Mujitsu and Tairaku's Shakuhachi BBQ

Itamar,

Grinding the node 10cm from the end will likely help some. You may have an aspect ratio issue. (Bore width in relation to length) A forum search for "aspect ratio" will pull up a lot of information you can relate to the details of your flute.

Also, a good tip is to make as many flutes as you can and gradually learn what works by comparison.

Good luck!

Thanks for the advice

It was hard (for me) to find the specific info to my problem searching the forum for "aspect ratio" so i went over to www.navaching.com and read what i found about the aspect ratio.
it was 176cc and 555mm which meant it had a high aspect ratio of 31 (am i correct?) which make sense since the higher octave was coming out way easier then the lower. so i widened the lower node (my bamboo have only 1 node other then the mouth piece about 6cm from the bottom), and filed also the mouthpiece node flush and widened the blowing edge bore diameter. that made some improvement, Ive also widened the blowing edge arc and  filed some more the chin rest side to a sharper angle because i felt that its easyer to get the lower octave by blowing with that angle.
That made a pretty good improvement on timbre volume and accessibility of the lower note.
I had to shorten the flute to about 50cm  (instead of 55.5 to get it to play D (hope it was a good decision) so i guess that AR might be a lil high again   (but its still way better then it used to be at first)

now it still got a bit of tendency towards upper octave but its better then it was at first.

another question is why when lower octave plays D the upper octave plays D# ?
(though im yet to drill any holes in it so maybe there is a way to fix it by fingering and its just me clueless about the techniques of the Shakuhachi)?

P.S. the bamboo have some of its skin scratched off at some points (well it was stored at our garden storeroom for about 20 years), should i worry about it?

Last edited by Itamar Foguel (2009-09-18 21:57:28)

Hi Itmar, Congratulations! What a wonderful journey you have just embarked on.

Itamar Foguel wrote:

I just begun to build my first shakuhachi using a non root 4cm wide bamboo.

ill first state the problem: after opening the bore and cutting the blowing edge of  the flute, when i test blow it, its easy to get the 2nd octave note and it plays fairly clear (and sharp)  but the first (lower) octave really plays low and weak and with a lot of hissing sound (and kinda flat)
so its generally easier to get the second octave then the first.

I have no idea what is the problem and what i need to do...

It sounds like either your bore is too small for a decent AR or the shape of the bore is irregular (maybe the nodes nee more removal). As others have written, let the experience help on your next flute. Find another piece the same length but with a slight bigger bore and do everything exactly like you did on this one and see what the results are.

Enjoy the trip!

Itamar Foguel wrote:

I must say that it is still a mystery to me why the second octave plays half tone higher then the lower octave (D# instead of D). Im yet to find info regarding the subject.

Ro and ro kan octave tuning problems are sometimes the result of 1/2 the bore length having too much or too little volume (space) in relation to the other half. Here is further information on this. http://www.shakuhachiforum.com/viewtopic.php?id=1333
The link discusses a possible fix for a flat ro kan. For a sharp ro kan you can try the opposite.

Enter at your own risk! The "cart before the horse" rule still applies!   Good luck!

Your enthusiasm suggests you have the energy to engage in another flute, to which you will apply what you have learned from this one, plus, it will be another unique culm of bamboo and will present its' own characteristics. for me this is all interesting.

this one is about 50cm isn't it ? I'm trying to understand your tuning comments. You should look up a fingering chart to check yourself.

In many ways a flute is never completed so long as it is still in your possession, because as you learn something from current work, you then go back to earlier flutes and see if you can apply that understanding.

I spend a lot of time on the bore, blowing end shaping and bottom end shape before drilling and individually shaping each hole. I first look at the tone and volume balance of the registers, ease of transition between octaves, ease of blowing response etc, then begin with hole 1. the hole closest to the bottom end I balance this hole, Tsu, with Ro, all holes closed, in Otsu and kan. Then I move to hole 2, Re and balance that, and so on
I take changes slowly, often waiting a day or more before making that irreversible decision. But I do a lot of blowing throughout the day on that flute, making sure that what I am hearing, or not hearing, is consistently repeated, This is why I say the most important skill in making a Shakuhachi is your blow.

The great thing about making your own flute is your liberty to do anything you like to it, without being responsible to anyone for the consequences. Actually, it can be a very useful lesson to mess something up as you then see directly the effect of that change, And sometimes it can be reversed.
Also, it can be useful at this early stage to make only one change at a time, then spend time considering that before moving somewhere else, so you do get to hear what changed by that alteration.

Patience....persistence......

Kel.

I am curious as to how well bamboo will respond to decoration with something like a 'poker-work' hot tip.

Kel.

A general practice that my teacher and his father (Tsurugi Kyomudo) use in checking/setting the utaguchi depth and back angle relationship is to hold the shakuhachi between your thumb and forefinger at the 3 o'clock and 9 o'clock positions (if you imagine that the utaguchi is 12 o'clock) just under the utaguchi node, letting it hang loosely/freely.  Rest a pencil or dowel across the utaguchi and back.  The pencil should be parallel to the floor.  The round-off of the back outside part is a matter of personal choice and comfort.

Jeff Cairns wrote:

A general practice that my teacher and his father (Tsurugi Kyomudo) use in checking/setting the utaguchi depth and back angle relationship is to hold the shakuhachi between your thumb and forefinger at the 3 o'clock and 9 o'clock positions (if you imagine that the utaguchi is 12 o'clock) just under the utaguchi node, letting it hang loosely/freely.  Rest a pencil or dowel across the utaguchi and back.  The pencil should be parallel to the floor.  The round-off of the back outside part is a matter of personal choice and comfort.

I do this with my finger instead of a pencil, rotating the bamboo 180 degrees so that I feel the relationship from both sides. Different to using a pencil as it is the feel rather than the look.
But the intention is the same, that a line between the bottom of the curve and the back rest is perpendicular to the culm.

Kel.

I think that by starting a second flute you would develop your understanding and be able to compare that with the first.

If you alter the depth of the curve in the utaguchi it will influence the pitch of all hole as the distance will have shjortened. changes to other aspects of the blowing posture will mainly influence the blow, make it generally sharper or flatter depending on what you do. You can take material off the top so that your lips get closer to the edge, this is a most dynamic aspect of the flute, small alterations can make a large change, you may not wish to make the curve too shallow that you then have to deepen the curve, affecting the pitch of all notes as mentioned, particularly on a short flute.

Keep on blowing, does it sustain a soft note, a loud note ?

Kel.

Itamar Foguel wrote:

I think tonight i will try to measure, mark and drill (actually use the burn method since i dont have forstner drill bits) and see what happen.

I must say that it is still a mystery to me why the second octave plays half tone higher then the lower octave (D# instead of D). Im yet to find info regarding the subject.
Usually second octave tend to play flatter then first octave right? and you fix it by petrubation and a tapring bore?
(or maybe im just messing all the info up and mixing it right now...)


Ill go with it for now and drill away even if the flute will play wrong, but i would love it if someone could enlighten me on the subject.

This may be too technical, but you have a problem of bore profile, in which the bore is too either too narrow at the velocity node or too wide at the pressure nodes of the notes affected. The velocity node for the fundamental occurs at 1/2 the length from utaguchi to first open hole and the pressure nodes fall at the utaguchi and the first open hole. Since you are speaking about the second octave, in which the wavelength is 1/2 that of the fundamental, check the areas 1/4 and 3/4 the length from the utaguchi to the first open finger hole for being too narrow, and at 1/2 the length from the utaguchi to the hole for being too wide. It could be a combination of factors at those points.

You need to be precise about how many kan notes are sharp and how much and check those wider areas. For areas that might be too wide you can try John Neptune's technique of putting small pieces of folded wet newspaper at the critical points. If by adding mass at those points you lower the pitch then you need to add material to the bore at those points. If it makes things worse you will need to widen the bore there.

Good luck

Toby

BTW I did some research, and generally a contraction at the top of the bore will sharpen the second mode overall, so you can probably make things better by enlarging the top of the bore to the same diameter as the lower part,

Toby

I have to admit that now i found myself thinking on the conclusions from this flute and on the next 1, the bamboo i got atm is kinda straight with a node every 40 cm or so...i think how can i make a tapring bore...maybe fill some way to make it tapering... or just open up the node completely and make it cylindrical. or keep the node and do spacific add on from glue and such inside the bore for fine tuning....

i must also ask why are you all using water based varnishes instead of polyurethane normal varnish with thiner? that water based lacquer seems to peel and do some problems and have a rather long drying time, at list on my flute it seems rather more problematic then normal laquer, good points about this water based i noticed is the nicer smell and safety (touching and inhaling the varnish vapors and such)