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Discussion Starter · #1 · (Edited)
Unfortunately, my previous limb stability discussion got rather hostile and was closed.

Before it got ugly, the subject was brought up about "side to side" limb movement as opposed to "front to back" movement.

It was suggested that the "side to side" movement is the better discussion and I said that I would see if we could get another video made with the same bow. My kid, my friend, and I are obviously not professional videographers, just inquisitive minds with an iPhone and the SLOPRO app. We used a piece of green poster board behind the limb to give it more contrast.

If anyone would like to continue a decent discussion, feel free to add your own video. This is NOT a discussion about one limb against another. Hopefully we can get a number of different limbs and designs. Not only can we compare them to each other but we can also see the effects of different release and form
 

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I would like to see a tangential shot of the tip track from release to arrow separation. An index line on the limb down the string groove. I do not know that I am interested in the after shot motion at all.

Getting the fingers off the string and the result of that would be interesting.

A clip like the above of with a well tuned arrow, a stiff arrow, and a weak arrow would be nice.

I don't see anything in side shot that gives me any relevant information
 

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Discussion Starter · #3 ·
I would like to see a tangential shot of the tip track from release to arrow separation. An index line on the limb down the string groove. I do not know that I am interested in the after shot motion at all.

Getting the fingers off the string and the result of that would be interesting.

A clip like the above of with a well tuned arrow, a stiff arrow, and a weak arrow would be nice.

I don't see anything in side shot that gives me any relevant information
Rusty

That's all beyond our capability, especially since I have no idea what most of what you said even means. :sbrug:

If you'd like to work on such a video and post it, have at it. I'm sure it would be interesting.

I admit, I'm a pretty basic, common sense type of thinker, but it would seem to me that a limb that was more "whippy" after the shot, would be prone to more movement during the shot. I sure could be wrong, but it doesn't make sense to me that they would somehow become weaker or stiffer once the arrow is gone. It would seem to me that they are what they are, all through the shot cycle.
 

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I don't see how any conclusion can be made from a bunch of videos without control of all the other variables. Even if you used one shooter, riser, string, arrow, rest, tab.... How could you say for sure the movement was the limb and not just a bigger form flaw or tuning error/difference with one shot than another.
 

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Discussion Starter · #5 ·
That's a good point Andy.

Again, the common sense side of me takes over and says that if a person's release is less than perfect, like mine CERTAINLY is, it shows what a limb does in response to that. To me, it shows more than what a machine would show because nobody has a release like a shooting machine using a mechanical release.

Therefore, common sense here again, if a limb shows little movement with a poor release like mine, it can only be that much better with a better release. A better form/release isn't going to make the limbs respond worse.
 

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I agree with Andy. Also, I have no concern about what a limb does in slow motion. How does it feel and how does it perform is all that matters.

Why should archers sit around studying slow motion video trying to be armchair scientists and engineers? There are too many variables and making claims and conclusions in an unprofessional way serves no useful purpose.

In that other thread, we had 2 experienced archers telling us their first impressions of a bow. Over time, we will get impressions from more people and they will be more than first impressions, but long term impressions then. This is what matters.

Heck, we saw that video of international archers shooting high end olympic bow setups and none of them worried about the waggle of their bows in slow motion. If their coach is smart, he will never show them that video and create useless and needless doubts about the bow's capability. The coach just wants them to keep shooting gold, and the waggles aren't stopping them from doing it, unless they put it in their mind that it might, and then who knows what a doubtful mind will do.
 

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How do you know your bad release with limb H was as bad as your bad release with limb S? And without a target how do you know if it matters? I'm sure the limb manufacturers have a lot better cameras than your cell phone. If they could make definitive conclusions from those videos don't you think they would use them in their advertisements?
 

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you have some basis for your thoughts, sylvan. but whether it really matters during an actual shot is the question.
i have found that eliminating tip motion on my longbows gave me much more yardage when flight shooting because all the energy in the limb transfers to the arrow. but, a longbow is not an recurve and the same criteria does not apply there. when i designed a recurve we measured all the deflection and moments of force in both limbs and the riser. that gave us a basis for how the bow performed. but after all that, the decision on whether to build that bow for production was made by people shooting hundreds of arrows in an effort to see how the bow "felt" during and just after the shot. not very scientific, but very important.
i think as you shoot more arrows that you will find that a lot of the things you wonder or obsess about now will become less and less important.
 

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Discussion Starter · #9 ·
Please Steven. if you don't think the conversation is worthy of anything, just don't participate.

This is not about any other limb other than the one I posted, and the ones, if any, someone else chooses to post in comparison.

What a limb does in slow motion, is what a limb does in real time. It's not like they are different actions. The slow motion only allows us to see it with our naked eye. I happen to find it quite interesting.

For one, by doing the "front on" shot, I see that I am torqueing the bow :)33 - :35 mark) to the right upon release, something I didn't know I was doing, at least to that extent, and something I need to definitely to work on.
 

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If i just thought it wasn't worthy of anything, i would just not participate, but since I view it as harmful, i must participate by making the statement I did. But, I will respectfully say no more about it here.
 

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I've had concerns about it mainly for a reason that I've heard mentioned at least twice by experienced archers. One was in a limb comparison by MartinO of several limbs, one of them Hex 6H where he reported that every so many shots an arrow would fly off target for no reason he could discern.

I assumed that if limbs function great most of the time, and send an arrow flying once in awhile, it most likely is archer error. If that can happen to an archer of Martin's caliber, of course I worry if I am steady enough to handle such limbs.

This was an issue for me because I've been wanting to upgrade from my Hex 5W limbs, and wondered if I should wait to see how the Hex 7 turn out for ILF, or go with Hex 6 (I decided to go with Hex 6 limbs). But seeing the after-wobble of the Hex 6 and 7 limbs in the video, I have wondered if that somehow is a reflection of their sensitivity to torque or release or whatever it is that sends the occasional arrow flying.
 

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Discussion Starter · #13 ·
How do you know your bad release with limb H was as bad as your bad release with limb S? And without a target how do you know if it matters? I'm sure the limb manufacturers have a lot better cameras than your cell phone. If they could make definitive conclusions from those videos don't you think they would use them in their advertisements?
Again, a very good point. That very thing is what got me thinking about all this in the first place? With all the talk from a number of different manufacturers about "torsional stability" (and they all talk about it, Hoyt talks about it, Samick talks about it, W&W talks about it, Uukla talks about it, Border talks about, SF talks about it, etc) the only thing we do know is that at least for two of the companies, it sure looks different, so how do you know if it matters unless it shows up at the target? If a limb looks like cooked spaghetti when shot, what does it matter if the arrow ends up in the 10 ring? If a limb looks like a leaf spring when shot, and the arrow ends up in the 9 ring, again what does it matter?

Your final question is the real question in my opinion. As I said, they ALL use the concept of it in their advertisements to one extent or another, but as long as it's just talked about, nobody really knows what "it," or lack of "it" looks like, acts like, feels like, or performs like. And as you said, certainly not to each individual archer with individual form issues.

Therefore, as long as it's kept in the "concept" realm, pretty much any claim, for or against, can be made. Is it really any different than Hoyt saying that our internal testing shows that "red" limbs perform the best and ours are the "reddest" of any limb on the market today.
 

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Around 5.00 you may find some relevant footage.
 

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Discussion Starter · #15 ·
Great video Greysides.

At about 6:30 note what is said:

"This is of course the movement after the arrow has left the string. But stable follow through means higher stability at the time of shooting."

This is what I was getting at when I said the following:

"I admit, I'm a pretty basic, common sense type of thinker, but it would seem to me that a limb that was more "whippy" after the shot, would be prone to more movement during the shot."

Thanks for posting that, I'd love to see more.
 

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I dunno, sylvan, I've never given this a lot of thought, but after the shot - after the string flings the nock past the riser - limbs are free to move differently by far than "during the shot" ...... during the shot, the limbs are "loaded", under pressure from the string and the resistance that is the weight of the arrow.
So to my way of thinking, during the shot, the limbs' motions are dictated much differently than after the arrow is free.....due to different inputs.
Maybe.
 

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Discussion Starter · #17 ·
I dunno, sylvan, I've never given this a lot of thought, but after the shot - after the string flings the nock past the riser - limbs are free to move differently by far than "during the shot" ...... during the shot, the limbs are "loaded", under pressure from the string and the resistance that is the weight of the arrow.
So to my way of thinking, during the shot, the limbs' motions are dictated much differently than after the arrow is free.....due to different inputs.
Maybe.
I would agree that it could be different under load than after the shot but it would only be a matter of degree.

In other words, if its stable after the shot, it is going to be stable during the shot but maybe to higher degree under load.

If it's more whippy after the shot, it is going to be more whippy during the shot, just to a lesser degree maybe under load.

In other words, to a large extent, I think it finishes the way it starts. The most stable limbs after the shot will have been the most stable during the shot. The least stable after the shot, will have been the least stable during the shot.

If we attached a number to stability, 1 being the most stable and 10 being the least stable. Lets also assume as you have suggested that under load, limbs tend to be more stable.

Lets assume that under load, limb "A" is a 7, and after the shot it is a 10.

If limb "B" is a 6 after the shot, there is no way it can be anything other than a 6 or less under load.
 

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While I do not worry about what goes on with my limbs during and after the shot, I do find it interesting. I also like to know "why" things happen as they do, and "what" effect those things have on accuracy, felt vibration, etc.?

My initial thoughts are that the more radical the side to side tip movement is after the shot, is a likely indicator of increased side to side tip movement during the powerstroke, which would seemingly have to have a negative affect on accuracy. Unless some human input, such as hand torque in the cause, then any data gathered cannot be correctly assigned to the limbs themselves.

An elongated after the shot fore and aft limb tip/string movement would seem to me to indicate a less efficient bow, leaving a higher percentage of energy transfer into the riser than would be preferred. But is that an accurate assumption? Who knows, it is well beyond my field of expertise.

Lastly, a personal experience has me wondering how much praise or disdain we can assign to a certain set of limbs. In my personal experience the limbs are SF Premium Carbons in a medium length. On a 25" Spigarelli BB those limbs seem smooth enough, but rather docile, and the accuracy seems to be fairly good given my ability level. Even with the new broadband limbsavers installed, the bow was fairly loud, and had more than a little felt handshock. Those same limbs, minus the limbsavers, connected to a 21" Dalaa riser were much quieter, no noticeable handshock, and while there was no stacking through my draw range, the limbs felt like they were a cutting edge, high speed set of limbs.

So, how much good or bad data in testing is really on the limbs, and how much should be assigned to the riser length/design/pocket angle?

All things that do peak my interest, but at the same time none of it enters my mind during shooting.
 

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As a company Win & Win strongly believes in testing. They have developed a shooting machine that replicates a finger release and have made extensive use of high speed motion capture and tracking to guide their product development. Win and Win still believes that minimizing movement of the string after the shot is and indicator of better performance of the limb and riser during the shot. Win & Win also has a team of world champions on hand to provide subjective feedback, shoot for score, etc.

Measuring string follow through for the purposes of product development is only possible in labratory conditions. Shooting feel is done by hand. Actual limb and riser dynamics requires resources and training not generally available even to smaller manufacturers let alone the average archer.

When shot by a machine the bow will do pretty much the same thing every time. This makes it possible to study the dynamics at play. However, when shot by hand the shot reaction can vary wildly depending on the archers imputs. Because of this it is not possible to draw conclusions other than how it feels compared to other bows and how well it shoots "for us".

Below are some video links of lab testing on Win & Wins shooting machine.







Rasyad
 

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"This is of course the movement after the arrow has left the string. But stable follow through means higher stability at the time of shooting."

This is what I was getting at when I said the following:

"I admit, I'm a pretty basic, common sense type of thinker, but it would seem to me that a limb that was more "whippy" after the shot, would be prone to more movement during the shot."
Of course, something not stated was how the conclusion "stable follow through means higher stability at the time of shooting" was arrived at. Was it empirically determined (observed) or concluded by logic alone?
 
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