Primitive Archer
Main Discussion Area => Bows => Topic started by: mwosborn on January 18, 2014, 10:01:01 pm
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Here is one of the bows I am currently working on. Hackberry static curve - 64" ttt, 1.75" to midlimb then currently tapered to 3/4". Stave was cut and sealed in 2011.
Pictures are at a brace of 4.5" and then drawn to 13". Currently 36# at the 13". Final picture is immediately after unbracing.
This is my first static and I am going very slow with the tillering. Have been very careful to keep limbs bending very similar as I reached this brace. Have not exceeded 40# and have slowly exercised limbs after each wood removal. It looks to me that the outer 1/3 of the limbs need to be bending more - wanted to get opinions on this as I not sure on a recurve like this. What you think?
Secondly, the limbs are starting to take some set (even being careful) the right limb more than the left. My original plan was to make an unbacked bow. However, it looks as if I might be better off putting some sinew on the back. Opinions on this? I need to get to 27" draw and I am shooting for a 45-50# bow when finished.
I plan on narrowing the tips when I get closer to finished - will be asking questions about this if I get that far.
Thanks for any help!
Mitch
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Mitch, I've not worked with hackberry but everything looks pretty good. Both limbs from mid limb out could bend more.
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Yep, I think the outer limbs could to bend quite a bit more, which might help your set problem.
As long as you leave them nice and thick you can make the tips as narrow as you're comfortable with. I think my current project for my grandpa has tips 1/8th at the knock, but they're twice as thick as the outer working limb. Nice and light.
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Yes mid to outer. Right side looks a little more stiff than the left. Can't wait to see it done. Looking great so far
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What Pat B said........
DBar
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Thanks for the quick replies guys. Guess I can head back to the garage and work on those outer limbs!
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Removed some wood from mid limb to curve. Increased brace to 6" and pulling 38# at 16". I think it is bending better. Still stiff in the outer 1/3 from what I see. Left limb is a little weaker than the right. Increasing the brace caused a tiny bit more set. What you say?
Thanks - Mitch.
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Did you heat temper the belly?
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I was going to ask if you toasted the belly too. It seems like you are really taking your time and it looks like it is coming along good. If it were mine, I would keep on tillering until you are within a few inches of full draw, and if the limbs are bending evenly, give it a good toasting and a slight reflexing.
It reminds me of a sinew backed recurve that someone posted a while back that turned out good, but 64 inches is too long for a sinew back to me. You sure have some good looking hooks bent into that one. Good luck with it.
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As it stands your bow is between 60-65 lbs, if you were to pull it to full draw. Don't pull it there yet, but this should give you an idea of how much wood removal its going to take to achieve your 45-50 at 27". You're very close and your tiller is beginning to look real good. It may be just a matter of evenly removing a bit more wood to get to your desired poundage.
Yes, many of the guys who do a lot of hackberry toast the belly, on a form. It helps the hackberry maintain its profile with minimal set. I'm not sure though if its not too late to do this. Maybe some belly toasters (Marc St Louis, Blackhawk, Pearl Drums, Ryoon) will chime in soon on that topic. See the chapter in TBB-4 on the topic. Good luck!
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Id suggest tempering it now. If you don't? You will have excess string follow and set and wont be happy with hackberry. I think the left limb looks nice and right is stiff half way.
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Sweet looking bow! Temper it now and take the set out as you do. Very nice.
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First of all that is coming along really nice. I think the advice to get the outer third working was right on and also heat treating the belly but I would only heat treat the inner third. Hopefully stiffening up the inner third of the limbs will transfer more movement to the outer third where it needs just a touch more bend.
Just my 2 cents, I've done it before and it has worked for me.
Mark
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Thanks for the suggestions!
Pearl - i used a lot of what you have in your build-along to help me - good stuff! I did heat a little bit of reflex into the limbs after I had it roughed out (didn't toast it dark like in the build along - just afraid I would burn the crap out of it). In hind sight, I think that the limbs where still to thick when I heated - they where probably about 5/8" or maybe a bit more. Would it be ok to still go ahead and toast the limbs now?
Mitch
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Thanks Mitch. Id toast it now if I was working it. No more bending until you do though. You cant really burn the wood if you don't try to. It takes a bit for the wood to start turning color to start with, burning it takes much longer. My pics where from a junk camera I had at the time, it wasn't that dark in person. Make it look like an over-done marshmellow. I hold in one spot 3-4" away until it starts darkening nicely, then slide the gun ahead about 1" and repeat. It keeps the heat even and the added stiffness even. It will take about an hour per limb, roughly.
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It looks pretty good to me, I think the set the right limb is taking is about 1/3 the way out from the fades, just inside this area closer to the fades is just a tad stiff.
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Just out of curiosity how much does your bow weigh, is it somewhere between 19 and 20 oz?
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I think I will take your advice Chris and give it a good toasting. Probably have to let it sit a week or so before trying to bend it again (I hate waiting). Thanks!
Badger - I have no idea what it weighs right now - the tips are still pretty bulky and I have not shaped the handle area at all - it "feels" fairly heavy still.
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I went ahead and toasted it - and straightened the limbs back out while doing so. Will let it sit for a few days to rehydrate some before bending again (have a few others to work on while I wait ;D). Still not sure if I will add any sinew or not. Started working on some back sinew while I was waiting for the belly to toast. We will see how it holds up without. Thanks again for the advice.
Mitch
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Looking real good. I think you'll be glad you did the heat treatment even though the waiting to go back to work on it is frustrating, should come out with a better resting profile from less set when done. You seem really tuned into the tillering process, this bow is gonna be a nice one.
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I really like the use of the graph during your build.
I often forget how much additional information is available using this tool.
I'm just a beginner, but it looks like a very nice bow.
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Looking good,little stiff mid outer on the right limb looks like to me,left limb look good. Set happens with wood bow ,the key is for it not to be excessive and looks like you are doing a fine job managing that. Hackberry is a good bow wood,light and pretty strong but it can go away fast, so slow and easy as you have been doing is the way to go. :) tempering will help for sure. :)
Pappy
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Looking top shelf Mitch.
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Man, I like how neat and organized your shop is. And that ring stand? Awesome. Looks like it is going very well!
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Thanks guys - will give it a few days rest and then try and tiller it out.
Parnell - Usually my shop is pretty messy & cluttered - doesn't look too bad in that picture though! The ring stand is an old one from my chemistry lab at school - works pretty well for holding up the heat gun. Got the idea from Pearl - otherwise I would have been standing there holding it for 2 hours!
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Boy it's look'n good. Really like the way you did your tips. I'm assuming there going to be static unless I missed where you mention it earlier.
Again it looks good, I can't wait for more myself. :)
DBar
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Ok I waited for 5 days - decided to continue on. Had to start with the long string again (flat against the handle) and continued to tiller. Currently at 5" brace. Pulling 40# at 18". (goal is 45-50 @27") Pics are at the 5" brace, pulled to 18", and then the unbraced profile right after unbracing. The last picture is me screwing around with the picture viewer on my computer.
Here is what I am thinking...limbs seem to be bending pretty evenly - still look stiff in the outer 1/3. My concern is that the limbs are getting pretty thin in the area approaching the curve. I am afraid to thin them much more at the current draw length. I haven't done a static recurve before - will that area start to bend more as I increase draw length? Or do I need to just remove some wood? The tips are still thick - I have not reduced them at all so maybe that is just messing with my mind.
I am thinking to remove wood evenly along the length of each limb and getting it bending some more and see what it looks like at a little longer draw. Trying to go slow to keep set minimal (the toasting helped)
What you think?
Thanks
Mitch
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It is coming along nicely! Jawge
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How wide are you just before the bend of the statics and into the statics? I always hear Mike in my ear saying thinner, thinner you wuss.
I find its handy to really go over all of the limbs focusing on limb thickness, only takes a tiny amount more thickness to really show up stiff in shorter working limbs.
Looks great. 8)
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Don't be afraid to get those limbs bending all the way to the static, or just short so you don't lose any bend. Your circle shows exactly where you need to work. If you don't get the whole thing working you will take set right off the fades, that's the worse spot to take it IMHO.
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Don't be afraid to get those limbs bending all the way to the static, or just short so you don't lose any bend. Your circle shows exactly where you need to work. If you don't get the whole thing working you will take set right off the fades, that's the worse spot to take it IMHO.
+1 :)
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Jawge, dwardo, Pearl, Matt -
Thanks for the advice - exactly what I needed to know before moving on - will get that area bending a bit more. Just needed someone with more experience to say it was ok. :laugh:
Mitch