Ball and socket help for character

Discussion in 'My Work In Progress' started by MikkelSandbag, Apr 14, 2013.

  1. MikkelSandbag
    MikkelSandbag New Member
    I am trying to do something similar to what wolfv is doing with their "friction ball and socket clamp." The main issue I'm running into so far is that I'm not sure how much space to leave on the socket part of the device. I guess what I'm asking is how much room does one need to leave between moving parts? Does the material expand/contract during or after the printing process? I've included a screenshot of what I have so far; hopefully it is clear what is going on. Thanks!
     

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  2. UniverseBecoming
    UniverseBecoming Well-Known Member
    What material would you like to print in?
     
  3. MikkelSandbag
    MikkelSandbag New Member
    Either the full color sandstone or the strong and flexible plastic. I just need something cheap.
     
  4. UniverseBecoming
    UniverseBecoming Well-Known Member
    I haven't done it before, others that have will post their experiences if one of them happen to stop by the forum and see your thread. I do know that you basically need zero clearance so it cannot be printed in situ without being extremely loose. The minimum in situ clearance for strong and flexible 0.5 mm and for full color sandstone it's 0.9 mm so those clearances would be way outside the range.

    If it were my design challenge and I were doing a design for CNC I would go with 0.0254 mm and use a snap in design. The materials are designed to come out of the printing machines to be as close as possible to real world measurements, however they do not have this kind of accuracy for the two materials you are interested in. Consequently, I would go with a clearance of zero and if needed the ball could be sanded if the joint ended up being too stiff.

    For easy snapping in of the ball I would design in 3 or 4 slots on the ball, think collect chuck, so the ball could flex and become smaller during the snapping in procedure. The sand stone material is not very flexible at all, but you might get away with this small amount of flex without it cracking.

    Are you doing an action figure?



     
  5. MikkelSandbag
    MikkelSandbag New Member
    Wow, that's really helpful! It's not an action figure per say, it is a little robot guy that I was hoping to give his shoulder joint the ability to move a little, just for fun. I just wasn't sure how much room to make when modeling it, but it seems that it is best to not make a whole lot of room between the ball and the socket but just to have them pretty much be on top of each other, if I understand what you are saying.
     
  6. AmLachDesigns
    AmLachDesigns Well-Known Member
    If you want to do a 'snap-in' design, then I think that rules out FCS (sandstone). I have not used it myself, but it seems that it is rigid and brittle - i.e. more of a 'snap-oh dear!' design.

    I would use strong and flexible for sure. For in-situ printing of the joints (or other mechanical parts) in wsf they recommend a min clearance of 0.6mm. Also be aware that if you print these joints there may be powder residue in them that you will have to 'work out' before they operate correctly. Here is a page that may be useful designing mechanical parts for 3d printing there are more tutorials here tutorials. Of course if you go for polished wsf the interior surface of the joints will not be polished!

    You can also search the forums (use the link at the top of this page not the general (and useless) SW search), as several people have created these type of joints successfully before.

    Good luck
     
  7. MikkelSandbag
    MikkelSandbag New Member
    Thank you. This is all really helpful :)