Do we have any engineers in the house?

[Badger]

     I finally found a theory that the only one who agrees with me is me. This relates to tilering the bow. I know they shoot fine and without problems the way most of us tiller because for most of my life I used the same methods that are still popular today.

    But, from a standpoint of pure physics it would seem to me that none of the forces that are present during the draw have any relation to the forces present during the shot. I would think that the best method for a pure clean shot would be to draw the bow back supported directly in line with the arrow rest and pulled at the point on the string exactly where the arrow knock will be placed. I say it should be tillered to draw straight back from here. My logic is that the  bow hand is no longer relevant and the point on the string where we draw the bow is not relevant. The only thing relevant is how the mass of the arrow relates to the limbs through the string.

   Hopefully one of our engineers can come on and either straighten me out or confirm what I am implying. I am only hard headed when I firmly believe I am right LOL> 

  I will concede that balance of the bow when drawing is important for proper shot execution and for this reason I still always tiller where my index finer lies on the string. But speaking just for arrow flight purposes what method would make more sense?

[bjrogg]

I'm certainly not a engineer but I find your question interesting. If it was only about the arrow I think you might be right, but I think one of the biggest reasons we tiller bows like we do is for the survivability and longevity of our bows. Posiblly we could do both but I believe the bow probably takes priority. But I could be wrong lol

[bubbles]

Does a D loop like on a compound accomplish a more even draw? The drawing force is at small point above and below the nock.

[Badger]

  Bubbles, I am ignoring the draw all together and concentrating on the shot after the string has been released.

[mwosborn]

If I have learned nothing else as I began building bows, I have learned this...  The "simple bow" involves some pretty complicated "physics".  It is a combination of a levers and springs.  Lots of forces acting on the bow before draw and after release.  Oh...I am not an engineer but I would think that hand placement on the bow relative to hand placement on the string have an impact on the forces after the release. 

[bubby]

Sounds like you need some good slo motion film of the release?

[Badger]

If I have learned nothing else as I began building bows, I have learned this...  The "simple bow" involves some pretty complicated "physics".  It is a combination of a levers and springs.  Lots of forces acting on the bow before draw and after release.  Oh...I am not an engineer but I would think that hand placement on the bow relative to hand placement on the string have an impact on the forces after the release.

  I think they do have some impact but I don't think near as much as we tend to think. The string has to get rid of the slack on release which I am sure it does very quickly, from that point on it is just the arrow and the bow, even the hand holding the bow has little influence.

[Badger]

     I can easily come up with several good reasons for tillering a bow to the way it is held such as more balanced in the hand and more stable to shoot, Less stress on the limbs, possibly quieter etc, but better arrow flight is not one of them.

[Del the cat]

Two points are always in line...
Del

[mikekeswick]

Badger - try a thumbring them Eastern fellas knew a thing or two!
I don't see what you are saying about the position or bow hand/pulling point on the string not being relevant? 

[Badger]

Badger - try a thumbring them Eastern fellas knew a thing or two!
I don't see what you are saying about the position or bow hand/pulling point on the string not being relevant?

  You and a few others are missing the point. Its all about tillering. I say it is not relevant to tillering because most of us let go of the string when we shoot the bow.

[BenBen]

I think we tiller bows the way we do to be able to store enough energy without damaging the bow.
What I mean is this: if bows were tillered as you said (supported directly on the arrow rest point, and drawn exactly on the nock point), you should draw them like that in real life as well, to get the maximum energy of your bow. But in real life points don't exist, only surfaces. The thing is, that you're in some extent "obliged" to draw a bow with your hands, which means that you can't draw it the way you'd tiller it and you have to take this fact into account as you tiller a bow.

To sum up, we DON'T tiller bows the way you mentionned, cause in this case the shape (tiller) of the bow as you draw it (with your hands) would be hinged or at least uneven and less energy would be stored in the bow. Of course once the string is released, only the force applied by the string (via the limbs) matters, but this force is directly linked to the energy stored in the bow wich is determined by the way you tillered and then drew the string.

I hope it's clear enough 

BenBen

[BenBen]

What I wanted to show actually is that this quote

"it would seem to me that none of the forces that are present during the draw have any relation to the forces present during the shot"

appears to be flawed

BenBen

[George Tsoukalas]

Badger, I have to admit that I read your post several times and could not follow it.
Anyway, I tiller from the center initially and then either in front of  a mirror or through digi pics make the bottom limb a bit stronger (1/4") or even at full draw.
Jawge

[RyanY]

If I understand correctly, I think an effective way of discovering if we're tillering our bows for optimum effect on the arrow would be to take high speed video of a huge sample of bows being shot. We could see tiller at full draw but also how the limbs behave through the shot. Are they traveling equally in terms of unbending and in terms of speed, where is vibration directed after the shot, or is there limb deformity during the shot that may indicate a tiller shape that is not quite where it's needed. Differences and increases in symmetry could possibly indicate small losses in efficiency.