Trad Gang
Main Boards => PowWow => Topic started by: Bob Morrison on November 07, 2011, 05:56:00 PM
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What is more important mainly in recurves. Limb side to side stability with good speed or a little less side to side and more speed?? Nice problem or do you offer both????
Bob
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I would go with more stability and good speed.
Both side to side and face to back.
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Just me, but I would think a more stable limb would perform better than a less stable one.
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To me, stability is number one on the list. Speed is nice, but ranks a distant second.
I have bought and sold more bows than I should ever admit to. There have been some burners in the mix, but I don't own a one of them anymore. The ones that have stuck around have been those that are more stable. To me that means forgiving of form errors, of which I have more than my share.
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I'll gladly take stability over speed, but thankfully, such decisions aren't and either/or situation any longer. My main recurve sports Winex limbs, and they are by far the most stable (and quite fast) limb I've used.
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I've been working with a different carbon and some different layups. 2 that I'm real happy with. Both are stable, one is super stable costs a bit more, very quiet. I'll do some chrono work with them tomorrow........ I'm glad to see I got more response from TGers than the other 2 sites combined. I'm also working on the longbow,double carbon fast but kinda flippy....I'm going to try the layup that is so stable in the recurve and see that I get.
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I vote for great stability and good speed. Stability and quietness are paramount.
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Bow limb stability for me also.
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Limb stability over speed every time. Accuracy and forgiveness trump speed.
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Bob I vote for both and it sounds like you are going to get it.
I personally do not believe we have to settle for either or.
If you can build a stable recurve then you should have absolutely no probs with the longbow. Unless its a heavy D and R with poor verticle stability.
In that case its back to the drawing boards unless you settle for a verticaly unstable bow as some have.
I wouldn't and I am sure you won't. I ended up haveing to take reflex out until the bow was a bit more of a d shape with strung.
God bless you and good luck,. Steve
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Steve, I'm happy with both layups, I'm just not sure if there is a thing as too much side to side stability??? I only got to shoot 8-10 arrows out of this evening, it felt real good. chrono will tell me whats going on.
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Please define side to side and front to back stability and how it is measured. I hear the term a lot and don't always know what is meant (I think people use the term differently).
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Side to side is limb ability to twist. front to back is like resting the bottom limb on your leg and having it fold in or collapse,worst care... As far as I know there is no measurement for this.
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Stability with good speed. :thumbsup:
Bill
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Bob, I'm impressed that you are still experimenting and looking for innovations after you've ALREADY come up something so good in your current designs.
It's good to hear your most stable design is also very quiet.
For my personal choice, it is Quiet (#1), Stable (#2) and Speed (#3). Like any good American, though, I only want it all!!!
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Originally posted by Hawkeye:
For my personal choice, it is Quiet (#1), Stable (#2) and Speed (#3). Like any good American, though, I only want it all!!!
I agree 100%
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I will echo what most have said, stability over speed, but mostly I want a bow that is whisper quiet upon release.
If it shoots a 12gpp arrow at 190fps so much the better!!.......... :laughing:
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I have had and shot a few bows that the limbs were very unstable front to back. I dislike that the most, even though the bows shot just fine. I always refer to that as the limbs being too "Bouncy".
As far as side to side stability I do know that is an issue bowyers have to ponder when designing a new limb. Limbs have to be made for the general public and be designed to be strung and unstrung for the folks that really don't know what they are doing or don't take care in being careful while string. To make them "Dumby Proof" hinders the line of performance the bowyers can achieve I would guess.
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Chrono, shooting machine 9 GPP 28". 4 shots high thrown out.
Less stable averaged 191.1
More stable Averaged 194.2 Plus 3.1 FPS
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I vote for more speed and more stability.
GRIN :clapper: :clapper: :clapper:
Looks good Bob. God bless you all, Steve
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Here's my take on it Bob... i've been testing about 4 different Matrix Carbon lay ups myself and have had various results. if you can get the right Matrix design on the very back of the limb it helps both speed and stability. if you put it both belly and back the torsional stability (side to side) jumps 50%....
But.... getting that dad burn stuff to to hold up without shearing the core it's glued to isn't easy. I'm looking into getting a hybrid matrix using carbon and S-glass laid up next go round.
The only way I'm getting both speed and stability and having these things hold together is using a double carbon and putting a thin layer of glass under the belly carbon..... it's expensive though.
with the added stability you can narrow the width profile and trim mass weight & get rid of the parachute effect...... THEN you can get both....
The prototyping is never ending as we get newer materials available.... give me a call sometime Bob... I'd love to swap some tech info with you some time.... Kirk
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OK, help me out. If stability can not be measured, how do you know you have it, or more importantly don't?
Based on the above posts, it is clear that materials affect stability, what other design elements affect it also?
Thanks in advance for your explanation.
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If you go to pick up your bow by the tip and it flips apart in your hand, you have very little side to side stability. If you rest your bow tip on your knee and it folds up,,, very little end to end stability. This does not mean your bow will not shoot just fine, it will be less forgiving. I'm have been hunting with a test longbow limbs that fold up on my knee, They shoot fine and I've taken one deer with them... Switching to test recurve today. Gluing up a set of real stable longbow today, hope it does the same as the recurve did.
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I am with most others and as you mentioned, for me Stability means forgiving. I am very interested to see what your working on Bob.
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Do not try this at home. It is just for concept sake.
http://s1097.photobucket.com/albums/g343/Borderbows/?action=view¤t=00048.mp4
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There are two types of stability in bow limbs. "Vertical stability" and "torsional" stability.
They can both be measured by the bowyer with the use of weights and dial indicators if you want to get technical. But the only time that method would be incorporated, or useful is in comparing two identical limbs using different materials for an increase or decrease.
Having good torsional stability is very important, and effects the tracking of the limbs through the draw cycle. When you see photos of bowyer's with a tiller stick of 18" holding the bow at half draw while they look down the limbs.... this is what they are looking at. the limb tracking. if the limbs are stayng perfectly straight through the complete draw cycle. this would mean it is tracking well.
The question that is most commonly asked is, when the torsional stability becomes borderline weak, can the tracking, and more importantly the consistency of the shot be effected by a less than perfect release.... the answer is yes... BUT... and i say BUT.... it requires a much better than average archer to detect the difference in most cases.
a bow that doesn't track well at all will be noticeably inconsistent to most archers.
"Vertical stability" on the other hand is one of those things that is criticized unjustly my many. There are many very high performance bows out there that are considered vertically unstable that you can flat out drive tacks with.... if the timing of the limbs are perfect, and there is enough preload to stop those limb tips dead it has no effect on accuracy at all.... I could name a half dozen on the market that are competing in IBO wold competition that many guys would deem vertically unstable....and these same bows are taking the titles.
Where you run into a disagreement on this is that some feel that slight inconsistency of finger placement on the string at full draw will have more effect on the timing of a bow that is vertically unstable.... this inconsistency isn't noticed too much on the line, as it is when shooting in different body positions out of a tree stand or when canting the bow to extreme angles.
With a bow that has very stiff outer limbs and excellent vertical stability, it would be very difficult to alter how those limbs are bending by shifting the applied pressure to the string with your fingers.....
this vertical stability issue is, and always will be debatable.IMO
i hope this helps
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Originally posted by Jason R. Wesbrock:
I'll gladly take stability over speed, but thankfully, such decisions aren't and either/or situation any longer. My main recurve sports Winex limbs, and they are by far the most stable (and quite fast) limb I've used.
Jason,
Your draw length makes for excellent speed no matter what! :) But, you're right, you want limb stability along with the speed.
I loved the article you wrote in the October/November TBM. Very touching and I can identify with your sentiments.
Bill
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What Kirk Said, And if you ever want to try a bow that is super fast , verticaly and horizontaly stable then try one of his bows.
On the other hand I want both stability and speed and work to get the extra stability so that I can slimline those limbs and knock that weight down.
In answer to what do you do design wise to add stability.
Stability works from the bottom of the stack to the top.
You can use slightly thicker glass on the belly and gain stability. Most bowyers go the opposite way.
You can trap to the back. It does the same thing by removing glass from the back.
You can thicken the core and use less glass. A thick core adds a lot of stability. This is why longbows are inheriently more stable than flat longbows and recurves.
You can shorten the recurve.
You can adjust tapers
You can adjust preload.
I worked really hard to develope a limb that could be belly mounted and have a 7 14 in brace height. If you ask a Talon 11 owner they will say it was worth it. The problem was to get the stability at a lower brace. I did this because I hate compromising. I want a bow that gets the stability but will also keep the arrow on the string to get maximum thrust and use the energy that the limb has without wasting it.
I just could not see having to have an 8 3/4 inch brace height and losing an inch and a half of powerstroke.
Its quite a subject and one that Bob is wise to be delving into.
God bless you all, steve
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Totally ignorant here with regard to practical experience but will relay my interpretation from reading.
Much R&D has and is still invested by World Class limb builders in order to reduce limb torsion as generated by the finger release.
Much of the speed increases have been a welcome bi-product as a result by the successful endeavor to reduce torsion.
Also, have read that the static limbs are some of the most challenging limb designs for reducing torsion, thus reliance on man made materials have taken precedence.
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Originally posted by BobCo 1965:
Do not try this at home. It is just for concept sake.
http://s1097.photobucket.com/albums/g343/Borderbows/?action=view¤t=00048.mp4
That bow in the video has excellent torsional stability. but i wouldn't EVER do that to a bow. That's absolutely abusive right there. :mad: Who ever would do that to a bow is nuts! :rolleyes:
if you want to compare one bow to another. you hang weights off the tip with the bow unstrung and measure the deflection.
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Kirk, I saw a picture of a scale that can be used for limb deflection. And it looks like I can use a spine tester to accomplish the same thing. pic was on different site.
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Friend:Also, have read that the static limbs are some of the most challenging limb designs for reducing torsion, thus reliance on man made materials have taken precedence.
I agree in part. However the designing and r and D is anything but manmade material. We do have to learn or know how to utilize that material , whatever it is. Personallhy I use a lot of wood. I like certain woods even better than foam for cores in some designs...
However if I were to build a bow to go to Alaska or Aftika I belive I would recommend a complete composit limb because of the imperviousness to weather .
God bless you, Steve
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Originally posted by Kirkll:
Originally posted by BobCo 1965:
Do not try this at home. It is just for concept sake.
http://s1097.photobucket.com/albums/g343/Borderbows/?action=view¤t=00048.mp4
That bow in the video has excellent torsional stability. but i wouldn't EVER do that to a bow. That's absolutely abusive right there. :mad: Who ever would do that to a bow is nuts! :rolleyes:
if you want to compare one bow to another. you hang weights off the tip with the bow unstrung and measure the deflection. [/b]
FWIW the test was done at and by Border Bows (Hex6 limb), I think they knew what they were doing. ;)
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[/QUOTE]FWIW the test was done at and by Border Bows (Hex6 limb), I think they knew what they were doing. ;) [/QB][/QUOTE]
You honestly think so eh? I wonder if they would honor their warranty if you did that to one of their bows? NOT!
I'm not questioning the fact that that particular bow has incredible torsional stability. but... putting that video on a public forum with no explanation except "Don't try this at home" is nuts! You know someone is going to ruin a perfectly good bow trying that...
it's stupidity is what it is... IMO.
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deleted...double post.
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As far as that bow in the vice picture, I would be interested in knowing what the draw weight of the bow is. A heavier draw bow would handle that test much better than would a light weight bow.
That said...yes, stability is much more important than is speed...as it doesn't matter how fast one misses. A problem in the archery field though is stability is a much more subjective measure than is speed. Speed is easy to measure. Take a given draw weight, a given draw length, and a given arrow weight...and we can determine speed and efficiency. Unfortunately though, not many archers have form and accuracy good enough to determine a good stable bow...so too often speed becomes the target priority.
This video isn't a "perfect" stability test, but the perfect test would require an archer with very consistent near perfect form that makes no changes in their perfect form without an intentional decision to do so. Without this ability, it is difficult to obtain a controlled objective test. SO...for this reason, I produced this video to illustrate SOME characteristics of stability and another way of observing traits that are often associated with stability. I hope this video is beneficial.
Thanks for viewing.
http://keepitsimplearchery.webs.com/apps/videos/videos/show/14179600-limb-stability-demo
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I looked far and wide for the video i did on testing vertical stability and i cannot find that ting to save my life.
Hey Lee, In your test procedure in the video it's rather hard to see the limbs flexing really well. and doing your test using the weight of the bow itself doesn't really show you what you need to see, and it wouldn't work too well with a heavy riser target bow with 35 pound limbs.
If you put the bow in a vice at the riser. you can grab the string with your hand and pull it towards the tips back and forth and see how easily it moves. this is much easier to feel the movement. most guys describe vertically unstable bows as "Floppy limb bows".....
here is the rub... and where all the disagreement starts. First and foremost important, beyond a shadow of a doubt.... is that vertical stability cannot be measured accurately at brace height.... period.....
how stiff the limb is at brace height has nothing to do with how easily you can alter the pressure point on the grip at full draw. a 40 pound bow still has 40 pounds of pressure on those limbs at anchor. Shifting from a high to low pressure point on your grip , or rotating high or low pressure to the string, effects a stiff limb bow exactly the same as it does a bow that seems floppy at brace......
it's a total misconception that stiffer limbs are harder to change the pivot point on, or more forgiving in that regard than a floppy limb bow.
i know... i know... I'll get arguments over that statement till dooms day arrives. :rolleyes: But it's true.
i've got a film somewhere with a couple different bows on the tiller tree cranked down to full draw, while i rotate the finger pressure on the string using a string hook 2.5" wide shaped like your fingers are at full draw..... regardless of what those limbs feel like at brace whether they are stiff, or floppy, it still takes the identical amount of pressure at full draw to rotate the grip, or the finger hook. 50 pounds is 50 pounds at full draw....
So now a guy has got to ask... So what difference does poor vertical stability have on a bows performance..... it's limb bulge at the end of the power stroke.....That limb bulge is the center of the working limb continuing forward after the limb tips stop. this robs the stored energy that could be transferred into the arrow shaft, and adds vibration to the bow.
Even shooting the stiffest of bows like a Howard Hill style. until you learn to locate your grip in the perfect pivot point applying even pressure on the grip, the dad burn thing will shake your teeth loose..... the reason the shock is more pronounced on that style of bow is that there is so much more mass in the outer limbs the string has to somehow stop, and never really succeeds because there isn't enough string tension or preload in a D style bow.
So the guys that shoot them well learn to heel down on the grip, and they shoot heavier shafts. simple as that.
The bottom line is those floppy limb bows are just as accurate and forgiving as the stiff limb bows if they are timed right, only they have a bit more vibration and rob part of the stored energy..... as a bowyer i hate leaving stored energy on the table like that.
How's that for a long winded response. :rolleyes:
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I'm not a bowyer but I do shoot a lot and have owned a bunch of bows. It seems to me a lot of the stability issues can be minimized with the grip.
For instance I shoot a certain recurve because the grip fits me so well and I can flat hit with his bows(not stating names). The bow has wide limbs which I assume is helping the stability, it also has some limb bulge. Just curious of your thoughts on how the grip effects the stability from y'alls point of view.
I realize like the spine of an arrow- there is static and dynamic stability as well as torsional and vertical. That being said I shoot heavier bow in the 55 to 65 range so I guess that helps.
SL
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That last sentence didnt come out right. I know the bow is either stable or not-but can a unstable bow be made stable with the right grip from a shooting standpoint?
Ok- I'll shut up now :knothead:
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i've got a "barn burner" of an aggressive r/d longbow that's 60" in length. that puppy flat out hauls a 10gpp arrow the fastest i've ever seen. but it can't hold a candle to the stable shootability of a 64" mild r/d longbow - now that bow could pretty much shoot itself with consistent accuracy ... and with a "forgiving" nature when i screw up my form, to boot. oh yeah, gimme consistent accuracy over speed any day, thank you.
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The Border bow in the pic is in the mid 50's. I had a set of Border limbs fail and they offered me the limbs in the pic as temporary replacements until the new limbs could be made. I turned them down because the cost of shipping is expensive. As for them doing the test, it was done on Sid's personal bow just to show how stable their limbs are. They do not recommend anyone do it nor would they warranty the limbs that were tested like that.
Back to Bob...The best limbs I ever shot, other than the Borders and Winex, that had both speed and stability were Groves limbs. Harold Groves had a two step glue up process (Dyna stess, he called it) which essentially but a preload built right into the limbs. Since the process required two glue ups the first glue used had to withstand the heat of the second glue up and Harold, to the best of my knowledge, never revealed the glues he used. I am very happy to see you doing so much R&R as I really would like to find a USA made limb that could shoot along with the Borders and Winex. You seem to be following Border's lead on this and if you need a testor, I shoot a 17" DAS Gen I riser and would be happy to give you some feedback on some 58" limbs that are in the mid 50's for weight. It's too bad Harold Groves died just before all this carbon stuff came into the bow builders shop. I wonder what kind of bow he could have made with it. Good luck with your project. As I said, I would love to find a USA made limb that performed as well as the ones I shoot now.
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I think it's awesome that we have reached a point in traditional archery where performance, even on mid-priced bows, has become so good, but so uniform, that we are seeing stuff like this in an attempt to set one brand apart from another.
It reminds me of the old "takes a licking and keeps on ticking" Timex commercials. Fun to watch, but have very little to do with any real world performance. Certainly not anything that 99.99999% of us could ever appreciate.
Takes a lickin\\' - Keeps on tickin\\' (http://www.youtube.com/watch?v=7_fKppH8B0g&feature=related)
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Kirk, can you explain why you look for that stability at 18 inches with the stick? Why 18 inches and not another increment? Thanks Flint
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I understand the advantage or percieved advantage of stability at full draw but doesn't a more stable limb "recover" better than a less stable limb and wouldn't that have some influence on the arrow as well ? Wouldn't a more stable limb transfer more energy to the arrow.
I will admit that I for one hate the floppy limb tipped bows, one reason I prefer to shoot a D shaped longbow.
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Mr Carlson, With all due respect, I am and to the best of my knowledge Kirk is not following Border bows in any respect. I believe my bows perform at least as well or better than anything Border is making.
I am saying this because I do not nor have ever followed anyone. Especially in building bows.
Here is why. I want to and do develope my own bow designs and limbs and work out the kinks on my own with God's guidance. I don't need to follow a man or copy his work or use his ideas. I want to hit this with no preconcieved ideas. Especially when it comes to overall bow design.
I pretty much started this stuff of using I beams in the bow risers because I wanted to eliminate broken and cracked risers without going to aluminum.
To the best of my knowledge I honestly do no know of any bowyer using I beams in the risers clear back until you get to the old Bears .
I first used wood. some still cracked. Then I went to Phenolic I beams and voila , problems cured.
This is an example.
If I were to ever follow anyone it would be someone like Bob Morrison,. It would never be Border bows , No offense taken here but I want to make this clear. I share with Kirk, I share with some other bowyers. He shares with me. but there is no following being done by any of us.
I believe my Talon 11 bow with double carbon foam core or yew is as good or better than any bow built in the world. Same with Kirks double carbon foam core and I would imagine the new bow that Bob is coming out with .
God bless you , Steve
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Come on gents, how impressive is all this stuff, and what does it really prove?
This is about the cheapest wood core ILF limb you are going to find. They retail for about $70. The riser is quite a bit heavier than the bows shown in Keep It Simple's video and the limbs are only 28 pounds.
(http://i1138.photobucket.com/albums/n525/TurkeysFearMe/IMG_1366.jpg)
(http://i1138.photobucket.com/albums/n525/TurkeysFearMe/IMG_1369.jpg)
Not only did I try it at home, but I did it with crap limbs and lived to tell about it. No trick photography, no slight of hand, just a set of cheap limbs and a moderately strong wrist.
:laughing:
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Turkeysfearme,
I don't think the test is a dangerous test myself...not if you are holding the string against the limb so it doesn't go over the edge .
That said, if you notice, you are holding the upper limb...which TYPICALLY has either an even tiller or more often than not a positive tiller when compared to the lower limb...yet in your photo you can clearly see the tiller is significantly less on the lower limb. What does that mean??? It means your limbs are flexing considerably. You probably have near 2" of flex there. Also, to illustrate it, don't just hold it at a horizontal, but rock it up and down and see how much the bow "bounces" as you go up and down. To see that, you can't use a freeze frame photo...but would need video. Additionally, not all bows are equal. The one you have may very well be a very stable design despite the noticeable flex in the photo.
Originally posted by Kirkll:
Hey Lee, In your test procedure in the video it's rather hard to see the limbs flexing really well.
That's the objective of a stable design. 8^) but it is also why I chose to use the light weight kid bow. With a 60# adult bow, it would be even harder to see.
I also believe (as a GENERAL RULE...but not absolute rule) that a stable bow is one that actually BEGINS to stack IMMEDIATELY after the desired draw weight. My reason for this is...if a bow remains so smooth on the draw that it continues to gain say 2# per inch out for several more inches...when one heals down on one shot they are overflexing the lower limb and underflexing the upper limb...but the bow's limbs are so smooth it doesn't dynamically correct itself...but with a bow that begins to stack slightly just beyond full draw the bow will resist this to some degree as you overflex the lower limb, it will stack and resist the flex...and self correct to apply the force to the path of least resistance...and therefore will continue with drawing the upper limb instead.
That is an over simplification of course and I am aware of that...but I think this is one reason why bows like the HH type bows are so stable. They self correct because they are stiff and don't have a smooth draw force curve.
Unfortunately, stack is inefficient in terms of speed but this may have SOMETHING to do with the old belief that slower bows are often more stable (not always of course...as one could have a poorly designed slow bow too).
There are of course other ways to stiffen a limb as well...and I am not suggesting otherwise.
With today's glues, technologies, designs, and materials (like carbon)...I feel we are able to push the envelope to better balance the desired traits...and as a result believe the traditional bow has evolved into a superior product today than it was 50 years ago.
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Well, FWIW, I did rock it up and down but I don't have the ability (or skill) to post the video. Yes, there was more bounce than in your video, but nothing close to touching the ground like I think you suggested. Then again, it SHOULD bounce more. That metal riser is probably 3 times the weight as any of the risers you showed, not to mention that the thick core of a longbow limb isn't going to flex as much as the thin recurve limb. It's the nature of the beast.
Second, based on some of the claims in this thread, you would think that a cheap 70 dollar limb would twist substantially more than my photo shows. Especially with a rather heavy metal riser, but as you can see, that wasn't the case.
I didn't post this to discredit anything or anyone, I was honestly curious what a cheap beginner limb would do under the same circumstances. I satisfied my curiosity. At 70 bucks, they "took a lickin' and kept on tickin'."
:biglaugh:
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Originally posted by Kirkll:
it's a total misconception that stiffer limbs are harder to change the pivot point on, or more forgiving in that regard than a floppy limb bow.
i've got a film somewhere with a couple different bows on the tiller tree cranked down to full draw, while i rotate the finger pressure on the string using a string hook 2.5" wide shaped like your fingers are at full draw..... regardless of what those limbs feel like at brace whether they are stiff, or floppy, it still takes the identical amount of pressure at full draw to rotate the grip, or the finger hook. 50 pounds is 50 pounds at full draw....
The last sentence is why I somewhat disagree with you...but I am not sure if I can clarify it perfectly on words alone.
Let's say we have two bows...and each bow is 100#@28" (just to work with a nice even number not that any of us around here would shoot that much weight).
Now, let's say bow A has a draw force curve that allows it to gain 3# per inch out to 30" and bow B is smooth to 28" but then begins to stacking and gains 4# per inch to 29" and 5# per inch at 30".
Now, let's say you put both bows in a vice and had a way to brace the riser so you could only draw ONE limb just to see the work load of the limb...and that you did this with a scale...and measured both limbs to the same flexing point necessary to produce a 26" draw (under-flexing it a lot), a 27" draw (under-flexing it slightly), a 28" draw (exactly the same as a perfectly balanced 28" draw on a strung bow), a 29" draw (over-flexing it slightly), and a 30" draw (over-flexing it a lot)...and record the weight necessary to produce that bend. We could observe and record the differences between the smooth bow and the bow that stacks. What happens to each bow when you draw with an altered pivot? With a low wrist (or visa-verse) you altered the dynamic tiller of the bow...say slightly over-flexing one limb (the lower in this case) limb to a 29" position and slightly under-flexing the other limb to perhaps the 27" position.
Bow A - the NET draw length may be near equal to the 28" balanced draw and with the smoother bow you might still get very close to 100# and you don't notice any difference in feel, even though the bow no longer has a 50/50 split...because the loss of draw weight on one limb is equally balanced by the gain on the other limb...say a 48.5/51.5 combination with the smooth draw even if the bow is out of balance.
Bow B - with the stacking bow the loss of pull weight on the less flexed 27" limb would be less than what was gained on the stacking 29" limb...perhaps only a 1/2# or some minor amount with a 48.5/52 combination resulting in a net pull of 100.5#. This is no doubt a small increase...but we are only discussing theory here anyway, but could this be enough to effect the relatively minor weight of an arrow? I think so. The increase in net pull weight with bow B I believe would seek the path of least resistance...and therefore be more prone to self-correct to obtain the balanced 100# draw where the limbs are more in time with one another. Additionally, bow B would be more prone to produce more shock (like a Hill bow) and a stack drawing feel that the archer draws it out of balance.
To illustrate this further.
Now lets say this person has BOTH low wrist with the bow hand and a hard pull with the ring finger on the drawing hand (along with a light pull of the index finger) and really exaggerates this...over-flexing the bottom limb even more so and under-flexing the upper limb even more so...
Bow A - Produces a 47.5/52.5# split (or something similar)...a net result of still 100# draw at 28" as the loss of draw weight was equally offset by the increase in draw on the over-flexed limb on the smooth drawing bow.
Bow B is produces a 48/53 balance )or something similar) due to the stacking limb gaining more than the loss on the under-flexed limb...and a net draw weight increased to 101# despite drawing the bow to the same 28" draw.
100# isn't 101#. I believe the more stable bow is likely to seek balance to have the path of least resistance for the 28" draw and would correct the pivot to the 50/50 split...and if the archer strong enough to maintain (force) the altered fulcrum that is out of balance, I believe the extra draw weight on the over-flexed limb will somewhat reduce the effect of poor timing in two ways...1. even if not eliminating the archer's error...it will reduce it, and 2. produce more acceleration on the limb that has to travel the furthest (which may help the arrow, but is likely to more shock).
That's probably as clear as mud so I tried to high light the main points. It seems to me that this reasoning would explain the exceptional stability that the HH bows are famous for. Regardless of why, what I know is HH bows are EXTREMELY resistant to torque (both vertical and lateral) and they are very stable bows. Their design is very self correcting and that is why those bows are so stable. Unfortunately, these designs are also more difficult to shoot so one ends up robbing Peter to pay Paul.
This is why finding the optimal balance of traits/attributes is important when trying to match up a given bow to a given archer...and is also why not everyone likes the same bow. We all have our own issues or lack there of...and therefore prefer different things from a bow.
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Originally posted by Turkeys Fear Me:
Well, FWIW, I did rock it up and down but I don't have the ability (or skill) to post the video. Yes, there was more bounce than in your video, but nothing close to touching the ground like I think you suggested. Then again, it SHOULD bounce more. That metal riser is probably 3 times the weight as any of the risers you showed, not to mention that the thick core of a longbow limb isn't going to flex as much as the thin recurve limb. It's the nature of the beast.
Second, based on some of the claims in this thread, you would think that a cheap 70 dollar limb would twist substantially more than my photo shows. Especially with a rather heavy metal riser, but as you can see, that wasn't the case.
I didn't post this to discredit anything or anyone, I was honestly curious what a cheap beginner limb would do under the same circumstances. I satisfied my curiosity. At 70 bucks, they "took a lickin' and kept on tickin'."
:biglaugh:
I am NOT at all offended by your post. In fact, I welcome it. I think it is good to pursue truths and to make objective measurements/observations. I don't know what that bow weighs...and I would suspect the riser is indeed heavier than my bows...especially the kid bows. I do however have a 24" riser in my adult Protege bows...which adds mass. As a result though, I also have to use less limb core...so my limb cores are nothing like the deep cores seen in a HH type bow.
In archer...one things affects another. Pursuing the ideal balance is what each of us wants.
Thanks for posting.
I haven't been here much lately, and it is good to stimulate the brain cells in archery physics.
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Turkeys:Come on gents, how impressive is all this stuff, and what does it really prove?
Turkeys , this conversation is just one little aspect of bow building. To build a great bow you look at all aspects and work to harmonize the unit. Its not impressive until you shoot a bow that is built by a bowyer that uses this approach to bow building. Then you say, How did you do that. Truth it its all of it put together that gets impressive.
As one gentleman stated and not one answer to his statement. It seemed to him that the grip would make a great difference.
Truth. Stability is what it is. A good grip that consistantly places the hand will certainly help if the bow has mediocre stability by placing the hand position exactly the same each time. This is one of those other things that you need to add up to making a bow great. Only the folks paying attention to what a bow is doing will notice it.
BTW. I am glad you are happy with your 70 dollar bow and also that you still have your fingers all intact. I hurt myself pretty bad just moving a string over once and having a limb flip on an unstable bow. Holding a bow in your hand by the tip sideways could be a learning experience. Just because you got away with it does not make it a wise thing to do.
As you can see I kind of lack in diplomacy compared to some of my fine friends in here. But it takes all kinds.
God bless you all, Steve
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Originally posted by flint kemper:
Kirk, can you explain why you look for that stability at 18 inches with the stick? Why 18 inches and not another increment? Thanks Flint
18" to 20" is just about where a working recurve bow starts to open up and transfers the weight to the working limb. A static tip, and semi static will draw a little further before the string starts lifting off the belly of the limb tip.
What happens with a bow with poor torsional stability is that torque on the grip can cause the limbs to get off track which can effect arrow flight. even plucking the string can effect it.
I've got a wee bit different way that i go about checking my limb tracking on a recurve limb. if you'll watch this film clip you can see how i'm torquing the bow a little bit as i'm working the limb. this particular bow has pretty decent torsional stability. what i'm doing here is double checking my true center vs dynamic center on the limbs under pressure.... often times you can shape two limbs perfectly the same and they will not track the same.... the better your stability is, and the more homogenois your core is, the less chance you will have for a weak spot in your core that effects the tracking....
(http://i171.photobucket.com/albums/u301/kirkll/Bow%20building/Shop%20Video%202011/th_Tracking1.jpg) (http://s171.photobucket.com/albums/u301/kirkll/Bow%20building/Shop%20Video%202011/?action=view¤t=Tracking1.mp4)
This is where using carbon composites with real homogeneous cores help out a lot. the very best cores in wood are bamboo action wood, birch action wood, and yew wood IMO. the ultimate is syntactic foam, or in some cases like Boarder they use a carbon fiber foam matrix material. old Sid won't give up the recipe on his secret sauce for that stuff, so we are slowly coming up with our own recipes.
The advantage of wood cores and glass is they are pretty darn predictable, and give the bowyer room for adjustment. Once you start into the carbon matrix stuff you are only as consistent as your carbon supplier and how you use the stuff in the limbs. You can come up with some seriously high quality limbs that are rock stable, and add performance to the bow too once you get the bugs worked out..... but the prototyping is expensive.
Kirk
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Originally posted by Sixby:
BTW. I am glad you are happy with your 70 dollar bow and also that you still have your fingers all intact. I hurt myself pretty bad just moving a string over once and having a limb flip on an unstable bow. Holding a bow in your hand by the tip sideways could be a learning experience. Just because you got away with it does not make it a wise thing to do.
As you can see I kind of lack in diplomacy compared to some of my fine friends in here. But it takes all kinds.
The bow really isn't mine, it belongs to my 11 year old son. He took the photos for me. He's quite excited though, knowing how stable his limbs are. Right up there with the best of them it would seem.
;)
Seriously, it would appear as though you missed the point of my experiment. Either that or maybe I watch "Myth Busters" too much.
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Kirk, excellent video and explanation. Ok my next question in regards to your video is this. If you are pulling on the string and it is not being pulled back in a straight line could that be some of the effect of limb twist in your tip section? Also how true are your whole limbs at this point? It looks like you ahve trapped them here? I have found that if your limbs are not identical that will show variation as well. Getting to the true meat and potatoes of True bow building and what most people do not know about or to look for. I like it. Thanks for your contributions. Flint
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Glad the video was helpful. One of these days i'm going to get my bow building vedeo completed.
There are a lot of different ways to skin a cat building these things, and the long bows are by far the easiest to work with and get balanced out.
Whether you are building take down bows, or one piece bows by hand. everything is built and shaped from center line out. i have gone about it in a number of different methods.
The bow in the video is a semi static recurve and has tip wedges. i always trap the tips to the belly side of the limbs to remove excess weight. how much i trap them depends on the bow design and what the tips are doing.
to answer you question, as you put pressure on the string and draw the bow. Whether you are drawing by hand, off a peg, or even on a tiller tree, the riser needs to pivot at the intended shooters pressure point. typically this is done at the deepest part of the grip to start out, and get your limbs bending right. then depending on the archers preferred grip angle, and where the actual pressure is going to be applied to the grip, you time the limbs accordingly to the pessure point.... on an ILF rig it's something the archer can do. On a custom bow it's something the bowyer does. And buying a stock bow off the rack, you learn to find the balance point and grip the bow accordingly.
so it really doesn't matter how evenly the bow is drawn during the build. You are watching the limbs tracking as pressure is being applied, and adjusting the limbs and tip notches accordingly. Once you drop the string, the limbs go back to the braced position. when you are testing like this you are watching the limbs closely being drawn, as well as being let off. if it isn't tracking properly, one side of the limb is stronger than the other, or your tip notches are not shaped properly., or the limbs are out of alignment. limb alignment is critical too.
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Kirk, I enjoyed the video so much that I went ahead and watched all 13. Very good material, you show lots of patience! Thanks, drop me an email when you get time, Grizz
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Keep it simple, somehow i missed your post or we posted at the same time.
HH bows are EXTREMELY resistant to this type of altering. Their design is very self correcting and that is why those bows are so stable. Unfortunately, these designs are also more difficult to shoot so one ends up robbing Peter to pay Paul.
yup.... self correcting is right. you have to get that pivot point just right, and shoot saw logs out of the thing, or you end up picking your dentures up out of the dirt.... that will make you pay attention. :notworthy: :notworthy:
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I appreciate your posts too. If it wasn't for people like you, Sixby, Big Jim, and many others that are willing to share their experiences...the envelope wouldn't be pushed further and further. Keep up the good work.
I should have mentioned that it is my opinion that bow B (a bow that stacks AFTER one reaches the desired draw length) is actually going to be more stable since it will self align in order to produce the least resistance...while bow A (the one that continues to be smooth for several more inches of draw beyond the archer's need) will be less self correcting as its smoother limbs allow for the timing to come out of balance and still produce a near equal draw weight.
Now, this isn't to say I think a bow should stack prior to a desired draw length...as we want a smooth draw to our needed draw length in order to maximize efficiency of a design...but once a draw length is obtained I do think the ideal bow should match the archer's draw length by utilizing a limb core to limb width ratio as well as a riser length that produces a good balance of both efficiency (smooth to their draw) and a good resistant beam strength to correct for altering pivots (by having limbs that will begin to stack if they are drawn BEYOND the archer's need and therefore self-center the fulcrum).
In the end though...the second bow (the more stable one by design) may also NEED a grip to better meet an archer's hand so they don't fight the self centering design of the bow...which could happen with a very strong man and a light weight draw. The grip should still match the archer.
Now back to more important things...if I can just get that dang fly! Maybe I need to find a more whippy tipped bow to get it. LOL.
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You are definitely talking my language Lee. building a bow to specific draw lengths with a bit of room on the tail end doesn't leave any performance on the table. Call it "doing our part to conserve energy"
I've been using core to glass ratio to get more consistent performance between different draw weight bows for years now, but very few bowyer's actually incorporate it into their system. if all the bows we built were right there in the mid 40's to mid 50's and a guy could get real consistent glass thickness, you'd never have to mess with grinding glass.
Getting back to our stability discussion. i think there is a lot of archers out there that are consistent enough in their hand placement and shooting abilities that are willing to sacrifice a bit of vertical strength to gain smoothness and speed. There is always a trade off in these designs. But..... what may "Appear" as an unstable bow to some, are absolutely incredible bows to others.....
With lower poundage bows vertical stability is much more noticeable. That's the beauty of using wood cores..... if you lower your glass to core ratio on those light weight bows, you are not only lowering the mass weight in the outer limbs and picking up performance.You gain stability with a deeper core using less glass or carbon. a 40 pound bow is always going to seem floppy compared to a 60 pound bow.
You ever hear that old expression, " I shoot heavier poundage bows more consistently than i do light poundage bows."
Then you run into these guys that can pick up anything and blow nocks with it.
bottom line is that a compromise can be made and have a sweet DFC, good flat trajectory, and speed, that shoot very consistent in the hands of an experienced archer....
what really gets my goat is the guys that associate high performance with instability of the bow.... :nono: that is down right incorrect. it's true a higher performance bow can be more sensitive to less than perfect form with lighter weight shafts.... but to make a statement that you prefer a slower bow because its more forgiving is down right hog wash.IMO
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Very cool post!!!
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Agreed.
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Kirk: limb alignment is critical too.
1 highly underlooked factor.
I get bows to work on and cannot believe how bad some of them are when it comes to the very basics.
That string should absolutely deadline the center of the bolts on a takedown dead center the limb completely to the tip. anything else is an inferior bow. Period.
there are so many factors that make a great bow. All or most of them are neglected or are approached with pre-concieved attitudes by many bowyers.
Core is another one. contrary to what so many bowyers say. Core makes a difference. sometimes a very great difference. I hear statements like you could use air for a core if you could get it to hold the glass together, it just makes no difference.
For some reason those same bowyers will say speed makes no difference. Why???(Rhectorical question)
Because they do not want to or do not know to pay attention to the details like Bob Morrison is doing and like Kirk is doing and Zipper and so many other really good bowyers. The old saying,. The Devil is in the details can be used to apply to this subject we are on. I would change that to say that the Greatness is in the details though.
I believe Turkeys asked who are we trying to impress? I would say me. When I do that them it makes me happy.Get by or good enough are two things that will never be heard in my shop.
God bless you all, Steve
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Originally posted by Sixby:
I believe Turkeys asked who are we trying to impress?
Actually Sixby, that isn't really what I said.
What I asked was how impressive is all this stuff, and what does it really prove?
What I was curious about is what level of limbs would actually stand up to what was being shown in the other videos and pictures that were posted. It was even implied that it "shouldn't be tried at home" or something along those lines. I proved to myself that what was being shown could actually be done by a set of cheap $70 limbs. That's why I asked, how impressive is all this stuff, and what does it really prove?
Not a slam in any way, just a fair question in light of my own testing. I don't think I ever suggested that design wasn't important, or that performance wasn't important, or that lateral or torsional stability wasn't a good thing. What I was suggesting is that the tests being used to show those things might not be all that enlightening or remarkable.
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I was curious about the rigid test that I saw on the KISS site. Everyone of my bows passed the test, Howard Hill, Big Jim, Great Northern, Border, Toelke, EagleWing, Robertson even my Ed Scott........except my Carbon/Foam ILF limbs. So what does that mean......I don't know.
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Peter, What is KISS????
Quite an impressive list of bows that you have there.
God bless you, Steve
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Dear Mr Turkey terrorist,
I'm having a hard time trying to figure out what exactly your are contributing to this thread. :dunno:
It wasn't long ago we had a perfectly good debate going on another topic that turned into a "I didn't say that...." "What i did say was...." kind of thread and the administers ended up pulling the thread.
i would like to ask you sincerely not to trash out a perfectly good thread here if you would be so kind....
on the other hand if you truly have something to contribute i'm all ears and eyes....
hey Steve.... I've seen some very high end bows that the limb alignment was off on enough that it makes me wonder if the riser actually warped....I could see no way a bow would ever get sent out like that.... :dunno:
i had it happen to me back when i first started building these things and was trying to use solid block risers with no reinforcement.....needless to say it didn't take long to learn to foot a riser after that.
have any of you guys ever had a riser move on you after doing your shelf cut out? or send out a beautifully smooth tracking limb only to have it take a twist later on for no apparent reason?
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Originally posted by Kirkll:
Dear Mr Turkey terrorist,
As much as you seem to enjoy making things personal when people have a different opinion than you, I'd rather not take part in that.
Thanks anyway.
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Originally posted by LongStick64:
I was curious about the rigid test that I saw on the KISS site. Everyone of my bows passed the test, Howard Hill, Big Jim, Great Northern, Border, Toelke, EagleWing, Robertson even my Ed Scott........except my Carbon/Foam ILF limbs. So what does that mean......I don't know.
I would suggest, as a GENERAL (but not absolute) rule, it would mean those bows are more resistant to torque and are inherently stable designs.
Lateral and torsional stability are only two attributes of a bow though. There are many others that are needed to produce a great bow. Some of the bows in your list though are indeed very nice bows (the reason I say some is not to imply some are not good bows...but is only because some of them I am not familiar with).
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Oopsie I meant KISA, guess I had 70's rock groups on my mind, lol. I quess what I mean is, is this stability concept more common than perceived.
I have a variety of bows, mostly longbows, and I don't notice any lack of stability, with one exceptions. Two of my Carbon/Foam limbs, longbow configuration on wood risers are in my opinion excessively floppy, and I hate them for it.
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Just so no one thinks that I don't appreciate ILF longbow limbs. I have a pair of Sky ILF longbow limbs with on layer carbon and wood (bamboo) core that are not floppy and have a stable feel.
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I want a stable forgiving cow, if it is fast, thats just a plus.
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Originally posted by Pepper:
I want a stable forgiving bow, if it is fast, thats just a plus.
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Originally posted by LongStick64:
I quess what I mean is, is this stability concept more common than perceived.
In my opinion, yes. That's is why I did my own test with a cheap set of limbs. Some people took that as me trying to start an argument, but it was really only me seeing for myself, just how common it actually was, and sharing my findings.
Originally posted by LongStick64:
I have a variety of bows, mostly longbows , and I don't notice any lack of stability, with one exceptions. Two of my Carbon/Foam limbs, longbow configuration on wood risers are in my opinion excessively floppy, and I hate them for it.
In my opinion, I think you may have answered your own question. A traditional "deep core" longbow limb will perform better in Lee's test due to the thickness of the limb. An ILF longbow is somewhat different in that for the most part, most are basically a thin core recurve limb without the curve. The curve helps in giving a thinner core limb it's stability. Take away that curve and the limb gets a little whippy near the tips. You don't have the deep core to give it any rigidity. Most recurve limbs maintain a wider profile through the curve, giving them their torsional stability.
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TurkeysFearMe,
I am not at all surprised that your $70 limbs did well. It isn't the cost that determines stability, but design. You can use expensive materials or inexpensive materials and in either case produce either a stable design or an unstable design.
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Originally posted by Keep It Simple Archery:
It isn't the cost that determines stability, but design. You can use expensive materials or inexpensive materials and in either case produce either a stable design or an unstable design.
I totally agree with you Lee. That's why I asked the question, which for some odd reason some people took offense to...
"How impressive is all this stuff, and what does it really prove?"
How about vertical versus torsional stability? Would you agree that for the most part , a deep core longbow limb will tend to be more stable vertically, whereas a thinner core but wider recurve limb will be more stable laterally?
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Originally posted by LongStick64:
I was curious about the rigid test that I saw on the KISS site. Everyone of my bows passed the test, Howard Hill, Big Jim, Great Northern, Border, Toelke, EagleWing, Robertson even my Ed Scott........except my Carbon/Foam ILF limbs. So what does that mean......I don't know.
Curiosity got me looking for that test you were describing on rigidity and this is what i found.
i don't think it is what you wer talking about, but it was a fascinating article on internal friction in a limb core....
how we could relate this to limb stability is beyond my red neck engineering abilities. :biglaugh:
check it out...
http://www.primitiveways.com/Bow_and_Arrow_Efficiency.pdf
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Sixby...sent you an email. I don't understand your response to my post about the Border video and my kudos to Bob M.
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Originally posted by Turkeys Fear Me:
Originally posted by Keep It Simple Archery:
It isn't the cost that determines stability, but design. You can use expensive materials or inexpensive materials and in either case produce either a stable design or an unstable design.
I totally agree with you Lee. That's why I asked the question, which for some odd reason some people took offense to...
"How impressive is all this stuff, and what does it really prove?"
How about vertical versus torsional stability? Would you agree that for the most part , a deep core longbow limb will tend to be more stable vertically, whereas a thinner core but wider recurve limb will be more stable laterally? [/b]
In terms of the bow itself...the average longbow will generally be more torsionally and vertically stable than a recurve. I suspect the reason a lot of people torque the longbow though is because longbows typically have a less contoured grip. Additionally, most recurves have less shock than most longbows and are also smoother on the draw. Not always, but generally. As a result, while the recurve may be more sensitive to errors, its action and feel may be more prone to promote good form. A longbow (especially the traditional D shaped longbow) may be more forgiving of errors, but its action is generally rougher with more shock and more stack...and therefore is harder for some archers to obtain good form with. In bows, one thing I have learned is many things are a rob Peter to pay Paul situation...and we have to find an ideal balance.
Back to your question...in terms of limb structure, a recurve is generally more ribbon like. The reason for this is the recurve generally has a wider limb and less core and as a result will is easier to flex in either direction. This is also why recurve tends to be smoother on the draw. of course a longbow can be designed that way as well, but when done so it usually ends up being less stable. this is commonly observed in some of the hybrid longbows on the market today. Adjustment can be made to correct this phenomenon though. For example at any given bow lengtg the riser like to be increased and the limb length decreased which increase the torsional and lateral stability of the limbs, but unfortunately increases the level of sensitivity in the riser. we all have different strengths and weaknesses in our form, therefore we all have different preferences. limb core adds to both lateral and torsional strength. it also adds stack as a result and reduces the smoothness of the draw. for example a broomstick is very hard to flex or twist (despite its low cost, haha). This is why we have to find the optimal balance in order to produce a perfect bow for a given archer.
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Originally posted by Turkeys Fear Me:
How about vertical versus torsional stability? Would you agree that for the most part , a deep core longbow limb will tend to be more stable vertically, whereas a thinner core but wider recurve limb will be more stable laterally?
That's a good question.... a deep core long bow will have both lateral and vertical strength and stability, but doesn't have the ability to store as much energy as the recurve design.
The wider thinner limbs of the recurve bow need that width for lateral or torsional stability to keep it tracking right without any twist. or i should say "used to need that width".
Now this might not seem near as exciting to the archer, as it does to a bowyer. but with the composites available to us now. it's made things possible to do things with these limbs that could not otherwise be achieved.
There have been huge gains in limb design in just the last few years by bowyer's all across the nation just by thinking outside the box and utilizing the materials we have available now.
This is the challenging part of designing a recurve limb. as you change the geometry of the limbs shape it stores the energy, and applies more or less pressure in different locations of the limb. a much shorter working portion of the limb is used too. the leverage that hook on the end has, and how much it opens up makes a huge difference on how much width, or reinforcement with the use of composites it needs to maintain stability. it's relatively easy to get your torsional stability with extra width, but the wider you go the thinner the limb becomes and issues with vertical stability come into play.
The ultimate recurve bow would have a deep core, and narrow width that has both torsional and vertical stability.....But.... that one is a tough one to pull off..... we have some nice hybrid long bows out there doing it......but.... we are getting closer all the time finding the ultimate recurve bow....
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Originally posted by Keep It Simple Archery:
I disagree with that last statement. My reason for this is a recurve is generally more ribbon like. The reason for this is the recurve generally has a wider limb and less core and as a result will is easier to flex in either direction.
Again, I would agree with you, but only to the extent that the thinner core, wider limb is straight(er). The curve itself resists twisting, allowing a thinner, yet shallower core to work. In my opinion, that's why the ILF longbow limbs can have issues in that area. They've eliminated the curve, which is what was helping with the torsional stability.
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Originally posted by Kirkll:
The ultimate recurve bow would have a deep core, and narrow width that has both torsional and vertical stability.....But.... that one is a tough one to pull off..... we have some nice hybrid long bows out there doing it......but.... we are getting closer all the time finding the ultimate recurve bow....
Now we're getting down to business. THAT, in my opinion is what Border is trying to accomplish. By making the curve larger and tighter, he can narrow out the last few inches of the limb profile and still keep the core thin. BUT, by doing so, in other people's opinion, you create other not so friendly issues.
They key is finding the happy medium.
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The best thing about Border is that they think outside the box and push all the limits and make other bowyers try harder. The bad thing is that they are in Scotland. I surely hope that Bob M can accomplish what he is trying to do.
Turkeys...just curious....i'm not a bowyer but what "other not so friendly issues" are you referring to with Border limbs. I'm soon to be 68 and have shot some of the best and a lot of the not so good bows over the years. Winex and Borders, aside from the Groves, have been the best shooters for me. The biggest problem with HEX series of Border limbs is stringing them but even that is not an issue if you use the stringer they send you.
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Originally posted by Bill Carlsen:
Turkeys...just curious....i'm not a bowyer but what "other not so friendly issues" are you referring to with Border limbs.
Bill...
I have no personal experience with the Borders other than shooting them a few times. The people that I know that own them love them but as you said, they are a little temperamental when it comes to stringing them, and some have even said keeping them strung.
This is just a personal opinion, but I would question the ability of such a tight curve to withstand expansion and compression forces long term. It may NEVER be a problem but I wonder if that might be why Border seems to be so sensitive when it comes to what limbs are used on what risers and with what arrow weights.
You are right, they do think outside the box and make people re-think their positions.
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Originally posted by Turkeys Fear Me:
Originally posted by Kirkll:
The ultimate recurve bow would have a deep core, and narrow width that has both torsional and vertical stability.....But.... that one is a tough one to pull off..... we have some nice hybrid long bows out there doing it......but.... we are getting closer all the time finding the ultimate recurve bow....
Now we're getting down to business. THAT, in my opinion is what Border is trying to accomplish. By making the curve larger and tighter, he can narrow out the last few inches of the limb profile and still keep the core thin. BUT, by doing so, in other people's opinion, you create other not so friendly issues.
They key is finding the happy medium. [/b]
Well that's not entirely the case regarding the tighter radius hook and the ability to narrow the tips. i can build a totally static tip just using glass and tip wedges and can accomplish very narrow tips....
Actually What boarder has going for them is that they lay up their own carbon matrix material and have developed a core material that is compatible.
A radical hook on the end of any recurve limb puts a tremendous amount of pressure on the working limb. The carbon composites, if used correctly allows you to narrow up the whole limb and push the envelope on the geometry. The geometry part of it is had explain, and all the stored energy in the world isn't going to do you any good if you can't harvest it..... getting the right amount of preload to stop those hooks dead, transfer the energy, and stay within reasonable stacking limits is the key.
Hey Bill, i know you are a big Boarder fan, and i'm not saying they they don't make an excellent bow, because they do.... But Boarder has nothing to do with how hard i try, or set my prototype goals. or any other bowyer i know either for that matter.
This thread isn't about this brand is better than that brand. it's about stability. and i certainly don't see Sid in here contributing to to this topic.
Those boys over there have had their share of set backs too...Carbon alone doesn't make the bow.
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Originally posted by Kirkll:
Well that's not entirely the case regarding the tighter radius hook and the ability to narrow the tips. i can build a totally static tip just using glass and tip wedges and can accomplish very narrow tips....
But what good is it? By doing that, you lose all the benefits of a working recurve and you've accomplished nothing other than narrow, heavy tips that will likely compromise yor dental work. It's the deep hook and the narrow tips combined that give the performance gains.
But, you are still trading them for what some consider less desireable traits, especially in a hunting limb.
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What i was referring to is pretty much a static tip hook, not so much a working recurve. The advantages of a static tip is a shorter working limb without loss of the string angle. the static tips are generally harder to keep stable the farther out on the hook you go. the heavier tips on a recurve won't effect vibration near as much as lack of pre-load and improper timing. It's all a balancing act i find fascinating myself.
you can even incorporate a static tip into a r/d long bow to help pic up some early weight and help the shorter draw length shooters pick up more performance. flipping the tip a bit on a long bow makes a huge difference in getting better string tension at a lower brace and improves the string angle too.
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It's a shame we don't have one independent testing facility where all these theories can be stacked up against each other. Kind of like the Consumers Report of traditional bows.
Until then we will just have dozens of different designs, all purported to be the best, many times for reasons that can't really be measured.
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I'm not technically knowledgeable enough to even get into this discussion but I have to say that when I got my first set of ILF limbs and DAS riser for my wife I shot one arrow with it when setting it up for her and went in and ordered one for myself. At that time there was a lot of sentiment about the bow being "non trad" and my only response to the whole issue was that the bar on limb performance had been raised. I am actually happy to see this discussion as I think it is long overdue. There is a lot to be said for the beauty and allure of all wood bows, but with new limb materials, designs and lots of other new ideas I look forward to bow performance getting more attention than the cosmetics. The prettiest thing to me is seeing that arrow going where it was intended to go, quickly, smoothly and consistently. I truly think the best is yet to come regarding bow performance. You guys keep playing with your ideas. It is time the Asians got some competition.
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Here is the problem I have with the way this conversation is going. I was building this limb you are talking about , Deep hook. static. Stable laterally and verticly before Border ever came out with theirs Hex 5 and Hex 6.
Kirk was building a static tip carbon bow that is stable and super fast. Both bows utilize 1 1/2 inch width limbs,.
The only thing Border has that I have not worked with is the composit core. I guess. I have not personally seen it.
Border was touting maple limb cores when I know Bob Morrison , Hummingbird , Kirk and I were building foam core double carbon bows.
Its the following Borders example remark that kind of got under my skin. I apologize for that.
Mr Carlsen I understand you have never shot one of my bows. Have you ever shot a Bigfoot or a foam core Hummingbird or foam core carbon Morrison?
Bob testing stability and using new materials is not something new. It is something we all do if we want to produce a better product. He is not one of the bowyers that is behind the eightball. But there certainly are some.
God bless you, Steve
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Turkeys Fear:But what good is it? By doing that, you lose all the benefits of a working recurve and you've accomplished nothing other than narrow, heavy tips that will likely compromise yor dental work. It's the deep hook and the narrow tips combined that give the performance gains.
Did you read Kirks post you posted and answered. He said he could build a static tip using only the glass and wood with a tight radius. It adds no tip weight at all. A tiny tip wedge that you way more than make up for with narrowing the tip material.
You say there is no benefit. Then you simply need to shoot one.
What you said about compromising your dental work is absolutely wrong. The static bows that I build and that Kirk builds are some of the smoothest shooting most shock free bows in the world. Kirk can show you a vidio if you want that shows limb movement after the shot. Vibration and ossilation, His bow limb stops a tremendously long time before any other bow limb tested. In fact its amazing.
I own one of his bows and that is why I keep using them as an example. I know that the limb works.
You make broad statements like this and expect respect.
For instance. You say the static tip as described have less desireable traits than a working recurve.
I disagree and I can give you reasons for my disagreement. Can you back up the broad statement you made with fact? What are these less desireable traits ? Why is the static tip inferior? Oh and what in the world has this got to do with Bob's thread on Stability?
God bless you, /Steve
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Originally posted by Sixby:
Did you read Kirks post you posted and answered. He said he could build a static tip using only the glass and wood with a tight radius. It adds no tip weight at all. A tiny tip wedge that you way more than make up for with narrowing the tip material.
You say there is no benefit. Then you simply need to shoot one.
What you said about compromising your dental work is absolutely wrong. The static bows that I build and that Kirk builds are some of the smoothest shooting most shock free bows in the world.
Yes, I read his post very closely. The only way I can answer your question is to simply say that we seem to have differing definitions of what a static recurve is.
The tip of a true static recurve does not uncurl...at all. A true "static" tip, by definition, exerts force by reason of weight alone without motion. I was referring to the static tips of old, not a radical hook, which seems to be what is now considered by some to be a static tip.
It's easy for someone to say that they make some of the smoothest, shock free limbs in the world. Without independent, objective testing, nobody can prove you wrong.
Or right.
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This thread was started to get a few ideas. Look where a few of you have taken it. Done.