Support bearing for Z axis threaded rod?



  • Hi all!

    So there is my question: I have 2 12mm rods for small steel heavy platform with LM12 bearings, stepper with integrated z rod, delrin anti-backlash nut. Do I need to support that rod at the top? (Stepper is mounted at the bottom) Or if I won't support it - I will get less probability of Z banding ?

    Thanks!



  • You should not restrict the leadscrew axially in both ends, ideally tou should leave it floating. I had problems with vibrations, so i added a 628 bearing for radial support, but the leadscrew is still floating axially.



  • @lhelge Thanks! But what to do with bottom part as my screw is integrated with stepper?



  • @briskspirit Not what you want to hear but any chance you could get those screws changed? The trouble is, lead screws with motors attached are primarily for driving in the X or Y directions. Using them for the Z axis means that the stepper motor bearings have to take the full downward load, not only of the screw, but also bed which you said was a heavy steel platform. Stepper motor bearings aren't usually designed to take this sort of end load on the shaft.



  • @deckingman This is the only problem with the bearings? It is FFCP clone and I am at the middle of nowhere...(It is disassembled for upgrade process with Duet, 16T gears, 8x2T rod and etc...) Right now I need to assemble it(without problems as z-banding and etc) to print some parts ))) It is a loop )))


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