Author Topic: Bend radius and compression loading of osage  (Read 859 times)

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Offline High-Desert

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Re: Bend radius and compression loading of osage
« Reply #15 on: September 12, 2017, 05:43:25 am »
I think when someone says "any wood has an ideal thickness," it's not meant to mean any one wood species, but an individual Stave. I think that's what makes steves technique so useful, it doesn't matter what species you start to make a bow with, it allows you to design a bow from the stave you have.
Eric

Offline Dances with squirrels

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Re: Bend radius and compression loading of osage
« Reply #16 on: September 12, 2017, 07:02:14 am »
Ok High Desert, but that's not an accurate statement either. An individual Yew stave can make an efficient 1" thick English longbow or 1/2 thick flat bow, each with minimal if any set. One twice as thick as the other? I'm not trying to be difficult, I'm just concerned about the message that could be sent to the less experienced and don't want to limit or disuade their experimentation or enjoyment.

Offline Badger

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Re: Bend radius and compression loading of osage
« Reply #17 on: September 12, 2017, 07:19:00 am »
Ok High Desert, but that's not an accurate statement either. An individual Yew stave can make an efficient 1" thick English longbow or 1/2 thick flat bow, each with minimal if any set. One twice as thick as the other? I'm not trying to be difficult, I'm just concerned about the message that could be sent to the less experienced and don't want to limit or disuade their experimentation or enjoyment.

  Sure you can do that but you haven't optimized the design. The whole idea is to give the bowyer one more tool he can use when building bows. Most of the yew elbs I have seen are badly underbuilt and have taken way too much set. They don't need to take any set even after years of shooting.

Offline Badger

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Re: Bend radius and compression loading of osage
« Reply #18 on: September 12, 2017, 07:30:12 am »
    I got a bow from Wayne Olive, a 64" 55# recurve. One of the most well made and performing bows I have ever handled. The bow is 2" wide and weighs 25 oz. Most guys would build this same bow at about 18" oz but I bet they would not perform near as well. He chose dimensions that would handle the strain without breaking down is all it amounted to and it was reflected in exceptional performance.

Offline High-Desert

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Re: Bend radius and compression loading of osage
« Reply #19 on: September 12, 2017, 07:56:36 am »
I get what you are saying DWS, but it's still true, the statement just doesn't explain the whole process, it's not an equation. The ELB and the flatbow wouldn't be the same design, so maybe it should read something like "for any piece of wood, at a given design, there is one correct thickness."  Design meaning profile, tiller, length etc. that's just my take in it, I'm by no means correct.
Eric

Offline Badger

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Re: Bend radius and compression loading of osage
« Reply #20 on: September 12, 2017, 08:12:08 am »
I get what you are saying DWS, but it's still true, the statement just doesn't explain the whole process, it's not an equation. The ELB and the flatbow wouldn't be the same design, so maybe it should read something like "for any piece of wood, at a given design, there is one correct thickness."  Design meaning profile, tiller, length etc. that's just my take in it, I'm by no means correct.

  Eric you are correct, the weight of the bow is actually the thing that should have the least influence on thickness. Accomplished bowyers have been monitoring the condition of the wood for a long time, mostly not even doing it consciously so it is not a new thing. I never realized I was doing it until I held a small class and had to explain what I was doing. I had to think about the steps in order to explain it. If we know the wood we are working on and we usually build similar style bows we can hone in on the right design. But if we like to try different designs using different woods and a wide variety of weights it pays to have methods that will guide us instead of building a dozen bows to hone in on something.

Offline PatM

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Re: Bend radius and compression loading of osage
« Reply #21 on: September 12, 2017, 08:15:36 am »
Steve, Many underbuilt bows from recent years are that way because of your mass theory being a bit too skewed the wrong way. ;)


Offline Badger

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Re: Bend radius and compression loading of osage
« Reply #22 on: September 12, 2017, 08:22:15 am »
Very possible, I actually find it pretty liberal in most cases but if not applied exactly right I can see where a bow could be underbuilt. You have to allow more mass for every design change that adds stress.

Offline PEARLY

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Re: Bend radius and compression loading of osage
« Reply #23 on: September 12, 2017, 08:27:52 am »
You guys make my head hurt! I know you are trying to help, but if I had to guess most new folks would "flip" right through all this and have no clue. I know I don't. :) I just grab a stave and make a bow. I've never weighed a bow and never measure anything after the initial penciled in lay out is done. But I don't make a top performing bow either, well, not that I would know of.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Badger

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Re: Bend radius and compression loading of osage
« Reply #24 on: September 12, 2017, 08:37:18 am »
  Pearl, I am pretty sure you are doing it just naturally and not even realizing it, a lot of guys are.

Offline bradsmith2010

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Re: Bend radius and compression loading of osage
« Reply #25 on: September 12, 2017, 02:27:24 pm »
I take the mass principle as a guidine,,
once I see how the wood is responding,,then I follow that,,
watching the wood, and shooting through a chrono tells me alot as I go,,
there are alot of plates to spin,, to get to full draw and good durable performance,,
I learn something here every day, that helps me get there,, thanks guys,, :)

Offline upstatenybowyer

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Re: Bend radius and compression loading of osage
« Reply #26 on: September 12, 2017, 03:07:30 pm »
I take the mass principle as a guidine,,
once I see how the wood is responding,,then I follow that,,
watching the wood, and shooting through a chrono tells me alot as I go,,
there are alot of plates to spin,, to get to full draw and good durable performance,,
I learn something here every day, that helps me get there,, thanks guys,, :)

+1, except I don't have a chrony.  :(

My intuition tells me to first consider the species and quality of the stave I'm using and begin with a roughed out bow that is a bit too wide and bit too thick, but bending.

Then I use Steve's no set tillering as a guide, pulling it to the target draw weight asap and trying to get a nice even bend asap.

From there, I take off an even amount of wood across the limbs (not as easy as it sounds) until I finally reach 1 or 2 inches shy of the target draw length.

After the sanding and such hopefully I'm right where I want to be.  :BB
« Last Edit: September 12, 2017, 03:13:37 pm by upstatenybowyer »
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline Beadman

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Re: Bend radius and compression loading of osage
« Reply #27 on: September 12, 2017, 05:43:12 pm »
I take the mass principle as a guidine,,
once I see how the wood is responding,,then I follow that,,
watching the wood, and shooting through a chrono tells me alot as I go,,
there are alot of plates to spin,, to get to full draw and good durable performance,,
I learn something here every day, that helps me get there,, thanks guys,, :)

+1, except I don't have a chrony.  :(
In a nut shell that's the way I do things too.What confirms things for me I'm not stressing the wood too much when tillering towards the end to full draw too is the feel of it when I unbrace it.If it feels very stout yet that's a good thing and I did something right.That might be a wrong or an illusioned observation meaning it's just really dry wood....lol, but it has worked for me.

My intuition tells me to first consider the species and quality of the stave I'm using and begin with a roughed out bow that is a bit too wide and bit too thick, but bending.

Then I use Steve's no set tillering as a guide, pulling it to the target draw weight asap and trying to get a nice even bend asap.

From there, I take off an even amount of wood across the limbs (not as easy as it sounds) until I finally reach 1 or 2 inches shy of the target draw length.

After the sanding and such hopefully I'm right where I want to be.  :BB
You got to stand for something or you'll fall for anything.
Ed

Offline upstatenybowyer

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Re: Bend radius and compression loading of osage
« Reply #28 on: September 12, 2017, 05:49:50 pm »
Heck ya Ed. That moment the string slips off and the bow responds says a whole lot for sure.
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

Offline Dances with squirrels

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Re: Bend radius and compression loading of osage
« Reply #29 on: September 13, 2017, 02:28:06 am »
Steve, I hear ya on bow making classes. When I started holding them and having to explain EVERYthing in detail, instead of just doing it, I learned a lot..... more than THEY did, I think  :)