measure draw in order to establish band length?

Discussion in 'General Slingshot Discussions' started by couchOUCH, Jan 15, 2014.

  1. couchOUCH

    couchOUCH New Member

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    hello all. first time poster.

    How do I measure draw? is it from the fork to a person's eye while their arm is fully extended?

    physics stuff:

    what is a decent stretch length for theraband gold in order to maximize speed and velocity of ammo?

    I'm looking to attain accuracy for the time being. Any band width and thickness reccomendations to start off with?


    Thanks in advance
     
  2. tivo532

    tivo532 Junior Member

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  3. VWscooby

    VWscooby Senior Member

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    Draw length is measured from fork tips to where ever you pull the band's back to when firing. In my case it's my chin. Like tivo532 says the band calculator lets you tailor the rest once you know your draw length. :)
     
  4. couchOUCH

    couchOUCH New Member

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    I'm not sure where I will end up drawing too. I figured somewhere around the front or side of my face.

    Thanks again folks!
     
  5. dolomite

    dolomite Banned

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    Much like archery, usually the corner of the mouth or the junction between ear and jaw bone is a good place to start. The key to accuracy is consistency, pick a comfortable spot and stick to it. My tbg target bands are 20mm to 15mm taper, enough power to send it with some authority but light enough to hold for a bit whilst aiming. Try bright white or yellow marbles, they're like tracers rounds, it's easier to adjust your aim based on flight path.
     
  6. Flipgun

    Flipgun Well-Known Member

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    Get a tape measure, hold it in your fork hand and the tab in your pouch hand and fake a shot. check the distance. There you have inches and centimeters.
     
  7. Ghosth

    Ghosth Over the hill but still swinging!

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    Most people find a draw point, similar to archery. A spot where they draw back to, that is repeatable. Hinge of your jaw, corner of your mouth, ear, or something similar.

    With your thumb and finger holding one end of the tape like they would hold the pouch, other hand holds the other end like it would hold the slingshot. Mark the distance between the 2 points.

    If your shooting full butterfly, the hand with the pouch will be way back behind your head. Giving a much longer draw.

    Pick something that feels about right, an inch one way or the other on your first set of bands is not going to throw you off much. By the time your doing your 4 or 5th set of bands you'll know exactly where you hold.

    Point for now is to just get close, and get started shooting, see what feels right.
     
  8. buckshot500

    buckshot500 Hoonigan Jeeper

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    Well this thread is informative!

    Nice link, and I now realize I'm going to need a metric meter stick.

    Google has converters, but that takes too long.
     
  9. Ghosth

    Ghosth Over the hill but still swinging!

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    I have 1 tape measure that does both inches/metric. No one else is allowed to know of its existence, much less touch it. :)
     
  10. odeek9

    odeek9 New Member

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    band length

    HI-A graduate of MIT I am not but I shouldn't really need to be in order to use this formula. According to my conversion table -(BTW it's http://www.worldwidemetric.com/measurements.html) which can then placed on your taskbar if Googling is too time consuming- my band width at the fork is approx. 1.3 inches!

    My entries on the Theraband calculator are 63.5, 5, 5, 9.52. Is my one remaining brain cell malfunctioning or what? Something is definitely wrong. Help please:confused:
     
  11. seppman

    seppman Folding-Ladder Expert

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    Let me try to help... as I see, you are trying to find a compromise between speed and bandlife. With this in mind, try playing with the following:
    start off with the band length. it is more or less always the same: your drawlength devided by 5. this way you will get decent speed and still some band life. so with a draw of 63.5 cm, cut them to 12.7 cm (that is the "active" length) plus some space for attaching them to the fork and pouch, add 3cm. to make it easier to cut: 16 cm.
    now for the tapering: the slower the speed, the longer the bandlife.so far so good. you also have to think about the drawweight you'd like (depending how much rubber mass you use). as an overview, I'll give you some examples how the tapering and the rubbermass effects the speed:

    1)slow speed, easy draw, 14mm width at fork, 9mm width at pouch.
    2)highspeed, hard draw, 56mm at fork, 19 mm at pouch. nearly 3 times rubbermass, double the speed from 1

    to cut a long story short: to aim for the middle with decent speed and a decent draw weight try 22mm at porch and 11mm at pouch. if the draw weight feels too strong, go down with the width like 18 to 9mm and so on.

    16 cm long, 22mm at pouch, 11mm at pouch. play with it. it has to "feel" right. if it doesn't, change it.

    hope that helps as a start.

    p.s.:i forgot to mention, if you want to increase the speed, make the tapering "more aggressive": 22m-->9mm etc. keep in mind that the banddimensions always should fit the ammo size/weight you are shooting!
     
  12. odeek9

    odeek9 New Member

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    Thanks Seppman-that does give me some guidelines. Since I'm learning to cut my own bands & the black latex sheets from Simple Shot are inexpensive I'm going to lean towards speed as opposed to longevity. I like the feeling I get when I see my shot going fast with a flat trajectory-laser like. I'll use your guidelines to play with the numbers and see what I come up with
     
  13. seppman

    seppman Folding-Ladder Expert

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    For extreme speed you'd need an extreme tapering and maxed out bands (that depends on the latex you got. 5.5:1 or 6:1 is a good point to start off or just cut an untapered piece and pull it out and measure the max pull lenght). also "fast" is relative. i am shooting 8mm steel and 100 m/s is more than fast enough to cut cans. maybe even 80 m/s are. I dont need 150 m/s. but thats just me. go play with different band dimensions. you will find what suits you best very fast.