Primitive Archer
Main Discussion Area => Bows => Topic started by: LEGIONNAIRE on August 11, 2010, 01:23:42 am
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Does anyone know what the different styles of siyhas are? im trying to make a couple for a bow but i dont know how to cut them glue em or why they are useful since they dont bend.Thanks
Cesar
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ken75 or kenh should be able to help. they definitely help with string angle, keeping stack at bay. they do lots others too.
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Howdy, Sort of a complicated set of questions. From an engineering stand point the siyahs are there to increase early draw weight and thereby make a more efficient bow. From another perspective they are just the recurve part of a recurve bow. Tim Baker especially goes into this in different volumes of the BB series. Different styles of horn bows have different siyahs. In most cases the siyahs are spliced onto the end of the working limb and are made out of a natural crook or radically steam bent wood. The usual splice is just a V splice. Remember in traditional horn bows the belly side of the splice will be covered with horn and the back of the splice is covered with sinew. That combination takes most of the stress off the wood to wood splice
You might look into obtaining a copy of Ottoman Turkish Bows by Adam Karpowicz. He has some excellent observations on siyahs in general and excellent advice for building Turkish style bows. Ron
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MP gave you the basics - there are lots of different lengths and shapes of siyahs depending on the culture who made the bow.
You don't necessarily need a V splice to attach siyahs. The Ming period Chinese used a flat splice; which can then be wrapped (or not with modern glues). The dowel string bridges you see below may or may not be included. I make the siyahs 1/2" thick by laminating several pieces of 1/8" and/or 1/4" hardwoods with the grains set at an angle to each other, for strength and beauty; rather than hunting for the perfect tree crook, or steaming. From the 1/2" wide base, I then taper them to 3/8" or 1/4" at the notches.
(http://i21.photobucket.com/albums/b282/kenhulme/AsianSiyah.jpg)
The angle of these siyahs is 45 degrees:
(http://i21.photobucket.com/albums/b282/kenhulme/SiyahDesign.jpg)
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KenH thanks for the info. Now you got me thinking about trying them. Do these work better on certain types of wood than others. Meaning the actual bow material. osage, hickory, ash, oak, maple
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The limb wood shouldn't make much difference; unless it's an oily wood where glues don't adhere well. I've made siyahs and glued them even on unsanded exterior of bamboo.
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great stuff Ken. Thanks Aero Ken is the man you wanna se then I guess for siyah business.
Thanks ron.
Ken, can you elaborate on your siyah making process. maybe a closer pic of the siyas will help me understand. So you glue lumber 1/8 in untill you have enough to get a siyah?
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Cesar
Stick to KenH's basic design, and experiment...Use your imagination........
With your skill, you will come up with something new, workable, and effective...
Don't loose the spirit.
Ron...Okiecountryboy
God Bless
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from what he said in his post, he glues the 1/8" or 1/4" lumber with the grain at right angles to one another, sorta like making hardwood plywood. this is one of the reasons plywood holds up so well is because it has to break across all those directions to come apart rather than just in one direction.
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Yep. I use a scroll saw to cut out multiple copies of that pattern I posted, making sure the grain runs different ways. Hard woods - Ash, Cherry, Maple, Mango for beautiful grain. Ninety degrees difference in grain between pieces is best, but you just don't want the grain running the same way on every piece in a glue-up. Then I glue up at least three of the cutouts. I've made the glue-up both 3/8" thick and 1/2" thick. I think the 1/2" is better. Then you can taper out to 3/8 or whatever near the nocks. I drill and cut the nocks, and do major shaping surgery all before gluing to the limb.
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Howdy, Well Ken's way is not quite traditional, but it looks great and I have no doubt functions as well as the originals. I'll have to give it a try myself. Ron
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Oh great, now I wanna make one of those bows. Will I ever get a break from this hobby?
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nope. i havent looked at a tree the same, since i was like 13. 14 years ive wondered what kinda bow is hiding in different trees. lol
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man I didnt want to hear that,I cant walk past a tree without scanning it for straightish sections long enough for billetts or staves.Ive only been doing that for a year or so,now youre telling me its a permanent affliction!!!!
like wise im going to have to try a bow with siyhas now as well!!
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Yep. Just caught the bug myself and am starting to find myself looking at trees differently.
Ok another question - If you want to put siyhas on a backed bow would you glue the backing on first or put the backing on after glueing the siyhas on?
Am I getting in way to deep or what? :D
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well, the siyah part is unbending, so you wouldnt need to go quite that far with the backing, but id probably put the siyahs on and then put the back up to it. i know i contradict myself saying that, but its what id do lol
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i gotta agree, depending on the backing material you may not get a good enough glue joint for it to hold. unless it were something like a good flat hickory backing id glue the siyahs on first. of course if you were splicing the siyahs in it wouldnt really matter, but thats more complex to do and i dont think it would be needed on such a simple design.
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Thanks guys.
Too many ideas and questions ;D
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If you're going to build a "two wood" bow - that is back with wood - then I would glue the back and belly together first. You can glue in some added reflex that way. Then glue the siyahs to the back. If you look close in the photo I posted on page 1 here, you'll see that that bow is Black Locust backed with 1/8" Maple.
If you're going to "splinter back" with cloth, rawhide or snakeskin, then glue that on after the bow is finished. The area where the backing and siyah meet can be covered with a few turns of colored embroidery thread over wrap.
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Great thread everyone, thanx for the help Ken I greatly appreciate it, thnx for pointing us on the right track.
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In a long flat splice like this, you guys think TBIII would hold, unwrapped?
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In a long flat splice like this, you guys think TBIII would hold, unwrapped?
Yes but I personally would v-splice everytime. Much stronger, doesn't need wrapping and no potential failure.