bow- class with crash- test- engineers
Yesterday I?ve finished a bow-class with 5 crash- test engineers working for the leading motor vehicle and aircraft manufacturers worldwide.
Cause they?ve to cooperate very often they decided to do a bow- class as a kind of team- building activity. One of them, a Greek engineer working in Germany got this idea, cause he is very interested in traditonal bowery of the antique past in Greece.
They finished the class with 3 flatbows, one short selfbow with a scythian design. One of them worked the most difficult and time- sucking stave I had in stock, he has to finish the bow at home.
We talked a lot about the physics of different bow- designs, as a summary I?ve to say, that these 3 days were the most exciting bow- class I?ve ever done.
I post some of the ideas and suggestions of these guys, cause they are very interesting and worth to be discussed.
Fadeout of the grip into the limb: the wider and longer a bow?s limb is, the longer the fadeout has to be done. As a roughly rule of thumb keep in mind, a bow?s limb with a width of 4cm needs the same length (4cm) as a fadeout....etc....
Rectangular cross- sections are the best cross- sections for oscillating objects like a bow?s limbs, don?t round off the edges of the limbs to much, otherwise you?ll provoque the shear forces to destroy the bow.
The rounding of the edges means a loss of energy too.
They adjugded the attachment of the string in almost every bow- design as to be very sleazy. The best attachments has to be done like the Scythians did it with the grooves at the recurved ends of the limbs or with bone- or antler-plates at the sides of the ends of a bow. If the string is properly attached, there will be almost no loss of energy caused by the strings self- frequency. Compare it with a sleazy attached guitar- string.
Bow- design: the most stable design is the Scythian bow- design, cause if you look from the side at it, it is somehow folded in length. This folded profile is the main reason for the fact that a Scythian bow has to have a very good transfer of energy, there is almost no self- frequency in the limbs when the string has been released. A straight- profiled limb is vibrating much longer, this means a loss of energy. This could be applied to the Plains Indians double- bow design too.
They didn?t agree in short bending- sections for to amplify capablities of a bows at all, as it discussed by the flight- bowyers. The shorter the bending- or working section of a bow is, the more useless mass has to be moved. Make the whole limb working and use lightweighted materials with stable cross- sections.
I?ll go on to discuss with them, it is really interesting and inspiring.
Michael
We agreed in going on to discuss via email,
Cause they?ve to cooperate very often they decided to do a bow- class as a kind of team- building activity. One of them, a Greek engineer working in Germany got this idea, cause he is very interested in traditonal bowery of the antique past in Greece.
They finished the class with 3 flatbows, one short selfbow with a scythian design. One of them worked the most difficult and time- sucking stave I had in stock, he has to finish the bow at home.
We talked a lot about the physics of different bow- designs, as a summary I?ve to say, that these 3 days were the most exciting bow- class I?ve ever done.
I post some of the ideas and suggestions of these guys, cause they are very interesting and worth to be discussed.
Fadeout of the grip into the limb: the wider and longer a bow?s limb is, the longer the fadeout has to be done. As a roughly rule of thumb keep in mind, a bow?s limb with a width of 4cm needs the same length (4cm) as a fadeout....etc....
Rectangular cross- sections are the best cross- sections for oscillating objects like a bow?s limbs, don?t round off the edges of the limbs to much, otherwise you?ll provoque the shear forces to destroy the bow.
The rounding of the edges means a loss of energy too.
They adjugded the attachment of the string in almost every bow- design as to be very sleazy. The best attachments has to be done like the Scythians did it with the grooves at the recurved ends of the limbs or with bone- or antler-plates at the sides of the ends of a bow. If the string is properly attached, there will be almost no loss of energy caused by the strings self- frequency. Compare it with a sleazy attached guitar- string.
Bow- design: the most stable design is the Scythian bow- design, cause if you look from the side at it, it is somehow folded in length. This folded profile is the main reason for the fact that a Scythian bow has to have a very good transfer of energy, there is almost no self- frequency in the limbs when the string has been released. A straight- profiled limb is vibrating much longer, this means a loss of energy. This could be applied to the Plains Indians double- bow design too.
They didn?t agree in short bending- sections for to amplify capablities of a bows at all, as it discussed by the flight- bowyers. The shorter the bending- or working section of a bow is, the more useless mass has to be moved. Make the whole limb working and use lightweighted materials with stable cross- sections.
I?ll go on to discuss with them, it is really interesting and inspiring.
Michael
We agreed in going on to discuss via email,
This is extremely interesting Redhawk, I'd like to see what they would think of the Turkish Flightbow, or any design with a non-bending section near the nock.
If the scythian design does prove to be the best from an engineering perspective, the mind boggles as to why siyahs were added to bows, especially as those adding them seem to have begun with a scythian design in the first place.
Regards
If the scythian design does prove to be the best from an engineering perspective, the mind boggles as to why siyahs were added to bows, especially as those adding them seem to have begun with a scythian design in the first place.
Regards
If you read Archery: The Technical Side, you will see the same ideas. However, there are other things that influence the performance of a bow besides simple energy storage. Watching some of the recent bows being shot in Utah and talking to the bowyers, suggested to me that they might be onto good ideas. The fact that they are replicating traditional designs by independently working out reasons to do the same things is helping explain why our ancestors came up with so many models of bows.
I have personally found that working recurves had more flexibility than rigid eared bows. This meant shooting them was not so consistent, but this could just be me and how I shoot.
I have personally found that working recurves had more flexibility than rigid eared bows. This meant shooting them was not so consistent, but this could just be me and how I shoot.
A bow is an entity, as Bede said, it is not a simple storage and release of energy.
But anyway it is very inspiring to discuss with experts focused on the aspects dealing somehow with bowery.
The diversity of the bows of the past fulfil more or less the ideals of a good bow. Finally the needs of the archer, hunter or warrior are the determining factor.
The greatness of the Turkish hornbow- design is within the very well balanced cross- sections and the reduction of the siyahs, compared with
mongolian- hornbows. This is what one of the engineers said when I showed him some pics in Klopstegs book.
What is in my mind now: thanks to the new communication techs we?ve a globalized world, a todays bowyer has much more infos about a lot of bow-designs of the past. He could somehow summarize the good qualities of several bow-designs into one new design( something like a "hybrid")
But somehow there is no further development of hornbows. Maybe it is not necessary?
Michael
But anyway it is very inspiring to discuss with experts focused on the aspects dealing somehow with bowery.
The diversity of the bows of the past fulfil more or less the ideals of a good bow. Finally the needs of the archer, hunter or warrior are the determining factor.
The greatness of the Turkish hornbow- design is within the very well balanced cross- sections and the reduction of the siyahs, compared with
mongolian- hornbows. This is what one of the engineers said when I showed him some pics in Klopstegs book.
What is in my mind now: thanks to the new communication techs we?ve a globalized world, a todays bowyer has much more infos about a lot of bow-designs of the past. He could somehow summarize the good qualities of several bow-designs into one new design( something like a "hybrid")
But somehow there is no further development of hornbows. Maybe it is not necessary?
Michael
I would be very surprised if a modern engineer could improve on traditional bow design with natural materials. What has been done with modern materials never ceases to amaze me though. Modern compound bows really saved archery as a sport.
But what the bow designers are not able to do is to instill spirit into modern bows. And for some of us that is the magic quality. Besides, modern bows with the best to offer do not quite function as well as the best of the ancients'. This is even more amazing. -j-
But what the bow designers are not able to do is to instill spirit into modern bows. And for some of us that is the magic quality. Besides, modern bows with the best to offer do not quite function as well as the best of the ancients'. This is even more amazing. -j-
Depends on your parameters for "function." The best modern target bows provide more accuracy than any traditional bow, and the best modern flight bows cast their arrows to substantially longer distances than traditional flight bows. So...well, unless we insert some cultural and sentimental parameters (which are by no means insignificant) in, it may be a bit hard to justify that assertion.jack farrell wrote:
Besides, modern bows with the best to offer do not quite function as well as the best of the ancients'.
"the best modern flight bows cast their arrows to substantially longer distances than traditional flight bows"
I would not be so sure. Since arrows are nearly as important as bows in this discipline, one should remember the modern records were made with tiny carbon shafts, not with wood arrows of the past - thicker, longer, heavier and with fletches not made of razor blades or mylar. These modern records may not be so great anymore.
Engineers who look at bows seriously quickly realize how complex they are and the progress in understanding the mechanics has been very slow. The progress has been made mostly in materials like carbon and especially high stiffness strings, but designs have not changed too much.
Adam
I would not be so sure. Since arrows are nearly as important as bows in this discipline, one should remember the modern records were made with tiny carbon shafts, not with wood arrows of the past - thicker, longer, heavier and with fletches not made of razor blades or mylar. These modern records may not be so great anymore.
Engineers who look at bows seriously quickly realize how complex they are and the progress in understanding the mechanics has been very slow. The progress has been made mostly in materials like carbon and especially high stiffness strings, but designs have not changed too much.
Adam
Well, maybe, if you put it that way. I can see (and agree) why it's rather unfair to compare traditional bows and arrows with, say, a modern compound bow with a modern ACE arrow and the full battery of sighting and stabilizing accessories. But that brings up the question of the parameters we're using for comparison: whether it's just raw range/accuracy, or taking account of other factors like weight of arrow, striking power, technique, additional equipment, and the like. When we're just comparing raw accuracy or range without caring about everything else then modern designs have definitely surpassed traditional ones in those respects.
"modern designs have definitely surpassed traditional"
Ok, make one out at the plains with only a folding knife.
Ok, make one out at the plains with only a folding knife.
Ease of construction certainly isn't part of the very restricted variables of "accuracy or range" that I was talking about....
I think the point here is that the bow is essentially an 'ancient' device. If you want to consider only pure efficiency as a weapon - then the bow has been completely surpassed by modern weaponry. That's why we no longer go to war armed with bows.
Some people see a mis-match of modern industrial technology when applied to an ancient device that predates that culture. These individuals are drawn to traditional archery in its various forms. There are other archers however, who may see archery as a pure sport and so welcome the use of the modern technology to enhance consistency etc.
Considering all the advances that have been made in engineering and technology, it is probably more surprising that ancient weapons can come so close to performance achieved today. Possibly something which should be considered is that the human component in the 'shooting system' of archer, bow and arrow plays such a huge part that it can often be a bigger variable than the difference between modern or traditional equipment.
Some people see a mis-match of modern industrial technology when applied to an ancient device that predates that culture. These individuals are drawn to traditional archery in its various forms. There are other archers however, who may see archery as a pure sport and so welcome the use of the modern technology to enhance consistency etc.
Considering all the advances that have been made in engineering and technology, it is probably more surprising that ancient weapons can come so close to performance achieved today. Possibly something which should be considered is that the human component in the 'shooting system' of archer, bow and arrow plays such a huge part that it can often be a bigger variable than the difference between modern or traditional equipment.
"I would be very surprised if a modern engineer could improve on traditional bow design with natural materials."
This seems to imply that modern materials are superior, well in someways they are but sinew for example is one of the best known materials for storing elastic energy.
One of the drivers for modern materials development has been stiffness, that is not actually overly desirable for a bow. There are several reasons for that, one of the most important is that a stiff material requires a thin bow which is not vary stable. An optimum bow out of modern materials propably should not look like the old ones.
With modern analysis methods a horn and sinew bow propably could be made a little bit better but I don't think that would be important.
Besides there is really nothing wrong with the old design as has been shown in comparison to modern ones. "If it is not broken, don't fix it......."
TM
This seems to imply that modern materials are superior, well in someways they are but sinew for example is one of the best known materials for storing elastic energy.
One of the drivers for modern materials development has been stiffness, that is not actually overly desirable for a bow. There are several reasons for that, one of the most important is that a stiff material requires a thin bow which is not vary stable. An optimum bow out of modern materials propably should not look like the old ones.
With modern analysis methods a horn and sinew bow propably could be made a little bit better but I don't think that would be important.
Besides there is really nothing wrong with the old design as has been shown in comparison to modern ones. "If it is not broken, don't fix it......."
TM
Don?t take me wrong.
I would never made a bow with modern materials, I don?t like modern bows at all.
But the laws of physics are significant for any kind of material and I?m a very curious guy who likes to look beyond his own nose.
Every now and than I?m thinking about some further- developments of traditional bow- designs and therefore I discuss a lot with engineers, chemists, biologists, instrument makers.........other bowyers
Nowadays we?ve a global view on the complete tradition of bowery, that?s really a great chance to "pimp" the old designs.
Michael
I would never made a bow with modern materials, I don?t like modern bows at all.
But the laws of physics are significant for any kind of material and I?m a very curious guy who likes to look beyond his own nose.
Every now and than I?m thinking about some further- developments of traditional bow- designs and therefore I discuss a lot with engineers, chemists, biologists, instrument makers.........other bowyers
Nowadays we?ve a global view on the complete tradition of bowery, that?s really a great chance to "pimp" the old designs.
Michael
...just try shooting one of those contraptions from a horse at full gallop!! The kind of accuracy attained by the horse bow was adequate for its mode of use - generally short to medium range, with a high rate of 'fire'.Hyarmendacil wrote:
Well, maybe, if you put it that way. I can see (and agree) why it's rather unfair to compare traditional bows and arrows with, say, a modern compound bow with a modern ACE arrow and the full battery of sighting and stabilizing accessories.
Horsebows were the Kalashnikovs and Hechler & Koch MP5s of their time. You would never think to compare the accuracy of either of them with a competition target rifle would you.
Actually, I do believe that an engineer could improve traditional bows using only natural materials. Here's my reasoning:
1) Only analyzing the effects of the shape (in a computer simulation, say) is not enough.
2) Bowyers of the past were restricted to using materials found in their regions.
3) Bowyers of the past were, however, experts at knowing the materials - one piece of bamboo differs from other pieces of bamboo
4) An engineer of today could, potentially, investigate typical properties of all relevant materials from all over the world.
Thus:
If this engineer also had the feel for the materials, thus being able to pick the absolute best of everything, could very well end up with horn from Vietnam, wood from Brazil, sinew from South Africa, air-bladder glue from Australia, string from Norway and whatever additional binding he would feel appropriate from Canada.
While these countries may be bad examples, some form of combination of this type could very well end up with a bow that outperforms any traditional (regionally bound) bow.
1) Only analyzing the effects of the shape (in a computer simulation, say) is not enough.
2) Bowyers of the past were restricted to using materials found in their regions.
3) Bowyers of the past were, however, experts at knowing the materials - one piece of bamboo differs from other pieces of bamboo
4) An engineer of today could, potentially, investigate typical properties of all relevant materials from all over the world.
Thus:
If this engineer also had the feel for the materials, thus being able to pick the absolute best of everything, could very well end up with horn from Vietnam, wood from Brazil, sinew from South Africa, air-bladder glue from Australia, string from Norway and whatever additional binding he would feel appropriate from Canada.
While these countries may be bad examples, some form of combination of this type could very well end up with a bow that outperforms any traditional (regionally bound) bow.
There already exists some design programs that are capable of limited synthesis given some viable starting point. A competent structural designer can do a lot from just one analysis.
Modern bows have suffered from the development of the compound as nothing much has been done since.
The material needed is a high-strain low-modulus one, with no creep and no hysteresis, there does not exist one today.
TM
Modern bows have suffered from the development of the compound as nothing much has been done since.
The material needed is a high-strain low-modulus one, with no creep and no hysteresis, there does not exist one today.
TM