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Main Boards => The Bowyer's Bench => Topic started by: RayMO on September 25, 2008, 08:42:00 AM
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I have made a half dozen BBO (Dean’s method here) and several flat self bows using hickory staves, some have been shooters but I really have not been satisfied with any of them. So I am looking for a simpler approach that results in a good bow. I know that some may argue that dropping trees and splitting staves and pulling on draw knives is great fun, but all it every did for me was make me sore.
Here is an approach I have been thinking about, have not tried it just thinking about it, what do you think?
1. Get de-crowned board from saw mill (not to hard to do in Mo and a lot easier than splitting logs). Any good hardwood would do here, (Ash, cherry, maple, etc.)
2. Layout the Pyramid shape on the board, going down to 3/8 on the knock end. I am thinking 2 inches at the widest point, but the exact dimensions are not that important to the procedure, say 68 inches long.
3. Leave the cut out blank maybe 1/2 inch thick (uniform thickness no taper)
4. Here is a part I am not to sure about, I would like to put bamboo (maybe hickory) on the back also and glue in about 3 inches of reflex. Not so sure how that will work without a tapered blank?
5. Here is the part that is a little different: From what I understand the Pyramid should bend to a good circular tiller (assuming a uniform blank) and draw weight should be achieved by uniformly reducing the thickness of the belly. It is my plan to simply use a jointer for this (looking for easy here, no facets no bowers edge).
6. If all goes will (that’s funny) I will have a bow at this point. But a circular tiller with whippy ends is not my idea of a sweet shooting bow, so I would then plan on adding an overlay to the grip and overlays on the belly ends to stiffen up the ends and the middle.
Anyone every tried an approach like this?
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I did a Pyramid style bow from a home depot board I tapered from fades to tip, tips being .5" thick. I didn't back it nor did I reflex it.
If Your adding reflex I would taper it so you can get the bend of the reflex, well that is what I had read. O I did my with Red Oak.
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(http://i2.photobucket.com/albums/y16/mysticguido/53AT24.jpg) My Avatar is the same bow after I finished it. It is sitting at 51#@24" and is 70" N2N
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mysticguido
Thanks for the input, nice looking bow. I was thinking the same thing about the backing. Anyone else?
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Pyramid bows should have a circular tiller. Wide near handle wood should be doing a big share of the bending as opposed to the tips. The trick to tiller such a bow is to not tlet the handle bend too much as that might make it shocky. Mysticguido's bow is an example of an elliptical tiller. Jawge
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1/2" is too thick. Start with 3/8 and make sure your profile is perfect and you shouldn't have to do a lot of belly tapering. Most of the tiller in a pyramid bow is accomplished through the taper in the sides. If your wood is good, desing is solid and your technique is flawless, you probably won't have to belly taper at all. I made a pyramid red oak in about 10 minutes coming straight off the bandsaw tillered. It was 1/2" but 72" long.
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Thanks Jawge, I was hoping you would jump in here. Leave the handle wood thick during the weight reduction process, got it.
What's your thoughs on backing? Not to do or not to do, but puting in reflex during glue up.
RayMO
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Just saw your post John. Ok, 3/8 and not 1/2. That is exactly what I was thinking also, just use a jointer to reduce evenly along the limbs and no tappering on the belly thickness.
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Ray if you are going to use bamboo for a backing I find it best to shape up the bamboo to it's finished dimensions and pre-taper the bamboo down to the bow tips before I glue it onto the bow. It might be easier to use the hickory as backing for the first one as you can shape it up when it is glued onto the bow, unlike bamboo...Glenn...
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Thanks Glenn,
It never occured to me that you could shape/reduce a hickory backing after it is glued. I have only used bamboo so far and you are pretty limited with it after the glue up.
I am kind of confused on the backing issue.
Most agree that the thickness should be tapered if you are going to put reflex and a backing on. However, the Pyramid bow gets most of its shape (tiller) from the shape of the limbs and I wonder what a taper in thickness would do to the tiller of a Pyramid bow? To me the advantage of the Pyramid design is that you do NOT have to mess with a taper in the thickness.
I guess somethings you just have to try.
Anyone made a Pyramid bow with backing and some reflex at glue up time???
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You are making this harder than it has to be. Start carving. Stop thinking. The beauty of a pyramid bow is its simplicity.
I wouldn't necessarily back it. I prefer a selfbow. If you are doing bamboo get Dean Torges' video, "Hunting the Bamboo Backed Bow".
Why do you want to back it? If you want simple, selfbows are it. If you do the selfbow, go with 1/2" thickness.
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Ray if you do any bow with bamboo I think it is essential to shape it up so that you can pre-taper the bamboo and take the stress off the outer bow limbs and reduce some string follow. Bamboo is probagly one of the harder backings to work with but it does look and perform nice that's for sure...Glenn...
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Ray, I never did a bamboo or a wood backing. Like john, I like selfbows too. I do back some bows if needed. I prefer silk, linen, burlap and rawhide. Again pyramid bows need to get that near handle wood bending quite a bit. Jawge
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George I like all of my bows bending near the handle. The bow will store energy if it bends near the handle the most and bend all the way to the tips but bend gradually less, some styles of bows will vary on this but basically I like to see them bending coming off the handle. For pyamid bows I prefer a selfbow myself.
I do find it hard to get the near handle timber bending when the width of the limb flares out to it's widest measurement only 2 inches up from the handle, I like to take the flares up to 5" above the handle it is more gradual transition from the handle and not as abrupt, I find that style much easier to get the near handle timber to bend...Glenn...
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Thanks for all the great input I really appreciate it.
I had an old hickory stave in the basement that I took the back off of years ago. I cut it out in a Pyramid shape Saturday. 68" long 2 1/2 wide to 1/2 inch. Have not done anything with it yet.
Last hickory bow I made that was a shooter was back in 2001. The lower limb exploited on me. I always felt that the wood got too dry in the house during the winter (it was sealed). Made me wonder about the durablility of selfbows without backing.
Oh well, I also have about a half dozen hickory selfbows from years gone by that have too much string follow and at least a half dozen of Dean's BBO which the tiller is less than perfect on. I keep thinking one of these days I will get a wooden bow that I am satisfied with, but then maybe that is not possible. :D
I have always liked a bamboo backing because I believe the stuff makes a bow more durable, but the bows I have backed with bamboo have all been 64" (osage belly) and less so I don't have much experience with 68" and longer.
I am not going to back this lastest attempt :D here we go again.
RayMO
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Ray, Is the reasoning for the hickory backing to induce reflex to the limbs? If so, you don't need thickness tapered backing. Parallel is perfect for a pyramid bow. Just glue it up into a reflex. Then shape and tiller as you would for a straight limbed pyramid. Just my 2 cents worth.
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Yes, linc I was just trying to stop the bow from taking a set. I could steam a slight reflex in but that would actually put more stress on the back of the bow.
I was trying to accomplish the following:
1. A bow that is very easy to tiller, hence Pyramid shape. I was even thinking board bow and tiller (really just reduce weight) with a jointer. Simple and repeatable.
2. Put the backing on to prevent set and add duability to the bow.
Now, I know there are a lot of different opinions about this by guys that know a whole heck of a lot more than I do. In the TBB it is sort of concluded that backing is not need for bows 66" and longer, I don't know....??? I guess when you have build 68" bows and had one break and several others take sets you begin to think backing is a good thing no matter how long the bow is.
The real bottom-line is that I am just trying to come up with a "good" shooting bow that I can count on and reproduce each time. With a lot of guys it is the challenge to take a stave with a lot of character and by great tillering and patience come up with a great shooter. My objective is kind of the opposite here.
Anyone???
RayMO
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A tapered bamboo backing on a pyramid bow should accomplish your goals. Once you get the process down, it is more of a science of assembly than the art that stave bows generally are.
However, a glass bow is superior in ease of manufacture, consistency and durability to any wooden bow or composite. If your primary goals are those, you might want to reconsider your desire for an all-natural bow in general.
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Thanks for your input John. I have made some glass bows also, they are ok but I am not that happy with them either; however, I have drawn blood on more than one occasion with them. You are right that what I am suggesting is more of a science than an art. And you are certainly right about a glass bow being easier to make. Just depends on what you want.
Anyway it is just all talk at this point, after the season I think I will get busy trying it out.
The challenge I am proposing is somewhat different:
I am just trying to come up with a "good" shooting bow that I can count on and reproduce each time.
Again, thanks John
RayMO
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I'd certainly say the Bamboo Backed whatever will do it. As for "good" shooting, most well-designed and constructed bows can accomplish that. Most shoot where they are pointed. In fact, I'd argue the shooter does the shooting, not the bow. What is it that you don't like about your other BBOs?
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Yeah, I agree completely about the shooting. Good form is good form and it doesn't matter what you are shooting.
I find the BBO to be very durable with great cast, my problem is that I have never been able to get one tillered to suite me. I am pretty particular I guess. The last one I worked on (about mounth ago) got a hinge in it and I just layed it aside because it would not hit the weight I want. To big of a hurry when working on it. I do have two of them that are shooters. I got one layed out right now ready to glue the backing on. I don't consider myself much of a wood worker, I think it really takes a good eye and patience to tiller a BBO even using Dean's facet approach to end up with a well balance and timed bow. I have always glued R/D into my BBOs, maybe that is harder to tiller?
I have always wanted to get at least two wood bows that I am satisfied with and the confidence that I can make another one just like it before I commit to hunting with it.
As far as the glass bows go they are ok, but they don't come close to what a master bowyer does. you feel it in the balance and release.
Regardless, I am enjoying the challenge John! And I could write a book about what not to do...
RayMO
That bow laying on that spike picture of me is a glass bow I made.
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For me, the biggest chance of coming up with a good bow is to get the glue-up from Dryad and follow the instructions contained in the DVD.
It results in a very good performing bow and a high percentage of successful outcome.
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Bjorn,
I know that Dryad bows are very highly thought of. What are the basics of the Dryad approach to tillering? Do they recommend reducing the belly in facets? Flat reduction? Can you get the DVD without buying one of the glue-ups?
RayMO
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If you are making a pryamid bow aren't they fairly wide? You would have to have a fairly large dia. bamboo pole to cut it from. Wouldn't you be better of with the hickory backing for a pryamid bow.
I like a narrower bow around 1.25" wide for a bamboo backed bow I like to use around belly for the bamboo backed bows as against the flat belly bows which I have gone right off these days...Glenn...
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Yes Glenn, I think you are right on all counts. It would be difficult getting a piece of boo that wide flatened out (2 to 2.5 inches).
The BBO bows I have made are as you suggest. I was just thinking that a flat bow design maybe easily tillered with a jointer than a round belly with a scrape.
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Glenn St Charles used a small jointer in "Billets to Bows" video and lots of folks complained about it, but he explained that he was trying to make a living making bows and time was of the essence.
I have used a large edge sander with good results on an osage self bow (don't tell anyone).
The only flaw I see in your plan is that wood is not a uniform material. You will be unlikely to be able to reproduce a result or to tiller without going through the usual steps of floor tiller through final draw. The wood will still have to "learn" by bending and getting worked in from exercise and shooting.
Dean says something along the lines of "dry wood expertly tillered" is the key to less string follow and a good shooting bow.
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Yes Shaun, I suspect you are right and as you said there is no short cut to teaching the wood to bend even if all blanks were uniform which we know there not.
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RayMo tha tillering approach is facets using a protractor. You reestablish the facets as material is removed.
And the blank get exercised between frequent trips to the tillering rack-7 trips approx.
I believe the 'Faceted Tillering Method' is also used by Dean Torges.
I do not know for a fact if the DVD is available by itself; but it does/did show up as a line item on the Dryad website.
You can buy glue ups from Dean Torges too(when he has them) and Raptor Archery among others.
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I see making self bows as an evolution, with room for going in all kinds of directions and lots of opportunities for trial and error, you have to love the process at least as much as the result.
My best bow so far is an R/D; Bamboo, Bloodwood, Osage, that John Strunk and I glued up together and I tillered using his method, it was an honor to work with the guy.
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You got the "love the process" right, but it would be nice to get close to a bow you real like once in a while. :D
Life just isn't right if there is not a bow in progress... :thumbsup:
RayMO
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Ray, I do this all the time. It is one of my fav ways to play with new ideas and materials. I generally use oak cuz the bug bites me and I run down to Lowe's.
Basically, what I do is a lot like you are describing. I have a planing table that I made that allows me to run my power hand planer over a board and take it down to any desired thickness. I am tall and pull long, so I usually start with at least a 70" bow, 2" or even more wide, and a little over 3/8" thick. Perfect boards and backed bows
If the limb's side taper is uniform, even circular tiller is essentially automatic, although wood is wood.
I cut in a narrow handle, and then add fades as short as I can get them, to leave the working limb some length. I add a thin lam (1/8"-3/16")of some "better" bow wood to use as a fade, so I can get it really thin if I have to to prevent the handle popping off. So on oak I would use good hickory or mulberry. On hickory, maybe osage or ipe. Then, you can add little tapered lams on the belly side of the tips and sweep them in from the sides to make a thinner/deeper, lighterweight slightly stiffer tip to make the bow shoot sweet.
On a backed bow, it changes a little. Instead of just a handle with fades, I often put a power lam on the front under the backing. This doesn't work as well with fabric as it does with hick'ry or bamboo. Then the handle on the belly side won't be as likely to pop off. I have used a short piece tapered each direction with a table saw, planes and/or sander, and usually don't go thicker than 1/8". I have also used some thicker veneer, I think it was 1/32" thick, and created a taper by glueing a 4" piece on top of a 6" piece on top of an 8" piece on top of a 10" piece, on top of a 12" piece, on top of a 14" piece. See what I mean? Like a human pyramid. Running a sanding block over it after it dries takes down the little stair-steps, and the backing goes on over that. I do the same thing if I want thicker, narrower tips. Putting them under the backing, not on the belly, prevents then from having to take much load either in tension or compression, and creates a tiny bit of set-back or reflex.
One of the things I like about that there method is that you can get away with a lot in areas you aren't asking to bend as much, like the tips. If you tried putting a veneer on the belly, , esp. where it bends much,it wouldn't work.
Reflexing a pyramid limb will change how it behaves. Both will get the limb working even more close to the handle and in the first half of the limb.
I have had the best luck getting it to a good even tiller (usually automatic with consistent thickness and even side taper) and then reflexing either by adding semi-recurves close to the ends, or by adding a long, even reflex that extends the length of the limb. That kept tillering concerns pretty simple. Middle of the road didn't work well with a pyramid, for me.
I would taper a bamboo backing, or the limb will be getting stiffer and stiffer toward the tips, really overworking the inner limb. This is due to the bamboo's crown. If the thickness is consistent, the limb will be thin at the edges, and crowned close to the handle, but full thickness and square at the tips. A hickory backing that keeps the flat back and belly and the rectangular section might be a better choice.
And BTW, since I draw 29" (and I like it that way) a backing is a necessity on a 66" bow for me. Or I have to go 3-1/2" wide.
A pyramid bow doesn't have to be wide, but the same rules about material selection apply. I could make a long pyramid design in good hickory (I live in a dry climate) and go 1-3/4", but if I was trying to make a 66" or even a 64" out of oak, I wouldn't dream of having it less than 2-1/2" wide. At least.
Even with the thick spots added, The tiller is predictable, if not automatic. I put it on the tree and carefully bend it just far enough to see it bend a little. The backed bow I just described; thickened handle with fades and stiffened tips, will bend right off the fades first. From there, if I need to get a TINY bit more bend, I just take a little off the sides with a plane. If I need a bit more, I scrape the belly a little. Or, I take the belly corners off just barely and take the belly flat down next, kinda like the faceted tillering method.
You will never get away from having to adjust tiller a little, esp. if the handle is below center, or whatever like that. Just watch that handle bend a touch and chase the tiller out from there.
The last one I made, linen backed, was @ 7/16" thick, 68" long, 2 1/2 at the widest, glued with 2 layes of linen into 3" of reflex, with veneer-stiffened tips with a handle and a single piece power lam about 1/8" thick tapered down, about 12" long. I restored it to a circular tiller over all but the last 7" of limb tips. I drew the taper to a point and then added lines that started 3/8" wide and ran till they hit the taper lines, so about the last 5" was parallel.
I had to do some minor adjusting at the fades, and some slight belly scraping mid-limb, and some narrowind and smoothing near the tips. I ended up with a rectangle cross section maybe 3/4 of the way out and the belly side of the ends reverse trapped a little and sanded round. I did that mostly to save weight and because I could get away with it.
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Thanks Springbuck, sounds like you have already tried what I was thinking about. Thanks for sharing all the details.
RayMO
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all right, ray, i have been watching this thread for almost 2 weeks now with baited breath...i am going to make my first pyramid in the very near future for a friend of mine...start making the bow! i can't wait to see how this turns out. i have learned so much from this thread already.
thanks
stan
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Stan,
It will be a while, I have decide to go back to a BBO bow that I have a hinge in and finish it even if it comes down to 20#. I think I can learn something from working the hinge out.
But, don't let me stop you, go for it and let us know how it goes for you.
My bow building does not get serious until after the hunting season which is late January for me.
Actually I have 3 bows started now, one hickory stave that is pyramid, and two Torges style (whatever that is) BBO. So many bows to build and so little time :D
It is good to hear that you got some value out of this threat. Thanks to all who have provided your skill and knowledge.
RayMO
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the design idea is what i use when i have several bows to make around christmas time. the other guys are right its super simple and effective. depending on the wood i make it wider and shorter. I make the profile .5 " thick toleave room for tillering and weight. then if it gets a backing i glue in 2-3" of reflex if no backing it gets tempered. i have found my tempered pyrmid bows take less set. because the circular tiller bends more near the handle they tend to take some set, thats why they get reflexed or tempered. I can start on a pyrmid board bow and be shooting it (allowing for glue time) in about 2 hours.
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Sulphur, please tell me how you "temper"??
RayMO
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Use a heat gun on the belly side of the bow. DON'T SCORCH the wood. I saw that someone taped the gun to a piece of 2x4 to keep it at the same hight.
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Especially with whitewoods you do "scorch" the belly wood to temper it and this adds to the compression strength. This works OK on oily woods like osage but works really well with white woods. Scorch it to brown, not black. After you heat treat the belly allow the wood 2 or 3 days to rehydrate before stressing it or it will probably break. If you are working with a backed bow you should pre-tiller the belly a bit and heat treat it before you glue on the backing. Urac will take some heat treating but most other glues can't take the heat. Never heat treat the back of a wood bow; backed or unbacked.
Marc St Louis wrote a chapter in the newest TBB(IV)about heat treating wood bows. Pat
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Sorry meant burn not scorch... Thanx pat for the correction.