Primitive Archer
Main Discussion Area => Bows => Topic started by: winstaples on December 18, 2007, 05:33:37 pm
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Hey Guys,
I am ashamed to ask such a simple question, but how do you correct propeller twist in a limb tip or the last 1/4 of a limb. Many of my flat bellied bows when they reach weight have the one side of the tip farther away from the string than the other when viewed from the belly side when the bow is strung. On a few bowes I think this may be because the limbs are out of line from one another and perhaps not solvable. One bow I have like this was spliced at the handle and the center of one limb is way off from being lined up with the center of the other.
But it seems that I read somewhere that thinning the 'strong' side of the limb (that bends the least, is farthest from the string) or moving the nock on one side or the other deeper should correct this problem when it is less severe and everything else is OK. I have tried thinning the limb on a few bows and did not seem to get any improvement so I am not sure what really is a solution to the problem of slight propeller twist.
Does anyone have any solutions or can you suggest a good reference on this problem.
Win
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Everything you tried will work if the twist is not too extreme.With bows with a lot of twist,I will clamp one end down and grease the twisted part with Crisco.I like crisco because when it gets hot it smells like fried chicken.Then I take my heat gun and slowly work it over the area with the twist.When it starts to turn a little darker in color and you will start to smell wood I stop and twist it in the direction I want it and hold it in place with a clamp until it cools.I keep repeating this until it lines up.
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You may not have to remove the twist. Check out Jawge's site. He has a real corkscrew on there that he built. Lots of good info on Jawge's site. Pat
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Hi, I second what Pat said. Propellered tips are more a cosmetic than a performance issue. Unless of course you're building a recurve. Ron
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Hi,
I've had long (>68") flatbows, especially hickory, with propeller twist. If it's less than 1/4 twist at full draw, I honestly couldn't tell the difference in performance or accuracy if I removed it. Some I've left, others I've fixed, and it didn't seem to make one bit of difference. For some people, me included, it looks bad. I've removed it with direct dry heat (heat gun) and veg oil, using a large C clamp and a 1 gallon plastic milk jug filled with water as a counter weight.
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If the stave is naturally twisted by less than 20 degrees I don't bother correcting it. However, often a twist can be caused by the bowyer because of uneven wood removal. To fix it, if that is the case, then take wood from the high side. Jawge