Why Orient Bamboo Core Upside Down?
Watched Duvernay's DVD and was struck by the fact that the bowyer puts the outside of the bamboo strip towards the belly. Since it has more power fibers than the inner, why wouldn't you use it like you do as a backing? I wouldn't think it would have any better compressoin properties than the inner side, but it has better tension properties with the fibers there. I understand that during the building process you want the bow to curl up, does this facilitate that?
In a composite bow, the function of the "power fibres" is taken over by the sinew layer. When the bamboo core is prepared, it is scraped flat on both sides so the outer skin is removed.
Bamboo bows without horn bellies were made in China and the skin side was used as the belly if the back was covered with sinew.
Bamboo bows without horn bellies were made in China and the skin side was used as the belly if the back was covered with sinew.
I understand about the sinew doing a lot of the hardest tension work, but still the core probably does some amount of tension/compression work. So I'd think it would be beneficial to orient the power fibers on the tension side.
I finished watching the DVD last night. They don't leave much of the core in the Korean bow, I suppose it is a moot point when there is such a thin layer. Very much different situation than my own bow's design, which has a substantial core thickness and beinds over a much shorter area.
That was really a good video, I learned a lot in a short amount of time. The master's techniques are applicable to all kinds of bow construction.
I finished watching the DVD last night. They don't leave much of the core in the Korean bow, I suppose it is a moot point when there is such a thin layer. Very much different situation than my own bow's design, which has a substantial core thickness and beinds over a much shorter area.
That was really a good video, I learned a lot in a short amount of time. The master's techniques are applicable to all kinds of bow construction.
Keep in mind, that the power fibres not only work in tension but also are good for some compression work :D .
As Sinew it is pretty simple to add (and so add some strenght to the tension side of the bow), in my opinion it is more benefit to use the rest of the power fibres after flattening the belly side to help for the compression work.
As Sinew it is pretty simple to add (and so add some strenght to the tension side of the bow), in my opinion it is more benefit to use the rest of the power fibres after flattening the belly side to help for the compression work.
I suppose the material with more power fibers might have better compression strength, not sure why this would be the case but it is certainly possible. I would have though the horn would need less help than the sinew.
I still think it is more a matter of being able to make the Korean hornbow highly reflexed prior to addition of the sinew.
Are there any other styles of hornbow where bamboo was used as a core, and was there a particular orientation that was recommended?
I still think it is more a matter of being able to make the Korean hornbow highly reflexed prior to addition of the sinew.
Are there any other styles of hornbow where bamboo was used as a core, and was there a particular orientation that was recommended?
Chinese bowyers place the skin of the bamboo on the belly side for archery bows and on the back side for strength bows.
Isn't it true also that the Bhutanese bamboo self-bow uses the outer part of the bamboo on the belly?
Also do Bhutanese bowyers apply alot of heat-treatment to the bamboo?
Also do Bhutanese bowyers apply alot of heat-treatment to the bamboo?
There is an article on Bhutanese bows in Primitive Archer magazine. And I do seem to recall that they heat temper the belly bamboo to increase its compression strength. I can't remember for sure but I think they put bamboo on both back and belly. Seems like they also lash two limbs together at the handle.
In any case, if I was making an all-bamboo bow I would certainly put the outer surface towards both faces (back and belly). As the core in a composite bow, though, you must make the decision of which orientation to use, and that is where I was initially surprised by the Korean bowyers choice. I really think it boils down to it being the way the strip wants to bend, which allows the bowyer to assemble the bow with considerable reflex without needing to use devices for holding the profile.
In any case, if I was making an all-bamboo bow I would certainly put the outer surface towards both faces (back and belly). As the core in a composite bow, though, you must make the decision of which orientation to use, and that is where I was initially surprised by the Korean bowyers choice. I really think it boils down to it being the way the strip wants to bend, which allows the bowyer to assemble the bow with considerable reflex without needing to use devices for holding the profile.
Hi all..i wanna ask you something...you think that its a good ideea to glue a handle between the 2 strips of bamboo. iff i wanna make an asiatic bow using bamboo on the back and on the belly side????or it is better to leave the bow like that, withoute gluing any handle between the 2 strips of bamboo???and do you think it will hold on a bow like this..made only from bamboo>>???whatt dimension will be the best to be an the safe side???i would realy like to make an asiatic bow from bamboo....becose i dont have acces to horn...so this s cheaper way to do it for me for the moment...it will be like a learning process...its no use to buy expensive materials like horn, and to do a bad job and to ruin the materials...so i would like to give it a try using only bamboo and maybe sinew( sinew its something that i have for the moment)
My bamboo/hickory core is 38"/965mm. The skin side faces outward and the handle section is glued to the hickory backing. The siyahs are mulberry, upper 12", lower 9". These are not shaped yet. The bamboo outer skin has been removed, much the same as making bamboo arrows. If I was using all bamboo, I would glue the skin face of the back to the inside face of the belly.