Primitive Archer

Main Discussion Area => Bows => Topic started by: Kidder on December 14, 2020, 10:19:45 pm

Title: Limb twist verification
Post by: Kidder on December 14, 2020, 10:19:45 pm
Looking for some confirmation on what I am seeing versus what I am reading about limb twist. As I look at the limb from the nock end with the belly facing up the limb appears to be twisting to the right (appears to be twisting clockwise when looked at from the end). That would mean the right side of the limb in the picture is the weak side, correct? It feels like when I take wood off the other side it makes it worse. Bottom line, from the picture do I take wood off the left or right side of the belly? Thanks!
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 14, 2020, 11:01:58 pm
this looks like in Jay Massey book,,
this always confused me,,but I think Jay had it figured out,, I would just take wood off belly side, I would be hesitant to take off the back any,,
Title: Re: Limb twist verification
Post by: Pat B on December 14, 2020, 11:19:28 pm
How does the bow shoot? If it shoots well don't worry about the twist. A little twist won't hurt a selfbow.
Have you checked the thickness across the limb. Uneven thickness can cause twist.
Title: Re: Limb twist verification
Post by: Kidder on December 14, 2020, 11:28:34 pm
How does the bow shoot? If it shoots well don't worry about the twist. A little twist won't hurt a selfbow.
Have you checked the thickness across the limb. Uneven thickness can cause twist.
I’ve just got it strung on the short string and pulling about 18 inches. I want to chase the twist away through the tillering process. Thickness appears to be more on the high side of the belly, but this appears contrary to what someone on the twist sticky thread said “resist taking wood off the high side”.
Basically from the photo what is the strong versus weak side? Thanks
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 15, 2020, 12:33:15 am
ok Ill commit .. the side to the left in the photo I posted,, or the side the string is closest too,,just like the photo in Jays book,,
I have correct twist removing wood before, but if I dont do it for a long time, I forget how it works,,
Title: Re: Limb twist verification
Post by: scp on December 15, 2020, 01:42:04 pm
Wood as a natural material would not bend evenly just because both sides are even in thickness. The stronger side would resist bending more than the weaker side. That means the weaker side would be closer to the string. The photo can be counter-intuitive. The wider right side is the weaker one.

Anyhow for that amount of twist, I would just view it as the way the bow "tells" us which limb should be the top and it is "trying" to be center-shot. I believe this anthropomorphic view is nicely "primitive".
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 15, 2020, 03:15:30 pm
the limb is twisting exactly like the illustration in Jays book,,, I have confidence he would not publish misinformation,, I guess its possible,, but I think if you follow his advice,, it will correct the problem,, its pretty easy,, if it does not,, then just scrape the other side,,
Title: Re: Limb twist verification
Post by: scp on December 15, 2020, 04:39:26 pm
bradsmith2010, I think that's what I said. In spite of the axis line, the weaker side is wider on the left side of the drawing and closer to the string on the right side of the drawing. It would be clearer if the axis line was drawn from the string to the center of the limb.
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 15, 2020, 04:48:19 pm
thanks SCP, wasnt sure ,,but just wanted to clarify,, it can be confusing :)
Title: Re: Limb twist verification
Post by: Kidder on December 15, 2020, 07:59:58 pm
Thanks for the assistance everyone. I’m thinking it may be partially because of the nature of the wood in this case (it’s a board with rings that are angled 30 degrees or so) and partially due to thickness issues. Either way, I’m tillering through it and it’s not getting worse at least. This is truly a humbling craft and you masters are at a whole different level (and we all know who you are!)
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 15, 2020, 08:26:42 pm
ok as stated, it not gonna hurt it ,, and sure it would shoot fine like that, , you could apply a little heat toward the tip in the not working part, and just bend it back straight,
Title: Re: Limb twist verification
Post by: bownarra on December 16, 2020, 01:21:09 pm
More often than not these things are layout issues.
Also very possible that the growth ring orietation is to blame.
The easiest way to fix it is to leave it alone :)
Orientate the bow so that the string is 'offset' towards your arrowside. It will help make the bow less picky with arrow spine.
Regarding that photo from the book. The nock should be deepened on one side and material removed from the opposite side of the limb, not how the book shows it with nock being deepened on the same side as the material removal. Hard to describe in words!
Title: Re: Limb twist verification
Post by: PatM on December 16, 2020, 03:12:20 pm
The book does show the opposite side.       Left side material, right side nock deepened.
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 16, 2020, 03:36:01 pm
ok I thinkn I get it,, hope you get it worked out and send pics,,
Title: Re: Limb twist verification
Post by: scp on December 16, 2020, 04:31:01 pm
Regarding that photo from the book. The nock should be deepened on one side and material removed from the opposite side of the limb, not how the book shows it with nock being deepened on the same side as the material removal. Hard to describe in words!

But if you remove some wood from the side of the stiffer side, you might be forced to deepen the nock on that side. That's why the drawing also appears to suggest removing wood without deepening the nock. Even though it makes sense to move the whole nock to the stiffer side by deepening the weaker side, there would be a limit to how narrow the nock can be.
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 16, 2020, 06:17:35 pm
ok in the pic,, is he showing two ways to align the string,,
Title: Re: Limb twist verification
Post by: Kidder on December 16, 2020, 11:28:56 pm
ok I thinkn I get it,, hope you get it worked out and send pics,,
Doesn’t seem to change at all. No matter how much wood I take off the strong side. So I’ve got to think it’s either the nature of the wood, or more likely not quite perfect layout. So I’m going to live with it. The good news is I think I’ve got the tiller pretty decent with about 3 inches to go....
Title: Re: Limb twist verification
Post by: bradsmith2010 on December 19, 2020, 07:52:59 pm
ok enjoy shooting,, :)
Title: Re: Limb twist verification
Post by: George Tsoukalas on December 20, 2020, 07:12:22 am
I think it's fine.
I'm fussy about tuning. I lie a silent bow so I would shoot it from the right side as pictured so it doesn't whack my forearm.
Jawge