Author Topic: Wood Bows in a Production Environment?  (Read 3496 times)

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Offline mmattockx

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Wood Bows in a Production Environment?
« on: October 15, 2021, 01:10:03 pm »
Back before fibreglass lams existed there were plenty of all wood commercial bows produced. Considering the inconsistencies inherent with wood and the time required to carefully tiller each bow to match the properties of the wood in that particular bow, how did anyone manage to turn all wood bows out on a production basis and have a quality, consistent, reliable product?


Thanks,
Mark

Offline bownarra

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Re: Wood Bows in a Production Environment?
« Reply #1 on: October 15, 2021, 02:47:16 pm »
Laminating :)
If you can get quality STRAIGHT grained backing woods consistantly you are off to a good start (Velum was a pre-glass 'glass' which helps here).
Same with the belly wood really, wavy grain, dips, wiggles etc lower compression qualities so making tillering more important. The straighter grained the wood the more consistant it will react.
Grinding cores to a taper that will get you very close to tillered at glue-up/clean up is another way to skip a whole bunch of work. Understanding your designs width taper and how that correlates to thickness taper will take the guess work out of taper rates.
Don't go too 'extreme' with your designs.
It's not that hard if you can get the wood ;)

Offline PatM

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Re: Wood Bows in a Production Environment?
« Reply #2 on: October 15, 2021, 03:06:12 pm »
Back before fibreglass lams existed there were plenty of all wood commercial bows produced. Considering the inconsistencies inherent with wood and the time required to carefully tiller each bow to match the properties of the wood in that particular bow, how did anyone manage to turn all wood bows out on a production basis and have a quality, consistent, reliable product?


Thanks,
Mark

 They typically used woods which lend themselves to mass production.  Lemonwood and Hickory.
   Then lamination was the next step.

Offline mmattockx

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Re: Wood Bows in a Production Environment?
« Reply #3 on: October 15, 2021, 03:10:17 pm »
Laminating :)
If you can get quality STRAIGHT grained backing woods consistantly you are off to a good start (Velum was a pre-glass 'glass' which helps here).
Same with the belly wood really, wavy grain, dips, wiggles etc lower compression qualities so making tillering more important. The straighter grained the wood the more consistant it will react.
Grinding cores to a taper that will get you very close to tillered at glue-up/clean up is another way to skip a whole bunch of work. Understanding your designs width taper and how that correlates to thickness taper will take the guess work out of taper rates.
Don't go too 'extreme' with your designs.
It's not that hard if you can get the wood ;)

What you describe is basically my approach to this with the goal of removing as much of the art of tillering as possible from making a bow, but I also measure the stiffness of each piece of wood I use and have to customize limb dimensions to suit that particular piece of wood in order to hit a target weight. I can't just buy a lift of boards and make a bunch of bows from them with identical dimensions and have them all come out at the same weight and performance. There is just too much variability in the wood for that to work well.

Perhaps getting consistent wood was much easier a century ago, but it still seems amazing to me that it could be done on any commercial scale without having each bow fine tuned by a skilled hand.


Mark

Offline Selfbowman

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Re: Wood Bows in a Production Environment?
« Reply #4 on: October 15, 2021, 03:46:41 pm »
I think if they hit within2-3# they called it good for the most part. But Iím not as old as some of the guys here and have only been at it for 17 years . But yes what you see left mostly are Lemmon wood and hickory. Arvin
Well I'll say!!  Osage is king!!

Offline Don W

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Re: Wood Bows in a Production Environment?
« Reply #5 on: October 15, 2021, 04:15:05 pm »
You're talking about a time when skilled labor was skilled. Think about all the tools and equipment mass produced that took skilled workmanship. The industrial revolution brought about advancement in production, but finishing steps where still skilled labor for many years after and I'm sure the Europeans had bow making down even before that.
Don

Offline bownarra

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Re: Wood Bows in a Production Environment?
« Reply #6 on: October 16, 2021, 02:56:49 am »
You can't completely remove the tillering. Even glass bows need some tillering.
I wouldn't bother measuring density of the wood. Feel is good enough to get you in the ballpark. As long as you aren't dealing with junk wood!
The way to hit weight is simply to make the bow 5- 10# overweight then remove the excess by narrowing it. Weight loss is proportional to width reduction.
There were lots and lots of bows made from fancy tropicals but you tend to see the lemonwood and hickory bows because they were mass produced, just lots of them in existence so you are bound to see more of them. These were cheaply produced in large numbers for youngsters. Check out the TBB for the section on laminated bows....plenty of examples of old lam bows there - with fancy woods aplenty. These sort of bows are valuable and mainly in a collectors collection, hence why you don't see them.
Here in England the bowyers of old could get any wood...not now! Not saying I agree with how they were acquired but they could get just about any wood.

Offline mmattockx

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Re: Wood Bows in a Production Environment?
« Reply #7 on: October 16, 2021, 10:58:27 pm »
You can't completely remove the tillering. Even glass bows need some tillering.

I understand and agree with that, I am just trying to minimize it.


I wouldn't bother measuring density of the wood.

I'm not measuring density, I am measuring the material stiffness. I make a bend test sample from each board I am going to use and measure/calculate its modulus of elasticity so I can calculate how thick the limbs need to be for my desired weight. As I build up a number of data points for the various woods I am using I will need to do less testing and will be able to look at past results instead but I haven't done enough to have a good baseline yet.


Mark

Offline Selfbowman

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Re: Wood Bows in a Production Environment?
« Reply #8 on: October 17, 2021, 12:01:03 am »
Farm out the tillering if needed. If this is about mass production. But I think you are on the right track to eliminating as much tiller as possible. Arvin
Well I'll say!!  Osage is king!!

Offline PatM

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Re: Wood Bows in a Production Environment?
« Reply #9 on: October 17, 2021, 12:28:22 am »
It would be interesting to see how density compares to material stiffness.

Offline mmattockx

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Re: Wood Bows in a Production Environment?
« Reply #10 on: October 17, 2021, 01:41:57 am »
Farm out the tillering if needed. If this is about mass production. But I think you are on the right track to eliminating as much tiller as possible. Arvin

I am not thinking of production for myself, just was wondering how people made it work considering how much variability there is in wood. I'm avoiding the tillering as much as I can because it is a hard skill to gain and I don't want to make 300 bows just to get a handle on it. So I substitute engineering ability for artistic tillering ability and use the skills I already have to make it work instead. Lots of ways to skin the cat in the end.


It would be interesting to see how density compares to material stiffness.

See, there you go making me think I need to start keeping track of that as well. It isn't hard to work out with boards as my source material but I haven't been bothering for the most part. Maybe I will start measuring and recording density as well going forward. In theory, more data is better but eventually you have so much data it becomes difficult to sort the wheat from the chaff and get useful information out of it.


Mark

Offline Gimlis Ghost

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Re: Wood Bows in a Production Environment?
« Reply #11 on: October 17, 2021, 01:52:51 am »
By the time of Henry VIII England had over harvested its best stands of Yew to the point that it was difficult to get decent quality staves for long bows. It was necessary to import Yew from mainland Europe as far away as Central Europe. Even then over harvesting in some countries forced them to curtail further sales to England.

Its unlikely that by the late 19th century any lumber companies were specifically harvesting trees with an eye to the best wood for bow staves but some no doubt put aside the best straight grained wood to be picked through by buyers. Anyone in the business of making bows would pick and chose from what was available, paying a premium for wood that suited their purpose.

While Osage Orange is widely considered the best wood for bows, while the trees are very commplace in much of the USA its not that easy to find mass quantities of straight grained staves. If it were all wooden self bows mass produced in the USA would have been Osage Orange.
Years ago I looked up a few sites selling Osage Orange staves and could not find any that I'd have risked making a bow of with my limited skills. I did find a number of staves that had fine looking wavy grain for half the length , the grain giving it the look of a Kriss sword. I considered buying two such staves and cutting them in half to make two takedown bows, one with straight grained limbs the other with those snakey Kriss shaped limbs.

Offline Selfbowman

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Re: Wood Bows in a Production Environment?
« Reply #12 on: October 17, 2021, 06:40:06 am »
It would be interesting to see how density compares to material stiffness.

Pat you will find a direct coalition between densely and stiffness Iím pretty sure. Arvin
Well I'll say!!  Osage is king!!

Offline Don W

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Re: Wood Bows in a Production Environment?
« Reply #13 on: October 17, 2021, 08:15:42 am »


I am not thinking of production for myself, just was wondering how people made it work considering how much variability there is in wood. I'm avoiding the tillering as much as I can because it is a hard skill to gain and I don't want to make 300 bows just to get a handle on it. So I substitute engineering ability for artistic tillering ability and use the skills I already have to make it work instead. Lots of ways to skin the cat in the end.




Mark


I started a similar thread with a similar idea a while ago. I've actually started trying to take detailed measurements of bows (I have a few posted on my website) with the thought of reproducing of the measurements of a working bow.

If the wood species are the same it will get you pretty close. Adding extra "even" thickness for higher weight or a different wood (until it's known) will also get you close.

My suggestion was if enough people helped keep track, eventually we'd have a pretty good database full of known dimensions of good working bows.

My problem is time, and there didn't seem to be much interest in participating.
Don

Offline Selfbowman

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Re: Wood Bows in a Production Environment?
« Reply #14 on: October 17, 2021, 09:36:11 am »
Don I think TBB already addressed this in that the more dense the less the wood would float. So pine had to be about twice as wide as Osage for example.  I think that weight = density= stiffness they all three make up the mass in a working bow. How you distribute the mass is the secret to better performance. This  Is more technical than I can do the math for . But itís my gut feeling. Mark it might be easier to build 50 bows . Just saying. Arvin
« Last Edit: October 17, 2021, 09:50:45 am by Selfbowman »
Well I'll say!!  Osage is king!!