Author Topic: how to calculate possible draw from given bow lenght  (Read 1796 times)

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Offline freke

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how to calculate possible draw from given bow lenght
« on: January 27, 2017, 05:32:19 pm »
Hi
I mostly build "longer" bows, 65-69" and with my +28" an I in the comfort zone, but I see from many posts that shorter bows and shorter draw is very popular and want to try.
I am building a much shorter bow than usual, It was intended for my son but his intrest for cellphone games are bigger than leave the house so the bow will not be HIS next bow.
It is white wood selfbow, reflex-deflex design and 54" ans bendi handel , how do I calculate max draw ?

Is there any general calculation to find best lengh?

Thanks in advance,
Jonas

Offline willie

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Re: how to calculate possible draw from given bow lenght
« Reply #1 on: January 27, 2017, 06:14:16 pm »
one way would be to determine your draw length to working limb length ratio for your existing designs.
this ratio should work for the bendi handle also, if of similar  materiel

Offline loon

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Re: how to calculate possible draw from given bow lenght
« Reply #2 on: January 27, 2017, 06:50:06 pm »
rule of thumb of draw length 1/2 the bow length for bendy handled would give 27" for that
with less brace height you can have a bit more draw

If it's really good, fibrous whitewood and you have a good cross section and backing, why not 28+"? Might break or take set though (ABSOLUTELY NO WARRANTY)
« Last Edit: January 27, 2017, 09:31:00 pm by loon »

Offline PatM

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Re: how to calculate possible draw from given bow lenght
« Reply #3 on: January 27, 2017, 08:09:52 pm »
How old is he? 54" will handle  anything a kid is likely to pull.

Offline DC

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Re: how to calculate possible draw from given bow lenght
« Reply #4 on: January 27, 2017, 08:14:43 pm »
In the infamous words of Del, pull it til it breaks and then back off a bit ;D ;D

mikekeswick

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Re: how to calculate possible draw from given bow lenght
« Reply #5 on: January 28, 2017, 04:06:06 am »
Half the staves length.

Offline freke

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Re: how to calculate possible draw from given bow lenght
« Reply #6 on: January 28, 2017, 05:51:25 am »
Think I got it 1/2 stave lenght, Tanks

The boy is nearly 12 now, he has unfortunalty lost intresst in all fun, fishing, hiking and shooting.....

Offline loon

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Re: how to calculate possible draw from given bow lenght
« Reply #7 on: January 28, 2017, 06:17:27 am »
sorry..

would like to see pics of the bow

Offline freke

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Re: how to calculate possible draw from given bow lenght
« Reply #8 on: January 28, 2017, 05:01:45 pm »
sorry..

would like to see pics of the bow

Hi, some pictures but it is not finish and I struggling with the tillering - it has not been drawn more than the 20"  and low string height, seen on the picture.
Right side up, I think.