Author Topic: poundage increase per inch  (Read 18070 times)

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Offline adb

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Re: poundage increase per inch
« Reply #15 on: April 19, 2013, 01:25:33 am »
It will be interesting to see how this new data will compare with the large number of existing f/d curves for various bows.

There is data showing higher initial draw weight bows increasing poundage in a linear progression.  Low initial draw weight bows increase in draw weight more drastically per inch toward the end of the draw.

Do you have this info? Or can you direct me to where it is? I'd love to have a look at it! I've never seen or heard of any.

Offline JackCrafty

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Re: poundage increase per inch
« Reply #16 on: April 19, 2013, 01:31:07 am »
Here's a link to another archery forum with an r/d discussion:

http://www.archeryinterchange.com/f285/f-d-musings-nerdiness-bible-69957/

But you can google "bow f/d curve" for more data.
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Offline adb

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Re: poundage increase per inch
« Reply #17 on: April 19, 2013, 01:31:37 am »
Thanks!

Offline JackCrafty

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Re: poundage increase per inch
« Reply #18 on: April 19, 2013, 01:36:38 am »
Here's an f/d diagram comparing Turkish bows of different poundage.

http://www.atarn.org/islamic/Performance/Performance_of_Turkish_bows.htm
Any critter tastes good with enough butter on it.

Patrick Blank
Midland, Texas
Youtube: JackCrafty, Allergic Hobbit, Patrick Blank

Where's Rock? Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How to Cook It?  200° for 24hrs then 275° to 500° for 4hrs (depending on type), Cool for 12hr

Offline adb

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Re: poundage increase per inch
« Reply #19 on: April 19, 2013, 01:53:16 am »
So, if we look at the 65# target bow... it moves basically 20" (slightly more) from brace. So, that's 3.25# per inch.

Offline JackCrafty

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Re: poundage increase per inch
« Reply #20 on: April 19, 2013, 01:59:18 am »
I don't have a calculator, but yes.

And the higher the final draw weight, the steeper the curve and the higher poundage per inch.   The lower the final draw weight, the less steep the curve and the lower the poundage per inch.

(using the computer's calculator I got closer to 3# per inch, assuming 21 inches of travel).
Any critter tastes good with enough butter on it.

Patrick Blank
Midland, Texas
Youtube: JackCrafty, Allergic Hobbit, Patrick Blank

Where's Rock? Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How to Cook It?  200° for 24hrs then 275° to 500° for 4hrs (depending on type), Cool for 12hr

Offline Gordon

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Re: poundage increase per inch
« Reply #21 on: April 19, 2013, 02:40:12 am »
I looked back at my FD charts and I am consistently seeing about 3# per inch.
Gordon

Offline DarkSoul

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Re: poundage increase per inch
« Reply #22 on: April 19, 2013, 05:24:16 am »
No... I disagree. The bow I just finished increased its draw weight 40# in 10". Just because it ended up at 95#, doesn't mean it has to increase more. This is about poundage increase per inch, not final draw weight.

If a 55#@28" bow started at 15#@18", it would still end up at 55#@28" if it increased it's draw weight 40# over 10".

So a 30#@28" bow (for a women target shooting) also gains 3 pounds per inch, with a power stroke of 20"? Do the math. It would mean a negative draw weight at brace height.

It just depends on the draw weight of the bow, but for most bows (around 40-60 pounds at full draw) we can expect an increase of 3-4 pounds per inch.
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Offline Pappy

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Re: poundage increase per inch
« Reply #23 on: April 19, 2013, 06:18:57 am »
Usually about 3 per inch on mine in the 50's if tillered correct it should do that through out the draw,if not and it all comes at the last part of the draw,that is what we call stacking,not very pleasing to shoot like that. :) I would think on a heavy bow that number would increase accordingly.  :)
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Offline twisted hickory

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Re: poundage increase per inch
« Reply #24 on: April 19, 2013, 07:57:34 am »
I usually see a 2-3# increase for each inch and my bows are 45# to 65# hunting and target long self bows.
Greg

Offline lostarrow

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Re: poundage increase per inch
« Reply #25 on: April 19, 2013, 09:50:46 am »
Quote
So a 30#@28" bow (for a women target shooting) also gains 3 pounds per inch, with a power stroke of 20"? Do the math. It would mean a negative draw weight at brace height.

 30# divided by 20"=1.5#/inch

Offline adb

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Re: poundage increase per inch
« Reply #26 on: April 19, 2013, 09:59:42 am »
That's what I was thinkin'.