The coolest Fletching Invention Ever?

Discussion in 'Off Topic' started by JoergS, Jul 3, 2014.

  1. JoergS

    JoergS Administrator

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    A young inventor from Prague, Jan Kokes, contacted me a while ago, saying that he had invented (actually filed a patent application) a completely new fletching invention, with huge advantages compared to the common vanes.

    I was interested of course, but then I did not hear back from him for a long time. Now he sent me an arrow with his "turbine" vane!

    That's right, a single blade, much like an arch... I could not believe it, but the thing flies amazingly straight and I think it is also faster. The spin rate is really high.

    Can't wait to shoot some 1000 fps material of the thing in flight!

    I have a feeling we are witnessing the next big thing in arrow technology.

    [​IMG]
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    [​IMG]
     
  2. JohnKrakatoa

    JohnKrakatoa Loudest boom on Earth

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    Hell yeah brother Czech! I expected somethong bigger. This is very cool, innovation!
     

  3. BoyntonStu

    BoyntonStu New Member

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    Is the arrow all the same diameter or is there a special shape?

    I would expect a asymmetrical sideways force that would steer the arrow.

    However, since it spins, the angular momentum may be the reason that it shoots straight.

    Looking forward to the weight and speed tests,
     
  4. bigdh2000

    bigdh2000 Administrator

    Be interested to see your video.
     
  5. Will

    Will Thread Hijacker

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    This is very interesting! I have often wondered if, on modern high-speed compound bows, the fletchings would make any difference at closer ranges. Just out of curiosity, I have shot several unfletched carbon arrows at 30-40 yards in the past. They all hit just about exactly the same as normal, fletched shafts. However, this was done with 100 gn field tips, not broadheads.
     
  6. JoergS

    JoergS Administrator

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    Front heavy symmetrically tipped arrows need no fletching. But a broadhead will "want" to steer the arrow.

    This "turbine" will make the arrow spin MUCH faster than a normal one.

    Again, this may well be a huge step in archery, potentially the biggest one since CF arrows and eccentric cam wheels came along.
     
  7. BillHays

    BillHays Member

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    Very nice concept.
    I can see an easier approach, way to do this though... the mounting to the shaft is a little wonky....
    Instead, imagine something like premeasured/die cut tape or sticker strips instead... maybe two inches long at most... pull the backing off the sticker/tape and wrap it around the shaft leaving a tab/half fin... then the sticky side adheres to sticky side creating the whole fin.
    With a die cut asymmetrical sticker that adheres to itself you could easily get the desired spin with minimum drag AND super easy installation.... You might suggest something like that to the guy before a big company comes along and does exactly what I suggest based off his concept.


    Quick and dirty illustration of what I mean... precise angle of attacks and other measurements would have to be done for making a die for cutting and making the precision vane/fin
    [​IMG]
     
  8. JoergS

    JoergS Administrator

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    Bill, the first samples Jan sent were made much like this. But it turns out that the "arch" design works a lot better than a vane like shape.

    Much testings will have to be done anyway... I think that the arrow weight and speed will call for different sizes and shapes of the turbine.
     
  9. ruthiexxxx

    ruthiexxxx ruthiexxxx

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    Oh wow...this is SO exciting ! Can't wait to hear more about it and see some videos / tests. Bill's modification sounds very interesting. Vanes / fletching have been a bit problematic for me. Since I got into shooting this one the arrows often go right through the target and backstop which tends to tear the vanes off...a bit of duct tape would only take seconds to replace.
     

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  10. BillHays

    BillHays Member

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    Interesting... I guess a lot of tests are still needing to be run then.

    Of course with the sticker/tape setup, as I showed, the shape of the fin can be anything you'd like it to be, square, triangular, ellipse, holes in it, etc.. ... it all depends on the die cutter...
    Probably an easy way to setup for multiple experiments and have the ability to resize and reshape on the fly... a person could just use a cheap cnc laser cutter, and cut the shapes out of adhesive backed printer paper... like that used for affixing address labels and such.

    Anyway... like I said before it's an interesting concept... and can probably be developed quite a bit more.
     
  11. BillHays

    BillHays Member

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    Very true Ruthie... you could even have a bunch of precut "TurboVanes" all ready to go when you might need them.
    That's one of the cool things about slingshots and other like primitive weapons... fixing them up to firable condition can be done with the most basic of tools and material.
     
  12. BoyntonStu

    BoyntonStu New Member

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    Good solution.

    I don't enjoy being treated by actions whose past tense sound like duct.

    OTOH Present tense is mutually satisfying.
     
    Last edited: Jul 4, 2014
  13. Ghosth

    Ghosth Over the hill but still swinging!

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    I can see that arch being huge for crossbows.

    Only thing I caution is watch so that you don't exceed the revolution threshold of your ammo.

    This is something those of us who make our own boolits and shoot them in rifles have to deal with.
    As speed increases, rifling in the bore adds twist, too much speed and twist and even hard cast lead bullets will deform.

    Will be watching this thread with great interest.
     
  14. ruthiexxxx

    ruthiexxxx ruthiexxxx

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    a very quick experiment with a 'vane' made from a bit of pipe cleaner held in place with duct tape (in the UK we call it Gaffers' Tape) was interesting though early days. I don't think the whisker biscuit liked it too much but it seemed to fly well from one of my slingbows with an open leather arrow rest.

    The vane in the original pic looked like paracord but probably isn't...Is it solid or flexible?
     

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  15. BillHays

    BillHays Member

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    Years ago I used to shoot/throw darts quite a bit... at that time there was a type of flight/fin called dimplex... basically it's a foil made from a mylar with dimples in it.
    Using the tape/sticker wrap method and having a dimplex-like vane, MAY be the best option of all.
    Super simple to make and modify... using that you could have a true "TurboVane"
     
  16. CEZ

    CEZ New Member

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    Will there be a video of this? I bet a ballistic jelly and broadhead test would look cool.
     
  17. JoergS

    JoergS Administrator

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    I already did some hispeed filming, but I had no operator and the results weren't very good. It does spin though, a lot faster than conventional arrows.

    Hispeed footage of arrows in flight is weird... you see how much the arrows oscillate.
     
  18. JoergS

    JoergS Administrator

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    I already did some hispeed filming, but I had no operator and the results weren't very good. It does spin though, a lot faster than conventional arrows.

    Hispeed footage of arrows in flight is weird... you see how much the arrows oscillate.
     
  19. BoyntonStu

    BoyntonStu New Member

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    Exactly why I am experimenting with short heavy bolts/flechettes.

    The bolts eliminate archers paradox and oscillation inherent in long flexible arrows.

    Spin can be carved into a bolt without needing fletchings.

    My present projectile fits somewhere between arrows and bolts and could benefit from fletchings.

    However, sliding fletched bolts down a rail may not work if the rotation is immediate.

    My bolts are just under 0.5" in diameter and 12" in length.

    Great thread!