Proof of Concepts

Discussion in 'Conventional slingshots' started by MountainStorm, Oct 6, 2013.

  1. MountainStorm

    MountainStorm Termite

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    Testing some materials, some construction techniques, some design elements, some ergonomics and of course slinging stuff down range...

    Heat formed cell cast acrylic fused together is my latest fascination. This prototype is testing joint strength, material strength and is looking like a fun shooting frame.

    Too bulky for carrying around, but an easy one for plinking on the front lawn.

    [ame]http://www.youtube.com/watch?v=lF5AMBhr6Io[/ame]

    More to come :)
     
  2. Jeremy

    Jeremy Senior member who totally rocks a pink Scout! Pink

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    Nice. I'd love to see it being shot.
     

  3. MountainStorm

    MountainStorm Termite

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    Did not have a lot of time to video today but my little girl was kind enough to shoot a minute or so of me flicking a few rocks into the woods.

    [ame]http://www.youtube.com/watch?v=VhX9_O-Yjm8[/ame]
     
  4. G_Y

    G_Y aiming the less

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    Very good looking slingshot. Would not use screws in plastic, they could fly into your eye when often used.
    The 45 degree angle of the hand-protector let springback ammo fly over your head, i hope. Joerg does it more unpredictable with his solid wood plate.

    Not shure if solid hand protectors are dangerous for eyes because spring back ammo.

    A few days ago steel ammo sprang back from a tree into my direction, over my head. Good luck. Marbles are same as dangerous.
     
    Last edited: Oct 7, 2013
  5. MountainStorm

    MountainStorm Termite

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    I've got a healthy respect for the pain these sling shots can inflict. I am using the screws to test out the same concerns you mention. You notice I am not holding the slingy up to my face at this time. Slap back from a failed part could be very bad for my modelling career.:p

    Here's the reality. The draw force of the rubber is only a few pounds. I could suspend my 250 pound body from one 8-32 screw that has a 1/2" of thread in a piece of cell cast. Yes there may be a video of me demonstrating that coming to the Slingshot Channel Official Forum :)

    Shear strength is poor on such a small fastener but tensile strength is more than adequate to resist pull out from even the strongest elastic.

    What could cause a failure over time is the wiggle back and forth from the bands going around the forks. That's why through bolting would be better than tapped. However the ability of the plastic to survive stress is still a question in my mind...it's stout, but will it hold up to thousands of flexes?

    Tubular bands are easy to use, but that's about all from what I can tell...I am more interested in flat band slings but I thought I would develop something for tubes as well. This slingy is not in any way shape or form ready for prime time...I just wanted to show you all a test bed and get some feed back.

    The rock deflector would be best if it had a sacrificial cover of leather over the plastic to absorb some of that energy and avoid chipping. I think the angle could be less but this one will not send a shot back at the shooter.

    Expect many changes in the next iteration.

    Thanks for the input.
     
  6. xXdoomXx

    xXdoomXx Junior threadjacker ag. J

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    In my old school I had worked with that. nice :)

    J