Primitive Archer
Main Discussion Area => Bows => Topic started by: lewstewns on April 16, 2014, 03:07:10 pm
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hi guys. this bow i,m working on is uk ash. 60" nock to nock.shot about 50 arrows yesterday leaving it strung for about 3 hours.when i unstrung it had this much set. i estimate its pulling about 70lbs+ at 28". I want to get it down to half that so my question is-Is this much set acceptable or do you think its gonna blow before i get it down to 30-40lb?lew
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Too short, too heavy my friend. That bow should be pulled 24-25" max and 40-45# max. I see your bottom limb is stiff mid way out as well. Those are a few things that lend to excessive set.
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If it hasn't blown yet it's not likely to if you reduce the weight. Particularly if you do so by removing wood from the belly rather than narrowing it.
Is there any reason you shot it in at such a high weight and then decided to halve the weight?
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What Pearlie said!
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Generally you should try not to draw a bow over the desired finished weight. I would start a new one personally.
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Our Ash really likes to be heavily trapped and heat treated.
It is way stronger in tension than compression.
Your fades look too abrupt as well, make them 2 inches long and with a very gradual taper.
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+1 to Mike's comment. If you find the RIGHT piece of ash here in the UK you can make warbow weight bows (100#+) without heat treating at all, and only minimal trapping - just a gentle rounding of the back really - but generally speaking our ash is far less dense than desired and as Mike said, toasting the belly and trapping the back gives really good results.
It's absolutely imperative that you keep it dry as well. Even if the length, weight, tillering and design are PERFECT the ash will take set and lose performance if it gets even slightly wet during the tillering process. It needs to be kept on a radiator while you work on it, and sealed with quality sealant like yacht varnish to keep as much moisture out as possible. One guy I know goes as far as washing his hands constantly while working ash to remove all sweat and his hands get ruined and cracked but it ensures the wood stays dry.
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To quote Jawge, "Set is set", shoot it till it breaks, take the advice given and use it as a learning experiance.
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If it hasn't blown yet it's not likely to if you reduce the weight. Particularly if you do so by removing wood from the belly rather than narrowing it.
Is there any reason you shot it in at such a high weight and then decided to halve the weight?
+1
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Set is your best teacher, not good for the bow but neccessary for the student. Look where it took set, those places were bending too much. You should have caught the set much earlier in the process and reduced what you were asking of the bow or adjusted your tiller. Spend some time looking at your set and what it is telling you. Set don't lie!
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I couldn't agree more. Were and how your bow is taking set will tell you a lot about how you're tillering it.
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Addressing your thread title: How much set is acceptable? In an ideal scenario, no set is 'acceptable'. But I'd have to say after reading a mountain of PA threads that it seems some bowyers are willing to 'accept' (or even anticipate) some set depending on their designs, their chosen wood, and their manipulation treatments, be it heat, glue-up, etc How much set? The answer to that is one that comes with experience as I think you can tell by some of the comments which are directing you to be sensitive to where the set occurs and why it occurred in that area because then you'll be able to answer your own question.
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If it hasn't blown yet it's not likely to if you reduce the weight. Particularly if you do so by removing wood from the belly rather than narrowing it.
Is there any reason you shot it in at such a high weight and then decided to halve the weight?
The only reason was ignorance Pat.thanks for all your comments .Better to learn by a mistake i guess!
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Was the bow flat when you started or did it have some reflex. The reason I ask is
if it was flat that's not that bad,if it had reflex that's much worse,all wood bows
take set.String follow is tried to keep to a minimum,you see lots that start with 3 or 4 inches of reflex and wind up with 1 inch,that is 3 inches of set. If it starts flat
and has 2 inches of string follow that is also set but will effect the performance more. So to answer you question a couple of inches of set is very exceptable at least for me. I have seen very few that can build a wood bow with no set but lots that can build one without string follow. ;) :) :) advice above will help a lot,keep the wood dry,go slow / look a lot while tillering/never go any futher than you need to see the problem area/fix and move on and never pull over intended draw weight. Simple ??? ;) :)
Pappy
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thanks Pappy.it was flat to start.its actually a board from a timber merchant.i,m really annoyed with myself for shooting it now.i was going to my friend's farm for a shoot anyway and couldnt resist taking the damn thing with me!I think i,ll work it down anyway and see what happens.i,m pretty new to this game.this is my 4th attempt and i do think i,m learning every time i make mistakes.i spent a few months last year making a sinew backed uk oak bow. the belly blew a puff of smoke out when i drew it so i now know that uk oak cant handle the compression when you sinew the back!!
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Not all set is the same either. Assume you are starting with a natural straight board. Some bows can take 2" of set and still have pretty good early draw weight while another bow may feel mushy. All you can really do is work the bow to full draw weight and read the signs the bow is telling you as you progress. If it starts taking set early in the process the wood is either wet or you are asking too much. If the set is only in certain places then the tiller is not even. If you only have a litte set right near the handle it can translate to 4" at the tips.
Tim Baker mantra: Wide enough near the handle to take no set, wide enough mid limb to take little set. ( something like that)
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You got some great advice. Pappy had a good point that all bows take some set and Badger is right about letting set be your teacher. Just looks worse when you start from flat. Im so used to seeing bows that start with reflex. I start with plenty of reflex so if I get string follow I throw it out. I know some bows shoot great with a little string follow and most older bows we see have string follow. Sounds like you found a new hobby and I hope you stick with it. They just keep getting better the more you learn and make.
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Not only is the bow too short for the draw length, the draw weight is not really relevant, but your handle is way too long. Keeping the handle as short as possible allows for longer working limbs.
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Looks like you've gotten a lot of good advice. The first thing that popped out to me was the long handle.
Just follow the advice you get on here and you'll be making good shooters before you know it.