1. One of the easist ways to increase a bows efficiency is to decrease the amount of working limb

2. One of the easiest ways to increase energy storage is to decrease the amount of working limb

3. One of the easiest ways to stablize a highly reflexed recurve that is squirrly is to decrease the amount of working limb

4. One of the easiest ways to avoid twisting limbs in big recurves and reduce mass is to decrease the amount of working limb.

You might have guessed by now I am becomming a fan of hinge bows, bows that do all their bending in a very short area near the fade. I have only done two of these with all wood bows and was extremely impressed with the results. The wood could not hold up to it so I won't be making anymore. Could glass almmed bows tolerate a very short bending area?

Makes since to me, compound bow limbs don't move much via cams and what not and they're pretty zippy and stable.

...or bend in the handle design. I've always said that design stores much energy as long as the bending is kept to the minimum.

Even a bow a narrowed handled bow that bends through the fades stores lots of energy.

Jawge

Jawge, theoreticaly a bend right in the middle of the handle would give you the most energy storage.

...and a very sizeble thump. :) Jawge

i never had a glass bow, recurve or longbow that was worth a darn if it bent near the riser. and i made a lot of them and tested them.

I agree with Larry.To a large extent there is a lot more to limb design than one might think.Characteristics change and there is always some trade offs because of the tasks required in a bow limb.What you have been saying may sound good to you.Have you ever thought if it was a good concept lots of bows would be built in that maner.Well they aren't because people discovered a long time ago it is an un desireable trait you don't need in a bow.Thats a breakage just waiting to happen.People have worked out various formulars that have limits.Just stick to tried and true methods and cherry the best from that.More importantly come up with a good combination of charateristics and you will have a winner.That perfect bow could still be out there but I haven't seen it yet. Case in point my 60# 58" York recurve works well strong stable,has exceptable accuracy.My wifes 47# 63" Sabo hunter shoots faster smoother and is pomore accurate but is not real stable in limb profile and is rather fragile compared to my York.Thats the trade off.For me somthing in between would be perfect for my needs OSR.

I agree with Larry and in fact believe the most efficient bow is a bow that has a very solid riser that is relatively long and short limbs with a static or semi static tip and a working area that is in the outer limb backed up by smooth transtition toward the fades. When you pull a bow that is X long the limbs are going to bend X amount. The key is to arrange this so that the limb moves progressively and that the working area is a very smooth bend with the fade area long and bending only as the pressure increases on the outer limb so that the limb draw force curve is very even all the way through the draw cycle. ]I did not copy Damon Howatts or Martins design but I sure kept the precepts in mind when I started building bows. Riser length on a Howatt Hunter is 26 inches, Riser on a Super Kodiak is 26 inches Riser length on an EagleWing Steppe Eagle is 26 inches,. These all break the limb and riser combo into basic thirds. The rest is placing the working area correctly and not overworking any part of the limb. Also maintaining string angle so that at same brace the angle is lower and the pinch less. This means that the tip of the limb is moving a shorter distance ala the mentioned short movement of the limbs of the compound limbs., The shorter distance the tips travel from full draw to brace return the faster the arrow comes off the string and the quicker the bow is with less vibration ectr when the limbs are timed and have good stability..

That's my story and I'm sticking to it.

God bless, Steve

Larry was it bending anywhere else? I am talking about a rigid limb with a hinge. Like the asian bows almost.

I think Daan Perry called such bows "high-geared." Somebody called them that...

How-some-ever, I think the answer to No. 2 is false.

Jim

Sixby you said it better than me.Thats exactly what I was trying to get across. Unfortunatly I learnt the hard way when I was young dumb and stupid.I am 55 now and know better .One can never to be to old to learn.Aisian bows are different again.There are static tips or traditional Korean types of bows.I prefere the Korean types .My personal preferance would more a combination of Drake and the classic 60 's californian target type bows.The semi static tips with the smooth ness of target bows. OSR

usually, when a limb has any bend at all near the riser, even though the recurve is working etc., when you release the string the limb sort of double clutches and bleeds potential energy. i have never seen a rigid limbed bow that hinged off the riser that shot worth a darn. just my experience, not claiming that it's a fact if some configuration i never tried works some way. the modern asian bows i shot last year had full working limbs. i just used them at a point where they were gaining the most #/inch.

Mr.Hatfield, how would you characterize the Martin Saber one-piece recurve? Or the Browning Wasp - they both seem to have similar limited deflex limb profiles, and my Saber seems to flex at the fades. I've broken two wasps at the fades, and the saber is showing horizontal stress lines in the finish at the fades. I have a 29" draw. Not disagreeing with anyone here, just trying to further my education.

Most all of the tradeoffs we so often speak about in glass bows are related to the amount of limb bending. I stiffened up my own fade areas on wood bows and moved my bend out further from the handle and just like the glass bows I got more speed. I didn't gain the speed because I moved away from the handle, I gained the speed because I shortened the working or bending area.

If a bow limb was entirely rigid except for a hinge it would be 100% efficient minus the string weight because the energy would have no where to go but into the arrow. The more working limb the more room the limb has to distort and vibrate way the energy.

Why don't recurves have 12" of reflex in them? Because they would become unstable and the thin limbs would deform and flex all over the place. A hinge bow you can put 12" of reflex into the limbs and they remain solid as a rock.

All the answers above were based on shortening the working limb which is correct, but instead of increasing the length of the static outer limb they all used longer risers or power lams.

Osr, I admit to being young and dumb at 66 years old with a few thousand bows built under my belt. Not just building bows but mostly experimenting.

I played with this idea about 10 years ago and have been playing with it again lately with a slightly different approach and I am extremely impressed with it. Not really practical for a woodbow as it just won't handle the strain, possibly fiberglass may not handle it either, I don't know fiberglass that well.

Sixby, when you move the limb away from the handle you are sacrificing stored energy to pick up effiency. We all do it, we have all found long working limbs ineffective.

I would not be surprised if we don't start seeing longer static areas in the outer outer limbs. Most of the tradeoff we put up with are to reduce working limb area.

Badger I am probably where you were 10 years ago.I have my own theories and will be taking a different track.I am probably wrong here but flight shooting would be the proving ground for bow efficietcy as far as power is concerned.I also want smoothness and accuracy.I know fibre glass and will be making my own glass lams.I should get good powerfull glass because I can control my quality better than currently available.Machines can only be so good.I will admit I don't fully understand where your comming from.I do however apreciate your opinion.Larry has done it professionally and much of what he says sounds good to me.All we can do is try these things.Good luck all the best. OSR

OSR, don't worry I never take things personnal here, all in good fun. I fully expected to take a beating on this one when I posted it.

Cutting to the chase I see it like this. If we want more power we get it two ways, more energy storage and more efficiency. These two items tend to fight one another and we look for the best middle ground.

We usually get more efficncy by shortening the limb or the working limb, reducing mass in the limb. To some degree we control tiller shape which is another way of controlling working limb.

For more energy storage we usually reflex the bow more or increase string contact with the recurves or both. Once we get to a certain point it becomes unstable and we have to back off.

I took a slightly different approach, instead of backing off when it became unstable I decided to simply deal with the stability issue which was making the limb more rigid, which just so happened to deal with efficiency issues at the same time.

I would like to see actual results of a glass bow built like this. I have seen the results of a wood bow. Everything I have heard so far just deals with the issue by backing off and shortening the limb instead of just the working area.

I'm sorry to hear your experiments failed. Not even 2" wide in the working area with hickory backing would hold up? Are you thinking 62" ntn? 12" radius hooks? 18" riser?

If you want more info on rigid limbs check out Talisman crossbows, Phil makes a very interesting crossbow using rigid limb concepts.

Crossbows aside, a lot of Asiatic horn bows use the concept of course it is the horn and sinew that make it even possible.

Then there is also the Oneida compoundbows that work on similar principals.

"I'm sorry to hear your experiments failed. Not even 2" wide in the working area with hickory backing would hold up? Are you thinking 62" ntn? 12" radius hooks? 18" riser?"

I used a stiff area of fade and riser of about 14", if it wold have been glass I would probably have gone to about 21'.

I was actually 2 1/2" wide. One of them held up pretty good for a dozen or so shots and then started faining. Both bows are still working one I could not get over 35# and maintain the reflex, the other bow lost most all of it's reflex and dogged out.

Badger I knew a custom bowyer that found a way to build short, fast bows but they didn't have much cast.. They tended to be accurate close up but lost accuracy pretty quick after a certain point. The arrow would travel along and then just seem to drop pretty quick down range.

Have you found this to be true.. That you have to balance cast with speed and "flatness"?

Frank

What Larry H. Said.

Frank, speed is flatness. If they dropped quickly down range they were not comming out of the bow very fast.

I thought we were talking selfbows so forget what I said. :0 Jawge

Badger I saw your other post with pictures of one of the bows. I saved the pictures and when I have time I'm going to duplicate them in supertiller and start working on what I'd have to do to make a glass laminated one. Don't know when or if I'll have time to actually build one but the challenge is exciting.

It would be helpful if everyone would stop using the word "cast" as if it were something different than "speed". It is not.

I honestly don't know how well it would work on a glass bow but I do think it would allow for massive reflex to be used without compromising stability. On my test bow I achieved 120% stored energy per draw force. Far above anything I have ever done with more conventional designs.

Badger here is the FD curve of that bow using the numbers you posted using the free drawcurve program downloadable here. http://www-personal.umich.edu/~cdsnyder/drawcurve/index.html#Download

JusPassin, cast is a description of an effect of speed. Yes, greater speed, greater cast, but while one bow might propel a 400 grain arrow at 200 fps, a second bow might propel a 500 grain arrow at the same speed. The second arrow will travel farther. That second bow has greater cast, though the same speed.

Your a thinking man Jim and thats correct.I know that to be true but never thought of that myself I must be getting old.Kenitic energy comes into play too.A ping pong ball moving at the same volocity as a baseball can't carry the the same distance because the weight difference. OSR

A bow that works sorta as the OP is suggesting is the hybrid or the Holmguard. It has the narrowest point where the limb are thinner not at the riser but a bit along the limb.

The hinge bow as described, as a recurve, seems oddish as the point to a recurve it to maintain efficient limb tip to string angles, even though the bow is somewhat tippy.

Bowlin, the biggest point goal is as you say maintaing low string angles but also taking advantage of the designs ability to tolerate excessive reflex and stay stable. The holmgarde principle does come into play with narrow outer limbs not usually tolerated by recurves.

It would pretty much be a waste of time if the extra reflex and norrower limbs were not taken advantage of.

"That second bow has greater cast, though the same speed."

So the second bow has more force, or power. Is that how you define cast ? With identical arrows the second bow would have greater speed.

Runner, I don't think its anything new or anyreason to believe it would be a hotrod. The horn bows have worked on this same principle for centuries. It might have some bugs involved finding the sweet spots but I feel like it would be very durable if the glass can handle the tight bends.

To much thought, string her up and shoot the thing.LOL

Mine snapped at the fade, and hit my unattractive mug...so much for 'working at the fades' for this boy 8^[

So on the Next bow-

With Dire Wolfs' technique, and Byron Fergusons' designs, I worked over the last 14" of limb to sweeten the draw weight (It was too heavy for me) but not lose stability or accuracy on my longbow, a mild D/R Samick. Byron said to leave the fade area a little beefy to resist limb twist and torquing, and let the last 14" or so do the work. He said it wouldn't be as fast, but would be more stable. He is right, as usual!

So I have an accurate bow, and only dropped 8fps over the chrono, and dropped 10% draw weight. The arrow speed dropped 5%, so it was a good trade for me, and many thanks to Byron for writing his book, and Dire Wolf for walking me through the actual shopwork.

TinHorn

Mine snapped at the fade, and hit my unattractive mug...so much for 'working at the fades' for this boy 8^[

So on the Next bow-

With Dire Wolfs' technique, and Byron Fergusons' designs, I worked over the last 14" of limb to sweeten the draw weight (It was too heavy for me) but not lose stability or accuracy on my longbow, a mild D/R Samick. Byron said to leave the fade area a little beefy to resist limb twist and torquing, and let the last 14" or so do the work. He said it wouldn't be as fast, but would be more stable. He is right, as usual!

So I have an accurate bow, and only dropped 8fps over the chrono, and dropped 10% draw weight. The arrow speed dropped 5%, so it was a good trade for me, and many thanks to Byron for writing his book, and Dire Wolf for walking me through the actual shopwork.

TinHorn

You obviously would not work the bow into the fades, make a gentle transition into a more severe bending area and then a gentle trasition back out of the bend, .

Well the completely unscientific side of me says that if you cause torsion in an appendage at one end, by the time the other end responds it will be amplified.

We are essentially working to snap a hinged string straight as fast as possible. to do so you need maximum snap at the point where wood meets string. The furthest point from that along the wood is the center. So if that is where the most energy originates then the more snap you will have.

It also justifies the less mass on the limb portion. It is harder to whip the fat guy at the end of the skate line than it is to whip the little guy.

One word...

Bullwhip.

I guess you could call it a high geared bow. The two bows that I did make had a very unique feel. They start accelerating slowly and then rapidly build acceleration, you can really feel oooomph toward the end of the stroke. It is kind of exhilerating.

A thought, and Devil's advocate perhaps... could the 'oooomph' have been handshock, i.e. misdirected energy?

steve, the longbows i bring to the shoot have limbs that are immobile out to around 10" from the nocks after stringing. even at a low brace. i learned how to do that working with a guy at battelle northwest labs in richland wa.. the draw curve on them is a straight line, as they gain exactly the same #/" from the first inch from brace through 30". at 30" they lose about 1/2-1# per inch because the entire limb is bending at that point. they are fast and stable and hold all the records for american longbows. the r/d is shaped, in conjunction with the takeoff angle, to create opposing moments of force that basically freezes the main portion of the limbs due to the extreme tension created. i had to design some pretty trick lams to get that done. one of the three lams is double tapered. all are full length continous lams that are the same thickness in the center and taper equally both ways from center, and as i said, one tapers down and then thickens as it nears the tips. the template for making those lams is very much time consuming and exacting work, hand sanding 1" grids for 70" and getting all zones within .001 at all points with no bumps or ridges.

No handshock at all.

Larry that is exactly how I like to tiller out my D/R boo backed bows, it works.

What I am reffereing to above would only really apply to recurves with a very large amount of reflex. I like to see a force draw build very fast in the first several inches before it levels off. Lots of reflex does this, a short working area allows more reflex to remain stable.

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