Author Topic: Got some rotation in my limbs  (Read 1742 times)

0 Members and 1 Guest are viewing this topic.

Offline Hunter Van Winkle

  • Member
  • Posts: 58
Got some rotation in my limbs
« on: October 11, 2011, 01:26:15 pm »
Nearing completion of an Osage flatbow. As I thinned the tips towards the end, I noticed what seemed to me to be severe twist or rotation.

I was thinking... If the limb is twisted to the left, could I remove wood from the right to straighten it?

Another option I was considering was, if the limb is twisting to the left, just to cut off the part that's out of alignment and remake the nocks.

Of course there's always the heat option.

What do you think?


Offline Pat B

  • Administrator
  • Member
  • Posts: 37,637
Re: Got some rotation in my limbs
« Reply #1 on: October 11, 2011, 01:32:54 pm »
Does it twist only when strung?  If so you have uneven limb thickness from side to side.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Parnell

  • Member
  • Posts: 5,556
Re: Got some rotation in my limbs
« Reply #2 on: October 11, 2011, 01:55:13 pm »
Glad you've got this going.  I'm working on a similar bow but with some recurves and got the same thing going.  My string is lining up nicely at the arrow nocking point so I'm not too concerned.  I tried using some heat to straighten it out some but didn't like putting stress on the side undergoing stress because the area to be straightened had the thinnest section of the back's growth ring.  I'm tillering out the bow removing wood from some areas on the opposite side of the bow than the twist and looking for it to pull out some.  Remaking the nocks could be an option too.  I've got pin nocks going now that are 1/2 inch", but with the bow being 61" I can easily loose some length and make overlayed nocks that are helping to pull in line more.  Not sure yet.  I've done it before and it can help some.

I've made bows with some twist before and they perform just as well.  Sometimes, I think it's better to let the material do what it wants to do without trying to control it too much or change it, so long as it shoots good.

Good luck,

Parnell

P.s. Welcome to P.A.!
1’—>1’

Offline Del the cat

  • Member
  • Posts: 8,322
    • Derek Hutchison Native Wood Self Bows
Re: Got some rotation in my limbs
« Reply #3 on: October 11, 2011, 02:28:37 pm »
It's all about how it looks and moves between brace and full draw.
You havn't got much width to play with to move the nocks sideways which is the first option.
Second option is heat.
I'd want to see a picture of it braced really.
Have a look at my bowyers diary, the last bow I did had some severe twist although it didn't have recurved tips. It may be of help.
This link is to the first post for that particular bow...
http://bowyersdiary.blogspot.com/2011/09/yew-primitive-stave.html
There's about a dozen posts during the build.
Del
Health warning, these posts may contain traces of nut.

Offline Hunter Van Winkle

  • Member
  • Posts: 58
Re: Got some rotation in my limbs
« Reply #4 on: October 11, 2011, 03:21:48 pm »
Pat, I believe the twist is much more pronounced when braced, i'll check when I get back to the shop. If it is twisting to the left, remove wood from right?

Thanks everyone.

Offline Stingray45

  • Member
  • Posts: 330
Re: Got some rotation in my limbs
« Reply #5 on: October 11, 2011, 04:55:23 pm »
I believe if it twists to the left you remove from the left. Because a twist to the left I believe means there is too much wood on the left, causing the string to pull that way. Or meaning the left side is stronger than the right and overpowering it to pull the limb that way.
Is there anything better than wandering the earth with a stick and string in your hand?

Offline Pat B

  • Administrator
  • Member
  • Posts: 37,637
Re: Got some rotation in my limbs
« Reply #6 on: October 11, 2011, 04:58:43 pm »
If it is a difference in thickness remove wood from the thick part by making it thinner. That is generally why a limb will twist when strung.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC