tube and rod rotation clearance

Discussion in 'Design and Modeling' started by TOM_TOM_TOM, Sep 26, 2011.

  1. TOM_TOM_TOM
    TOM_TOM_TOM Well-Known Member
    Hello,
    i have a design with 2 separate parts that need to rotate freely one inside the other, like a rod and tube, on black strong flexible. I was wondering what is the clearance to allow for this? I can't have too much play, it needs to be tight but rotate without much resistance. I was thinking something like 0.15mm all around? or would i need more?
    Thanks
     
  2. stop4stuff
    stop4stuff Well-Known Member
    If the moving part is to be printed in situ, you're going to be looking at 0.7-0.9mm gap, but using a few design technoqies you can bring the gap down to 0.5mm, more info here; http://www.shapeways.com/tutorials/designing_mechanical_part s_3d_printing_the_whoosh

    However, if the parts are to be printed seperately 0.1mm all round gap would allow for print tolerances, but if you're willing to do some post production work, you can make it 0mm and adjust as needed with tools.

     
  3. TOM_TOM_TOM
    TOM_TOM_TOM Well-Known Member
    These are 2 separately printed parts. I've just submitted a job with 0.2mm, but I'll try 0.1mm next time. thanks
     
  4. TOM_TOM_TOM
    TOM_TOM_TOM Well-Known Member
    I just got my parts which are seperate with 0.2mm clearance.

    In will insert but not turn. There are parallel edges, 90 degree corners, and 270 degree corners. There was enough clearance for the parallel edges and 270 degree corners and probably 0.15mm would have been enough, but the 90 degree corners seem to be expanded, and I might need 0.3mm.

    I had to shave the inside corners to get it to rotate but there's still a lot of friction. IMAG0437.jpg