"Stu Special" Super Thrust Arrow

Discussion in 'Show off your homemades!' started by JoergS, Feb 1, 2014.

  1. JoergS

    JoergS Administrator

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    OK, based on Boyntonstu's latest very interesting threads, I looked at improving my "toilet brush" ammo a bit.

    The nine inch nail tips worked very good, but all penetration ended at the plastic handle of the brush.

    So I made a new "arrow", from a 12 mm steel tube (1mm walls). The tip is massive steel, and the "hooks" are made from flat steel, sharpened towards the front and rounded at the back.

    The loop for the sear is recessed into the tube. This offers no resistance to tissue once the tip is in.

    I tested it against the "Dragon scale", and - believe it or not - it tickled the Dragon. The 330 gram arrow crashed through the stainless steel plate and through the half inch quality plywood. Not bad! Of course this isn't as effective as the Smaug ballista - but it has a fraction of the draw weight and only 2 meters of a barrel length.

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  2. BoyntonStu

    BoyntonStu Member

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    Wonderful!

    I thought of designing retracting hooks but never even considered sharp fronts and rounded rears. Bravo!

    What is the speed of the 330 gm arrow?

    Is it possible to eliminate the loop by drilling a hole in the bottom of the tube?

    (perhaps the loop is needed to serve as fletching)

    Excellent design and workmanship!



    BTW I just built and tested a single moving pulley cocking assist to halve the draw force. Very simple design.
     

  3. JoergS

    JoergS Administrator

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    The loop is necessary for the sear/lock mechanism of the "toilet brush sniper rifle" I built a few months ago, but it also does serve as fletching (creates some drag).

    Don't know about the speed, but of course I can always add more rubber. It is quite cold right now, so I guess the speed won't be exciting. The weapon will still do it's job.

    The advantage of that arrow is that it is totally sturdy. Won't break, 100% steel.
     
  4. CEZ

    CEZ New Member

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    Cool, I just don't see the point at which the tip ends and the tube starts, did you weld it together?

    Do you think a smaller version would be good for hand-held slingshots? I'm experimenting with slingshot arrows and as nice as broad-heads are, penetration is stopped at the start of the shaft.
     
  5. Withak

    Withak aka Whitehawk!

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    Sweet. More destructive fun at the Sprave house!
     
  6. Snader76

    Snader76 Dysfunctional Member

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    Cool rifle and spear. Will it be featured in zombie movie?


    Sent from my iPhone using Slingshot Forum
     
  7. JoergS

    JoergS Administrator

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    Yes, I slotted the tube, put in the flat steel, turned down the end of the steel tip and welded everything shut.

    I don't see why this should not work for slingshot flechettes!
     
  8. BoyntonStu

    BoyntonStu Member

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    "Yes, I slotted the tube, put in the flat steel, turned down the end of the steel tip and welded everything shut."

    Is there a no weld alternative?

    Making hooks on a 12.7 mm CPVC projectile tubes has been challenging.

    Currently, I am cutting then into the tube. Not easy to engage the loops.

    Next, I plan to drill a hole, cut a finger strip towards the tip with a thin Dremel blade, and push the fingers outwards using heat.

    During penetration, the finger hooks should retract.

    I am working on a jig to automatically center a nail into the CPVC pipe.

    I will use mortar mix to secure the nail and to add weight.

    Thanks to you, we now have a whole new world of pulled fleshettes.

    I believe hooked fleshettes are superior to pushed arrows.

    It will be interesting to see how this develops.

    Perhaps a Fleshette group someday.
     
    Last edited: Feb 1, 2014
  9. JoergS

    JoergS Administrator

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    Stu, why not using a bent nail as a hook?

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    This is the easiest way.
     
  10. BoyntonStu

    BoyntonStu Member

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    New Fleshette hook design in CPVC

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    This hook design was easier to make and much easier to hook onto than cutting them into the pipe.

    I drilled holes through the CPVC and created fingers using a Dremel tool.

    After applying heat gun the fingers almost immediately sprang out.

    After they cooled, I tested their holding strength at about 40 pounds.

    (Keep the arrow moving towards the target and it will eventually hit it.)

    Pretty rough, but I always test new ideas fast and dirty.
     
    Last edited: Feb 1, 2014
  11. kohlqez

    kohlqez Accident-Prone

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    You should make one for the ballistae
     
  12. JoergS

    JoergS Administrator

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    Stu, 40 pounds isn't enough for my taste. I want a safety margin of at least factor two, and the (initial) draw weight of my sniper is about 55 pounds per side. But for a lighter arrow this seems very nice, quickly done and I like the "auto retract" feature.

    kohlqez, the ballista has no need for hooks, it pushes the arrow.
     
  13. BoyntonStu

    BoyntonStu Member

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    You can make these retracting hooks cut into your steel tube.

    I agree that anything that you count on or stand under, must first tested for at least twice the force.

    However in this case, if the hook breaks, the rubber retracts safely towards the fork while the projectile remains in the "barrel".

    OTOH These hooks are about twice as wide in CPVC as my previous hooks and I believe that they will hold. (There is almost no torque on them.)

    Next project: A 50 gm fletchette made from a nail coaxially placed inside the CPVC and captured using mortar and sand.
     
  14. JoergS

    JoergS Administrator

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    [ame]http://www.youtube.com/watch?v=-RCgFJTQEDQ[/ame]
     
  15. BoyntonStu

    BoyntonStu Member

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    Well done!

    It appears that the brush flies straighter than the bare fleshette with the loop tail.

    The "Stu Super Special" is 40" in total length.

    It will be interesting to see how well it performs with a proper fleshette.