Wood Bows in a Production Environment?

[bassman211]

I made quite a few bows for the boy scouts, and girls scouts in my area. Some times a run of 6 to 10 bows in the 20 to 35 lb. range. so that all would have their own bow. Made them from straight  grain hickory wagon wheel staves which were 1 and a half by 1 and half inch staves a bought from the Amish, and cut them edge grain. I laid them out Pyramid shape. Cut them carefully on a good band saw, and with a little belly tillering, and a linen back could turn  out a decent bow in short order. Not mass producing, but the best quickest way I found  to make decent bows by the numbers in the 20 to 35 lb range.

[Don W]

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 it’s my gut feeling. Mark it might be easier to build 50 bows . Just saying. Arvin

This doesn't help a beginner bow maker until he (or she) understands what it means, and that means making a number of bows. As you said, This  Is more technical than most beginners can understand until you've seen it working, if you can ever. And you need to understand the variations in the wood itself and give a little leeway.

Most beginners want to make a bow that shoots well and is within some reasonable draw weight range.

Take this bow for instance
http://www.primitivearcher.com/smf/index.php/topic,70563.0.html

Take this comment specifically (which helped me, and should help anyone else reading it)

Correct observation by bownarra and should have mentioned it but I don't make too many bendy handled bows myself.Making that thickness of .84 extend out a few more inches either way from the handle for a more eliptical tiller.
Shooting heavier arrows does reduce handshock a bit too making the bow more efficient with bows 5.5' in length.To really see if a bow has no handshock shooting an 8 grain arrow will show you too.Right now your shooting around a 11.5 grain arrow.

If I had beginning dimensions of this bow before going through the trial and error, I would have made the .84" longer. The only way we knew it was .84" and the .84" needed to be longer, was I documented it. I haven't documented the final numbers yet, I wanted to wait until it was well shot in, but the point is, someone could now take a HHB stave, match my measurements (or stick with the original and just make the .84" longer) and they would have much less trial and error to go through.

There will still be final tillering, but not nearly as much. I've copied like this twice now, and it's got me very very close. I haven't even needed to floor tiller and final tiller on one went straight to shooting.

I typically take a spreadsheet, layout the dimensions, then create a new row that adds .02" to each measurement. One could be a little safer and add .04", to give some leeway in tillering or add a little draw weight.

TBB is a great start, but there is a lot of conflicting information from vol 1 - vol 4, and it can get very confusing at first.

I've only done this with HHB, but I think Hickory would be very close to the same dimensions. I don't know how far off other wood would be.

If everyone documented their bow this way, and we could compile that info, a beginner could say, "I want a 60" maple bow, 45#@28" and if he could find a few examples with dimensions like this, I believe he could make his first bow shoot, if he had the woodworking skill to follow the dimensions as I described.   

Maybe he'll eventually learn to tiller a tough knarly knot ridden bow, or maybe he'll make 3 bows his entire life he hunts with.

I know an experienced bowyer can make a bow by feel, and I get that, but my 2 dozen shooters, and my three dozen broken remnants in the corner hasn't gotten me there yet, and at my age, I may not ever get there, but this kind of information will help me and many others make bows to hunt with, shoot when they want, and continue to make better bows (whatever that means)

[Selfbowman]

Don I’m not saying this information is not a good way to start. But then there are the Arvin’s in the world that can’t do the math . 😁😁 bowanarra was right about the tillering and Don you know how I feel about character bows. I’m all in on straight line bows. Does not matter how we get to a good shooting bow . The hope is we end up with one. Arvin

[RyanY]

Mark, if you can nail the width/thickness tapers to result in your desired tiller, you could make bows slightly thinner than expected with proportionately more width for the draw weight. My hunch is that most hardwoods don’t vary so significantly in elasticity that they would need to be different thicknesses. Width would be the biggest area for adjustment.

[mmattockx]

Mark it might be easier to build 50 bows.

Arvin, that works for you the way you can crank them out but at the rate I make bows I may be dead before I reach 50. Now that I am moved out to the country and can get settled for good here it should improve but my shop time is still limited enough that I will never be a big producer of bows.

If everyone documented their bow this way, and we could compile that info, a beginner could say, "I want a 60" maple bow, 45#@28" and if he could find a few examples with dimensions like this, I believe he could make his first bow shoot, if he had the woodworking skill to follow the dimensions as I described. 

I asked similar questions when I was making my first bow and there was very little in the way of solid info. All I wanted was very rough dimensions to get me in the ballpark and then I figured I would work it from there. I don't know if people are not interested in sharing or very few record much data on their bows and genuinely can't answer that sort of question, but it does make it tougher on the new guys trying to end up with a functional bow.

Mark, if you can nail the width/thickness tapers to result in your desired tiller, you could make bows slightly thinner than expected with proportionately more width for the draw weight. My hunch is that most hardwoods don’t vary so significantly in elasticity that they would need to be different thicknesses. Width would be the biggest area for adjustment.

That is an interesting approach to getting close quickly and then fine tuning from there. Once I have some more experiments out of the way I may give that a shot and see how it works out.

I have seen 10-15% variation in stiffness in maple and red oak, which is a fair amount to cover with just tillering the width. I have some hickory I will be testing next year and am interested to see how that turns out.


Mark

[Hamish]

In this day and age no matter how much you rationalised the production process, trying to make self or laminated wood bows, you would soon realise that you could make more bows/profit from making them out of modern materials, like fg, carbon fibre etc.



Mike, known as Bowanarra here made a pretty good effort at it a few years ago, with quality made bows, from quality materials, self and laminated traditonal bows (as well as some nifty fg bows too).  I think it ended up being a lot of work, for not enough profits, which is a real shame because he does a great job. (correct me if I'm wrong on why you stopped producing bows for a living please Mike?)

It was a different matter pre fibreglass. Timber suppliers knew what to look for, to meet the needs of the industry, so if you bought a truck load of timber you could be assured that most of it would be suitable for bows.

Patterns for layout, glue presses for laminating, jigs for splice cutting were all available at least since the 19thC. So too were mechanised saws, table routers for shaping the bellies of English longbows, various power sanders, belts and  inflatable drums for tillering, rather than scraping.

The best bows of the industrialised era were still made by skilled craftsmen, professional bowyers.

James Duff book Bows and Arrows, has some insight into how it was done professionally.
 Stemmler's book Essential's of Archery also has some good insights into the process too. He provides information on dimensions for bows of certain materials, styles and draw weights. In practice they won't necessarily give you an even well tillered bow, if you make them to the said dimensions. They might be whip tillered, overweight, underweight, twisted etc. You still need the eye and the experience of a bowyer to correct the issue when things don't go  how they were supposed to.

[bownarra]

Exactly right Hamish and thanks for the kind words. I'm still knocking the odd one out for some pennies but not for much longer. I want to get back to making fun bows, pushing the limits and breaking stuff.

[Badger]

One time I had to build about 2 dozen bows for a reenactment group. I built 28 assuming I might loose about 4 of them. I only had one weekend to build them. I cut them all out on a bandsaw and tillered them with a spoke shave. I believe I had about 30 minutes into each bow and they came out decent, weight went from 25# to about 50#. None of them broke. I spent the rest of the week making the strings.

[Hamish]

I'm impressed by bowyers that can make a decent bow in one day.
There are many excellent bowyers out there, that can make a wonderful bow, given their allotted time.

There are only about 2 bowyers I would trust with a 30 minute bow. Badger and Tim Baker. Both individual legends of the modern wood bow renaissance.

[Selfbowman]

I agree with that!! Arvin

[bassman211]

Badger, what wood, and were the bows cut from staves?

[txdm]

mmattockx and others,

Does bamboo provide a more consistent elasticity from tree to tree than hardwood? If so, then maybe bamboo laminates would be more predictable and mass produce-able...and couldn't you then use almost anything for the core?

[mmattockx]

mmattockx and others,

Does bamboo provide a more consistent elasticity from tree to tree than hardwood?

That's a fine question that I don't know the answer to. Hopefully someone else can answer it or point to some research that answers it.


Mark

[RyanY]

I could be wrong but I think some bow makers have done that with the outer face of the bamboo on the back and belly. Likely tapering the lams to very specific dimensions and minimal tillering done with removing material from the width.

[Hamish]

Bamboo laminates have consistency, but so would laminated wood from a proven bow species.

The problem with bamboo is that the "wood" under the power fibres is not as strong(in both tension and compression). To process the material into lamelles requires flattening, and much of the power fibres are removed.
It is possible to maximise the powerfibres, but it involves a lot of time, and effort to ensure you are doing it properly, so its not a cheap, or quick method if you do it properly.

Bamboo for the belly is more resistant to compression if you heat temper it, so that adds another level of time and labour.

Before fg was invented all bamboo laminated bows were seen as the apex of bow performance in regard to durability. They were some of the most expensive bows to buy because of the skill and labour involved.

Manufactured bamboo floorboards make a good belly timber, in regard to resisting chrysals.  They do take a lot of set, so it should be  glued into a reflex. The stuff is relatively light because much of the power fibres have been removed, so the limbs will look a lot thicker than a hardwood bow of the same draw weight. They still need a hickory, or bamboo backing, as the nodes have been severed and will break in tension sooner or later. They usually survive tillering and shoot in though. Don't be fooled.

Bamboo laminates are ideal for core woods, as it is relatively light, yet strong for its weight. 'That's why they are used for modern fg bows. You still need to remember the fg is doing all the work in tension and compression.