inclined to start my search. Simply call, ask for tech assistance, explain your application and 90% of the time the folks will gladly help....

    As a former bearing applications engineer, I've seen many a case where sage wisdom wasn't necessarily the optimum way to do something as compared to the factory engineered system.

    What would amaze me though is that someone would call, you'd explain, then they'd start to argue with you. At that point, I'd try to find a way to say, "go ahead and do it anyway you want but DON"T call us when it screws up...".

    Some would listen and some would hang up in a huff. Never knew (or cared) if they got it to work but occasionaly a guy would call back and say "you were right, thanks". Those were the people you were glad to hear from and they usually made great, cooperative customers afterwards....

    Sorry but my experience base doesn't include linear bearings...
    Last edited by NC Cams; 01-18-2006 at 07:27 PM. Reason: forgot something


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    daniel you are thinking 2-dimensionally as if only forces that will ever load your axis are up-down. What about forward-backward or left-right?

    In your example, if you mounted them to the side you are right, only top row of balls would be under load - WHEN the machine isn't doing anything. But when it digs into the material then the bottom row gets to work! In fact it is this bottom row that's most important as the top row only ever experiences the weight of the spindle and the axis it is carrying whereas the bottom row has to support the axis while it digs into the material.


  4. #4
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    Thanks for the info. I have done more digging and I think that i will be mounting them on the front of the y axis.


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