Author Topic: Overbuilt bows  (Read 2884 times)

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Offline StickMark

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Re: Overbuilt bows
« Reply #45 on: February 03, 2019, 05:31:38 am »
With boards, overbuilt seems to be best for me.  Don't get me wrong, I have dozens of "failed" bows in either the board or stave variety.  During my "phase 1" of learning, I chrysalled a number of hickory staves, because of too stiff inner limbs. With boards, I am not sure what exactly is the broad underlying cause of failure.  But crossing that line rsp3 mentions is risky and overbuilt to me means not crossing that fine line.  I am not that good of a bowyer.  Yet.

Willie: I think that a board comes from some unknown part of the country, is kiln dried or stored in a manner I'll never know, and you are on to something about Natives being specific about  choice of tree material. 

Overbuilt.  To me that means not chasing performance needlessly unless you are willing to risk the bow.  I built a 50" hickory shorty, originally drawing 20.5 inches.  Great bow.  Little set, under an inch. Wanted to go from 44# draw weight, go stronger.  So I shortened it to 48.25 inches, and it worked great, sitting pretty in my hands as I did not take the shot on a big Coues Whitetail, lol hashtag "Not dynamic in releasing". 

As the season went on, I got stronger, and kept puling the draw length out to 22, 23".  Well, the bow lifted a tiny splinter.

Should have left the bow at a ratio about 2.5:draw length.  Overbuilt. ( Leaving that extra length, a few inches and a bit of width)

Offline lonbow

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Re: Overbuilt bows
« Reply #46 on: February 05, 2019, 10:45:18 am »
I bent a pine arrow today until it broke. I realised that the splinter that was under tension barely took any set. The compression side took a huge amount of set. The wood cells on the compression side collapsed, as badger wrote earlier.

I think the reason, why perry reflexed bows take less set, is quite obvious. When unstrung, the shorter back of the bow puts the belly under tention. When bending the bow a bit, there is a certanin point, where the belly is neither under tention nor under compression. When bending further, the belly starts to compress.

In comparison, a bow made of a naturally reflexed stave with the same amount of reflex behaves different. When unstrung, the belly is neither under tention nor under compression. Whith the slightest bend, the belly starts to compress. When fully drawn, there is more compression.

When drawn to 28 inches, the belly of the perry reflexed bow is under less compression. Less compression means less set. As a result, the perry reflexed bow can be built narrower and lighter without being underbuilt.

lonbow
« Last Edit: February 05, 2019, 11:39:48 am by lonbow »

Offline SLIMBOB

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Re: Overbuilt bows
« Reply #47 on: February 13, 2019, 01:31:11 pm »
I tend to think that most of mine are overbuilt to some degree, although I would struggle to define the term.  2 inches wide when 1.5 would have worked.  66 inches long when 64 would have been fine.  If I manage to keep set to a minimum in the process, which is no given, then I'll take it, overbuilt or not. 
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Offline bradsmith2010

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Re: Overbuilt bows
« Reply #48 on: February 14, 2019, 12:24:53 am »
There is a point of diminishing return,,,.where the bow no longer performs well,,.even showing no set,,.

Offline Selfbowman

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Re: Overbuilt bows
« Reply #49 on: February 14, 2019, 05:04:28 pm »
Brad are you speaking of a longer draw but gaining less weight per inch on the end of a force draw ?
Arvin
Well I'll say!!  Osage is king!!

Offline bradsmith2010

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Re: Overbuilt bows
« Reply #50 on: February 15, 2019, 06:03:59 am »
Sorry I wasn't very clear,,.if you make the bow wider and longer to to reduce set,,,,at some point the bow will be to wide or too long or both,,,show no set,,..but will be too,,Overbuit to perform well,,,having slow cast,,,and handshock

Offline Ballasted_Bowyer

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Re: Overbuilt bows
« Reply #51 on: February 15, 2019, 08:52:11 am »
A bow can be overbuilt in actuality by tillering it to endure more stress than normal use requires. However, it can also be falsely overbuilt if the material is forced to compress beyond the elastic limit of the wood in the limb. A bow like this would be deeper and narrower than expected for the species, condition, and quality of the material. This would result in a heavy limb for its draw weight. Also compression fractures would be likely in the belly or the bow would weaken dramatically or lose tiller when being shot in. All woods have a limit to how thick they can be and remain springy to a certain bending radius. So tiller gently and overbuild by adding width, not depth to the limb all else being equal.
Acts 10:12-13  "It contained all kinds of four-footed animals, as well as reptiles and birds. Then a voice told him, 'Get up, Peter. Kill and eat.'"

Offline Selfbowman

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Re: Overbuilt bows
« Reply #52 on: February 16, 2019, 04:05:43 am »
Sorry I wasn't very clear,,.if you make the bow wider and longer to to reduce set,,,,at some point the bow will be to wide or too long or both,,,show no set,,..but will be too,,Overbuit to perform well,,,having slow cast,,,and handshock

So the weight of the mass it's self and the energy the bow needs to propel this extra weight forward at some point over comes the atvantage of no set?
Well I'll say!!  Osage is king!!

Offline Badger

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Re: Overbuilt bows
« Reply #53 on: February 16, 2019, 04:16:05 am »
    Usually when I think of over built I just think of a bow that is under strained and the front profile doesn't match the tillered side profile. Usually it is the outer limbs that are overbuilt.

    A few years ago I built some osage bows on the short side around 60" long and recurved, I went very wide in the working areas with them assuming they would come in heavy in mass but the opposite happened. They came in light in mass just very thin. I think it is best to err on the side of too wide on the inner limbs. The outer limbs seems to penalize us more for too much mass.

Offline Selfbowman

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Re: Overbuilt bows
« Reply #54 on: February 21, 2019, 03:57:44 am »
Steve I agree that extra width on the inner limb can go with the overbuilt side without hurting performance. More mass on the inner limbs is not as critical as the outter limbs. At least that's what I have found with the pyramid design.  Arvin
Well I'll say!!  Osage is king!!

Offline Bayou Ben

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Re: Overbuilt bows
« Reply #55 on: February 21, 2019, 04:31:01 am »
Arvin, how wide do you normally go with your osage pyramids?

Offline Selfbowman

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Re: Overbuilt bows
« Reply #56 on: February 21, 2019, 10:12:05 am »
Pretty much as wide as the stave permits. Most of my flight bows are 2-1/8 -2-3/8 making the mid limb about 1-1/4 on 28" of limb.
Well I'll say!!  Osage is king!!

Offline Bayou Ben

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Re: Overbuilt bows
« Reply #57 on: February 21, 2019, 10:19:30 am »
Glad I asked.  I didn't realize you went that wide.