Mujitsu and Tairaku's Shakuhachi BBQ

Butterfly bits are made short and long. There are couplers and extention rods to made them as long as needed.
Also, I find a rounded course wood rasp very useful. This a special rasp made for shakuhachi bore work and available from mejiro. It ships with a threaded rod. The rod is ok for hand work, but not suitable for use in the drill (it is brass and will twist apart). To use the rasp as a drill bit I had a stainless bolt (threaded for the rasp) welded to a long steel rod. This worked well and I use only the steel rod instead of the brass rods that ship w/ the rasp. These wood rasps come in two lengths, one course cut, one fine cut. They are not cheap, but I highly recommend them for any bore work.

I might mention that rasping out the nodes is far smoother then drilling; there is no "shock" as the rasp breaks through the node as there is w/ a drill bit.

Last edited by gmiller (2007-03-31 07:06:42)

Kabato wrote:

I've been figuring out everything before starting on my first really long flute (it's about a 2.7) and I realized I have no good way to remove the inner nodes. The top and root holes are no problem, but I doubt there's a drill bit long enough to get all the nodes. What's the best way to get them out?

I've never used a drill for this.  I put the root end of my bamboo on the floor and tamp through the membranes with very heavy metre-long pieces of steel rod.  (I picked these up for nothing from an industrial moving company -- one is about 15 mm in diameter and one is about 10 mm -- they're normally used as rollers to put under bank safes and other heavy things to be moved across a floor).  This took some faith the first time, but you can use a lot of force.  This is how I was taught and I've never damaged a piece and you don't really risk damaging the side walls at all either (something I'd worry about with a drill more).

After bashing out the nodes roughly, a long-handled ball-headed rasp removes the rest of the membrane meat.  Before I had a rasp long enough, I used two alternatives:  1) double-sided tape to wrap a few inches of very coarse sandpaper to the end of the metal rods or thin wooden dowels, and 2) a coarse needle rasp with the tapered metal end tightly inserted into some thin plastic PVC pumbing line as a long handle.  Neither of those solutions work as neatly or as quickly as rasp with a large ball (or teardrop) head welded to a metal rod.

-Darren.

kyoreiflutes wrote:

Darren, are you ever afraid of putting too much stress on your bamboo by using the bashing method? I've never heard of that method, but I'd be afraid of all the stresses.

Bashing (maybe "piercing" is a less fear-inspiring word), followed by rasping is nothing to worry about.  Driving the small surface area of of the rod against the large area of the membrane pretty much ensures the membrane will give and nothing else.  The inside and outside walls of the flute are naturally thicker at nodes (reinforced, almost like gussets), so everything else in the vicinity is plenty strong.

kyoreiflutes wrote:

Drilling gives enough stress, in my opinion.

Are you using a lot of force when drilling?  A sharp bit should do the work, no?  My only fear when drilling is that I'll accidentally score the bore walls.

-Darren.

hi,i was using all of the mentioned methods but at the end i stopped at the fire method. blowtorch + 1meter x12mm cromed copper tube from a shower. heats faster than iron, can be bend easy to access curves. can be heated not only at the top but anywhere i need. also i use it to smooth the bore when i like. no need to sand after that.leaves very nice smell of fire when playing. the top is smashed to a form of conus. in fact i burn the finger holes also and underburn them instead of undercutting. 12mm cause i dont want to open the choke point more for the beginning. hope this serves sb.

Hi Costa

I also burn my fingerholes. My only problem with this has been some very thick pieces that take a long time to burn through. These have developed short cracks from the holes, but don't seem to weaken the flute and have not yet developed into bad cracks.

Anyone else done this?

Cheers

John

costademaria wrote:

hi,i was using all of the mentioned methods but at the end i stopped at the fire method. blowtorch + 1meter x12mm cromed copper tube from a shower. heats faster than iron, can be bend easy to access curves. can be heated not only at the top but anywhere i need. also i use it to smooth the bore when i like. no need to sand after that.leaves very nice smell of fire when playing. the top is smashed to a form of conus. in fact i burn the finger holes also and underburn them instead of undercutting. 12mm cause i dont want to open the choke point more for the beginning. hope this serves sb.