Constrictor knot with loop?

Discussion in 'General Slingshot Discussions' started by BoyntonStu, Jan 24, 2014.

  1. BoyntonStu

    BoyntonStu Member

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    I would like to tie a constrictor knot with a loop built into the knot.

    To explain it better, imagine looping a cord and tying a constrictor knot to 'set' the loop. NOT!

    I want both the constrictor knot and the loop made out of a single piece of rope.

    Is it possible?
     
  2. Jeremy

    Jeremy Senior member who totally rocks a pink Scout! Pink

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  3. Mulgarat

    Mulgarat New Member

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    1. Double the band, that you get a "U" shape on one end
    2. Put the "U" end on top of the doubled band so now you have a loop.
    3. Pull the "U" end under the doubled bands and through the loop.
    4. Pull it tight!
    5. Divide the doubled bands and make a constrictor knot, so that the loop and first made knot lay on top of the x shape as highest layer.

    If you may want, i can add a few photos later, but have not time for it now ;)
     
  4. BoyntonStu

    BoyntonStu Member

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    I want to use a cord loop and not a tube loop.

    Let's say that I have two pieces of latex tubing that I want to tie together using a constrictor knot. After I tie the constrictor knot it will will have two tail piece that I would pull to further constrict the not.

    Instead of the tail pieces, I want a loop.

    I hope that I have described it well enough to understand my question.
     
  5. JohnKrakatoa

    JohnKrakatoa Loudest boom on Earth

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    1. question ... Why?
    The loop made from the same cord as the constrictor might compromise the constrictor.
    2. q... what is the purpose of the loop ?
     
  6. BoyntonStu

    BoyntonStu Member

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  7. Flipgun

    Flipgun Well-Known Member

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    I watched the vid. I see that you are using the flechette concept. The simplest thing would be to tie a loop of string and do a half hitch onto the tubes. If you use the constrictor knot method, you would have to do it before you connected the tubes. If that is what you want, then tie the cord into a loop and make the constrictor with the tieing knot in the middle of the loop, put your tube through the knot and attach the tubes onto the frame find the center of your tube and pull the knot tight. Good luck on getting them even.
     
  8. onnod

    onnod Im from Holland, isnt that weird?

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    Uhmm... let me get some rope and try! I'll be back

    Sent from my GT-I9300 using Slingshot Forum mobile app
     
  9. onnod

    onnod Im from Holland, isnt that weird?

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    This is my first try, it's useless because the loop won't hold anything, when you pull it it slips. But this is a loop in the top piece of rope and that isn't what you're looking for, right?

    Sent from my GT-I9300 using Slingshot Forum mobile app
     

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  10. buckshot500

    buckshot500 Hoonigan Jeeper

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    knots like these can be used to create a loop in cord or a sling in rope. These knots are a good way to tie two cord ends together so they won't slip apart.

    Other than a small lump of knot, the cord is essentially a continuous loop that is as strong as the cord or rope that is used.
     

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  11. buckshot500

    buckshot500 Hoonigan Jeeper

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    These types of knots can be used to tie the loop to something like a slingshot fork tip or whatever you need the constrictor part of the loop for.

    In other words if you start with a continuous loop, then use a prusik knot to attach the loop to the post.

    A prusik knot will also stay put on another rope without sliding up or down unless you release the tension on the main loop.

    The only thing I'm not sure about is whether this knot may loosen say after a slingshot release. as long as it has tension it won't slip.
     

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  12. BoyntonStu

    BoyntonStu Member

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    If you look at the bolt clamp that holds the 2 ends of the tubes to the fork, you can see that each end can be adjusted and therefore centering a constrictor knot is rather easy.

    I can't figure a way to avoid the open ends of a constrictor knot. After the knot is tied a simple overhand knot can be used to tie the ends to close a loop. However, I would not like the knot at the center of the loop. (I could ties a square knot off center.):confused:
     
  13. BeMahoney

    BeMahoney Builder of things

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    Hey you,

    I don´t really know what this shall be used for;
    As a freeclimber, alpinist, fisherman and sailor I dare to say
    that there´s a knot for every use..
    This knot business follows some easy rules of common sense.
    First question would be if you want a knot that can be undone?
    Where are the forces going to.. Is there a rope wrapped around
    wood/steel or anything like that?- Or is rather soft? (a climber,
    rubber tubes etc.)
    Depending on the load, there has to be taken care of the
    knot not cutting its own "throat" (fishing knots)

    I suppose you plan to tie some load (pouch aso) to a tube?

    There´s a knot called "Prusikschlinge" in german. It´s used
    to climb up rather thin rope that couldn´t be handled with
    bare hands: It can be done with e.g. 2 shoelaces, to make
    two slings to stand in with one shoe each. Bringing your weight
    to one foot solely, the other sling can be pushed upwards to be
    then used as a (higher) stand, then the other is pushed up.. aso.

    on the pic (wikipedia) you can see a double wrapped version,
    it can be wrapped three or four times..

    This knot is ideal to connect a thin sling to a thicker rope; reversibly.
    (When James Bond climbs up to the Meteora Abbey, he uses this knot..)

    https://de.wikipedia.org/wiki/Prusikknoten

    Hope this is helpful!

    Greetings to everyone,

    Be
     

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  14. BoyntonStu

    BoyntonStu Member

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    First question would be if you want a knot that can be undone? No

    Where are the forces going to.. Is there a rope wrapped around
    wood/steel or anything like that?-No

    Or is rather soft? Yes rubber tubes

    Depending on the load, there has to be taken care of the
    knot not cutting its own "throat" (fishing knots) N/A

    I suppose you plan to tie some load (pouch aso) to a tube? No, I need a loop to nock.

    There´s a knot called "Prusikschlinge" in german. It´s used
    to climb up rather thin rope that couldn´t be handled with
    bare hands:

    The knot needs to constrict to hold 2 Theraband tubes together at the pulling end.
     
  15. Ghosth

    Ghosth Over the hill but still swinging!

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    Ok, now I understand what your after.

    However, I think you need to understand that this question IS valid. "Depending on the load, there has to be taken care of the knot not cutting its own "throat"

    Considering that all the pull is going to be on this knot, chances are that in time it will do exactly that, cut through the rubber.

    IMO if you need to hold 2 tubes together so you can make a bow nock point, your better off using a heavy cord, tieing a single overhand knot in one end, insert it into the tube an inch, and tie a constrictor knot with light cord below it fixing it in place.


    Your trying to do 2 knots of dissimilar materials with 1 knot of 1 material and I don't think it will work.
    Constrictor knots are designed to HOLD not be pulled on.

    Best of luck.
     
  16. BoyntonStu

    BoyntonStu Member

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    Constrictor knots are designed to HOLD not be pulled on.
    If you can remember seeing Joierg pulling a constrictor knot tight with 2 pairs of pliers, you may change your mind.
     
  17. BeMahoney

    BeMahoney Builder of things

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    Hey Buckshot!,

    nice answer of yours! (which we gave rather simultaneously..
    when I answered, that post was not there..)

    High five!- But I think we might have been misunderstood?..

    That Prusik-Knot is a rather "soft" connection, anyway..

    But what ghost wrote is right!- That "single overhand knot
    in one end, insert it into the tube an inch" method will work just fine!

    I´m just wondering what two tubes (on each side?) are going
    to be needed for? It might be useful to use the tube itself as a loop,
    tying the loose ends to a fork? ..Lots of ideas..

    In the end BoyntonStu will be the one that learns from testing!-
    Hopefully to share the results!?

    Greetings to you guys,

    Be
     
  18. buckshot500

    buckshot500 Hoonigan Jeeper

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    I gave my answer without seeing the video first, but those knots are good for a variety of tasks.

    I know what you mean about posts appearing at the same time on this forum. Sometimes I wonder how many others are posting while I am taking so long to compose my answer.

    As for our answers both containing the prusik knot, would suggest it's universal usefulness. It has been handy to me to know and understand how it works.

    Climbers using 2 slings with those knots can ascend vertical rope rather quickly although some what awkwardly. In a survival situation, knowledge of this technique could be a life saver.
     
  19. BoyntonStu

    BoyntonStu Member

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    Results using the constrictor knot in a less than optimum manner:

    [ame]http://youtu.be/l_h52OBOc7k[/ame]
     
  20. Ghosth

    Ghosth Over the hill but still swinging!

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    There is a difference between pulling a knot tight once, with pliers, so that it truly secures. And pulling on a tag end of a knot, again, and again, and again.

    In that situation I would bet the farm that in 100 firings either the knot comes lose or it cuts the tube at that point. I'm guessing it would be the knot that comes lose.

    Same gun, same rubber, cut a 6" piece of paracord, or similar braided cord, light braided rope. Tie a single overhand knot, melt off the excess (helps if you roll it into a smooth taper) lubricate it with a little spit, shove it into the tube, and tie a constrictor knot behind it so it can't pull out.

    Like this

    [​IMG]


    The knot in the green braided cord is inserted, constrictor knot tied in white nylon (aprox 1/8 braided)

    I have aprox 1000 rounds fired with that shooter shooting .45 caliber lead balls. No slippage, no creep, no problems.

    Now, as it applies to your crossbow, I see a couple of things.

    A the method I described would work fine, whatever size cord you use, cut both sides the same insert the same distance, tie behind the knot a good constrictor and it should last a LONG time.

    B The way you have your gun setup, you can ONLY fire those PVC shafts.

    C there is no way to get your shafts streamlined so they fly straight at long distance.

    If you move your lock forward a bit, you can set up a slightly design using that same trigger and pin method. But use the pin to hold a string between the 2 sides and you can shoot almost any ammo. Set it up right and I suspect you could even shoot things like steel balls, darts, ammunition, sky's the limit.


    Not to say that what you built is bad, or that you wasted your time.

    Trying to show you that it could perhaps be improved.

    I've learned a lot here in a very short period of time.
    Don't want to believe me that is fine. But the old timers like Be, BrazilViking, listen to them.
     
    Last edited: Jan 25, 2014