Author Topic: Assymetrical or Symetrical limbs  (Read 7758 times)

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Offline Carle1953

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Assymetrical or Symetrical limbs
« on: November 22, 2008, 10:53:57 pm »
Hi everyone, I would like some input on limb length and its effect.  Some people are of the opinion that both limbs need to be the same length and others feel that the top limb should be longer.  I have an Osage bow that I made from a split that I got at MoJam this year.  I ended up with the center of the bow being in the middle of the handle.  I have read that some folks like to put the middle of the bow an inch or so below the arrow shelf, thus making the top limb longer.  Any input and opinions would be greatly appreciated.  Thanks, Carle1953

Offline Jbell

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Re: Assymetrical or Symetrical limbs
« Reply #1 on: November 22, 2008, 11:57:14 pm »
I have always done assymetrical limbs. Just makes the most sense to me. For me, when I shoot,the fulcrum on my bow hand is the meat of my thumb. With a longer upper limb my hand rests near the true center of the bow which in turn helps for a balanced and rock solid draw and shot. In my opinion when both limbs are the same length, unless you have a very low wrist style, you have just made the lower limb the longer limb by changing the pivot point. I have also noticed that some people with same length limb bows tiller it out that way then move their handle and arrow pass down a bit to get closer to center(which is like having a longer upper limb). But opinions vary with this topic and both do in fact work, try each style and you will find whats best for you.
Justin Blunt

Offline Pat B

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Re: Assymetrical or Symetrical limbs
« Reply #2 on: November 23, 2008, 12:03:42 am »
When I first learned to build bows, all the books said to mark a line 1 1/4" above center and 2 3/4" below for the handle. This makes an asymmetric bow. The top limb is longer than the bottom. In the last couple of years I have been making the center of the handle the center of the bow. It is easier for me to see tiller so that's why I do it. I also like the way the bow feels in my hand.
   It doesn't really matter which you build a wood bow as long as you tiller for it.      Pat
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Offline Jbell

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Re: Assymetrical or Symetrical limbs
« Reply #3 on: November 23, 2008, 12:16:02 am »
Pat is right, I think assymetrical is a bit tougher to tiller, seems like you are tillering  two different bows at once. Each limb has its own profile. . I am like you Pat I read Torges book and that is the way I have made bows ever since. Hmmm, I think I may try a symmetrical both next just for the sake of things.
Justin Blunt

Offline Carle1953

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Re: Assymetrical or Symetrical limbs
« Reply #4 on: November 23, 2008, 11:59:51 am »
Thanks guys, I have found that it is a lot easier to tiller a sysmetrical bow, since both limbs are the same.  For me and my method of using a curve guide ( I use a 6 " x 1/2" x 3/4" stick with a sheetrock screw) it lets me get the same curve in both limbs.  I do notice though that when I pull the string in tillering I have to put the pull point in the center of the string and in the center of the bow. This is not where I pull the bow when I am shooting it.  I use a two under, one over draw and I really don't know if that makes any difference about tillering.  Some say it does and others say it doesn't.  I do notice however that in pulling the bow with the nock point set to the arrow shelf it has a tendency to torque the bow from top to bottom making a loose grip hard to accomplish.  Should a person try to tiller so that the balance point is the web of the gripping hand with both limb tips pulling back the same distance?  The reason I am trying to figure all this out is that I want to build a bow for my wife.  As a result of a farming accident years ago she has only her thumb and forefinger on her left hand and has no way to prevent the bow from twisting top to bottom.  The way I look at it is if I can get as much input as possible from the accumulated years of experience from as many bowyers as I can my failure rate on this project will decrease.  I greatly appreciate all input and thanks to all.

Offline Kegan

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Re: Assymetrical or Symetrical limbs
« Reply #5 on: November 23, 2008, 03:15:56 pm »
I make the limbs the same length, then put the weaker limb on the top during tillering (unless string tracking dictates otherwise). Shoots better for me that way, and any manner of stringing I use can't mess up the tiller that way.

Offline ricktrojanowski

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Re: Assymetrical or Symetrical limbs
« Reply #6 on: November 24, 2008, 06:28:46 am »
I build with symmetrical limbs.  When tillering I put the handle in the tree where my hand would actually hold the bow.  Then clamp the rope on the string where the center finger would be.(three under)  Then tiller I figure this represents actual drawing pretty well.  I do want to try asymmetrical to see if it is any better.
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Offline Postman

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Re: Assymetrical or Symetrical limbs
« Reply #7 on: November 24, 2008, 03:49:44 pm »
I only have 2 symmetrical and 4 asymmetrical bows under my belt, but like the asymmetrical's balance. i feel they are easier to point and shoot, but may be biased due to my better (later) efforts being done this way

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Offline JackCrafty

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Re: Assymetrical or Symetrical limbs
« Reply #8 on: November 24, 2008, 04:02:53 pm »
I guess I like symmetrical limbs.  On all my bows, the arrow pass is at the point where the bow balances on my finger.
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Offline Pat B

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Re: Assymetrical or Symetrical limbs
« Reply #9 on: November 24, 2008, 07:09:36 pm »
With asymmetrical bows you have to decide which limb is the top early in the process. With a symmetrical bow you can wait until its tillered before you decide...and even then you can flip it and shoot it.    Pat
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Carle1953

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Re: Assymetrical or Symetrical limbs
« Reply #10 on: January 23, 2009, 04:29:02 pm »
Thanks everyone for your input.  I did get the bow built and my wife seems to like it.  We are waiting for the weather to get a little better so that she can start shooting it.  It is her hope to be able to shoot at MOJAM 09 and if all goes well maybe even OJAM. I will try to post pictures if I can figure out how to do that.  Thanks again