do you need a the pouch?

Discussion in 'General Slingshot Discussions' started by Peterburban, Oct 9, 2013.

  1. Peterburban

    Peterburban New Member

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    As the title says: do you need a pouch on a slingshot?

    As all katapults I've seen so far do have 'm I suppose "Yes", but can't you just attach a non tappered tbg from one fork to the other, put the ammo in the (marked) middle, pull and release?

    Like we shoot paper projectiles with office rubber bands? :p

    I ask this for my "big shot" project, which is comming to life! (I'll post some pics real soon). The fork and pole are ready.
    If I could just attach a 1meter full width TBG to the forks and put the ammo bag (300gramms) in the middle of it...
    Then I would only have 2 attachements instead of 4...
    (I'ts a trough the fork kind of slingshot, the forks almost straight up like a 'U')

    If a pouch is nescessary, any tips on size/form?
    I have some non-rupture kind of clothing fabrik, light weight, that I could use.

    Thanks a lot for all comments!

    I know I've been asking a lot more then I have been contributing but I am a complete newbie on this matther :eek:
     
  2. BeMahoney

    BeMahoney Builder of things

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    Grip

    One issue arising might be to "get a grip"
    on the TBG.. plus: if the pouch is from
    rubber, it´s going to be lengthened, too,
    which will result in friction with that bag..

    Why dont you just use some "parachute-silk"
    fabric?- as safely as the pouch is going "up",
    it will come back down!?

    What about some trigger-handle?-
    might be a lot easier to deal with..

    If you shoot 300 gramms at 180ft./second would that be
    540 Joule?

    Be safe! (a rts might kill you!?)

    9 mm Para/ 9 mm Luger (9x19 mm)~7,5 g ~350 - 450 m/s ~300 - 550 J

    .45 ACP (.45 Auto) ~12,0 g ~260 m/s ~320 - 600 J
     

  3. Withak

    Withak aka Whitehawk!

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    Interesting question. It will be curious to see what happens. My first concern would be the wear at the point you place the ammo. It seems that would be the likely first failure point, so perhaps your test will answer that question.
     
  4. Haecksler

    Haecksler Naturalist

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  5. Slagskimmer Mike

    Slagskimmer Mike thinks TBG smells better than roses

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    The pouch on the Slingshot Cannon is the biggest one I can remember ever seeing.
    I'd start by checking that out.

    I think the center hole+spherical ammo at 60% size is proven safest against rts shots.
     
  6. dolomite

    dolomite Banned

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    Short answer...Yes you need a pouch!
     
  7. CEZ

    CEZ New Member

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    Yes, you need a pouch, I have read about tests of pouchless shooters and the projectile usually goes in a random direction.
     
  8. Ryan Wigglesworth

    Ryan Wigglesworth Senior Member

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    <iframe width="560" height="315" src="//www.youtube.com/embed/-OZjHjJToVo" frameborder="0" allowfullscreen></iframe>
     
  9. Peterburban

    Peterburban New Member

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    Ok, thank you all for your replies!
    I'll make a pouch for the big shot, that melon hit looked painful but my lead throwing bag returning would be ... I can only hope there's a mistake in bemahoney's calculations...

    I also decided to shoot it upside down (fork is pointing down) so the pole is between me and the bands. It's not really down because I have to aim almost straight up.
     
  10. CEZ

    CEZ New Member

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    Well, there is, it's 450J:p

    By the way, that sounds kind of hard to achieve with a slingshot anyway, considering Joergs record breaking slingshot does 135J?
     
  11. BeMahoney

    BeMahoney Builder of things

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    a question of honour

    Even if this is hair-splitting :)
    my calculation was 60meters/second, 300gramms..

    which would be 540.. (just to be understood.. then I made 60m/s be 180ft/s)

    anyway..

    What counts (really knocks me off positively)
    is that people take care of another, share and
    learn and that kind vibe brought about with all that.

    I enjoy being here!- thank you!

    Be
     
  12. BeMahoney

    BeMahoney Builder of things

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    45mm steel ball

    respect mass? ;) :

    300 gramms equal a 45mm steel ball...
    and a steel ball/leadbag wont waste energy by sputtering
    (which I believe saved that womans life)
     
  13. CEZ

    CEZ New Member

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    I like to help out here too, just something that I noticed, 540J is a lot! More like Joergs cannon ranges, not slingshot.
     
  14. G_Y

    G_Y aiming the less

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    How about the draw-weight?
     
  15. Peterburban

    Peterburban New Member

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    the tbg calculator gave me 3 strands of full width on both sides :rolleyes:
    The fork has a clamping style attachment for the bands.
    I'll start with just 1 and build it up.
    I have to make sure the cocking/release mechanism will hold.

    Concerning the pouch:
    I'll make it as small as possible, light material, 1 attachment per side
    (it won't be easy to put 13cm of tbg in a small hole)

    this should keep the chances of rts as small as possible

    thank you all for your concern, I'm a bit nervous myself firing it up the first time

    pictures and updates coming this weekend!
    (hopefully not a pdf of an skull x-ray)
     
  16. MountainStorm

    MountainStorm Termite

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    Pouch yes...and perhaps a very special one.

    Seems to me with that much force the pouch is going to need some engineering to resist tearing...Considering the width of the bands and the number of bands I would think seriously about something like alloy tubing on either side with rope bails through a triple stitched sleeve above and below on a ballistic Nylon panel. The center hole should be reinforced too...
     
  17. G_Y

    G_Y aiming the less

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  18. CEZ

    CEZ New Member

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    3 full TBG lenghts per side? You will need a crank mechanism to pull that.
     
  19. BeMahoney

    BeMahoney Builder of things

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    Seatbelt

    I suggest to use a seatbelt of a car..
    Will be easily sewed with a sewing machine,
    I would definitely try this:
     

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