Author Topic: Question for you sinew bow types  (Read 1727 times)

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Offline sleek

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Question for you sinew bow types
« on: January 22, 2021, 03:04:49 pm »
I just made a sinew backed osage that stores 104.16% of its draw weight in energy. How does that compare to what you guys have? I am not experienced in sinew bow energy storage at all.
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Offline Digital Caveman

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Re: Question for you sinew bow types
« Reply #1 on: January 22, 2021, 03:49:15 pm »
I'm not sure I understand you.  Weight is a force, energy is force times distance.  What is your energy storage, and what is the draw weight?
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Offline sleek

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Re: Question for you sinew bow types
« Reply #2 on: January 22, 2021, 03:54:58 pm »
It draws 44 pounds and stores 45.83 foot pounds of energy.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline eastcreekarchery

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Re: Question for you sinew bow types
« Reply #3 on: January 22, 2021, 04:38:58 pm »
It draws 44 pounds and stores 45.83 foot pounds of energy.
how did u calculate that foot pounds value?

Offline sleek

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Re: Question for you sinew bow types
« Reply #4 on: January 22, 2021, 04:48:41 pm »
You measure the bows draw weight at every inch of draw. Add those measurements up and divide by 12 to get foot pounds of stored energy.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline eastcreekarchery

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Re: Question for you sinew bow types
« Reply #5 on: January 22, 2021, 05:04:48 pm »
How fast does it shoot an arrow at 10 gpp? That seems like a more visceral demonstration of bow performance. Your bow may store 45.83 ft-lbs of energy with your calculation method but the design of the bow will determine how much of that energy goes into the arrow.

Offline sleek

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Re: Question for you sinew bow types
« Reply #6 on: January 22, 2021, 05:16:16 pm »
How fast does it shoot an arrow at 10 gpp? That seems like a more visceral demonstration of bow performance. Your bow may store 45.83 ft-lbs of energy with your calculation method but the design of the bow will determine how much of that energy goes into the arrow.

That method isn't specific to me for energy storage. I learned it from others on here, and its the only way I'm familiar with, on how to do it.

Your statement about how fast the arrow shoots is correct, and I dont know, I didn't have good lighting today to measure its speed. I am however very familiar with this design and know about what to expect from the arrow. Im looking for comparison to other sinew bows to meter how good this is.Which is why I asked my original question.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline eastcreekarchery

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Re: Question for you sinew bow types
« Reply #7 on: January 22, 2021, 05:42:06 pm »
Why r u interested in energy storage efficiency? Just curious bc i dont think it would be an accurate measure of bow performance but maybe im wrong n ur interested in something else related to it.

Offline sleek

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Re: Question for you sinew bow types
« Reply #8 on: January 22, 2021, 05:53:00 pm »
Why r u interested in energy storage efficiency? Just curious bc i dont think it would be an accurate measure of bow performance but maybe im wrong n ur interested in something else related to it.

Simply because higher energy storage gives an arrow more potential energy to use. It is a balancing act between energy stored and energy delivered.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline eastcreekarchery

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Re: Question for you sinew bow types
« Reply #9 on: January 22, 2021, 06:01:24 pm »
Oh i see. You’re interested in seeing how much of your potential energy is being converted to kinetic energy?

Offline sleek

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Re: Question for you sinew bow types
« Reply #10 on: January 22, 2021, 06:03:03 pm »
Yes. Exactly that. But in this case, im just wanting other folks energy storage numbers as a loose metric to Guage my bow against.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline eastcreekarchery

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Re: Question for you sinew bow types
« Reply #11 on: January 22, 2021, 06:09:41 pm »
Im curious to see how selfbows compare to sinew backed bows in this regard. Im also wondering how much reflex plays a role in this since reflexed bows tend to have a higher early draw weight which would result in a higher overall energy storage. Thats what ive read but I could be wrong.

Offline ssrhythm

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Re: Question for you sinew bow types
« Reply #12 on: January 22, 2021, 10:18:56 pm »
You measure the bows draw weight at every inch of draw. Add those measurements up and divide by 12 to get foot pounds of stored energy.

At every inch of draw from what brace height to what draw length? 

Offline PatM

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Re: Question for you sinew bow types
« Reply #13 on: January 22, 2021, 10:22:49 pm »
All the way from one to full draw.