Mujitsu and Tairaku's Shakuhachi BBQ

Tairaku wrote:

That was a misspelling. He meant "Comically widening the hole wall". He does that by working and drilling when he's tanked up on about 5 Bombay Sapphire martinis!

Dude, easy with the trade secrets!!

KL

dreamofnobody wrote:

What does it means “conically widening the hole”? May be some simple painting will be helpful.
What does it means ‘improve the tone’? Did you mean it sharpens or flattens kan note or some another thing?

Dream,

By conically widening the hole I mean "undercutting" like this:



Undercutting will sharpen the pitch of both otsu and kan. By improving the tone I mean it will give the tone more presence, power, volume and ease of playing.

Hope this helps.

Ken

dreamofnobody wrote:

How much 'bore' diameter of a hole differs from 'top' diameter? It is 1mm or more?

I would say it would be at least 1mm or more. I let my ears dictate how severe the undercut needs to be. If you prefer an inward tone, a very slight angle may be sufficient. If you like more outward presence, larger holes and more undercut will help. I prefer to undercut as much as I possibly can on wide bore shakuhachi. Thicker walls often benefit from a more severe undercut. For example, the first hole usually has the thickest chimney. (space between top of hole and bore) So, sometimes it makes sense to undercut this hole more. Also, the particular piece of bamboo may suggest the degree of angle to use. What does it want to sound like? If particular notes are weak, they can sometimes benefit form more undercutting.

Undercutting also raises the pitch so you have to be aware of that as you are working. It also changes the volume (space) in the bore. On thinner bore shakuhachi, that can be an issue.

I think it's really a matter of your preference. I tend to undercut more now than I did on earlier flutes because I enjoy the sound. But, that is just my preference.

One way to figure out what you like is to use different degrees of undercutting on different flutes. See what you prefer. You may find that your preference changes according to the peculiarities of each flute.

I hope this isn't too confusing!

Ken

It’s not confusing a bit. Thank’s Ken your explanations are great.
This thing needs self experience to figure it out like everything in shakuhachi. But it will be more sensible motion with this guides that I have now.

Ken-- I'm the guy who just emailed you about a partially finished shakuhachi that I got from you a couple of years ago that needs work, and you may have just given me the solution!

The low octave on my shakuhachi is great, but all of the notes in the second octave are VERY flat. The top two notes are nearly impossible to play (I'm pretty sure this is not just my lack of technique, since I can easily play a full two octaves on my homemade PVC shakuhachi).

What do you use to undercut the holes?  I actually do this on my wooden pennywhistles using a modified pocket knife blade.  The blade has been ground down to a mere sliver of a thing tapering to a very sharp point.  The cross section has a bit of a belly to it: I can rest that belly on the edge of the hole and then roll the sharp edge down to barely kiss the wood, allowing me to take off very thin controlled slices.

I'd assume I should start undercutting with the bottom hole, work on that one until the second octave speaks the way I want it to, then move North?  Do you undercut the same amounts on all parts of the circumference of the hole? I know recorder makers sometimes undercut different parts of the hole, but I forget the reasons.