Nock point/limb balance

[MWirwicki]

I second that, Badger.  Or was that third? 

Remember fellas, this is "primitive archery."  I wrap my hand around the handle area while applying light tension on the string with my draw hand.  I adjust my grip hand up or down until the bow feels balanced.  Then I nock an arrow on the string where it appears perpendicular to the top of my knuckle.  I loosely clamp a nock point or wrap masking tape there and shoot it for a bit, paying attention to arrow flight.  I adjust the point from there.

[Dances with squirrels]

Not me. I want to lay my bow out so that the bow center and grip is exactly where I know the bow will balance perfectly in my bow hand as I carry it, and then tiller it so it balances when drawn. I predetermine the nock height, and then adjust limb strength relative to those things. Quick and easy. Predictable and repeatable. I want to make the best I'm capable of and don't care if others deem them 'primitive' or whatever. To each their own.... lots of ways to skin a selfbow.

[DC]

If my nock point seems to be a bit high, which limb is too strong?

Here I am quoting myself. It seems that if a question even remotely involves balance it breaks down into a great long pissing match. I don't think my question is too technical or controversial. I would think it would be a rule of thumb that, " If your nock point seems too high you should reduce the weight on the (blank) limb." Brad tried to answer my question but he said ,"I think." I always like more than one answer, especially on the internet. Sorry Brad. If it turns out that there are two answers then maybe there is room for a urination contest

[Badger]

If my nock point seems to be a bit high, which limb is too strong?

Here I am quoting myself. It seems that if a question even remotely involves balance it breaks down into a great long pissing match. I don't think my question is too technical or controversial. I would think it would be a rule of thumb that, " If your nock point seems too high you should reduce the weight on the (blank) limb." Brad tried to answer my question but he said ,"I think." I always like more than one answer, especially on the internet. Sorry Brad. If it turns out that there are two answers then maybe there is room for a urination contest

   I think the reason you are not getting a straight snwer is because most of us just tiller the bow out watching the limbs to see which is stronger, we never look at nocking point and ask ourselves which is stronger. So in that sense I think we are not comfortable answering the question directly.

[Badger]

    will add that I have some tendency to tiller my bows even at brace and find I have to raise my nocking point about 1/8" to 1 /4". So I would guess the top limb is too strong but I am not certain.

[Carson (CMB)]

   I think the reason you are not getting a straight snwer is because most of us just tiller the bow out watching the limbs to see which is stronger, we never look at nocking point and ask ourselves which is stronger. So in that sense I think we are not comfortable answering the question directly.

Exactly.

Now entertaining your question, I would say that a high nocking point compensates for a stiff lower limb.

[DC]

Thanks Steve, at least that's an answer. I thought there could only be two, but I was wrong.

Oh two new replies, one top and one bottom. Great

[SLIMBOB]

That explanation nailed it for me Badger. So much of this for me is by feel without having given much thought to the actual mechanics. Zen and the Art of Bow Making I guess. Tiller for balance in the hand and fine tune arrow flight with the knocking point. I admire those that bring the mechanics into the equation and borrow from their work.

[Tuomo]

The original question was that "If my nock point seems to be a bit high, which limb is too strong?"

The answer is that neither of the limbs. The problem is that nocking point is not a parameter relative to tiller, so you can not deduce anything from nocking point. Second, nocking point is just there where you put it, it does not settle somewhere. Nocking point is high if you put it high.

 The right nocking point is where the arrow passes the hand (do a bareshaft test) and is has nothing to do with the tiller or geometry of the bow. If bareshaft test result indicates an unusual (what really is unusual high nocking point?) high nocking point, reasons may be in arrow, release or gripping the bow.

See my slow motion videos:
https://www.youtube.com/watch?v=gCsED0f-CV0
https://www.youtube.com/watch?v=5j1EoHfjftQ
https://www.youtube.com/watch?v=qKIlomh-kos

And finally this one:
https://www.youtube.com/watch?v=6iHEiBa7zMg

[loon]

The original question was that "If my nock point seems to be a bit high, which limb is too strong?"

The answer is that neither of the limbs. The problem is that nocking point is not a parameter relative to tiller, so you can not deduce anything from nocking point. Second, nocking point is just there where you put it, it does not settle somewhere. Nocking point is high if you put it high.

 The right nocking point is where the arrow passes the hand (do a bareshaft test) and is has nothing to do with the tiller or geometry of the bow. If bareshaft test result indicates an unusual (what really is unusual high nocking point?) high nocking point, reasons may be in arrow, release or gripping the bow.

See my slow motion videos:
https://www.youtube.com/watch?v=gCsED0f-CV0
https://www.youtube.com/watch?v=5j1EoHfjftQ
https://www.youtube.com/watch?v=qKIlomh-kos

And finally this one:
https://www.youtube.com/watch?v=6iHEiBa7zMg

What if you have to nock "too high" above the perpendicular of the arrow rest to avoid the arrow slapping into the rest or hand or flying tail down somehow? That would say something about the tiller..

[mikekeswick]

Man you guys get technical, never have figured out how one limb returns to brace before the other when the are attached with a string  If the bow feels balanced in my hand when I draw it back I set my nock about 1/8 high to start and adjust from there if needed to get good arrow flight. 
 Pappy

  Pappy, I do it exactly like you do, as long as the string attaches the two limbs they have to return at the same time.

Sorry but this isn't correct. Make a bow with a much thicker limb than the other to prove it.High speed videos also prove this. The string isn't and cannot be tight the whole time from release to brace height. Does a thicker tuning fork vibrate faster or slower than a thinner one? If you tied the two ends together do you think they would vibrate at the same rate?

[Tuomo]

loon - good question. But what is too high? Normal range is around 3-15 mm, has anyone used more or less? If tiller really had a big effect to nocking point, there should be also negative nocking point.

But, I have to admit that tiller (positive/negative) has a tiny effect to nocking point but it realizes in fine tuning if an ultimate accuracy is the most important thing. Even then the differencies are very small.

Mikekeswick - you have to first define what "brace" and "same time" mean.

See these, my slow motion videos. The bow has 1500 grains extra weight in upper/lower limb tip:
https://www.youtube.com/watch?v=oAXSMKogHgI
https://www.youtube.com/watch?v=8pYVmrWzTP8

As you can see, the heavier limb is slower and is it moving very little compared to the other limb. The bow is also turning a little. But, both limbs will be at brace at same time. Lets suppose that "brace" means the moment when the string is straight, then both limb tips have stopped. Of course, both limbs continue to vibrate, as in any bow. That bow shooted just fine, nocking point was just normal and so on. Just a little more handshock because of the extra tip weight.

See this video:
https://www.youtube.com/watch?v=xGgWZYny9RM

I was shooting bow, whose tiller was off. Still both limbs returned at the brace at same time - bow continues moving straight forward. No horizontal turning. Vertical turning is because of the finger release and string hitting to wrist guard.

See also this video (at 0:52, yumi bow):
https://www.youtube.com/watch?v=ir5GKAQG14g

As you can see, the string is tight the whole time from release to brace height. Of course, the bow turns and the string and limbs continue to vibrate after that, as supposed. Limbs do not vibrate at the same rate but they will return to the brace at the same time!

The last video (at 0:52, yumi bow) also proves nicely the nocking point "problem". Very asymmetrical bow, but still the nocking point seems to be just normal, or a bit too high. So, tiller has no effect to nocking point (except fine tuning mentioned before...).

[Dances with squirrels]

I disagree. The limbs aren't necessarily back to their original position, as it resides at complete rest at brace height, the exact instant the string becomes straight again. It still has moving to do... as your videos show... and more of it out of sync if the limbs aren't moving/returning in harmony.

[Tuomo]

Dws - thanks for the comment. But you disagree what? Seems that we have to define "brace", "same time" "original position" and "out of sync" also. For example, is original position limb tips (or any points in limbs) position in x-y-coordinates at time t=0? And so on...

I think that the problem is that limbs are thought to be independent but in reality the whole bow with string is an integral, one part system. Think of one-limb bow (which in reality is not possible) or bow where the second limb is absolutely stiff (an extreme example of asymmetrical bow). When bending that kind of bow, are the limbs out of sync or are the limbs returning to the brace at the same time, etc.? When bending, the bow tilts, or rotates, just like bows in those videos, just more pronounced.

Thus, I think that most bowyers think that limbs are in sync, etc., when the bow is not tilting, rotating in horizontal plane. Which is not the case.

There is much more interesting things what I don't know or I am not sure but would like to know. This "limbs timing" debate is very old but no one has presented a really good answer.

[PatM]

I'd like to see a perfectly "timed" bow in slo mo too.