Author Topic: string doesnt line up in the middle of the bow  (Read 1900 times)

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Offline Jarod187

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string doesnt line up in the middle of the bow
« on: August 06, 2011, 03:49:14 pm »
I have been workin on an osage bow with recurved tips. After i recurved the tips the string doesnt line up in the middle of the bow. i tried using pressure over a couple of days to straighten the limbs but with no luck. One limb is completely off center. I was wondering if i could put 3 100W bulbs in my hotbox to then apply the pressure to straighten the limb. Has anyone ever tried this?

Offline JW_Halverson

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Re: string doesnt line up in the middle of the bow
« Reply #1 on: August 06, 2011, 04:05:11 pm »
Not sure those bulbs will be able to create enough heat to get the wood to soften properly.  Plus heating the whole bow may relax the bends you've already introduced. 

I'd recommend a heat gun treatment to the bad tip.  That way you can torque it back into alignment and hold steady pressure to keep the recurve.  If the limb does not twist when being drawn, you alternatively could heat the handle and make a very gentle bend in order to bring the tips back into line.  The advantage of bending the handle is that it takes very little change in the handle to effect great change out on the tips.

Best of luck to you.
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.

Offline BowJunkie

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Re: string doesnt line up in the middle of the bow
« Reply #2 on: August 06, 2011, 04:11:29 pm »
Harbor Freight has heat guns for under 30 bucks if you can spare it.
Just a thought
Johnny
in Texas

Offline gstoneberg

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Re: string doesnt line up in the middle of the bow
« Reply #3 on: August 06, 2011, 04:28:33 pm »
The string doesn't have to run down the center of the handle nor do the limbs have look the same.  Is it in the handle at all?  I have made bows where the only place the string is over wood is one point in the handle.  In a crooked bow like that I always wait to choose upper and lower limb until I see where the string goes.  Then I select the limb that makes the bow the most center shot.  If you have to bend it, stay away from places the limb was bent before.  If the tips were recurved with heat, heating again there can cause the tip to return to it's former shape unless you have it clamped in a caul.  I've had decent luck bending bows in the handle as John suggested.  It takes a lot of heat though.  A heat gun is the way to go.  Light bulbs will never be enough.

George
St Paul, TX

Offline Pat B

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Re: string doesnt line up in the middle of the bow
« Reply #4 on: August 06, 2011, 04:53:04 pm »
Will you post pics so we can see just what it looks like.  Like said above, use a heat gun  to make your corrections.
  When I make recurves I usually have to heat and clamp them 2 or 3(or more) times to get the tips aligned and the string to line up down the bow. If only one recurve is out of allignment you can heat it with the heat gun, torque it just past center and hold it there for a few minutes.  Let any of the corrections sit over night to cool before stressing it.
  I just posted a build along on a 60" elm recurve from beginning to end at the top of the "Archives" page. You might get some info that will help you there.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline 4est Trekker

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Re: string doesnt line up in the middle of the bow
« Reply #5 on: August 07, 2011, 12:22:26 am »
I'm with Pat. Actually, "recurve" comes from the same Latin root word for "reheat."  No, just kidding... ;)  Truthfully, though, I inevitably heat recurves 3-4 to tweak the tiller.  It doesn't take much time or energy, and a heat gun makes it slick and efficient. 
"Walk softly, and carry a bent stick."

"And whatever you do, whether in word or deed, do it all in the name of the Lord Jesus Christ, giving thanks to God the Father through him."  Col. 3:17