Multipart Model

Discussion in 'Technologies and Hardware' started by jimmac, Oct 28, 2008.

  1. jimmac
    jimmac New Member
    I haven't even printed my first static model yet, but started wondering how feasible it is to do multi-part object that would be assembled after printing, allowing some motion.

    Would something like the click-on mechanism depicted on the attached image be possible with the default white strong & flexible material? Or should I simply have the joint done by adding some space in the model so the printer would actually print the two parts interconnected?

    The model in question is this robot -- http://www.shapeways.com/model/7817/dister_small_hollow.html
     

    Attached Files:

  2. WetMorgoth
    WetMorgoth New Member
    Either option is quite feasible to do. Use disconnected parts if you want to be able to assemble/disassemble the model at any point. Use the single model with air gaps if you know you never want to pull it apart.

    The nice thing about 3D printing is that it is possible to make shapes that you can't with any other production methods. If you can imagine it, you can print it.
     
  3. Dalhimar
    Dalhimar New Member
    I agree, it depends on what you want to do. If you want it to stay together until you take it apart the clip idea is good, but if you want a bit more permanent solution use the second with slightly varying hole+rod size.
     
  4. jimmac
    jimmac New Member
    Thanks for the answers guys, I'll try to take advantage of the magical 3D printing and do it in one piece :)
     
  5. Xcapee
    Xcapee New Member
    If printing interconnected parts, what is the minimum gap required? Is it the detail level? or finer?

    If I put a rod in a cylinder as a sleeved hinge, I want it tight fitting but free to move. If I stick to gaps of 0.5mm (detail level in WSF) I have 1mm "play" in the hinge. That seems a lot. Wil smaller gaps be fused?

    Anyone had experience with this?
     
  6. WetMorgoth
    WetMorgoth New Member
    Right now I believe our minimum tolerance is 0.1mm. Anything less than that will be fused by our backend processing. At 0.1mm you are at minimum printer resolution - some printing methods cause a rough surface to happen just because of the layered approach to printing. If you have gears and so forth that require a non-binding surface to function, I feel that you'd want to keep gaps above 0.25mm to be safe.
     
  7. Xcapee
    Xcapee New Member
    Thanks - that's a very practical answer :)
     
  8. Whystler
    Whystler New Member
    Sorry for this news ...

    I printed a ball and socket, where the ball had a .5 mm clearance between itself and the socket. In the Strong White and Flexible material, the ball was fused to the socket. It was not fused in the White Detail material.

    See $50 experiment within this topic for more info.

    -Whystler