I’m planning to do a tsugaru sized shamisen . I will not be making it traditionally:
The body(dou) will the a block of wood, not “four sides” glued together.
The neck(sao) will be an entire piece, not divided and attached as usual.
The neck(sao) will be attached to the body(dou) as usual.
So the measurements needed are:
The length of the neck(sao) alone.
The body(dou) length, height and width.
The length of the entire instrument.
And that’s pretty much it. Thanks in advance!!!
A sao, even when not collapsible, is generally made from 3 pieces of wood for material economy purposes. In the case that it cannot be collapsed, we call it a nobezao - but it still has the tenjin and nakago joints!
Dou are in a similar situation. You’ll be losing a lot of material hollowing out the interior and the labor involve will be intense, I suspect.
Its overall length will be approximately 100cm. You’ll find some variance here (non-tsugaru are generally 98, tanzao are 85 - 95; tsugaru may be 100 to 103). The neck penetrates the body and passes through it - so the overall length of the neck is the overall length of the instrument.
You can consult the link in my profile or my google document for data on dou length and width, which you can then use to figure out how much of the neck is fretboard and how much of the neck is spike.
However, you’ll need to refer to additional sources in order to determine the wall thickness and to account for the mild bevel on the dou sides.
Good luck
I think this will make it easier to understand!
Well, The measurements I calculated for the tsugaru are:
Dou(without bevels):
Blue part of the dou = 21cm
Green part of the dou = 20cm
Red part of the dou = 10cm
Sao(without bevels):
Blue part of the sao = 100/103 cm(Penetrated part included)
Green part of the sao = ?
Red part of the sao = ?
I’m really doubting if the “futozao part” is the red or green one. But well, thanks in advance!
(Also, what would be the total “green part” of the shamisen with the chibukuro included?)
A sao is classed as hosozao, chuuzao, or futozao based on the width of the fingerboard, as measured below the chibukuro. (So the green in your image.)
Older style instruments are more narrow - you can find texts that label anything 2.8cm or wider as a futozao. In fact:
Gerry McGoldrick, citing Futoma (1964) has the following dimensions for a necks and dou:
Hosozao 2.4 - 2.46
Chuuzao 2.55-2.61
Futozao 2.61 and over
Nagauta L19.7 W17.8 H 9.4
Kouta/kiyomoto L19.8 W17.95 H9.5
Tokiwazu/Shinnai L 20 W18.1 H 9.5
Jiuta L 20.3 W 18.4 H 9.7
Tsugaru L 21.5 W19.5 H10
However, modern futozao are generally 3cm or wider.
the thickness of a neck (your red line) is variable. I have shamisen with very hefty necks, I have shamisen with more slight, delicate necks.
A chibukuro adds a bit more than a cm to either side at its widest point.
A Dou made from a single block of wood will probably collapse when you apply a tight enough skin to it. The sides that are against the grain are very “breakable” in the direction facing inwards of the Dou, which is where the tretched skin pulls it.
Material economy is not the main reason the Dou is made the way it is. It uses boards with a particular grain direction to maximize strength against the skin pulling in.
Am I misrecalling in thinking that wadaiko are made from singular logs? Are the tensions so different?
I am posting here my original answer on the Bachido Discord, plus a few adjustments:
A circle is the strongest possible shape to withstand inwards pressure.
Furthermore, we can draw a direct parallel with brick made arch bridges, where the arrangement of bricks only make it stronger with pressure, as each brick acts as a wedge.
A Shamisen body is square(ish), and depending on how you cut the block and which direction you place the grain, you’ll either have it very fragile on two sides, or somewhat fragile on all sides. The square-ish shape causes the grain to lose the wedge shape that’s crucial for arch strength exactly at the middle of the arch, which incidentally is the part where the skin pushes the most against.
Heft makes up for loss of grain strength though. So if you are willing to go 25mm and up on edge thickness, and use a pretty elastic hardwood, you may be able to pull it off. I wouldn’t trust it 100% thought.
There was a question by @Brown on Discord:
What if the interior of the dou was rounded to form an arch?
Answer:
That would completely solve the issue, though it would possibly change the sound a bit (or maybe even a lot).
I’m not a mathematician, but I’m sure there are calculations that would show the required continuous grain section thickness whilst keeping outlier shapes around it (inside and out) relatively free.
All that to say that if you could keep an internal arch of wedges of a certain thickness, even if such arch would tend towards an ovoid shape, you could vary the external shape (corners) and internal shape (rounded corners) and get closer to the geometry that would produce a Shamisen sound. And given that the internal corner is a place where a lot of inward pressure exists (from the skin), one could even carve a line to force a sharper inside corner.
Here is an image to illustrate:
I am, however, curious to see what kind of side panel grain aesthetics you would achieve with a build like that.
@Brown asks:
I’d have to guess similar ones to taiko and koto, yeah?
Answer:
Depending on the size of the taiko, the curvature from top to middle can make it transition between more or less rings of the tree. A Shamisen, with the external squared corners will force a wider transition, showing wood from near the core at the middle of the panel, and wood from near the bark (depending on circumference of the tree, of course) at the corners.
Some woods have a beautiful and stable transition, some others have a tendency to detach. That being said, I am now picturing in my mind a Shamisen where the corners would be a chamfer showing a live edge (outer skin of a tree, with bark removed), similar to the edge of Murasaki’s shamisen stands. That can be quite the rustic look, especially on a medium brown wood.
As for koto, I can’t draw a good parallel, as I am yet to explore the techniques of its building process. Lots of unknowns for me there.
@TouhouLInuxFan
Feel free to ask anything else.
By the way, I’d like to invide you to join our Discord, as the conversation is more active there.
