Author Topic: Short lower limbs?  (Read 7342 times)

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Offline ShinneryOak

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Short lower limbs?
« on: November 17, 2009, 05:17:40 pm »
I'm reading Hunting The Osage Bow by Dean Torges and was a little surprised to see he advocates making the lower limb up to 1 1/4 inches shorter than the top limb. All the plans I'd seen before had basically equal limb length, with the lower limb tillered a little stiffer. He goes into a long list of benefits for this design, mostly better balance, durability, shootability, etc. Is  anyone using this design much ? 

Offline snedeker

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Re: Short lower limbs?
« Reply #1 on: November 17, 2009, 05:23:44 pm »
I make my bows 63" and shorter with lower limb 1-2 inches shorter, but don't bother often on longer bows.

Dave

Offline Dano

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Re: Short lower limbs?
« Reply #2 on: November 17, 2009, 05:49:38 pm »
Yep asymmetrical, you'll like it. ;)
"If the women don't find you handsome, they should at least find you handy."


Nevada

Offline NOMADIC PIRATE

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Re: Short lower limbs?
« Reply #3 on: November 17, 2009, 06:10:05 pm »
Being making them equal length and assymetrical, and from what I see, assymetrican are more quiet and accurate
NORTH SHORE, HAWAII

Offline Kegan

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Re: Short lower limbs?
« Reply #4 on: November 17, 2009, 06:31:46 pm »
I make mine equal length, but the top limb usually bends more (about 1/4"-1/2"). Given that I shoot with the heel down, this is perfect.

Offline kylerprochaska

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Re: Short lower limbs?
« Reply #5 on: November 17, 2009, 06:38:12 pm »
Ive made all mine with the bottom limb 1-2 inches shorter...(I read the same book before I made my first bow)  I like it better that way...thats really the only way you can get a center shot bow with a shorter riser section...IMO

-Ky
GBR!

Offline medicinewheel

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Re: Short lower limbs?
« Reply #6 on: November 18, 2009, 03:11:33 am »
Asymmetrical seems to work better for me, too, for making and shooting. I pretty much see it as a personal preference...
Frank from Germany...

Online Pappy

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Re: Short lower limbs?
« Reply #7 on: November 18, 2009, 05:56:23 am »
I make mine equal length,unless I have a problem and need to shorten the bottom  limb.
Never noticed any difference in the way they shoot. Also if you plan to do that you will need to pick the top limb at the start witch is not a big problem ,but I usually don't do that till I get them
to low brace and see where the string tracks. Either way works fine,to each there own. :)
   Pappy
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Offline Tom Leemans

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Re: Short lower limbs?
« Reply #8 on: November 18, 2009, 09:52:44 am »
I make mine with a longer upper limb too. When you use a bulbous handle and let the fulcrum hit the web of your hand, it makes for good pointability and a "quiet in the hand" feel.

Offline woodstick

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Re: Short lower limbs?
« Reply #9 on: November 18, 2009, 10:13:00 am »
im from oklahoma so all this shorter longer well i just dont need that kind of pressure on my little old head so i make all mine the same and it seems fine.
a drawn bow is a stick 9/10 broken

Offline ShinneryOak

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Re: Short lower limbs?
« Reply #10 on: November 18, 2009, 11:05:41 am »
Well I may have to try it next time. Torges says it does make the lower limb harder to tiller, especially on short bows. Does that seem true? 

DCM4

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Re: Short lower limbs?
« Reply #11 on: November 18, 2009, 11:18:36 am »
More precisely, Dean advocates putting the arrow pass at dimensional center.  Technically, from the of the arrow at least, the limbs are of equal lenght.  That the bending portion of the lower limb is shorter (part of it being occupied by handle) means, particularly on a shorter bow, it needs to be a little wider and carefully tillered to avoid overworking it.  I try to visualize the apex of the tiller curve at the arrow pass and it all seems to work out.

In fact, on a bow where arrow pass is arbitrarily positioned 2" above dimensional center, the upper limb is "shorter" in terms of the geometry at the string grooves, even if the bending portion is "the same."  That's why, I think, Dean and others assert such bows may tend to fatigue the upper limb more quickly.  Even though they have "equal" bending lenght, the positive tiller required to offset the asym of the geometry means they have to bend farther, causing more set.  Since we can't abide arrow nock downward travel on the power stroke, for want of interference, "negative" tiller is not an option.

In practice I make 'em all different ways and honestly any difference in performance I'd have a hard time quantifying.  But I do prefer arrow pass closer to center.

Offline dragonman

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Re: Short lower limbs?
« Reply #12 on: November 18, 2009, 01:47:24 pm »
There  is no doubt that every bow I've made the lower limb has been more stressed than the  upper and needs to be made stronger some how!!!
'expansion and compression'.. the secret of life is to balance these two opposing forces.......

Offline M-P

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Re: Short lower limbs?
« Reply #13 on: November 18, 2009, 10:05:31 pm »
Hi,  I've made them both ways and don't see a real difference in performance.  If there is a difference, you'd  just have to be either a better bowyer, or a better shot to notice.   Making them symmetrical is a little easier for me and allows me to flip the bow end for end if the string lays a little off center.  Historically you might take note of the fact that different cultures seem to have held strong preferences.  For instance,  the symmetrical bows of the Ottoman Turks and the very asymmetrical yumi of the Japanese are certainly very different.    Ron
"A man should make his own arrows."   Omaha proverb   

"There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves."    Will Rogers

Offline Jim Davis

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Re: Short lower limbs?
« Reply #14 on: November 19, 2009, 12:10:52 am »
It was standard British practice for centuries and American practice until the middle of the last century to make the lower limb one inch shorter so the arrow would pass closer to the center of the bow's length.

In the 1930s and 1940s, C.N. Hickman introduced a design with a longer handle and both limbs the same length. The bow hand was placed on the lower half of the handle, leaving an equal length of handle above. The arrow could pass at the center of the bow's length and still have the limbs equal.

I usually make my handles 5" or 5-1/2" long and gain about an inch toward center for the arrow. I make my limbs equal length and the bows shoot fine.

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