Primitive Archer
Main Discussion Area => Horn Bows => Topic started by: TheDukesArchers on September 15, 2014, 12:11:46 am
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When it comes to making horn bows, do you always need to have a sinew back? Would a bow that has a horn belly, but a wood core and back be considered a true horn bow?
I've been thinking actually of doing a Turkish style bow with a horn belly, hickory core and rawhide backing
DA
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James has made them with boo backing and with boo back and tempered boo belly(no horn).
Rawhide would only be a covering on a core backed horn belly bow.
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Sinew = Essential!
Horn can bend about 8 times further than wood.....
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sinew is a must have component, rawhide will not do the trick ,a bow made that way will take a lot of set, shoot sluggish,
to be a true hornbow, composite,, has the sinew,, historically -- bamboo has been substituted for belly horn.
but ,, I only know from what I have read and my own personal experiences,,, if you do succeed at building a bow the way you are attempting, and it works for you,,,,,please let me know,, you can post it on the regular bows thread page,,,, james,,
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Well Jaap Koppedrayer makes a bamboo back and horn belly bow with no sinew. I'm pretty sure it is a local variation in Asia. There is really no reason to believe sinew is necessary solely because of the presence of horn.
Horn is not going to increase the tensile forces on the back is it?
The sinew is there so that the whole package can be strained to the utmost.
Naturally the back should still be a high quality backing strip. I'm certainly not saying just leave a typical core to take the tension.
Here is the page with the bow described. Scroll down to Asian Horn Bow. Try not to get too riled up. ;)
http://www.krackow.com/html/bows.html
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Yes you can build a horn bow with no sinew but it will not shoot as well as a all wood bow. Horn is heavier than wood and without the sinew backing you cannot strain the bow past what you could do with just wood.
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What percentage does bamboo stretch before failure?
Personally I would see it as a waste of time making a composite with a bamboo back/horn belly. You just won't be able to strain the horn enough.
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It doesn't matter if the bamboo stretches or not as long as the horn can take all the compression.
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the original ? was
When it comes to making horn bows, do you always need to have a sinew back? Would a bow that has a horn belly, but a wood core and back be considered a true horn bow? I've been thinking actually of doing a Turkish style bow with a horn belly, hickory core and rawhide backing
DA
my reply:
sinew is a must have component, rawhide will not do the trick ,a bow made that way will take a lot of set, shoot sluggish,
to be a true hornbow, composite,, has the sinew,, historically -- bamboo has been substituted for belly horn.
but ,, I only know from what I have read and my own personal experiences,,, if you do succeed at building a bow the way you are attempting, and it works for you,,,,,please let me know,, you can post it on the regular bows thread page,,,, James,,
I can assure you ,that bamboo cannot,and will not come anywhere close to the limits of sinew,, -(ever)
bamboo was not part of the backing equation in the original post
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I'm no expert..BUT...I've made many sheep horn bows, elk antler bows, bison horn bows,water buffalo horn bows and James and chuck are correct.
The weight of the bow with horn and without sinew will be not very good to shoot, you need the combination of sinew and hide glue...Do Not use wood glue....and did I mention do not use wood glue?...I can see where the bamboo combo might work but I do not have any experience with that.
Lololol
Good luck.
E
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good points Indianguy
I have built all sorts of bamboo/horn/wood combos ,, they are a type of composite, and they will all shoot,, but have their limits,, as do ,,horn wood and sinew composites,, but the latter can be pushed much farther,,, and as far as wood glue for sinewing horn composite,,, such a waste of the natural resources when building hornbows,, when using anything other than the natural fish/sinew glues, you will only get minimal to marginal results,, there can be little to no creep of the limbs going back to seasoned reflex... I consider it a short cut with short commings ---simply put ,a backing, nothing more,,...good for wood bows but not good for horn bows
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So if a person made a tri-lam recurve with say a maple core, water buffalo horn belly and single growth ring backing of Hickory or similar, what would happen?
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they would be wasting some good horn ;D
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Very skeptical. That would defy everything we know about how bows work.
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what besides sinew can handle the the opposing force in tension that horn can handle in compression? Something like 2500 lb/inch if I remember right. You can make bows like you said with other things for backing but you aren't going to reach the potential of the horn. Esp if we are talking about a profile with lots of bend in a short area like these Asiatic horn bows.
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Good tensile strong wood stands far more tensile force than that. WAY more in fact. Horn is also not stiff which lowers the back stress even more.
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Well pat put your theory to the test and make one, we will all sit back and watch your progress with interest. :o
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This new "HORN BOWS" board it dedicated to discussing and building composite horn bows and their traditional construction techniques. It is not about hickory backed bows or horn bellied bows in general. These other bows should be discussed in the "BOWS" section. Lets keep "HORN BOWS" just for them.
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There are bow made entirely from horn in India and as I mentioned the bow that Koppedrayer makes IS traditional.. Clearly the method already works. Grayson even mentions hemp backed bows in China.
Saying that the bows have to fit some rule-book is a bit silly. They are all composites which include horn.
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Bamboo fits this Topic. I stickied to the top James' thoughts as to what a Composite bow was and I read bamboo in the description.
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Watching this one with great interest. :)
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Good tensile strong wood stands far more tensile force than that. WAY more in fact. Horn is also not stiff which lowers the back stress even more.
Yes the woods are more resistant to stretch BUT they cannot stretch as FAR. 1% verus 8% is quite a discrepancy......
Bamboo back is a waste of good horn. Why oh why would you do this?
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There must be a reason if it was a common type of bow, no?
It doesn't matter if the back stretches or not IF the belly is actually "collapsing" as it bends and not providing as much transferred tension to the back.
I see no reason why the horn would not be able to work almost to its full advantage in this scenario. Plus without sinew the "paying for its mass" issue would be further diminished.
One advantage I see is less susceptibility to moisture and draw weight fluctuations without a sinew back.
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I know this is an old thread, but I had a question regarding this. Would a silk cable work, in place of the sinew? It has some elasticity, and as a cable, would be easier to obtain and apply (for some of us :) ).
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Cable backings are generally more complicated than sinew backings, IMO, though I've never done a cable baking.
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Sinew isn't really that difficult, good sinew good glue and patience
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Whether or not it could make sense depends, like always, on design and purpose. No it doesn’t make sense if you make it like you would make a sinew-backed bow and just supplant the sinew with bamboo.
To evaluate when it makes sense, you need to look at the particular properties of the materials you are working with, and make them work together for the purpose you’re after. It’s a bit like the comment Saxton Pope gave on the Bari-tribe’s black palm longbow: for the conditions the Bari are used to shooting in (extreme moisture, dense forests requiring long arrows, shooting vertically most of the time), it’s a superior design, but Saxton Pope thought these bows were crap, because he looked at it from his own perspective only.
If a particular bow design has survived hundreds of years, there’s probably a reason it’s still there. If we think it's crap, its probably because we haven’t understood it yet.
If you have a not-so-elastic backing like bamboo, but which is very strong (high Modulus of Elasticity), you can add a horn belly, which is very elastic (in compression) but has a low MOE. The result is a bow with the neutral plane very close to the back of the bow. The back is not strained (stretched) a lot but due to its high MOE it still takes a lot of stress. In reverse, the belly is strained a lot (compressed), but due to its low MOE it isn’t stressed to its max. The stress-strain combo of both materials, however, can be combined so that both are perfectly in balance.
Basically, this is what PatM's been saying from the beginning of this thread.
Sure, the horn isn’t used to its full potential, but neither is sinew on a bow without a horn belly. I did some calculations on strain levels on turkish and korean bows. There, both back and belly are strained about 5%, which is about optimal for both materials (in terms of energy storage). In sinew-backed native american bows, the sinew is hardly ever strained more than 2.5%, so the sinew is never really put to the test. Are these bow therefore slow? No, as mass placement is more important than mass itself.
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I can't wait to see a bamboo backed 'hornbow'. As they don't appear to be too common may I suggest there is a reason for it ;)
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Maybe one of the reasons for them being so rare is that so many people are sceptical about them, being stuck in the mindset that horn needs sinew >:D
No, seriously, there are asiatic recurves bows made from just bamboo (and with stunning profiles), so why wouldn't bamboo + horn belly work?
Since bamboo is quite a lot stronger in tension than in compression (moving the neutral plane towards the back), it could benefit from having a belly that can withstand compression much better, for example by adding a horn belly. Also note that Koppedrayer's horn-bamboo bows are intended for a max 30" draw, whereas his horn-bamboo-sinew can stand 35" draws.
Supposing the design is the same apart from the added sinew, this acknowledges that the horn isn't used to its full potential.
And then there are still the horn-only gemsbok bows :P
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Gemsbok only horn bows shoot....well poorly at best.
Horn is 1.3s.g. so adding it to a bow will simply make it slower if the horn isn't used to it's full potential.
Just because bamboo makes great 'self'bows that is not a reason to add horn into the mix. Bamboo just isn't suited to a bow with a horn belly.
Horn and sinew can both stretch/compress about the same amount and have similar resistances to bending - this is what you look for in a well designed laminated bow. Try mismatching bow woods with different properties and see what happens - broken bows or lots of set depending on which way you do it.
Make some and see! ;)
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sinew (sg 1.3) and osage (sg 0.75) have very different moduli of elasticity (low versus high stiffness), and yet if you combine them (without horn) it makes really great bows.
Osage cannot compress the same amount as sinew can stretch, but if you combine them in the right amounts, the forces of compression on the osage will balance the tension on the sinew (plus some tension on the osage's back).
The point is that strain doesn't need to be the same on back and belly (how far it bends, which depends on the position of the neutral plane), only the stress (what force is exerted on each surface).
I suggest you ask Jaap Koppedrayer if his horn-bamboo bows are rubbish or not :P
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James Parker built an Asiatic style bow with boo back and caramelized boo belly. That was one quick little bow and pulled, I believe at least 30".
...but again, this thread is specifically for true Asiatic Horn Bows, not wanna-bes.
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Japp's boo backed composites are longer, 55-60" and have 5" more draw length with sinew back
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Gemsbok only horn bows shoot....well poorly at best.
Horn is 1.3s.g. so adding it to a bow will simply make it slower if the horn isn't used to it's full potential.
Just because bamboo makes great 'self'bows that is not a reason to add horn into the mix. Bamboo just isn't suited to a bow with a horn belly.
Horn and sinew can both stretch/compress about the same amount and have similar resistances to bending - this is what you look for in a well designed laminated bow. Try mismatching bow woods with different properties and see what happens - broken bows or lots of set depending on which way you do it.
Make some and see! ;)
As noted Jaap makes them. You're not thinking this through very well.
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...but again, this thread is specifically for true Asiatic Horn Bows, not wanna-bes.
"all composite bows with bone, antler, ribs, baleen, sheep horn, sinew,bamboo , and/or any ethnographically correct /historical materials will be accepted"
First post in this thread. I can't see what's wrong with discussing the properties, pros and cons of a bamboo-horn composite here.
But in any sense, we're not progressing anymore. It's at risk of becoming an unproductive discussion between believers and non-believers...
Joachim
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Not saying it can't be done but even with japp's bows they are longer than the norm with a few exceptions, and when he adds sinew hw gets 5" more draw length so there are limits to the boo backed composite
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i see this has come full circle again... my opinion, ((just saying))
their is no other natural material that can come close to the well established effects or perimeters of sinew in a glue matrix when applied to a bows back, especially in a composite horn bow, lesser effects will be had, if replaced with other natural materials, , one material may have a greater stretch property compared to another , and each different in gain or loss,, in cast, early draw weight, limb return speed, and set within the most bending part of any bow limb, of any design..
of course one does not need sinew on a per say horn belly bow, but it is nice if you have the sinew to back with, also, are you building freeform horn composite bows ,,or are you following true historical specimens ,and measurement,,
composite bows can be of any design, I was not trying to categorize any one bow as being legit or not.. this forum was and is intended to help ,teach,learn and show what each of us are capable of..
historically there is all sorts of composite bows, with sinew , without, with horn ,without, and soforth.
im going to go out on a limb here,, not intended for any one individual.
do your homework, build some bows , have failures and successes, learn from them both, then report back with the end results,
we are all here to learn and share , including myself.
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PatM - what bit am I not thinking about? Clearly somebody makes them - what i'm saying is that it's not an optimal mix of materials. I could sinew back a bow of pasta and make it shoot arrows...doesn't mean it's optimal...now does it?! I could also use balsawood to back ipe and make it shoot arrows but it may limit my drawlength a little....comprende?!
JoacchimM - Yes indeed you can make sinew backed osage bows but if you made a good self osage bow and added sinew what would happen? Do you see what I'm saying? Did I say that Jaap's bows are rubbish?
IF bamboo worked really well as a horn bellied bows back then there would be reams of them about...because they simply don't get made may suggest something about the design...maybe?
A true composites draw length limits are only reached because of the almost perfect blend of materials and their properties. Sure it's possible to make a bow with some/half/most of the same materials BUT is it going to be as effective....no.
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PatM - what bit am I not thinking about? Clearly somebody makes them - what i'm saying is that it's not an optimal mix of materials. I could sinew back a bow of pasta and make it shoot arrows...doesn't mean it's optimal...now does it?! I could also use balsawood to back ipe and make it shoot arrows but it may limit my drawlength a little....comprende?!
JoacchimM - Yes indeed you can make sinew backed osage bows but if you made a good self osage bow and added sinew what would happen? Do you see what I'm saying? Did I say that Jaap's bows are rubbish?
IF bamboo worked really well as a horn bellied bows back then there would be reams of them about...because they simply don't get made may suggest something about the design...maybe?
A true composites draw length limits are only reached because of the almost perfect blend of materials and their properties. Sure it's possible to make a bow with some/half/most of the same materials BUT is it going to be as effective....no.
But those examples are silly when comparing a horn bow backed with bamboo. Horn and bamboo are likely as favourable a mix as any highly regarded mix like bamboo and Ipe. or Osage and hickory.
Your sinew backed Osage in the above example would be capable of more draw length, just as adding sinew adds draw length to Jaap's bows.
PS Nobody is saying the mix would be as effective as the perfect blend at the optimum draw length but most composites don't actually reach that or the core breaks down if they do as noted elsewhere on here.
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PatM - what bit am I not thinking about? Clearly somebody makes them - what i'm saying is that it's not an optimal mix of materials. I could sinew back a bow of pasta and make it shoot arrows...doesn't mean it's optimal...now does it?! I could also use balsawood to back ipe and make it shoot arrows but it may limit my drawlength a little....comprende?!
JoacchimM - Yes indeed you can make sinew backed osage bows but if you made a good self osage bow and added sinew what would happen? Do you see what I'm saying? Did I say that Jaap's bows are rubbish?
IF bamboo worked really well as a horn bellied bows back then there would be reams of them about...because they simply don't get made may suggest something about the design...maybe?
A true composites draw length limits are only reached because of the almost perfect blend of materials and their properties. Sure it's possible to make a bow with some/half/most of the same materials BUT is it going to be as effective....no.
Hi Mikekeswick,
I follow your reasoning. Consider there may have been reasons not to add sinew on those bow, maybe because of relative humidity being very high, or some other reasons. My point is a horn bow without sinew isn't by definition useless (as suggested earlier in this discussion), and it can likely be optimized to be even a rather good bow, by taking design constraints of both bamboo and horn into account.
A lot of time during the history of mankind, making particular bows was a matter of make do with the materials at hand and the constraints posed by these materials in their environment to adapt the design to fit your needs. The Vikings were perfectly well acquainted with asiatic horn bows, having done conquests and raids through the Mediterranean along North Africa up to Turkey and Syria in their time, as well as through the eastern European steppes. But in Scandinavia, they used wood longbows, because in the cold and wet climate of Norway asiatic composites were utterly useless.
So one answer to the very first question (do you need to have a sinew back on a horn bow) could be:
no, but if you live in a dry enough climate, adding sinew makes more sense if you want the best bow.
I don't think we disagree. In the current situation, where you have hotboxes to dry your bows, where climate hardly influence which bows you shoot and where you can get any materials from anywhere in the world, it doesn't make sense to make a bow that is inferior in performance, unless performance is not your main goal.
But following this reasoning, we should all chuck away our wood bows and move over to compounds with glass fiber, carbon and kevlar.
Why would anyone want to build a sheephorn bow? Not because it's the best possible bow in the world. but because it's part of someone's cultural heritage. You don't find them around the corner either. Would they shoot better with a wood core? Yes! but you do need access to good bow wood. which the original builders of sheep horn bows didn't have.
It's the constraints that drive us, not the limitless possibilities.
Comprende?
I'm sure you do :) ;)
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I came to this thread, the whole forum acthally, because my intention was to build a bamboo/osage/horn bow. Thank goodness I checked here first. Now I know not to even bother.
:)
Just kiddin... I'm still doin it.