Primitive Archer

Main Discussion Area => Bows => Topic started by: Fred Arnold on July 02, 2014, 01:14:24 pm

Title: Input regarding limb twist
Post by: Fred Arnold on July 02, 2014, 01:14:24 pm
Regarding limb twist, I've always thought the strong side pulled the weak side over. In this picture that would indicate removing wood from the belly of the left side. Is this correct?

It's hard to tell from the photo but the twist actually begins close to where the arrow is pointing on the back of the bow. Thickness on both sides are the same.
Title: Re: Input regarding limb twist
Post by: son of massey on July 02, 2014, 01:26:38 pm
The limb pulls toward the weak side. The strong side is closer to the plane of the string when viewed from one tip than is the weak side.

SOM
Title: Re: Input regarding limb twist
Post by: Fred Arnold on July 02, 2014, 01:42:02 pm
SOM, so you are telling me that I need to remove wood from the right side?
Title: Re: Input regarding limb twist
Post by: George Tsoukalas on July 02, 2014, 01:52:08 pm
The weak side is closest to the string when it is strung.
Is this a picture of the strung stave?
If yes then the weak side is left.
If stave is naturally twisted only to the amount I see then leave it if less than 30 degrees.
If twist was caused by uneven wood removal fix it by removing wood from the strong side or right side.
Jawge
Title: Re: Input regarding limb twist
Post by: mikekeswick on July 02, 2014, 02:00:22 pm
Yes as George says what matters is if it was already there in the stave before tillering or was it a straight stave that twists as it's drawn.
If it's natural and you remove wood from one side only then the thin side becomes over strained and is likely to chrysal.
Title: Re: Input regarding limb twist
Post by: Fred Arnold on July 02, 2014, 02:38:26 pm
Jawge/Mike, The stave is shown as strung.

Originally the stave had a minor amount of propeller twist which was taken out with dry heat on the form. Relaxed and unstrung the minor twist that you see in the photo is barely discernible. Only when braced does it begin to show and being I can't see it drawn I'm assuming it gets worse.
On the tree it is detectable but nothing that would cause the string to slip from the groove.

Being this is likely to be my trade bow I wanted to correct it if possible. I've still got 5# remaining to meet my recipients high end requirement so a small amount of scraping won't be detrimental.

I appreciate your help.
Fred
Title: Re: Input regarding limb twist
Post by: PEARL DRUMS on July 02, 2014, 02:44:28 pm
Boy, if that string lays right, Id leave it.
Title: Re: Input regarding limb twist
Post by: SLIMBOB on July 02, 2014, 03:03:47 pm
Leave it is also my advise. Taking wood off to correct it  might be the wrong prescription.
Title: Re: Input regarding limb twist
Post by: George Tsoukalas on July 02, 2014, 04:10:32 pm
Yes, leave it. Jawge
Title: Re: Input regarding limb twist
Post by: Pat B on July 02, 2014, 05:19:59 pm
If you use a tillering gizmo and use it on both sides of the belly on each limb it will show you where to remove wood to reverse the twist.
Title: Re: Input regarding limb twist
Post by: Fred Arnold on July 02, 2014, 07:13:18 pm
Thanks to all!! I'm done :D and it's going to the finishing parlor.
Title: Re: Input regarding limb twist
Post by: son of massey on July 03, 2014, 01:26:35 pm
Apologies, I misspoke and George is correct, the string is closer to the weak side. But the bow does pull towards the weak side-I just pictured the outcome of that backwards somehow-limb twist throws me sometimes. A useful post showing this:

http://www.primitivearcher.com/smf/index.php/topic,27206.msg364058.html#msg364058

Sorry for misleading you-it was not intentional.
SOM