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Shaku |
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Updated
Cut about an inch of pipe and glue it into the coupling with pipe dope. Make sure it's seated against the inner flange. Complete the Edge Cut first and be sure the Setback point is at least as great as you want. The blowing edge will have a nice curve in it and the center of that curve is the setback point. Then make the End Cut. If the setback point is initially a little too great you can make it right with the End Cut. Sand the sharp corners (not the blowing edge) and smooth to your satisfaction. Use acetone on a rag or paper towel to smooth and clean PVC. The pipe will have printing along its length and acetone will remove it leaving a white shiny, smooth surface. Now you have a mouthpiece which can be applied to any of the tubes we'll make.
Although this mouthpiece works fine it doesn't look like much, but there are more aesthetically attractive alternatives.
Getting Tubular
But first, let's review: Aspect Ratio is the bore's length divided by its diameter or width. It's a measure of how thin or fat the bore is. We're using a standard diameter (20.7mm) available to all so the only variable is tube (hence bore) length.
We're going to explore Aspect Ratios between 28 and 31 using a hole size of 11.5mm (29/64"). All holes distances are calculated using the Factors (factor times length equals hole distance) and measured in millimeters from the flute's foot to the center of the hole. The measurements in the table below are experientially derived and are true for 3/4" PVC Schedule 40 tubes, 29/64" holes and the mouthpiece described. The factors apply to these conditions and length ranges and are optimized for an Aspect Ratio of 30. You can choose any length between 560 and 680mm and apply the factors to calculate hole distances.
|
Hole
|
Factor
|
28
580mm |
29
600mm |
30
621mm |
31
642mm |
C#
555mm |
C
588mm |
B
623mm |
A#
660mm |
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1
|
0.2077
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120
|
125
|
129
|
133
|
115
|
122
|
129
|
137
|
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2
|
0.3092
|
179
|
186
|
192
|
199
|
172
|
182
|
193
|
204
|
|
3
|
0.3961
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230
|
238
|
246
|
254
|
220
|
233
|
247
|
261
|
|
4
|
0.5169
|
300
|
310
|
321
|
332
|
287
|
304
|
322
|
341
|
|
Thumb
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0.5781
|
335
|
347
|
359
|
371
|
321
|
340
|
360
|
382
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1) Make a clean cut on the section of pipe, seat the mouthpiece and measure from the side of the mouthpiece (not the blowing edge) to the length you've selected from the table above. The length is the total length of the flute.
2) Cut the tube to length.
3) Draw a pencil line lengthwise on opposite sides of the pipe for radial hole placement. This is greatly helped by placing the tube in a section of 3/4" angle iron (either iron or aluminum or make something out of wood)--tubes like this are hard to wrestle down and hold steady.
4) Measure the holes and drill.
5) Chamfer the inner edges of the holes and both ends of the tube. I use the edge of a half-round needle file as PVC is easier to scrape and cut than file.
Using the factors will make the flute play in tune with itself. Should you also want your flute in tune with other instruments use the right most four columns. The C flute's Aspect Ratio is a little above 28 -- B is close to 30. Aspect Ratio probably has a greater effect on tone quality than any other single factor. Making tubes with Aspect Ratios of 28, 29, 30 and 31 will give you a very clear picture of Aspect Ratio and the Shakuhachi. Another important element is how easily a shak will play the higher registers. Notice the difference in jumping to the second octave with a 560 and a 680mm tube. High Aspect Ratio make the upper registers much more available--low Aspect Ratio is generally considered the better sound. Go figure.
With the removable mouthpiece and tube selection you'll have a wide range of shaks to test-drive, study and enjoy!
See The Synthesis for a final flute design.
Read about craft from the Japanese perspective in The Unknown Craftsman by Soetsu Yanagi.
Sabi, wabi and the directness of Korean craft.
This is the deepest book on craft I know of--get it from Amazon.
Don't worry--be Hopi!