Author Topic: Yew design layout 1" longer top limb??  (Read 5433 times)

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Offline bigcountry

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Yew design layout 1" longer top limb??
« on: July 28, 2008, 12:24:22 pm »
I am trying to layout a design for a yew longbow to duplicate the one in TBB1.  Basically a 1.25" wide pyamid limb tapering to 5/8" tips with a 4" handle and 4" fades (total 12").  I have enough wood for a 71" Tip to tip bow.

But what is confusing me, is they are calling out for a 1" longer top limb?  The ones I have laidout out of osage basically have even limb lengths and tillered for center of handle and string. 

Why would I want a 1" longer top limb?  I shoot three under by the way.

Thanks,
Mark
Westminster, MD

Offline Pat B

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Re: Yew design layout 1" longer top limb??
« Reply #1 on: July 28, 2008, 12:47:16 pm »
I lay out most of my bows symmetrically(both limbs even length) these days and it makes it easier for me to see tiller. Shooting with 3 under you add extra stress to the bottom limb but as long as the bow is tillered for 3 under there should be no problems.
  Are you building an ELB style or an ALB style?  What is your draw length? You can get your tips smaller than 5/8". For an ELB with horn nocks I would go 1/2" and for an ALB with tip overlays I would go 3/8" or even less.     Pat
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline YewArcher

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Re: Yew design layout 1" longer top limb??
« Reply #2 on: July 28, 2008, 12:47:35 pm »
Some bowyers make the top limb longer so that the bottom limb is stiffer (because it is shorter). To some this makes the tillering a little easier because you will alyays need a stiffer bottom limb because there is more stress upon it.....espically is you shoot 3 under.

Others claim that it gives the bow more balance in the hand.

Some bows I make that way but most times I make them even lenght. Its a prefernce thing that you will work out as you make bows.

SJM

Offline bigcountry

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Re: Yew design layout 1" longer top limb??
« Reply #3 on: July 28, 2008, 02:43:54 pm »
I lay out most of my bows symmetrically(both limbs even length) these days and it makes it easier for me to see tiller. Shooting with 3 under you add extra stress to the bottom limb but as long as the bow is tillered for 3 under there should be no problems.
  Are you building an ELB style or an ALB style?  What is your draw length? You can get your tips smaller than 5/8". For an ELB with horn nocks I would go 1/2" and for an ALB with tip overlays I would go 3/8" or even less.     Pat

I think I am going to make this symmetric too.  They say you want equal tiller for 3 under and tiller to be 3/8-1/2" longer more for split on one limb. 


I am still looking this stave over to see what I have.  It had some windshake damage, and I spent some time last night on the bandsaw cutting on it to see if the damage went deep. 

Since I have only 1.3" of room for the limb at its widest point and still stay with the grain, I figured its going to be a combo.  Not sure what you would call it.  Basicallly a stiff handle design with semi rounded belly.  Kinda like the design in the TBB vol 1. 

I orignally was going to make a flatbow design with wide limbs. But with the windshake damage, I now don't have the width desired.
Westminster, MD

Offline Pat B

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Re: Yew design layout 1" longer top limb??
« Reply #4 on: July 28, 2008, 03:27:50 pm »
If you look on page 7 for "15 Mile Yew" that I posted you will see the yew bow I recently made. This one bends through the handle because I had no more wood to work with but it is a very good shooting bow...it will be my hunting bow this fall.  It has a semi rounder belly and fairly high crowned back and it and 2 other staves were split from a log about 5" in diameter.    Pat
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

radius

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Re: Yew design layout 1" longer top limb??
« Reply #5 on: July 28, 2008, 03:32:59 pm »
The reason for making the lower limb shorter is that you are trying to get the arrow to fly out of the very center of the spring.

Offline bigcountry

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Re: Yew design layout 1" longer top limb??
« Reply #6 on: July 28, 2008, 04:10:27 pm »
If you look on page 7 for "15 Mile Yew" that I posted you will see the yew bow I recently made. This one bends through the handle because I had no more wood to work with but it is a very good shooting bow...it will be my hunting bow this fall.  It has a semi rounder belly and fairly high crowned back and it and 2 other staves were split from a log about 5" in diameter.    Pat

Oh, yea, I followed it.  I am pretty much eating up any info on yew and rounded belly designs.  You did a fine job.

I still have time to make it bend thru the handle.  I haven't cut it yet.  I have never done one of those bows.  But I figured, I have over 71" to work with. 
Westminster, MD

Offline bigcountry

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Re: Yew design layout 1" longer top limb??
« Reply #7 on: July 28, 2008, 04:11:57 pm »
The reason for making the lower limb shorter is that you are trying to get the arrow to fly out of the very center of the spring.

I figured that, but never seen anyone do it before besides production bows.  The guy I kinda learned from alwasy tillered the bow dead center of the string and handle. 
Westminster, MD