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Main Boards => PowWow => Topic started by: hera on March 06, 2008, 09:56:00 PM

Title: The mystery of efficiency between 3 under and split.
Post by: hera on March 06, 2008, 09:56:00 PM: (http://img411.imageshack.us/img411/3953/0803tiller008ir9.jpg)

(http://img341.imageshack.us/img341/3425/0803tiller010xy6.jpg)

(http://img509.imageshack.us/img509/3826/0803tiller013ut7.jpg)
Title: Re: The mystery of efficiency between 3 under and split.
Post by: hera on March 06, 2008, 10:19:00 PM: (http://img411.imageshack.us/img411/3926/setup1ml8.jpg)

(http://img186.imageshack.us/img186/2601/0803tillera002da7.jpg)

(http://img337.imageshack.us/img337/1452/0803tillera004cc0.jpg)
Title: Re: The mystery of efficiency between 3 under and split.
Post by: hera on March 06, 2008, 10:48:00 PM: (http://img186.imageshack.us/img186/8575/0803tillerb001cy6.jpg)

(http://img301.imageshack.us/img301/3833/0803tillerb003th7.jpg)

You can say : who care.

My doubt is,is there a little bit different ?
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Gene Roberts on March 06, 2008, 11:12:00 PM: So.....What's the point,Which one is more efficient?I personally shoot three under.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: robslifts on March 06, 2008, 11:15:00 PM: when you shoot three under the middle finger pulls directly at center of most bows and thus being more efficient jmho
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Matty on March 07, 2008, 12:14:00 AM: I like this post I think the right minds can create big waves here. One thing to think about though, is that MANY people don't hold the bow at the lowest portion of the riser or should I say put the majority of Force on that portion. I see lots of people put the HEEL of the hand on the Lowest part of the handle which changes everything. Then when you look at their Nockpoint it's 1" above top dead
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Benny Nganabbarru on March 07, 2008, 03:00:00 AM: Both kill. Both can blow an arrow clean through a big animal, and into the never-never beyond.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: ChuckC on March 07, 2008, 03:16:00 AM: Let's throw some added tidbits in there. There is no actual distance above center that the platform or shelf of the riser is cut to. One bowyer may chose 1" above center, others 1.5", still others right at center line. That brings even more changes to the puzzle.

ChuckC (from India today)
Title: Re: The mystery of efficiency between 3 under and split.
Post by: NDTerminator on March 07, 2008, 05:38:00 AM: it's 0430 in the morning, this makes my head hurt... :biglaugh:
Title: Re: The mystery of efficiency between 3 under and split.
Post by: hera on March 07, 2008, 05:47:00 AM: Sorry Jon.
:)
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Benny Nganabbarru on March 07, 2008, 05:54:00 AM: How does having a bow tillered for three-under affect this?

My bows tillered for split-finger are just as deadly when shot three-under... but the new Schafer that will arrive soon has been tillered for three-under.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: hera on March 07, 2008, 06:25:00 AM: IMO,just IMO.
there are not so big different in hunting situation.
But for a new bowyer like me,I just like to know the detail,I should not be too lax in this knowledge.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Orion on March 07, 2008, 09:46:00 AM: Hera: How did you measure/arrive at the center of the bow? Did you assume the center of the throat was the center of the bow or find that through actual measurement? If the center of the bow pictured is, in fact, the center of the throat, then the arrow shelf is only about 3/4 inch above center.

Most bowyers put the shelf 1 1/4 to 2 inches above the center of the bow. Or, stated another way, the deepest part of the throat on the riser is often not the center of the bow; it's above the center of the bow. If that's the case here, that would throw your numbers off. For what it's worth.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Kingstaken on March 07, 2008, 10:16:00 AM: In Hera's other build along, it lQQked like Hera had the bow's center balanced on the deepest part of the throat.http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=056510;p=10

I like the thought processes. Shows the mind of a true craftsmen. Not afraid to think outside the box.
Everyone knew from the beginning of time anything held above the ground would fall but it took Newton millions of years later to discover a great obvious theory. Imagine your friend said "Listen Jim, did you know that anything at rest stays at rest ....." you'd call the guys in the white suits on him or say you've drank too much again bubba. :biglaugh:
It wasn't until it was written down on paper, that the blood began to flow thru his brain bouncing off new ideas which lead to big advances in technology.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: hera on March 07, 2008, 11:00:00 AM: I should not start this thread.
:( :p
I dig into my dictionary when I read all reply......... :banghead: :banghead: :banghead:
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Bard1 on March 07, 2008, 11:20:00 AM: oooh poor Hera. Now his head hurts.

How's the new bow shoot Hera?
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Jeff Strubberg on March 07, 2008, 11:21:00 AM: You are making an assumption.

Why would pulling on the center of the bow be more efficient?
Title: Re: The mystery of efficiency between 3 under and split.
Post by: hera on March 07, 2008, 11:26:00 AM: quote:
Originally posted by Bard1:
oooh poor Hera. Now his head hurts. :knothead: Bard1

BTW,shoot really well,good balance and wide spine tolerance.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: ChuckC on March 07, 2008, 12:52:00 PM: Hera... nothing wrong with this thread. Making us think a little is all.

pass the aspirin please.
ChuckC
Title: Re: The mystery of efficiency between 3 under and split.
Post by: R H Clark on March 07, 2008, 01:56:00 PM: IMHO you will get max efficiency when both limbs are pulled and released with equal force.The question becomes how to achieve this.People grip the bow and even hold a string differently.That is why nocking point has to be adjusted for each person.Also why different tiller requires different nocking points.It's all part of tuning and is why a well tuned arrow will shoot faster than a poorly tuned arrow of the same weight.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Badlands on March 07, 2008, 02:32:00 PM: I always thought that it had to do with how the limbs reacted after release. If a string is held right at the center and released the limbs would react exactly the same at exactly the same time. If we can't hold and release the string from the exact center we have to compensate limb strength (tillering) to accomodate for the offset. In my mind, that is why a bow for a split fingered shooter is tillered more than one made for a 3 under shooter. The 3 under shooter is holding the string closer to the exact center.

Just my theory, I might be all wrong.

Brad
Title: Re: The mystery of efficiency between 3 under and split.
Post by: bowdude on March 07, 2008, 02:35:00 PM: True many people would hold a single bow in many different ways. Doesn't mean they are all correct. There is in the end 1 best way per bow style. It only takes more detailed measureing! Thanks Hera.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Greg Szalewski on March 07, 2008, 07:32:00 PM: Hera your thread once again got my interest. This is a topic I am still trying to learn more about. You see about 15 years ago I started to make bows and then taught a friend what I knew at that point. Well he took that and of course changed what I was doing wrong and made the arrow on the shelf the center of the bow. I naturally told him he was wrong and to prove it I wrote to Norb Mullany to have him confirm that. He said the center could be the shelf or the grip, but most put it closer to the grip. I was hoping for a more technical answer than that, and still am.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Jeff Strubberg on March 07, 2008, 08:34:00 PM: Quote
I always thought that it had to do with how the limbs reacted after release. If a string is held right at the center and released the limbs would react exactly the same at exactly the same time.
Efficiency-wise, the only thing that really matters is that the limbs recover together. Build two bows, one tillered split finger and one tillered three under. Shoot both off of a shooting machine in the style they are tillered to.

You won't be able to measure a difference between the two.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Mr.Chuck on March 07, 2008, 08:54:00 PM: The bottom line is three under is smoother release for the fact that all three fingers are working together. Split has it's variences, but not as mechanically in unison as three under. Ask a target shooter! :-) :thumbsup:
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Onehair on March 07, 2008, 10:15:00 PM: Being centered should be quieter. Why not? Why does 3 fingers under make so much noise?
Title: Re: The mystery of efficiency between 3 under and split.
Post by: whitebuffalo on March 07, 2008, 10:20:00 PM: ONe hair beat me to it,, Why is three under lounder??
Title: Re: The mystery of efficiency between 3 under and split.
Post by: R H Clark on March 07, 2008, 10:34:00 PM: Three under being louder is dependant on the tiller of the bow.Since I have a Dalaa and have experimented with tiller I've seen this first hand.Might not be the same for everyone but I find no difference in noise with three under when tiller is set to even.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: IN Bob on March 08, 2008, 12:02:00 AM: So what are the major factors determining tiller for a bow that will be shot 3 under style? is the tiller usually set close to "even" across the board, or does it depend on bow design, limb material, etc.

My experience is similar to one hair-- at least for standard tiller bows -- noiser to my ear and perceived less cast compared to split, at least on flight testing arrows of the same weight. Maybe I'm getting another 1/2" draw split.

what Jeff says makes sense-- if properly tillered should be little difference.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: R H Clark on March 08, 2008, 12:52:00 AM: In Bob
Nothing scientific just my theory.A standard tiller bow is somewhere between 1/8 to 3/8 pos or a greater distance on the top limb from string to fades.The bowyer does this to cause the limbs to pull evenly with a standard grip and split finger hold.

Three under would put more stress on the lower limb and cause the harmonics to be unbalanced thus more noise.That is the reason you will see the nock so high for three under shooters.They have raised the nock and cancled out some of that unbalance.

When you set tiller to even you remove some of the stress on the lower limb so that it isn't so unbalanced with three under.

When I shoot three under on an even tillered bow I get less noise,a lower nock,and less pressure on my bottom finger.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: Ray on March 08, 2008, 09:07:00 AM: Hera I enjoy following your work,you are a true master craftsman.
We have an old saying here(There is more than one way to skin a cat).This holds true in bowery also.If the final product is balanced in your hand,pleasent to grip,quiet and hits where you aim then consider yourself a success.Thanks again for your post-Ray.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: GameGetter on March 08, 2008, 01:11:00 PM: Hera,
From one bowyer to another-Keep thinking that way. That one little thing may not make much of a difference but when you add up all the one little things that you are doing: Well then, things begin to add up and before you know it you are building a better bow!
Title: Re: The mystery of efficiency between 3 under and split.
Post by: bowdude on March 08, 2008, 05:33:00 PM: Even tiller may work the limbs the same for 3 under but with the nock point 1 to even 2 inches above that what is the reult to the arrow? One result used to be when we used to use stick on arrow rests or god forbid those spring and plungers, is they would break! (been there done that, no longer 3 under shooter) Three under causes a fare amount of downward stress on the arrow as drawn. With some you can even see them bend.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: R H Clark on March 08, 2008, 07:51:00 PM: Bowdude
With even tiller I don't have to set my nock any higher than a split finger shooter.I think the ammount of stress put on the arrow is all on the shooter.I would think it would be easier to put more downward stress on an arrow with split finger.Whatever the case some folks are very accurate with three under, so it must not be all bad.
Title: Re: The mystery of efficiency between 3 under and split.
Post by: bowdude on March 09, 2008, 02:28:00 PM: Not saying its bad at all. Just saying everything has a give and take.