Fork Width and Acceleration

Discussion in 'General Slingshot Discussions' started by EyAlter, Nov 25, 2013.

  1. EyAlter

    EyAlter New Member

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    Did anybody ever experiment with different fork widths? I thought that a very wide fork (30cm) would accelerate the ball more than a normal fork because of the direction of the vectors, but I can't work it out. Any thoughts?
     
  2. dolomite

    dolomite Banned

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    I'd think just the opposite, that a straighter pull would retract more efficiently, thats just a gut feeling though.
     

  3. Tremoside

    Tremoside SINdustrial designer

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    Bill Hays and Gamkeeper John made a few videos of this topic. Measured with Chrony. As far as I can remember results were opposites but in this case I'm with Bill Hays. I'm not sure a 30cm with is still good but worth a try. Maybe Jörg made a comparison too, but not sure he tested those in the aspect of speed.

    Bill
    [ame]http://www.youtube.com/watch?v=2Q1uDfuJzaU[/ame]

    John
    [ame]http://www.youtube.com/watch?v=4Yg9RjauzY0[/ame]

    Have a nice day/night,
    Tremo
     
  4. coyote-1

    coyote-1 Member

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    From a sheer physical perspective, all environmental variables being equal the rubber will contract at the same rate regardless of vector. So one thing that might occur with a wider fork is the rubber gets a stretch of an extra centimeter - and that ought result in slightly higher speed. Another thing that might occur with wider forks is less interference from the rubber, less of stuff bunching up. This ought improve both speed and accuracy.

    EDIT: Just watched the vids. Critique of the first: The rubber might have bnne warming up, and therefore the first shots would be slower while you'd see subsequent improvement with nearly every shot. Critique of the second: The wide forks are ridiculously wide, thereby lending instability and possibly slowing things down. In addition, no two shots from a human stretching rubber will be identical.

    So those vids are utterly inconclusive. lol
    The correct technique would be to put the slingshot in a vise. Take perhaps three warm-up shots, then take three 'record' shots all from the same exact drawback point (say, one meter). Take that same rubber, let it cool down as you put it on the next slingshot. Then the same sequence: three warmups, three official shots. And on to the next.
     
    Last edited: Nov 25, 2013
  5. EyAlter

    EyAlter New Member

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    Well the guy in the second video uses the same bands.

    How much rubber would give you the highest velocity for a a 10mm steel ball? Lets say 20cm and 3cm wide. If you gave it 20cm and 4cm wide it wouldn't make it faster because the rubber simply has reached it maximum speed. But if you made the fork really wide now it might actually be faster than the original 20cm with 3cm width.
    (the dimension are just examples)
     
  6. kohlqez

    kohlqez Accident-Prone

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    Interesting topic... I don't think that the width would effect accuracy nearly as much as the symmetry of the fork tips but I could be wrong.
     
  7. JohnKrakatoa

    JohnKrakatoa Loudest boom on Earth

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    Three is a really really really low number of repetitions to consider the result conclusive at all..
     
  8. Obl1v1Aus

    Obl1v1Aus Meh!

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    other than give a wider base for a really extreme bands, I can't see any real benefit for wider tips.
     
    Last edited: Nov 25, 2013
  9. Ravensbull

    Ravensbull New Member

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    I by no means am an expert on anything but i have shot the same exact bands first on a small shooter with a one inch fork gap and then installed that same set on a frame with a two and a half inch gap back-to-back while screwing around and the one inch gap seems to feel and look noticably faster. No chrony here though...
     
  10. Arturo Borquez

    Arturo Borquez Administrator

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    from 2" to 4" wide the difference is meaningless, at same stored energy narrow forks are theoretically a small bit faster ... in real ss world NO DIFFERENCE ...
    Cheers
    Arturo
     
  11. EyAlter

    EyAlter New Member

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    But can you not use much stronger rubber if you have a wide fork than you would use with a narrow fork?
     
  12. coyote-1

    coyote-1 Member

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    The strength of rubber you can use is dependent on the overall structural integrity of your slingshot. The wider it is, the stronger it has to be in order to support the pull of the rubber.