Ready to brace Korean Hornbow
Here are some pics from my KHB.
I will try to brace it in November.
I will try to brace it in November.
WOW
Uli, sieht toll aus, dein Koreaner. Wie dick sind die Wurfarme? Sofern ?ber 1.2 cm musst du mit dem Body-building training beginnen...
Orginaldicke Holz/Bambus ca. 3-4 mm
Horn ca. 4-5mm
Sehnen max 2,5 mm
Meine beiden Koreaner haben eine max. Dicke von 1,1 cm und ziehen ca 65 Pund.
Gruss
Reto
Orginaldicke Holz/Bambus ca. 3-4 mm
Horn ca. 4-5mm
Sehnen max 2,5 mm
Meine beiden Koreaner haben eine max. Dicke von 1,1 cm und ziehen ca 65 Pund.
Gruss
Reto
Tom Duvernay or Jack Farrell can give more detail; but these bows are always braced using tepeliks the first time around.
How long should the sinew dry ??
I put on the fisrt 2 layers in may.
the second 2-3 layers in end of may.
and the last 2 layers middle of july.
I put on the fisrt 2 layers in may.
the second 2-3 layers in end of may.
and the last 2 layers middle of july.
Danke Reto, ich hab zwar schon genug Kraft, aber leider noch keinen Koreaner gebaut, das war "wolfhorn123"
;-) Uli
;-) Uli
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Here are wolfhorn's pictures. He used the cross section from Thomas Duvernay to help with dimentions.
![[external image]](http://img.photobucket.com/albums/v623/Samuraiwarrior/wolfhorn%20bow/7.jpg){kind=link}
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![[external image]](http://img.photobucket.com/albums/v623/Samuraiwarrior/wolfhorn%20bow/bowcutaway2.jpg){kind=link}
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![[external image]](http://img.photobucket.com/albums/v623/Samuraiwarrior/wolfhorn%20bow/KHB016.jpg){kind=link}
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![[external image]](http://img.photobucket.com/albums/v623/Samuraiwarrior/wolfhorn%20bow/KHB019.jpg){kind=link}
Here are wolfhorn's pictures. He used the cross section from Thomas Duvernay to help with dimentions.
Thanks a lot samuraiwarrior to add my pics.
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Here is one limb being bent on the dojigae.
Wolfhorn, when did you sinew it? If it is dry now, you can probably string it up, but the bow may gain some weight later with further drying. Have you made a string for it? [/img]
![[external image]](http://img.photobucket.com/albums/v623/Samuraiwarrior/wolfhorn%20bow/KHB001a.jpg){kind=link}
Here is one limb being bent on the dojigae.
Wolfhorn, when did you sinew it? If it is dry now, you can probably string it up, but the bow may gain some weight later with further drying. Have you made a string for it? [/img]
Hello,
No, i don?t made an string yet.
I must repair the bow.
Because on the other limb, the horn goes off from the bamboo, near the handle.
But nothing is broken, i will repair it and try it again.
I cut some sinew at the side from the limb and glue it again.
I hope it works.
No, i don?t made an string yet.
I must repair the bow.
Because on the other limb, the horn goes off from the bamboo, near the handle.
But nothing is broken, i will repair it and try it again.
I cut some sinew at the side from the limb and glue it again.
I hope it works.
Very nice Bow Wolfhorn 123 !!!, it?s great !
How long are the siayhs from the curve to the Tips ???
And how do you tiller a Korean Hornbow.
Good Luck !!!!!
How long are the siayhs from the curve to the Tips ???
And how do you tiller a Korean Hornbow.
Good Luck !!!!!
hi wolfhorn
What do you think about seperatione of the horn from the bamboo. İs the problem about taşin grooves or kind of glue. I lived same problem on one of my bow a year ago.I solve it with reglued and sinew wrapping. I thought that reglued would not be strong than the old one.
What do you think about seperatione of the horn from the bamboo. İs the problem about taşin grooves or kind of glue. I lived same problem on one of my bow a year ago.I solve it with reglued and sinew wrapping. I thought that reglued would not be strong than the old one.
Separation of horn from the limb near the grip is a very common problem in Korean hornbows. You are lucky to have caught the problem at this early stage, and not when it comes to shooting.
I should like to suggest that you immediately reinforce that place with sinew binding after repair, so that you can avoid a catastrophe later.
I should like to suggest that you immediately reinforce that place with sinew binding after repair, so that you can avoid a catastrophe later.
Hello everybody,
Here some pics from my bow with one defect (not broken) limb.
The horn goes off from the bamboo near the handle.
I cut off the sinew on the sides of the limb, sinew is still on the back.
On one side of the limb, also the sinew goes a little bit off.
I braced the limb that seems to be OK, again. I think this one works.
But i cannot say this, because the bow was not fully braced, only over the tepliks.
Maybe some more problems come, hopefully not.
I glue the defect area again, put sinew on it lengthwise, and then wrap around with sinew.
Then i will try it again, i hope that it works, i will see.
Never give up this work :)
Here some pics from my bow with one defect (not broken) limb.
The horn goes off from the bamboo near the handle.
I cut off the sinew on the sides of the limb, sinew is still on the back.
On one side of the limb, also the sinew goes a little bit off.
I braced the limb that seems to be OK, again. I think this one works.
But i cannot say this, because the bow was not fully braced, only over the tepliks.
Maybe some more problems come, hopefully not.
I glue the defect area again, put sinew on it lengthwise, and then wrap around with sinew.
Then i will try it again, i hope that it works, i will see.
Never give up this work :)
It would be nice to learn what happened with this bow or any subsequent projects.
indeed :)
In my case it is was shear stress failure.
The young mod is different in wood and horn, and the displacement provokes a large shear tension in the interphase. The glue imposes the limit, and probably the glue layer thickness in this case and/or the surfaces (many good posts on this around in ATARN). There was an ash HB that failed which i split opened to see what happened, and the split was at the glue layer level, not at the surfaces.
Had 2 cases like this on 2009 (birdseye maple), and in my case, i tillered the horn, sanded the interphace as i could with a dremel rotary tool, injected warm glue with a syringe, both in the interphase and in spots thru the existing glue residue, and gave a lot of clamping pressure to not make the layer much thicker. After that it didnt fail there, but slightly up and in a minor way...same process. Not clean, but I recovered it.
However, id ask whether this bow was braced slowly and warm...?
PS, A year ago I posted something about maths behind this. I already saw a paper on finite elements (it is somewhere in internet) applied to modern compound bows, and it is possible to do the same with hornbows, though involving a lot more work because modeling the materials, in specific the interphase, gives some problem in Ansys. If anyone has information about specific properties, we could give it a try.
If you cannot sleep (regardless Daniel), this will put you down in minutes
http://www.bio.vu.nl/thb/users/kooi/thesis.pdf
For others :D :
http://imechanica.org/node/8664
The young mod is different in wood and horn, and the displacement provokes a large shear tension in the interphase. The glue imposes the limit, and probably the glue layer thickness in this case and/or the surfaces (many good posts on this around in ATARN). There was an ash HB that failed which i split opened to see what happened, and the split was at the glue layer level, not at the surfaces.
Had 2 cases like this on 2009 (birdseye maple), and in my case, i tillered the horn, sanded the interphace as i could with a dremel rotary tool, injected warm glue with a syringe, both in the interphase and in spots thru the existing glue residue, and gave a lot of clamping pressure to not make the layer much thicker. After that it didnt fail there, but slightly up and in a minor way...same process. Not clean, but I recovered it.
However, id ask whether this bow was braced slowly and warm...?
PS, A year ago I posted something about maths behind this. I already saw a paper on finite elements (it is somewhere in internet) applied to modern compound bows, and it is possible to do the same with hornbows, though involving a lot more work because modeling the materials, in specific the interphase, gives some problem in Ansys. If anyone has information about specific properties, we could give it a try.
If you cannot sleep (regardless Daniel), this will put you down in minutes
http://www.bio.vu.nl/thb/users/kooi/thesis.pdf
For others :D :
http://imechanica.org/node/8664
I had it on my bed table for a while and I have to say I totally disagree with your comment.Outlaw wrote:
If you cannot sleep, this will put you down in minutes
http://www.bio.vu.nl/thb/users/kooi/thesis.pdf
Daniel
Daniel, maybe you need strongly coupled coulomb systems books for closing your eyes...but for many (me included), several pages of equations is enough for helping taking a nap...
If you didnt get it, ur issue not mine, but courtesy with everyone is the dress-code here, capicci? Moderate urself please, no pun intended.
If you didnt get it, ur issue not mine, but courtesy with everyone is the dress-code here, capicci? Moderate urself please, no pun intended.
Apparently I misunderstood your comment. I perceived it as deprecative of an in my opinion highly interesting thesis. The equations often left me amazed and clueless (the higher the chapter number the worse!), but not sleepy.
About the modeling and simulation... what type of model do you have in mind? And what do you want to simulate?
Daniel
About the modeling and simulation... what type of model do you have in mind? And what do you want to simulate?
Daniel