Primitive Archer
Main Discussion Area => Bows => Topic started by: jamesh76 on June 15, 2020, 03:28:29 am
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I have read posts for the last hour. I even have 4est trekkers post with the pine board in my shop. Lots of confusing terminology and info on this topic across multiple other posts. I am still confused and second guess myself every time. Based on this picture and view from this end of the tip. Which side is strong side and which side do you remove wood? Left or right side.
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As the string bisects the handle, i wouldn’t worry about that amount of twist, unless it gets worse when you draw it. But if you do try to correct that, you should remove wood from the side that is left on the photo. Full disclosure: I’m not that experienced.
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thanks for your reply, I understand its not that bad of a twist and would be ok with the alignment. I just want clarification on which is strong/weak and which side to remove wood. Hopefully there are several responses. I just don't want to second guess myself anymore.
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Strong side resists being bent towards the belly, weak side bends further. The left side is the strong side.
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I think right is strong side. Remove wood right side. More feedback needed please 67 views so far.
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If you get the twist out of it then the string won't bisect the handle anymore. Then you will have to bend the limb sideways to recorrect it. Is it worth it?
PS I've never been able to get twist out by tillering. I heat them and bend them.
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Before you do anything read the sticky at the top of this board for details on mechanics of limb twisting. Limb will always twist to the weak side.
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Remove wood from the left side of the limb till it is even thickness on both sides the length of the limb. Put the bow back on a form ,and heat treat the belly lining the limb tips up with the middle of the handle. Use heat ,and clamp as you go. That should remove the twist from limbs, and they should hold that way.JMO
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What I do is I push the back of the limb on one side or the other with my thumb towards the belly side whilst looking down the belly along the string. When you push on the back on one side with your thumb you are effectively weakening that side, so the side you have to push to untwist the limb is the stronger side.
If you were looking at a braced bow in profile and you wanted to see what would happen were you remove wood from one limb you push that limb and you can watch the opposite limb straighten; I try and imagine this same principle going on but as a section through the limb...
I would make a simple bow with a thin slat and get a rasp and play around. That’s what I did. It finally clicked
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Before you do anything read the sticky at the top of this board for details on mechanics of limb twisting. Limb will always twist to the weak side.
in this picture it twists left, so are you saying right is strong?
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Remove wood from the left side of the limb till it is even thickness on both sides the length of the limb. Put the bow back on a form ,and heat treat the belly lining the limb tips up with the middle of the handle. Use heat ,and clamp as you go. That should remove the twist from limbs, and they should hold that way.JMO
you didnt answer the question
Based on this view, is left or right strong side?
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Ref the sticky. This appears the same twist I have at this tip. Unless I'm a complete moron and am reading this incorrectly the left side is weak? .
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This is from a book on laminated “thou shalt not speak of” bows ... it starts ... The Limb
(https://i.imgur.com/Tuua3Dm.jpg)
(https://i.imgur.com/CNfZSAk.jpg)
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This is from a book on laminated “thou shalt not speak of” bows ... it starts ... The Limb
(https://i.imgur.com/Tuua3Dm.jpg)
(https://i.imgur.com/CNfZSAk.jpg)
thank you for sharing, so which side is strong side?
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Wood will always bend towards the weak side.
In the first photo that shows the limb twist along the length, the limb bends towards the left. Therefore remove wood from the right side near the tips.
By the way Tommy, what book are you quoting from?
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Stick and String. It’s an Amazon book. I built a couple of “those that shall not be named bows” from Binghams. I think it’s a really useful step by step if you have never done one before. Well worth it but to be honest I’ve learnt way more new concepts in bow building trolling this forum for ideas ...
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in this picture it twists left, so are you saying right is strong?
Yes right side is strong. Remove wood from strong side to bring limb into alignment. This is counter intuitive of course but is the correct course of action. Usually does not require much wood removal.
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Maaaan! I can't believe I got that wrong, AGAIN! Of course it is the right side which is strong. After I posted I even had it right all along in my head, I think I justed lapsed into my old thinking when posting.
This is why I always just concentrate on comparing thickness from side to side. If I do try to correct, I know I can't allow my self to do it without reading the sticky thread first )-w(
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I was sharing with James an article discussing bend-twist in beams. It describes how the different forces acting on and within a beam will cause twist. Basically if a beam (bow limb) is asymmetrical in strength, it will bend towards the weak side. They also discuss how direction of fibers can cause twist as well, similar to what we see in boards due to asymmetrical strength in different directions. The corrections would be to make the strong side weaker, or bring the string nock on the weak side inward.
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Thanks Ryan, Here is that article. Easy way to remember seems for me..... remove wood on the side you wish the limb would move.