need help choosing material

Discussion in 'My Work In Progress' started by pdb, Apr 10, 2012.

  1. pdb
    pdb New Member
    hey guys

    what is the best material for a mount for a phone. it has multiple parts. joints that allow 360 rotation. and will eventually be adapted to fit generic tripods

    ideally it must be very rigid and strong (i dont want the phone bouncing around every where when you take a picture). im thinking alumide but am worried at the brittle-ness of it.

    the example is 1.5mm dia. over 20mm length will most likely break

    i plan to use rods with diameters of 4.1mm ..... is it still as brittle at these tolerances ?

    i know the image might be a bit confusing but its only to show the basic structure .......i need to decide on a material before i can work out the mechanics.

    and what gap you have to leave between moveable parts?
    i can seem to find it anywhere? even on the materials page


  2. bradykineticcuriosities
    bradykineticcuriosities Well-Known Member
    Hey pdb,

    I'm also working on something with moving parts - I haven't seen any spec on movable parts for WSF or Aluminide, but I plan on shooting for a .2 mm clearance on the radius for my first test piece in aluminide.

    As for the brittleness, it might be best to do a small test print and see what it can withstand - this is what I plan on doing for my smallest parts (3.8mm thickness).

    Couple of points on your good looking model. Your "cross" mount is basically two unsupported wires - it might be stronger if you put webbing between them, like a swiss cheese I-beam, thicker where the cross meets... :p

    Gussets on the sides wouldn't hurt - these don't have to be big.

    I've got other thoughts, but you have a great concept there!
    Will you be driving the gears with anything?

  3. stop4stuff
    stop4stuff Well-Known Member
    Before you go with 0.2mm clearance, check out the Tutorials (linked to down at the bottom of every page), in particular, look at Material Design Rules and Advanced: Designing mechanical parts, part I, Advanced: Designing mechanical parts, part II as well as Advanced: Design rules & Accuracy, part III

    There's some good info :rolleyes:
  4. bradykineticcuriosities
    bradykineticcuriosities Well-Known Member
    This was perfect - the point about using "bumps" to maintain a tight fit but still allow for clearance was inspired.