Primitive Archer
Main Discussion Area => Bows => Topic started by: sleek on October 12, 2012, 01:13:10 am
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I am making an osage recurve with a draw weight of 45 lbs. It is 68 tip to tip, pyramid design, and just over 2 inches wide at the fades and 1 inch wide so far at the tips. Bow has 2 inches of reflex. My question is, do yall think I have the meat to make a 30 inch draw length at 45 lbs? the recurves will not be very agressive, just a mild tip flip that is just enough to allow the string to almost touch the limbs when braced. The recurves will be static.
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Strain in a limb is dictated by the ratio of width to thickness. You don't say what thickness you have. If you want a longer draw (all things being equal) you need a proportionately wider/thinner limb.68 is a bit long for a recurve - I never make them more than 64. Moving mass n all that.
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Sorry this is just my opinion as I've only used Osage once, so I s'pose I should shadup.
In fact, if I wus yyou I would read no further ::).
2" wide down to 1" sounds plenty wide enough, so it should be pretty thin and thus able to take the bend... but being a fairly short, I think you'd be better off with a short slight flip tip rather than a load of reflex.
Putting it simple I think if you want 30" draw it's better to loose the reflex.
If it can take 30" draw and no set, I'd be happy with that, rather than finding the reflex has pulled out during tillering and you are worrying that the wood has been overstrained. Mind if it's natural reflex leave it be and see what happens.
I just don't like heating in reflex and then pulling it all out, sometimes it's just nice to make the bow from the wood as it is, no heat, no tricks.
Del
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Well Mike, I dont know the thickness, I have only just got it to the point of being strung at a low ( 3 inch ) brace height and it need thickness reduction yet. I just wanted to make sure that the profile could take the stress. I made the bow long as it is because I have 8 inches of stiff handle and 6 inches each of no working recurve. I figured I better leave it a touch long for the long draw length.
Del, I listen when you speak, no worries there lol.... My plans are to do a light flip of the tips, the string wont even contact the limbs, just shy of it really. The 2 inches of reflex the stave has is all natural. I didnt put it in there, it grew that way.
Well, thanks for the comments guys, I am off to do some work on it now, hope to have it pulling 45@25 before I go to sleep... the the rest tomorrow night.
Oh, I wanted to add, this stave has thin rings, and a lightly crowned back, so I am matching the crowned back with an equally crowned belly to reduce the strain on the back. I hope this works, i really need this bow to hold and it is the most strained bow I have ever built....
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Yes, I think your design can go to 30". However you're very likely going to have some hand shock unless you narrow those tips. Over the years I've moved to shorter handles and now bendy handles in my osage bows. That's because I find them more pleasant to shoot and handier to hunt with. If I were doing it I'd lose the recurves, make the tips very narrow and concentrate on retaining the reflex you have with careful tillering. I don't think you need flipped tips at that length for stacking, and recurves get unstable if they're really narrow. I think you need narrow tips to combat hand shock with a heavy wood like osage, especially in a pyramid bow. I think I'm agreeing with Mike?
I'm trying to think if I've seen a pyramid bow with flipped tips? Nothing jumps to mind...but I'm senile so that isn't saying anything.
Good luck with it, whatever you decide to do design wise. Take lots of pictures. :)
George
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Well, I got it to 28 inches and it popped a splinter, near the fade, where it is hardly even bending. Came off a pin knot. The splinter is narrow and short, maybe 1/2 inch long and half as wide? I super glued it down, but now I fear I may have to back it? All I have is black silk. I am irritated. I left the bow wide, long, low poundage, my tiller is good, and it pops where there is very little bend? Why would it do that?
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Did you follow the growth ring up and around the knot? It's easy to draw knife through knots and violate the outer ring. That would be my guess.
George
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Its possible, the rings are thin, but I dont see any violation there, but again, maybe it is, ever so slightly? Looks like a thread wrap will have to do and be made decorative. I hate doing that....
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I understand, I don't like thread wraps either but it's what I would do too. The limb right off the fade is under quite a bit of stress, even if it doesn't bend much. Any pictures of your bow?
George
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No pics yet, I usually dont start taking pics until I start doin fine tillering. Thanks for the help...
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Dangit, just had another one pop, pulling 40@28. This time towards the tip. This bow is going to give me heart burn. I am now going to do all my heat treating I am going to do, then silk back it, finish the tiller, shoot it in, then throw a set of snake skins over it. Black silk is to shiny by its self.
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Good luck with the rest of your build. Sounds like you got a fighter there. >:(
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Well thanks Okie, I need the luck. I have about decided that because the rings seem so thin they wanna pop a splinter one ring thick, I will just lightly decrown the bow to increase the surface area under tension and say the heck with the rings. Then throw a silk and snake skin backing on top of it and call it good. That should work.... I hope?
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Decrowning really dropped the weight, but I think that is ok. I still have to recurve the tips ( shortening the working limb length ) and if that doesnt do it, I can cut 2 inches off, retiller, and heat treat if need be. No more splinters yet, and I was able to remove the one towards the tip completely. That is a good thing.
Just weighed it after finally getting it to 30 inches of draw, 43 lbs. It will go down to 40 by time I get the tiller perfectly tweaked. Then up after VERY lightly flipping the tips, and silk backing. Back down again as I settle in with final sanding and shooting it in. If she survives she gets rewarded with some diamond back skins. I sure hope I get to that point. Anyways, I need to wake up in 3.5 hours. Stupid hobby, I cant sleep until I reach a goal I set for myself. And sleeping with an unsolved problem? FORGEDDABOUTIT!
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Well, I got it to 28 inches and it popped a splinter, near the fade, where it is hardly even bending. Came off a pin knot. The splinter is narrow and short, maybe 1/2 inch long and half as wide? I super glued it down, but now I fear I may have to back it? All I have is black silk. I am irritated. I left the bow wide, long, low poundage, my tiller is good, and it pops where there is very little bend? Why would it do that?
Did a lovely Hazel primitive a while back and it lifted just like you descibe >:(, I ended up taking out a narrow trough of wood right through the little knot and filling it. Did the job, see pics here, it might make you feel less bad ;D
http://bowyersdiary.blogspot.co.uk/2012/08/splinter-repair.html (http://bowyersdiary.blogspot.co.uk/2012/08/splinter-repair.html)
Del
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Wow Del, thanks for the link. I love the inventiveness of that fix. One could use that to inlay all kinds of cool stuff, like exotic woods or turquoise even. You know, That gives me an idea...
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Pulling 40 @28 the splinters were popping where the wrap is on the upper limb. Not quite happy with the tiller in this picture. I am using heat to alter it...
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/tonysbowfulldraw.jpg)
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I don't see anything wrong with the tiller. The lower limb looks like it has a gentle twist coming off the fade, which is making it a little hard to see the bend, but it doesn't seem to be affecting anything. If I'm seeing that right, my OCD would make me take it out, but the bow will likely shoot fine the way it is. I think you have a keeper there.
George
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The tiller looks very good to me. It is too close to really tell, but the top might be bending a microscopic hair more that the bottom limb. I can't see nothing wrong with the tiller though really, it looks very even. I would give that bow a good backing, maybe rawhide or even good linen fabric, if you keep having trouble with splinters popping. I can't give a lick of advice on chasing rings, as I couldn't chase a 2" thick ring with a lazer guided draw knife.
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Here she is finished...
I thinned down an antler tine allot to get it to bend into shape for the arrow strike plate, I also left the tiller alone.
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6872.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6890.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6883.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6882.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6877.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6876.jpg)
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To be honest...
Your tiller looks okay to me too.
That prop twist right out of the bottom fade makes things a bit tricky.
Enjoy the bow for what it is and what you've learned, then move the the next project.
There is always a next project.
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Beautiful... I like the wrappings, ;D.
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Nice job, Sleek. You guys amaze me with all those bumps, knots, and whoop de doos!! ::)
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Thanks guys. Toomanyknots, I believe this is a piece I got from you by the way. The wrappings were needed, lucky I was able to make em pretty... Thought about doing a native paint job on them but decided to leave it.
Sharpend, you are deffinatly correct, I have lots of projects... I am building 5 other bows right now...
Lesken, those knots and such were no challenge, that was easy, but something new to me was trying to make the belly curve and match the backs curves and such, I think I did ok, but will try againg to do better on the next.
At first I was dissapointed with its speed ( dont know for sure my battery is dead in my chrono ) untill the bow showed me a speed deamon is not needed for power. I missed my target while shooting it and hit my cherry picker square on behind it. It had such an impact even at 25 yards, the field tip flattened the tip a good bit, split the arrow shaft almost 1/3 the way up, and it caused the end of the arrow head that fits into the shaft to split in several spots and role up, like a gun barell when the barell is clogged and fired. Lots of power...
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Thanks guys. Toomanyknots, I believe this is a piece I got from you by the way.
Oh poop, no wonder why it was giving you so much trouble, it was one of my sorry piece of crap staves! ;D You sure did a dang fine job with it!
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Now I didnt mean it that way, Im sure a more capable bowyer could have done just fine with it. I'm happy to have what I got from you, and everything I got is just as you described, thanks.
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Now I didnt mean it that way, Im sure a more capable bowyer could have done just fine with it. I'm happy to have what I got from you, and everything I got is just as you described, thanks.
I don't know about about, I know I sent you a couple staves that would be really quite challenging to any bowyer. I think so anyway. And I think you conquered that one right there, better than I could do for sure. Turned out beautiful. Do you have any up close pictures of the nock overlays? What did you use, antler?
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Both nocks, the rest, and strike plate are all from one white tail antler tine. Here are some pics...
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6878.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6873.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/Tonys%20bow/IMG_6887.jpg)
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This bow was stave 1 in this post. I had to take allot of the reflex out because of the splinters popping, but it still has 1.5 inches of reflex.
http://www.primitivearcher.com/smf/index.php/topic,33852.msg446336.html#msg446336
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Congrats on a shooter,nice job. :)
Pappy
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You made er.Very nice job.Those wider bows are a lot of work taking it off evenly etc.You're getting 30" draw with 1.5" reflex yet.That's very good in any bowyers camp.