Bamboo Core and Nodes?
I am a novice at Asian style composite bowmaking. I chose to use bamboo for a core for my first bow. I used a piece of boo (Moso I think) that had a few nodes in its 36" length. I flattened this piece into a board of approximately 1/4" thickness.
Recently I read a thread that made mentoin that Korean bowyers utilize bamboo with internodal lengths adequate to put a single node at the nonworking handle and no nodes in the working limbs.
Have I made a monumental blunder? I have a node in the working section of each limb.
Recently I read a thread that made mentoin that Korean bowyers utilize bamboo with internodal lengths adequate to put a single node at the nonworking handle and no nodes in the working limbs.
Have I made a monumental blunder? I have a node in the working section of each limb.
No, not a blunder. But you would want the same number of nodes above and below the point at which the arrow will pass and with similar spacing between each.
That is just to say that the position of the nodes should not unbalance the whole movement of the limbs.
That is just to say that the position of the nodes should not unbalance the whole movement of the limbs.
Thats a relief.
I did orient the nodes in the core so they were symmetrical with respect to position in the limbs. And I cut it so that I minimized the number of nodes. I think there is only one node in each limb and one in the handle area, but I can't really tell at the moment as I roughed up the edges before I sinewed last night. The piece came from the good end of an 8' strip, as I recall it had internodal lengths of around 9". Not my best stuff, but decent.
I did orient the nodes in the core so they were symmetrical with respect to position in the limbs. And I cut it so that I minimized the number of nodes. I think there is only one node in each limb and one in the handle area, but I can't really tell at the moment as I roughed up the edges before I sinewed last night. The piece came from the good end of an 8' strip, as I recall it had internodal lengths of around 9". Not my best stuff, but decent.
Preparing for my first horn bow. I have work down my boo core to approx. 1/8". I did this based on my experience with boo back osage bow. I now think I have made mistake and make it WAY TOO THIN.
Opinions???
Opinions???
I think it depends on your design. I only worked mine down to 1/4", it is still pretty stiff at that thickness. I was attempting to compensate for a few things. First, my horn strips are a little thinner than what is commonly used, and most likely a bit weaker (being spliced in the odd manner I used). Second, I had the notion that my design was a little longer than some, and for that reason the bend would be less severe and therefore a stiffer core would also be in order there. Third, I'm not looking to produce massive reflex so I didn't think I needed that flexible of a core.
Mostly I'm just doing this by "feel" which sounds like what you are doing also. It is certainly a test of our instincts as bowyers! Might have been wiser to go with standard design parameters, but I was never accused of being the sharpest knife in the drawer.
What I am quite interested in finding out, is what angle my siyahs wind up at brace. If the bow makes it that far, of course.
Good luck and hopefully someone who actually knows something about these matters will chime in.
Mostly I'm just doing this by "feel" which sounds like what you are doing also. It is certainly a test of our instincts as bowyers! Might have been wiser to go with standard design parameters, but I was never accused of being the sharpest knife in the drawer.
What I am quite interested in finding out, is what angle my siyahs wind up at brace. If the bow makes it that far, of course.
Good luck and hopefully someone who actually knows something about these matters will chime in.
'Too thin' can be an advantage: less limb mass and a faster bow. The disadrantage is that the core can give the limbs more stability.
If you still have the option if your limbs are going to be long, keep them broad. Even with short limbed bows, having a broad limb is not necessarily a bad thing. The very narrow limbs of modern Korean bows are a recent fashion. Back in the 1960s and before that, limbs were much broader.
If you still have the option if your limbs are going to be long, keep them broad. Even with short limbed bows, having a broad limb is not necessarily a bad thing. The very narrow limbs of modern Korean bows are a recent fashion. Back in the 1960s and before that, limbs were much broader.