Main Discussion Area > HowTo's and Build-a-longs
Yumi Build Along
bhenders:
I think I had a long piece of glued bamboo from Franks, OR I just sanded down a piece of bamboo that I already had so that it was flat on both sides. My memory lately is like a steep sieve!!! I had been thinking of doing what you were going to do but was going to use vertical bamboo flooring. I bought 10 pieces of that last year, cut them in half and cut them into 1 1/4 inch widths. I made a 'horse' bow style bow from a couple of pieces and it works!. BUT - I was digging around my garage and found two lamanated bamboo planks that are 8 ft long (from Franks) that I forgot about so I'm going to use one of them for the center.
I think that the oak will get crushed in the middle if you try to use it. How thick was the 'center' strip going to be?
I was going to measure my bow for you but from memory (at work now) my bow is less than 1 inch wide and about 1/2 thick. I'll measure it tonight when I get home.
Hillbilly Deluxe:
I was going to make the core go from 3/8 in the handle down to 1/4 at the top knock and just slightly thicker at the bottom knock. Someone on another yumi post said that I would probably want some form of wood in the core to give it more "spring".
Could you explain "crushed" better. Sorry I'm new to the bowyer world and don't understand all the lingo yet. My thoughts were that if I used Oak it would be something like a "board bow" with a boo back and belly making it that much better, no?
Hillbilly Deluxe:
By the way I really appreciate your input.
bhenders:
Well, the first bow I made was an oak board and I put bamboo on both sides. Very bad tiller and eventually the oak got crunched and finally broke... I believe the actual term is crystalised??? It just can't take the bending and the wood cells and fibers get crushed and finally fail.
I keep meaning to measure my yumi style for you but keep getting sidetracked by yard work. Like I said before it's was a "yumi style" becuase everything was wrong about it... except it looks ok when shooting. I still like to shoot it but I'm going to try to do a more authentic one this spring or summer. Check out the build along on paleoplanet.
From reading about yumi making, everything is shaped before the glue up and the bow is glued and then it's done. They have been doing it so long that they don't 'tiller' the bows at all. The only wood pieces are the two wood strips on the sides of the bamboo core which MAY leave them some room to adjust things.
I'm thinking 3/8 for the core is way too thick. Yumi bows are 'backwards' when unstrung and with a core that thick, it's going to take an elephant to string it. Check out http://www.yumi-bows.com/yumi.html for how a bow should look when it's being glued and wedged (is that a verb?). That's Koppendrayer's web site. I would love to get to his place sometime to see how he does things.
btw: I'm far from a expert on these things. There are a couple of other threads about making a yumi. I seem to recall one on here a while ago that was very good. Do a search on it... found it http://www.primitivearcher.com/smf/index.php/topic,11083.0.html very good write up.
also look at http://www.kougei.or.jp/english/crafts/0707/f0707.html
here's a build along on paleoplanet
http://paleoplanet69529.yuku.com/topic/22774/t/Yumi.html?page=1
bhenders:
I should add that yumi are shot with a thumb draw and the arrow on the 'outside' of the bow. Very different from the 'English' style. The Japanese use a glove with a stiff thumb (that costs an arm and a leg) so I just use the thumb from a heavy duty glove ( attach a leather strap and wrap that around your wrist to keep it on). You could also use a thumb ring like they use on horse bows. I've made a couple of thumb rings but shooting with them seems to introduce Quantum effects in my shooting (random scatter).
I've found that I never get string slap when shooting this way (and I always do when using an English release). It is also more like using a mechanical release because I think you get a cleaner release of the string.
One more .... the draw on a yumi is REALLY long. Typically past your ear. One should be careful not to get inside the draw.. LOL Might be problematic if anyone's ears stick out too far...
Once you get the next one done, go to youtube and watch someone shoot a yumi. For them, it's all about the procedure of getting ready to shoot. The 'zen' of doing. It's not even supposed to matter if you hit the target. I'm too western, I WANT to hit the target - but good form is nice because it makes shooting easier and it's kinda cool when the arrow hits the target and the bow flips around all by itself.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version