Increase the efficiency of your big slingshot! [Inspirational]

Discussion in 'New project ideas' started by BigLou, Sep 18, 2013.

  1. BigLou

    BigLou New Member

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    Hello slingshot builders

    I had some thoughts about a way to increase the efficiency of big slingshots.
    Unfortunately I'm not able to build my idea. So I thought that I share it with you:


    My idea:
    You cut the way of the rubberbands in half that slingshot becomes much easier to handle.
    I imagine with this idea that you are able to build slingshots that have the same strength as slingshots which are as twice as long!

    [​IMG]

    1. is the triggering mechanism

    2. are the rolls which lead the rubber(4) underneath the flying path of the projectile

    3. Hooks which hold the projectile and the rubber on the slingshot.
    Upper hook for holding the projectile
    Lower hook for holding the rubber and being able to stop the pre-pull of the rubber

    4. rubber

    5. two plates which prevent the upper hooks to fly off the rolls.

    It's not finished and not tested. I just wanted to inspire some slingshot crossbow builder. What do you think about this idea?

    Greets
    Big Lou
     
    Last edited: Sep 18, 2013
  2. BeMahoney

    BeMahoney Builder of things

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    Unfortunately..

    this has been done already:

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

    (can´t find the other video out 0f rd 300!- there´s
    also an x-bow with drawlenghtextension..)
     

  3. onnod

    onnod Im from Holland, isnt that weird?

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    nice drawing, but this doesn't give a straight flight path with an x-bow
     
  4. BeMahoney

    BeMahoney Builder of things

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    TheArtOfWeapons did it this way:

    [ame]http://www.youtube.com/watch?v=7Sz6jnlSvX4[/ame]
     
  5. BigLou

    BigLou New Member

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    Has it already be done in a big scale? Like maybe in a 1,5 meter crossbow slingshot?
     
  6. BeMahoney

    BeMahoney Builder of things

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    Go ahead!


    Show that to us :) :) :) everyone here likes heavy slapping,

    some even like bass!.


    I personally think its time to shoot a little strawberry-punnet,
    namely a VW Golf I Convertable :)

    (estimated 20 Rocketbungee-"ropes" to operate that!)-
    e.g. make it fly across the grand canyon or the niagra falls?

    A rude combination of "think big"/"Just do it" :)
     
  7. BigLou

    BigLou New Member

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    I can't because I don't have the tools and the place to build. I hoped that someone else could build it ;)
     
  8. dolomite

    dolomite Banned

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    No offense but it looks dangerous to me. bands break and when they do there can be quite some force behind it. you might end up knee deep in #2 if the band broke and sent #3(hooks) at your face. if you increase draw lenght, it does no good if you stop the elastic short as in the drawing. Keep with it and you're gonna hit one out of the park, just not this one without an overhaul. you don't want anything hard or heavy attached to the bands as a safety precaution. hope you don't think i'm being rude, just my opinion.
     
  9. Ghosth

    Ghosth Over the hill but still swinging!

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    Don't say you can't do it, tools are matter of planning investment wisely. Build space, well its amazing what you can do at the kitchen table if you plan your build well.

    You don't know what you can do until you try. :)
     
  10. dolomite

    dolomite Banned

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    ghost is right, my first build entailed nothing but wood, a handsaw handed down from my grandfather, sandpaper, and a leatherman tool. you can do a lot with just the will to do it.
     
  11. Tysonspapa

    Tysonspapa New Member

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    if you build it like that, the rollers will force your ammunition to fly downwards. rollers need to be vertical, as in the bullpup crossbow.
    [ame]http://www.youtube.com/watch?v=JGEovOb4GQ4[/ame]
     
  12. JoergS

    JoergS Administrator

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    Rollers should not be directed downwards. There is a hurling component in the shot otherwise, creates unpredictable flight pathes. If you must use rollers then they need to be sideways.

    Rollers add friction and mass, reducing the efficiency of the shot very significantly.

    Rollers do not replace draw length as the acceleration length is only slightly enhanced.

    Rollers dramatically reduce the band lifetime. Stretched bands are very very vulnerable, the slightest chafing will tear them in no time.

    I have pretty much given up on rollers. But beforehand, I experimented a lot with them. They do work, enhance the performance a bit (maybe 15%). But no comparison to a longer "barrel".
     
  13. Otees

    Otees Another Member

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    Same here dolomite :)
     
  14. BigLou

    BigLou New Member

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    Thank you all for posting :) You taught me a lot! Thank you!