Brett Breitwieser wants to play a Watazumi flute. Barring that he wants to play a flute like Watazumi's. He wants the Watazumi experience. Dave McCullen was already experimenting with novel long flutes. Dr. Gene Neill wanted to try his hand at making a big flute of PVC. Peter Riley had made attempts at chokan and was disappointed with the results.

So we pooled resources and began
The Breitwieser/McCullen/Neill/Riley/Watazumi Project
in order to find out more about designing and building long flutes (chokan) and long flutes with big bores.

Watazumi in action

Brett's 2.6 (785mm Length, 23.25mm Bore, made by Dave Mason ) with 10mm holes has a Equivalent Aspect Ratio (EAR) of 31.77. He wanted a BIG flute so he tried a 3.6 out of 2" PVC.

Dave's 3.2 (965mm Length, 20.1mm Bore, made by himself ) with 9.5mm holes has a Equivalent Aspect Ratio (EAR) of 43.65.

Gene wanted a chokan, but wanted the holes placed in the traditional locations as his hands are large enough to play a long flute. He picked 1" PVC (ID 26.2mm) and a length of 933mm.

Peter went with the 3.6 and a 1 1/4" bore.

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Equivalent Aspect Ratio (EAR)

(the 2.858 part comes from the sixth root of 545 which is the length of a 1.8 shak, which is the referent length.)

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A 3.6 (1090mm) made from:

1" PVC has a EAR of 37.0

1 1/4" PVC has a EAR of 28.03

1 1/2" PVC has a EAR of 24.02

2" PVC has a EAR of 18.67

All pipe used this these experiments was Schedule 40.

PVC pipe sizes

It's an under-appreciated fact that with standard shakuhachi the hole span (distance from center of thumb hole to center of first hole) is 36% of the total flute length. This figure stays constant over the entire range of shakuhachi and is independent from hole size, bore diameter or length. Only when we get to long flutes (chokan) does this figure change. On long flutes, special considerations have to be made to accommodate hand size--that is, the holes are configured differently in order to make the flutes playable. With chokan the span percentage drops below 36% and so we could turn things around and define chokan as any flute in which the span figure drops below 36%.

Brett cut his big (2") tube to length (3.6) and then got fascinated with its Ro:

The main thing I did was cut a piece of milk carton plastic to span the upper end and tape it in place... I trimmed it off so that the upper (flat edge) was big enough to stick my big fat (lower) lip into the flute but keep my chin out... this serves the practical purpose of giving me a way to exactly set my chin in the same place EVERY time... which gives me a remarkably consistent RO.

For now the end guard is just taped on with electrical tape, but my sister has dropped off her hot glue gun and I think I'll glue it in place as soon as I'm sure the end cap is exactly the way I want it. One of my family members has suggested that I use a slightly heavier piece of Teflon-coated plastic as the milk carton plastic seems a little thin and is prone to disintegration in the Arizona heat/UV... I should point out that the plastic end cap is slightly concave (dips into the tube slightly) so my chin position is right.

As far as trimming the ute... I originally had it narrower (about 38 mm) and was getting very good volume but was slightly out of tune... I widened it to your recommended 40mm+ by slowly sanding it down and deepened it slightly (almost to 9mm+) and now am almost exactly in tune but noticeably "windier" with less volume as far as the note goes but still adequate.... I think this is to be expected with the wide utaguchi.

I'm going up to Canyon de Chelly next week and will take the big tube with me (as well as my smaller bamboo flute)... maybe I will raise apparitions of the Ancient Ones that way. I hope to somehow buy or reproduce one of the Ancient Ones' flutes eventually. I have heard that they may be hard to play. But it seems like a natural fit for my "buffalo boy zensufi" style. Using new technologies to rediscover and recreate the past.... But hey, I want to build a solar pithouse too...

I've been pretty much a one note man all along, even when I still owned the Levenson flute (which I since have given to a more deserving student with a formal teacher) my style is not performance but to sit in solitude and RO RO RO the boat.... "merrily all the way, life is but a dream"....

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Dr. Gene Neill writes:

Eureka! My big, low, 933 mm, "F", PVC shakuhachi is finished and magnificent and in perfect pitch.

I simply marked off the hole locations according to the factors, adjusted them right or left for ergonomics and then drilled them quite small. And, by the way, I do not have any great difficulty reaching all the holes.

Then, with my Yamaha electronic tuner, I first verified that my RO was a solid 440 - 442 "F". Then TSU of course, with the small hole, came in flat, but I opened up the top of the hole and got my hoped-for perfect "G#" (this tuner does not show flats, only sharps). Moving on up to RE, the small hole was again - thankfully - flat, but when I opened it up at the top, it came out a perfect "A#". And, after opening up the tops of each of the rest of the holes, I got a perfect "C", "D#" and, with everything open, another "F".

Your calculations could not have been more flawless, and they also worked out perfectly for this huge flute.

And wait'll you hear it!

I can see now why Watazumi-Do got so turned on with his mammoth hochiku - this thing rattles the windows in my room, and does not require the exorbitant volume of breath which I anticipated!

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Peter Riley reports:

IT WORKED, Great God Allmighty, it worked!!! The 3.6 page plus The Utaguchi page did the trick. Until now the utaguchi proportions I have tried have been wrong. I have fooled around for years with these "big suckers" and have always been defeated. I used a 3/8" brad point drill on the first holes as it doesn't grab the PVC on the way through. Utaguchi from 1.25" pipe coupler and removable. The hard part, for me, was in the tuning as the development of a new embouchure and the low hooting sounds were unfamiliar. I am not at all sure that I have it now but what I do have is certainly worth messing with i.e. further experiments with utaguchi. There are two workable octaves which is better than ever before. So the point is, your splendid offering moved me into the "it's possible" mode for which I will remain grateful as will the great trees out back that have to listen to me hooting away.

Peter then wanted uniform, large holes:

In multiple tries at 3.6 I find the first hole consistently wildly sharp. Not surprising as it's a long way to the bottom from there. I have stubbornly opted for 11mm holes for their open sound. To flatten hole #1 pertubation (globs of kids modeling clay on thin wire) caused as many problems as it solved) The solution was to build a chimney, like a flute around the hole. Pieces cut from a coupler and glued onto the barrel with PVC cement solved the sharp problem wonderfully. If clever the hole can be stacked in an upward angle further helping with pitch. Bamboo in these large dimensions must thicken appreciably at the bottom as PVC does not. The other area that I found helpful was careful carving of the "chinage". If you are Dick Tracy it has one shape and Mortimer Fudd another.

And he went even further:

The chimney, ala Boehm and his flute, was first made from modeling clay. When this solved the sharp #1 hole I opted for pieces of PVC from a coupler of the right radius as a more permanent solution. If I modeled around it with epoxy paste it wouldn't even look bad. Rather than whittling both the coupler and the tube inside into the utaguchi I opted to extend the tube beyond the coupler so now only the tube has to be shaped. My bench top is covered with 2'" long pieces of tubing with curves whittled in them. It dawned on me that I should experiment with utaguchi made from modeling clay. This would come close to "adjustable" and later replace my first efforts with something more permanent.

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Here's the deal:

Pick a favorite flute and measure from the center of the thumb hole to the center of the first hole, call this the SPAN. Use a flute where your hands are not unnaturally stretched. (as a point of interest divide the SPAN length by the length of the flute--the result should be right at 36%).

1. Measure from the head of the flute to the center of the thumb hole. Divide this by the total length of the flute. It should be somewhere between 0.40 and 0.45. This is the X % of RED as seen in the graphic below.

2. Multiply the length of the chokan you're building by X % of RED, the result is the X % of Blue. Same percentage, different lengths. So the thumb hole in both flutes is the same percentage distance from their heads. Mark the Blue thumb hole.

3. Transfer the hole locations from Red to Blue, either by physically aligning flutes and marking off the holes or by measure/math. If measuring, mark the Blue at the dotted line seen below and measure from there.

The whole thing is about matching up the thumb holes of the two flutes, once that's done the rest follows.

To create a chokan by math alone, we need to create a Virtual Red Flute. Pick a comfortable SPAN. Say 250mm. Divide it by 0.36 and get the length of our virtual flute. (250 / 0.36 = 695) Use the table below for the hole locations. This table can be used for any Virtual length which is generated by any SPAN.

Hole	Hole Percentages for Virtual Red
Thumb	0.4417
4	0.5036
3	0.6173
2	0.7022
1	0.7986

The 'thumb' percentage (0.4417) is the X % of RED in the graphic above. Mark the rest of the holes, remembering to multiply times the Virtual Red Flute length (695mm).

Now that the chokan holes are located proceed with drilling. Start with hole #1. Drill small and enlarge until hole #1 starts to come into tune. The holes may not be the same size, increasing from #1 to Thumb. The trick here is not to drill #1 too big at the beginning. Always error on the small side, it's much easier to enlarge than to shrink.

Below is a table (built on a SPAN of 250mm) which lists the hole measurements for a 3.6 chokan--the math is all worked out, just measure from the head and mark the holes. Fiddle with the holes until the flute is in tune.

Some readers were put off by the discussion above about choosing a 'comfortable' hole span for Chokan flutes. 'Proper' hole placement (on any flute) creates a hole span of about 36% of the flute's length. Normal to large hands start to get strained with a span of around 240-250mm. What this means is that you can't play a flute of over about 700mm (2.3 shaku) with proper holes. A hole span of 250mm is about 10 inches, meaning that all the holes on any flute you will ever play fall within a 10 inch range--maybe a little more if you have very large hands.

Should you pick the greatest span you can UNCOMFORTABLY play? That way the holes will be closer to 'proper'. Or, since the holes aren't going to be proper, should you pick a more comfortable span? What this boils down to is whether you want to play the flute or not. Yes, you can design your flute to be closer to proper and torture yourself every moment you play or you can accept the fact that flutes over about 700mm will by necessity have 'improper' hole placement.

Flutes in the 2.3-2.4 range often create the greatest damage to the hands because there is a strong temptation to stretch the hole span just a little more to achieve hole propriety and it's probably a bad idea in the long run. With flutes of greater length, the holes will be so far from 'proper' that one might as well concentrate on making the flute very playable. Since you'll have to live with the impropriety of hole location, attend to other features you can do something about.

There's no compelling reason to have a hole span on any flute that's outside the range of your personal hand comfort. What would be the point?

For a page on Big Bore Flutes.

And see The Synthesis for a final flute design.

Hole	Hole distances for 3.6 Chokan 1090mm
Thumb	481
4	524
3	603
2	662
1	729

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Approximate Utaguchi sizes for Big Flutes

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