Do we have any engineers in the house?

[Marc St Louis]

Steve
What I meant by during the shot is the time between when the string is released and when the arrow leaves the bow.  Observing the arrow in that time period might tell you something.  If you want to tiller from rest to nocking point you'll first have to determine a nocking point

[scp]

I believe I know what you mean Steve although I don't really know the answer.  I would think that the arrow could tell you whether or not it is being shot properly in relation to how the bow is tillered by how it behaves during the shot

 Mark, I think the point is that it is not all that critical as some would have us believe, that's why we adjust our nocking point. I think on my flight bows I am going to start tillering them from the arrow rest to the nocking point. Bows will always need a good tiller but their is a range of places in the middle that will work fine.

The easiest way to tiller would be to make the center of the bow your holding point and keep bother limbs equal in length and stiffness. We should probably keep the arrow shelf as close as possible to the center holding point and tune the bow by adjusting the nocking point. That means during tillering we can just use the center of the string to pull on the bow. Keep it simple and do not overthink it too much. We will always have the adjustable nocking point to tune the bow properly.

[mikekeswick]

The reason I mentioned the thumb ring Badger is that it takes out  (most) of the problems of have three fingers on the string (making a flat) that has to be straightened out at release before the arrow gets a proper push. If you only have one 'fingersworth' of drawing area on the string you reduce this factor and therefore the differences during draw versus during release....thus (helping to) negate this problem that you raise.

[Badger]

Steve
What I meant by during the shot is the time between when the string is released and when the arrow leaves the bow.  Observing the arrow in that time period might tell you something.  If you want to tiller from rest to nocking point you'll first have to determine a nocking point

  I never really thought about that before Mark. I will give that some thought. I usually just get the limbs bending even and then select the point on the string I want to use.

The reason I mentioned the thumb ring Badger is that it takes out  (most) of the problems of have three fingers on the string (making a flat) that has to be straightened out at release before the arrow gets a proper push. If you only have one 'fingersworth' of drawing area on the string you reduce this factor and therefore the differences during draw versus during release....thus (helping to) negate this problem that you raise.

  The thumb ring does give beautiful flight, watching some of the slow motion videos showed them to be flawless.

[Badger]

Badger, in order to get the arrow to travel perfectly straight past the arrow rest (no porpoising up or down) you don't need to tiller the bow supporting it at the arrow rest, while pulling the string from where the arrow nock will be. In fact, that would ensure that it DIDN'T fly as well as it could have, had you tillered it while mimicking your own holds on both the bow and string.

If we do mimic our shooting idioms while balancing relative limb strength, we won't ever have to move the nock point to make up for limb strength imbalance. I set my nock point where I decided it would be before I even started the bow, and arrows fly perfect from shot #1.

You're right, bows don't have to be tillered perfectly to shoot 'ok', and sometimes folks have to adjust nock height to adjust limb balance, and they can make ammends. But the farther we stray from optimum, the harder bows are to tune, and the more harsh they are to the shooter and arrow flight. Conversely, the closer they are to optimum, the more inherently tuned they are, the softer they shoot, the quieter they are, the better the tiller holds, etc. You know, all the good qualities bowyers claim to strive for 

  Arvin, the quality of your bows speaks for itself. I plan to experiment with it a bit more. As I said earlier in the post. I can see a lot of good reasons to tiller from our holding points. I plan to try it out on a few flight bows shooting the ultra light arrows and see what happens. I know tillering the standard way I have to raise the arrow nock quite a bit to get clean flight.

[Dances with squirrels]

Steve, I'm not Arvin. I'm Jeff D.

Lol, here I thought you were ignoring me. Guess I should go back and look for where you may have addressed me as Arvin 

[Badger]

I always thought you were Arvin LOL

[Selfbowman]

Mark I am in your camp on this I think. A tuned bow and arrow will get you your best flight regardless of the tiller. A good tiller will make the bow easier to tune and give you the best flight.the point here is to get the best flight possible. Knocking point will affect this as much as spine. If the limbs come to rest evenly they will deliver less shock and deliver more cast. Think of a Asian bow with a longer top limb. I have never built one so I am not sure of it their cast or shock. This is over kill in your theory . But possibly may shed some light on the question. The problem is our hands get in the way. I don't know what to do about that. Or did I miss the whole point here. Lol Arvin

[Dances with squirrels]

There are some benefits to designing and tillering bows so their tuning is optimum, predictable and inherent, as opposed to seeking it by moving the nock point up and down, or trying to adjust pressure points under the bow hand by how we grip it. Through design and tillering, we can keep the bow's static balance point, our bow and string hand fulcrums, and the dynamic balance point all within very close proximity to one another, sometimes all one and the same, which makes for a bow that draws without a shift between the static and dynamic balance points requiring navigation during thoughtful tillering and each draw afterwards. Those are my favorite bows to shoot, and I can tell if a bow has those qualities before I draw its string 3".

[freke]

Badgar, intresting topic, could you visualize your thought and compare it with what you consider the usual tiller in sketches ?

Think that would help me to understand:)

[Jim Davis]

Steve, I'm late getting here, but as somebody said, it's a creative concept.

Since we always must hold the bow against the force of the string. (UNTIL THE ARROW IS GONE), the bow hand is always going to exert a force that is part of the vector that is traced by the arrow nock.

Since we hold the bow below the arrow, on release, there will always be a force tending to rotate the bow's top limb toward the archer. (As someone noted about a video early in this thread).

This idea is similar to the issue of making the limbs equal length or making the bottom one shorter. (And whether to make a shorter lower limb stronger than the upper limb--I say that latter practice makes no sense, because a shorter limb of equal strength will return faster anyway).

Ultimately, I don't think any of these ideas matter a whole lot. As has been said, adjusting the nocking point nearly always can get rid of porpoising. Adjusting the nocking point amounts to balancing all the forces during the launch of the arrow.

[Badger]

Mark I am in your camp on this I think. A tuned bow and arrow will get you your best flight regardless of the tiller. A good tiller will make the bow easier to tune and give you the best flight.the point here is to get the best flight possible. Knocking point will affect this as much as spine. If the limbs come to rest evenly they will deliver less shock and deliver more cast. Think of a Asian bow with a longer top limb. I have never built one so I am not sure of it their cast or shock. This is over kill in your theory . But possibly may shed some light on the question. The problem is our hands get in the way. I don't know what to do about that. Or did I miss the whole point here. Lol Arvin

  Arvin, I was always getting you and Jeff mixed up by your handles for some reason. I 100% agree on the good tiller. I am a little skeptical on the importance of tillering from a specific spot as long as it is close.

[Badger]

  Jim, one of the gusy here psoted a slow motion vidio of the arrow being released split finger, the arrow traveled less than 1" before it dropped due to the slack comming out of the string. This is what I was reffereing to. Not sure of the optimum way to compensate for that. I have a feeling it is somewhere between the finger point and the arrow nocking point.

[Jim Davis]

Steve, yes, the forces on the string will not be exactly where they were in static equilibrium. So, the nocking point is going to react to the new angles of force.

[Buckeye Guy]

Man you guys are confusing me with all this , guess I will just go back to letting them fly to the target on their own just like always Haha
Good read anyway Steve
keep on searching!
thanks
Guy