All Bamboo bow node spacing

[jhmonaghan]

If earlier posts cover this, my apologies...  I looked, and could not find...

Trying an "all bamboo bow" from scratch... bamboo both belly and backing, "store bought" FastFlex core....

I'm hacking at some 8' bamboo staves - 2" wide...  Comes the time when I'll have to cut to an approximate length... Two 8' pieces scraped to "flat" by a T square on the belly (concave) side....

Would readers advise 6' +/- bamboo limb cut as....

nodes close to each end?

nodes "away"  from each end ( one half average node spacing, say 5"- 6" )?

backing nodes and belly nodes align?

backing nodes and belly nodes not aligned - presumably offset by one half average node spacing....

[hermitking]

Jaap Kopedrayer may be the answer man on bamboo bow questions.  He makes a lot of japanese bamboo bows.  I would guess that the nods should match from belly to back just like it does on the plant.  They are designed to strengthen the trunk in wind.  Off setting them may create an unequality between back and belly and one may give way.  But I have know real experience so I am speaking only in theory.

[otis.drum]

some good questions there. there will be someone more qualified to answer this than me, but i like to put one node (on the back) just above the bows centre (3/4"). i use this when the bow is finished to sit between my index and middle finger as a reference point for my grip. i also do not cut the boo to a specific length first, but rather align the first node as mentioned above and then measure out from there. make the bow lenght to suit the nodes where ever they fall. i make my lower limbs 3/4" shorter also, and so in turn the nodes end up the same distance from the tips anyway (if they are evenly spaced nodes)

i am not qualified to answer the positioning of nodes on the bottom as i haven't done a boo belly bow (i believe it needs to be heat treated when on the belly), but half offset would make sense to me as the thickness of the bamboo wall above and below the node are different. you will notice this when you pre taper the boo. and so if the nodes where aligned you would create a strong point one side of the node and weak point the other. if you were to align the nodes you may wish to lay the boo in opposite directions to try to even this out. perhaps someone else has experienced this or knows better?

[KenH]

From all my reading on ATARN and other places, the primary requirements are
1.  No node bulge in the handle, space the handle evenly between two nodes
2.  Nodes as equally space from the handle on both limbs as you can
3.  If you belly and back try to match the nodes front to back.

[otis.drum]

interesting. i'd like to know why.

i have no problems with the nodes in the handle. it works well for me. how would this be a problem?

is ATARN refering to yumi or horse bows, or bows in general?

[Justin Snyder]

Since bamboo is grown not made it is difficult to match the nodes unless you cut both pieces from the same pole. I could care less where a node hits on the non bending areas. One end of the slat will have the nodes closer together. I use the part of the bamboo with the largest area between nodes. I lay out the bow so that the nodes are approximately the same place on the limb. If the nodes are quite some distance apart I might get one 6" from each end, one around midlimb, and one somewhere in the riser. The ones at midlimb will be approximately the same, one being a couple inches closer or farther from the center. The same will happen with the ones near limb tip. The point is to try to get balance. I have never made a bamboo belly bow, but I would recommend the same idea.

Maybe James Parker will read this and give you an answear. His bamboo dragons (bamboo back and belly) are some of the nicest bows you will find. Looking at the pictures of his I don't think he matches the nodes front to back.

[otis.drum]

justin, where can i see a pic of james parkers bows? thanks

[Justin Snyder]

Search bamboo dragon here on PA or go to http://www.huntworthyproductions.com/allnaturalbows.html  Yes the link is OK, he is a paying advertiser.

[otis.drum]

beautiful bows, excellent craftmanship, and nodes are not aligned. i'd like to hear his take on this topic. where he 

[Ryano]

Well my brother has made a quite a few of these boo backed/bellied bows and he off sets the nodes belly to back. He says they are much easier to tiller that way.

[Jesse]

nodes are stiff spots when tillering so if you match the nodes front to back you might just make the stiff spots stiffer. I would offset them. For me bows with only a few nodes are harder tillering around the nodes. The nodes are stiff but next to them its weak. I made one with ten nodes in the limbs and it was great.

[otis.drum]

ryan, i imagined they would be. great to get some clarification.

jesse, i agree, the bamboo isn't a consistant strengthed backing which makes it harder. one side of the node is stiffer than the other to i find.

[Gordon]

He says they are much easier to tiller that way.

How the heck do you tiller one of these things?

[otis.drum]

i think there's quite a bit of preperation to get everything bending nicely before they are glued up. like tapering the bamboo before glue-up. once it's glued up you really only have the sides to play with i suppose.

[medicinewheel]

He says they are much easier to tiller that way.

How the heck do you tiller one of these things?

I make them occassionally, my friend Chris (BOM in 2007  http://www.primitivearcher.com/smf/index.php/topic,3914.0.html  ) makes them all the time: The core gets tapered a little, both bamboo strips are worked down to an even side line. No tillering at all to save the integrity of the bamboo. Can be worked over the sides to balance.
Nodes must stagger from back to belly, if they are in the same spot this spot will be hopelessly stiff!