Primitive Archer
Main Discussion Area => Bows => Topic started by: toomanyknots on October 01, 2010, 06:13:26 pm
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Ok, I don't want to screw up and can't make my mind up. I want around 65# - 70# at 24" - 26", I have a nice piece of 2 1/4" by 3/4" (1 x 2 x 3) of red oak about 56" long. Now, the question is, if:
-it's a pyramid design 2 1/4" tapering to 1/4"
-with a 7" non bending handle
-1/2" thick
My goal weight is 70# at 24". But that is pretty heavy. 65# at 25" would be just as great. But is still about the least I want.
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What you want might be pushing red oak past it's limits so I am not sure .
With that weight I would keep a 24" draw not a 25". Unless you want to make a bendly handle bow or one with a shorter handle. But I'm am just a beginner so let's see what other people have to say.
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I am basically just looking to see if anyone knows or has a hunch around what length would reach 65# to 70# at 24" - 25". My last post here no one replyed to so I don't really have alot of faith for this one either, but I thought I'd try before guessing.
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2many , thats a lot of weight for red oak that short. i think your design could be very workable if you will either hickory back or rawhide back the board first. red oak makes a great bow ,but when going short, tension safe is going to be one of the most important things along with good tiller.hope this helps
one other thing i shorten my stiff handles on short bows sometimes 3 inches with an additional inch for each fade . this would give you 2 more inches of limb
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I'm also thinking you might be asking quite a bit out of that piece of oak. Also, 1/4 " tips at 65-70# might be pretty narrow. JMO.
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With a 1/2" board, 56" long, and a 7" handle you want 70#?? Good luck! You're asking too much of too little.
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"With a 1/2" board, 56" long, and a 7" handle you want 70#?"
Well, you think I need to shorten it? Cause I'm going with 56" right now. Ya, I may be living a little dangerously, :), but I'm doing it anyhow. I really don't know what to expect. I don't want 100# at 24", and I don't want 55# at 24". 60# to 75# is the goal. I don't want 75# pounds persay I just don't wanna come in light and bows this short usually when I even take a little wood off it effects the tiller, so I would like to come in as close to tillered draw weight to begin with. (used to rather longer bows, not so experienced with shorter bows) I don't have a scrapper either as of yet, I used rasps and fine files for the whole tillering process.
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There are a few on here that I think can pull that off. But they have alot more experiance ;) I know I'm not willing to try. When one explodes, it can be a dangerous thing :o Maybe put a few more under your belt then try it. 3/4 could but 1/2" ouch :(
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Hey Toomany...
Ya sound a lot like me....like to find out for my own bad self too. I've made several short self bows (39" to 50" that would pull 24-25") none as heavy as 70# but several at 55+/-.
I'm gonna start by saying that Ken 75 was way right about the safety/longevity advantages to a thin backer such as hickory....but having said that I have blown several up right in the kisser pushing self bow wood as far as it would go (look at the draw + 1" photo attached) So if your determined to do it you may wish to consider the following:
1] make your grip about 3" of flat and 1-1/2" fades both sides
2] a prymid design may not be the best choice for this project. It is a stellar design ....just not the first choice for this project. I would like to suggest a mollegabet or krohan style for two reasons:
a) The wide working limbs can handle 24-25 inches of draw, at a length of 10 to 11 inches (combined with full sized levers)
b) use the full length levers maybe even 1" longer. This will give full stroke draw with the least amount of required movement in the working limb. Also helps with an open string angle on short bows. The second picture is a 39" mollegabet that was drawing 24" .
3] The lever style of bows will give the speed (like your skinny tips would, but allow you to keep a tab bit more wood in the area. If you want to talk some more my TX# is: (231) 587-8542 and I'd be glad to help you if I can. Just so ya know, I do not advocate pushing the envelope for anybody except me, but if you are going to do it anyway, I might be able to minimize the damage.
rich
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Actually, I am going to put some pretty big 8 1/2" siyahs on there to get rid of stack. Inspired by the fella on here a while ago with the siyah bow that broke, that was a awesome bow.
Half eye: What thickness do you suggest at these dimensions for 60 to 70 at 24? Seriously, this is the reason I posted.
(freaking awesome bows by the way!, I bet they are faster than crap)
"Ya sound a lot like me....like to find out for my own bad self too."
Ya, everything else is a bit boring anymore, lol
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Toomany,
sorry for the delay.....put the mic. on two bows I'm finishing as we speak. I list dimensions for you: Both these bows are self bows and monolithic with nothing glued on. The working limbs are defexed and the levers are reflexed in the lever fades.
1] Red Elm....64" (has an 8" Chineese style handle) 65# + @ 28".....the working limbs are extra wide at 2-3/4" wide and 13" long and the lever from fade to bow tip is 14" (if the bow had a typical half-eye grip the overall length would have been 60+".
2] Black Walnut...59" ( 3" grip w/ 1-1/2" fades) 55# @ 28", It was much stronger but was specifically tillered to this weight. It has 12" working limbs and 13" levers. The working limbs are 2-1/4" wide at the grip and taper to 2" at the lever fade. The working limb thickness at the grip fade is .560" and at the lever fade it is .460"
I been researching some early Chineese bows and these two are a Mollegabet/ Chineese hybrid. If you want to help yourself with tillering the working limbs, I believe that the tapered chineese working limb is a plus.....compared to parallel working limbs with ALL the tillering on the belly. Hope these help....even if they aint red oak.
I see you added that you were going with some glued on siyha's....there is a whole lot about them ya might want to know....such as the effects of "high angle, no lift off" siyahs compare to low angle lift-off types. They are very different regarding stability, advantages/disadvantages and so forth. Not to mention brace heights, power stroke length's, anyway it isn't quite as simple as throwin some on....
rich
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THANK YOU HALFEYE! Extremely helpful!!! I have read that the best of all worlds is to have close to a right angle at full draw, but I fear mine will be more an acute than a right angle. Not by much though. At least this is what the third bowyers bible (I think) states on the chapter on composites. I believe I will go with too light verses too heavy for first try. And then go spend another 12 dollars and try a little heavier with the same dimensions. 12 bucks aint gonna break my bank. I'm thinking PRETTY much the same measurements, 56" long, 7" nonbending handle, 2 1/2" instead of 2 1/4", pyramid tiller with a straight thickness at 3/8ths thick,... Siyahs will be glued (and wrapped very well) on 3" of the limb and will be at 45 degrees and 8 1/2" long. I am going with pyramid tiller solely so I don't have to really tiller to much. :) I guess I could glue just a little wood block on the angle of the siyah for a string bridge?
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without trying to highjack yer thread here are some picks of 2 styles of horn bows....ya can see the differences in the siyah transitions.....the other pic is a chineese royal officer with an Infantry bow....which will demonstrate the 90 degree thing pretty well. maybe give ya some ideas.
rich
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Go ahead and highjack. :) Way more interesting than my posts, lol! I like the one at the bottom. Would love to make a "cheap imitation" of something round there. Probably would sinew it to reach a good weight without messin up the tiller if I was going to use all wood. Hey, I was worried about something with the siyahs and was wondering what you thought. I am going to glue em on following suit with this guys (sweet siyahs also) :
(http://i51.tinypic.com/2jzi85.jpg)
(http://i56.tinypic.com/dpiatl.jpg)
...but i was wondering if if might cause a hinge right where the siyah starts on a 56" bow. I doubt it, but was thinking of adding more wood, jumping from 3/8ths to 1/2", but then I thought that might cause a hinge too. So then mabie I should gradually tapper up mabie about 4" before the siyah starts? Just being over careful I guess, and probably not necessary. But little things always bother me. I know the tips are the least stress, but at 60#/70# or so, added to 56" long, kinda had me thinking... The siyahs I am making are going to have 3" of glue contact with the bow limb...
(ONCE AGAIN, awesome siyahs. Thank you for the inspiration to the poster of em, sorry I totally have no idea where the thread is I stole these pics from. Feel free if you made em to say so, the post wasn't that long ago on here...)