Author Topic: Design question  (Read 4686 times)

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Offline Ricardovanleeuwen

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Design question
« on: April 16, 2020, 12:46:56 am »
Could lighter draw weight bows shoot arrows faster  then a heavy bow due to theirs design? And wich designs shoot arrows fast?

Offline Del the cat

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Re: Design question
« Reply #1 on: April 16, 2020, 02:27:01 am »
Relative to their draw weight lighter bows shoot faster than heavy ones of the same style. E.G A 70# ELB won't shoot twice as far as a 35# ELB
The discrepancy isn't so much due to design, as any design can be scaled up or down...
There is probably an optimum set of dimensions for any design /material, but it also depends on the arrow. So what is optimum for a flight arrow isn't optimum for a 1/4 pound military arrow.
Increasing draw weight generally gives more speed, but you rapidly reach a point where the bow (or the archer) can't take the strain. If the bow is made too long the inertial of the limbs makes it slow... you can swish a short stick through the air quickly... but try to swish a 5' length!
Some designs are faster than others, say a flatbow is faster than an ELB (I'm not saying it actually is) but a porr flatbow wont be as fast a good ELB.
Biggest factor is the bowyer IMO
There are just so many variables.
Del
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Offline Ricardovanleeuwen

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Re: Design question
« Reply #2 on: April 16, 2020, 02:51:09 am »
Lets say the bowyer is me, A elm stave 65 inch, draw weight 40lb  at 28 with a rosewood Arrow spined to the bow , wich designs have the biggest potential to be fsster

Offline Jurinko

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Re: Design question
« Reply #3 on: April 16, 2020, 03:10:53 am »
Yes, efficient 40lb can outshoot overbuilt or set affected 50lb bow.

For high arrow velocities and light arrows you go for light tips and non-working ends of limbs acting as levers like Holmegaard design. For fast heavy arrows you need high stored energy, whole limb doing its share of work like Sudbury bow. For both cases you aim for low set and even slight reflex to have high initial draw and fat draw energy curve. There are great articles on this in TBBs.

Offline Hrothgar

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Re: Design question
« Reply #4 on: April 16, 2020, 06:44:07 am »
For a 65" elm stave you can hardly go wrong with a flat bow, pyramid style, and heat treat it. I think it was Badger a few years ago who made an ash flat bow around 40# and set a distance record with it, and distance is a good indicator of speed. There are other variables, like Del said, it depends on the purpose of the bow, etc.
" To be, or not to be"...decisions, decisions, decisions.

Offline PatM

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Re: Design question
« Reply #5 on: April 16, 2020, 07:34:21 am »
Static recurve every time.

Offline Ricardovanleeuwen

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Re: Design question
« Reply #6 on: April 16, 2020, 09:00:20 am »
Then ik try Both, and what about mollegabet?

Offline DC

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Re: Design question
« Reply #7 on: April 16, 2020, 09:44:13 am »
I'm not sure about a Molle. For most bowyers I think you would find that the tips are actually heavier than a conventional bow. The combination of the second set of fades and the fact that most of us are too chicken to make the tips as light as they could actually be means the the tips work out as heavy or heavier than a conventional bow. I've only actually weighed this on one bow and the molle was heavier. The stiffness of the tips may be someting else.

Offline Del the cat

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Re: Design question
« Reply #8 on: April 16, 2020, 10:22:04 am »
I'm not sure about a Molle. For most bowyers I think you would find that the tips are actually heavier than a conventional bow. The combination of the second set of fades and the fact that most of us are too chicken to make the tips as light as they could actually be means the the tips work out as heavy or heavier than a conventional bow. I've only actually weighed this on one bow and the molle was heavier. The stiffness of the tips may be someting else.
Very good point :)
Del
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Offline Ricardovanleeuwen

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Re: Design question
« Reply #9 on: April 16, 2020, 10:33:52 am »
Ah oke, i got plenty of elm staves  to Risk so i Will deffinatly try It soon, for now i try recurve first ( along with some other bows) i tried to make a form to flip the tips, not sure if this is what It need to be? The tape measure is in centimeters by the way

Offline Jurinko

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Re: Design question
« Reply #10 on: April 16, 2020, 10:57:20 am »
Too steep i think, i destroyed half finished bow on less curve. Definitely go with steam, heatgun ain't enough.

Offline DC

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Re: Design question
« Reply #11 on: April 16, 2020, 11:06:24 am »
That's a pretty aggressive bend, especially for first try. Just for a semantics lesson, "flipping the tips" is just a minor recurve, maybe a couple of inches(5cm). What you've got there are "big hooks" ;D ;D

Offline dylanholderman

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Re: Design question
« Reply #12 on: April 16, 2020, 11:14:44 am »
I would agree with making a milder bend.
My second recurve was a “big hook” recurve and it was a Pain in the butt, tips kept wanting to flip even after I got it braced.
65-70 degrees is what was recommended to me for my next one

Offline Ricardovanleeuwen

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Re: Design question
« Reply #13 on: April 16, 2020, 03:46:15 pm »
Ah oke, somewhere on here i Read that a quarter of a Paint can is good, dont know wich kind of cans you have? ;D i already used something a lil bit bigger then that

Offline Deerhunter21

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Re: Design question
« Reply #14 on: April 16, 2020, 06:48:04 pm »
i think if you did a quarter of that curve it would be good. it just keeps going down farther than you want if you get what i mean
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