The mystery of efficiency between 3 under and split.

[Badlands]

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

[bowdude]

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.

[Greg Szalewski]

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.

[Jeff Strubberg]

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.

[Mr.Chuck]

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!  :-)  

[Onehair]

Being centered should be quieter. Why not? Why does 3 fingers under make so much noise?

[whitebuffalo]

ONe hair beat me to it,, Why is three under lounder??

[R H Clark]

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.

[IN Bob]

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.

[R H Clark]

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.

[Ray]

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.

[GameGetter]

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!

[bowdude]

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.

[R H Clark]

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.

[bowdude]

Not saying its bad at all.  Just saying everything has a give and take.