Author Topic: Holding beyond brace  (Read 8043 times)

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Offline PEARL DRUMS

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Re: Holding beyond brace
« Reply #30 on: November 13, 2017, 01:01:30 pm »
Draw a normally braced bow 2" and hold it. Do you really suppose that hurts that bow anything like drawing 2" past its design full draw? Not only that but a bow drawn 28" is drawn 28" regardless of where it started, i.e 7" brace, 9" brace or 10" brace. 
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline DC

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Re: Holding beyond brace
« Reply #31 on: November 13, 2017, 01:39:32 pm »
If we are talking one bow. Shorten the string by 1". That will raise the brace height by about 2". Now when you draw the bow, remember that the string is shorter, you will bend the bow more to reach a 28" draw. At least that's the way I see it :)

Offline Pat B

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Re: Holding beyond brace
« Reply #32 on: November 13, 2017, 01:57:33 pm »
I think a 28" draw is a 28" draw no matter what the brace height is.
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Offline PEARL DRUMS

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Re: Holding beyond brace
« Reply #33 on: November 13, 2017, 02:02:05 pm »
I think so, but cant prove anything.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline bradsmith2010

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Re: Holding beyond brace
« Reply #34 on: November 13, 2017, 02:03:39 pm »
me too, I cant prove it either,,  (-P

Offline Danzn Bar

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Re: Holding beyond brace
« Reply #35 on: November 13, 2017, 02:26:33 pm »
Come on you guys....
Brace height to a point.  Brace height is a function of string length.
And that's all I have to say  about that.
DBar
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Offline Stick Bender

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Re: Holding beyond brace
« Reply #36 on: November 13, 2017, 03:20:11 pm »
I'm glad brace height came up I came here after shooting traditional FG bows for a lot of years and made several self bows before somebody let me know about the lower brace height  probably caused undo set on those bows ,now I don't brace a bow any farther then 7 in. From the back , fortunately I had all ready been shooting Fred Asbell's system so the hold time wasn't a issue , I release as soon as hit anchor.
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Offline Hrothgar

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Re: Holding beyond brace
« Reply #37 on: November 15, 2017, 07:34:29 am »
Interesting discussion,. Not being a physicist I don't know how to go about proving this, but the draw weight can't be the same on a bow braced 7" then pulled (to any length) versus a bow braced 1" and pulled. Of course I'm still trying to figure out arrow flex and oscillation.
« Last Edit: November 16, 2017, 06:23:11 pm by Hrothgar »
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Offline Badger

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Re: Holding beyond brace
« Reply #38 on: November 15, 2017, 07:37:44 am »
Interesting discussion,. Not being a physicist I don't know to go about proving this, but the draw weight can't be the same on a bow braced 7" then pulled (to any length) versus a bow braced 1" and pulled. Of course I'm still trying to figure out arrow flex and oscillation.

  Take a finished bow and put a long string on it. let the long string hang loose a few inches. Now draw it to 28" on your tiller tree and take a reading. Now brace the bow to a normal brace height and draw it to the same 28" point. You will be surprised at how close they are.

Offline PEARL DRUMS

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Re: Holding beyond brace
« Reply #39 on: November 15, 2017, 11:42:22 am »
I think that some folks may get string tension at brace confused with total drawn weight. Perhaps assuming that a higher brace height/string tension will equate to a higher total draw weight.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline bradsmith2010

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Re: Holding beyond brace
« Reply #40 on: November 15, 2017, 03:54:01 pm »
this if from the design chapter in volume 1

a low strung bow stores more energy
a bow braced at 4 inches, string travels 24 inches
a bow braced at 7 inches,string travels 21 inches
a high strung bow is more strained,tips in this case are advanced three inches farther,, causing considerably more bend,therefore,limbstrain,,

thats just what is says,, I dont make this stuff up,, Im not that smart,, )P(  page 47

Offline Badger

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Re: Holding beyond brace
« Reply #41 on: November 15, 2017, 04:08:25 pm »
this if from the design chapter in volume 1

a low strung bow stores more energy
a bow braced at 4 inches, string travels 24 inches
a bow braced at 7 inches,string travels 21 inches
a high strung bow is more strained,tips in this case are advanced three inches farther,, causing considerably more bend,therefore,limbstrain,,

thats just what is says,, I dont make this stuff up,, Im not that smart,, )P(  page 47

   Something that would be cool to try sometime is just draw some lines on a board. Draw the bow braced at 4" and then draw the bow braced at say 7" and see how much further the limbs actually travel. I guess you could do it with math but this seems like it would make it more clear. I have shot through a chrono using a high and low brace and didn't see any difference.

Offline DC

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Re: Holding beyond brace
« Reply #42 on: November 15, 2017, 04:45:08 pm »
At brace with the string straight the difference between 4" and 7" brace the tips move 3". As log as the string is straight it's one for one. When you draw the bow and the string is no longer straight the tip movement gets less and less. Up in the 26-28" draw the tips move about half as much as the string(at the arrow). I made a bamboo test bow to try out this kind of stuff. Now I'm going to have to tiller it properly so it doesn't look like a yumi.

mikekeswick

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Re: Holding beyond brace
« Reply #43 on: November 16, 2017, 03:53:41 pm »
A shorter string makes the limbs bend not just further to give the higher brace height but in a tighter arc. Shorter 'powerstroke' as well but I've never actually tested different brace heights through the chrono.

Offline Marc St Louis

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Re: Holding beyond brace
« Reply #44 on: November 16, 2017, 06:12:33 pm »
Never thought of it that way but I have to admit that Don's theory of the shorter string/higher brace height pulling the bow's limbs in a tighter arc makes sense.  Not sure how much difference that would make though, probably a bit on the draw-weight.  The power-stoke should remain the same though
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