Author Topic: Minimum bow length and width  (Read 7521 times)

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Offline dolgima

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Minimum bow length and width
« on: August 21, 2015, 03:59:49 am »
Is there any post or infromation about minimum length and width of the bow?(selfbow, all wood laminated bow)

firberglass laminated or sinew,horn laminated bow can be made shorter and narrower. But short, narrow self bow or wood laminated bow sometimes broke, have set, unstable.  why? because wood is weaker than fiberglass and can't strech like fiberglass?
I think wood laminated bow can be made shorter and narrower than self bow because  It can be made to distribute stress. Am i right?

what do you think about minimum length and width of bow?

Offline Del the cat

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    • Derek Hutchison Native Wood Self Bows
Re: Minimum bow length and width
« Reply #1 on: August 21, 2015, 04:20:37 am »
I don't think there is much difference between laminated and self...
On a laminated bow you can choose the best woods for tension and compression, and that will give a slight advantage.
It's about designing the bow to suit the wood you have.
People sometimes ask me "what's the best wood to make a bow?"...
I say it's the bit you have in your hand! (I also say Yew and Osage)
You can only use the materials you have...
Del
Health warning, these posts may contain traces of nut.

Online Pappy

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Re: Minimum bow length and width
« Reply #2 on: August 21, 2015, 07:00:11 am »
Wood have memory and usually some flaws, Fiber glass don't simple as that. :o As far as length I make them twice the draw length plus the non bending area[handle and fads] bendy handle can be shorter of course by about that much and still be pretty safe, I am talking self bows here, as far as how wide, weaker woods I make wider as a rule. :) As Del said more choices on lam bows in tension and compression wood so they can usually be shorter
if you like. :)
 Pappy
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Offline bradsmith2010

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Re: Minimum bow length and width
« Reply #3 on: August 21, 2015, 01:51:06 pm »
what Pappy said,, if you make a rule someone will tell you it is not right and how short they can make a bow etc etc etc,, but a good rule of thumb for consistent success is about what Pappy said,, even back in the days of the first Bowyers Bible,, that was the rule of thumb,,, and it still works today :)

Offline PatM

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Re: Minimum bow length and width
« Reply #4 on: August 21, 2015, 06:36:20 pm »
If you want to make a short and narrow bow you must use the best material for either side of the bow. Ipe and bamboo are always going to lead that race as far as readily available materials.

Offline bradsmith2010

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Re: Minimum bow length and width
« Reply #5 on: August 21, 2015, 08:31:36 pm »
I have never tried that , ,but what about osage and sinew,,

Offline LittleBen

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Re: Minimum bow length and width
« Reply #6 on: August 21, 2015, 09:29:12 pm »
Minimum bow length is very hard to answer.

Minimum length will depend on limb width, limb design (I.e. R/D or recurve or straight limb), draw weight desired, and materials used. Perhaps most importantly how well you tiller it.

I have gone as short as: bending limb = .90 x draw length in a hunting weight bow. My guess is you can probably go quite a bit lower if you go for a really aggressive RD shape and keep the weight in the 50# range. I'm talking about laminated bows of the highest quality materials here. Like hickory or boo backing and ipe or osage belly. I don't even consider stiff riser length in the calculation because it has almost no effect. I Consider only the ratio of limb length to draw length.

Really how short you go depends on how much string angle you're willing to accept and how wide you're willing to make the limbs.

Offline dolgima

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Re: Minimum bow length and width
« Reply #7 on: August 21, 2015, 10:10:11 pm »
Minimum bow length is very hard to answer.

Minimum length will depend on limb width, limb design (I.e. R/D or recurve or straight limb), draw weight desired, and materials used. Perhaps most importantly how well you tiller it.

I have gone as short as: bending limb = .90 x draw length in a hunting weight bow. My guess is you can probably go quite a bit lower if you go for a really aggressive RD shape and keep the weight in the 50# range. I'm talking about laminated bows of the highest quality materials here. Like hickory or boo backing and ipe or osage belly. I don't even consider stiff riser length in the calculation because it has almost no effect. I Consider only the ratio of limb length to draw length.

Really how short you go depends on how much string anglea you're willing to accept and how wide you're willing to make the limbs.


thank you for answer.
There will be many variable how short and narrow bow can be made. I want to know about   how wood properties affact the bow. There is limit of wood compression and tension. most wood can not stretch more than 1-2% of their length. so I think this is related with minimum bow length.    Also design,    laminated bow with reflex or deflex(perry reflex?) can make bow shorter and narrower?



I have made very short bamboo self bow. at first It shoots fast but it takes so much set after few month. what is the reason that bamboo bow has set?  too short limb length or  bamboo self bow just prone to has set?

Limbit

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Re: Minimum bow length and width
« Reply #8 on: August 22, 2015, 06:56:32 am »
If you do some research, you'll find bamboo takes more set than any of the conventional bow woods used. Of course it isn't a wood, but regardless, I don't think it lends itself to a longterm short bow due to its issues with set. I think this is why the Yumi bow is so long, but I could be off on that. Do you know about heat-treating the belly of bamboo? If you do this, it will normally take considerably less set. You should research the best way to do this in advance so you don't just burn the fibres. I am curious why you want short and narrow. Short and wide is very comfortable to shoot due to its stability. For instance the paddle-bows of Pacific Northwestern tribes are very comfortable (albeit tricky) to shoot. You are obviously wanting to pull to full draw, but why not learn a short draw? It's fast and instinctive. Maybe not as accurate depending on your skill level. Last, if you laminate multiple layers of wood, The wood will generally be considerably more stable, meaning you can probably get away with a shorter design than you would with just one wood. Like the other guys said, Ipe and bamboo. Hell of a combo!

Offline dolgima

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Re: Minimum bow length and width
« Reply #9 on: August 22, 2015, 08:17:31 am »
If you do some research, you'll find bamboo takes more set than any of the conventional bow woods used. Of course it isn't a wood, but regardless, I don't think it lends itself to a longterm short bow due to its issues with set. I think this is why the Yumi bow is so long, but I could be off on that. Do you know about heat-treating the belly of bamboo? If you do this, it will normally take considerably less set. You should research the best way to do this in advance so you don't just burn the fibres. I am curious why you want short and narrow. Short and wide is very comfortable to shoot due to its stability. For instance the paddle-bows of Pacific Northwestern tribes are very comfortable (albeit tricky) to shoot. You are obviously wanting to pull to full draw, but why not learn a short draw? It's fast and instinctive. Maybe not as accurate depending on your skill level. Last, if you laminate multiple layers of wood, The wood will generally be considerably more stable, meaning you can probably get away with a shorter design than you would with just one wood. Like the other guys said, Ipe and bamboo. Hell of a combo!

thank you I didn't know that bamboo take more set than other wood.
I know about heat treatment. I use heat treatment at bamboo backed bamboo bow(only belly side bamboo is heat treated). but I didn't try on bamboo self bow.
short and narrow bow is fast and efficient.  I make bamboo self bow like hornbow design and  normally shoot with mongolian draw