Check out this flute that I just sent off today. I had a one time (Please! Don’t make me make one of these again!) commission for a wooden Bansuri combo in A and B, same pitch as my low A and B flutes. The person who ordered it used to make bamboo Bansuri when he lived in India and I based this one on his instruments, which he kindly loaned me. This one is in Mopane (half of it sapwood), with a brass tuning slide and silver bands. The bore is about 23.5mm throughout. It should have been a bit bigger for these pitches but I was constrained by how much outer diameter I could get with this wood and still leave enough wall thickness at the sockets. Its somewhat on the minimum side there for my flutes.
Turning it was interesting. Using my gun drills I first got to a 3/4" pilot bore. Then the rest of the bore was roughed out with a little fly cutter mounted not quite at the end of some 3/4" rod. I drilled each piece from both ends and the bores lined up perfectly. The flycutter is some 1/16" steel, mounted in a half-cut slot in the 3/4" rod, and jammed tight and ground to the correct overhang. My regular flute socket cutters are something like this and these allow easy socket cutting with dimensional repeatability. It takes less than a minute to cut a head joint socket with these. Outside turning required making some new poppits for the lathe, and a plug for the live center end, especially when trimming the silver after mounting.
Tuning and voicing this flute this was a chore for my smallish hands. I used tape to cover up all the closed fingerholes and just removed tape as I went up the scale. An interesting feature is the plug position. To keep the octaves in tune the plug is right up next to the embouchure. Any farther and it would cover some of the embouchure. This is also where it sounds its best. The bamboo ones were cut close to a node with the same result. The holes were so big that undercutting had little or no effect for tuning the 2nd octave. So holes were simply tuned to pitch by reaming them to size.
Next to the flute for comparison is one of my Folk Flutes (a factory 2nd small hand if you look closely - note the thread wrapped around the middle joint socket on the Outside- some “thread strangulation” is actually useful, Terry!). Notice the radical difference in hole size and positions. My regular low flutes are much closer to the Folk Flute than to this Bansuri monster. One has to use pads and the pinkie to cover these things. The layout is as my client’s original bamboo Bansuri. I’ve seen these done also with the holes straight in-line. I suppose one could use piper’s grip, or something like a super piper’s grip and it helps to be born with large hands. Note how the 3rd holes for each hand are way down on the instrument. The fingerholes range 10-13mm in diameter, the range where some peoples’ fingers will fall in. In my field notes on the originals, I have one comment: “Ouch!!!” This is definitely a very non-ergonomic flute.
My hands are a little sore after working on this. Actually I’ve been about 50% more productive than usual since the beginning of the year in terms of the value of flutes sent out the door and my hands and arms are feeling it with a spot of some tendonitis. They are worn out from too much flute making. Fortunately there is Lark Camp starting Friday, followed by some recovery time. Playing musical instruments (this week swing guitar and Galician pipes mostly) is less demanding. Then I am off to a scientific conference at a sunny west facing beach in the San Juans at a marine laboratory with some of the world’s foremost echinoderm nerds (I’m an echinoderm nerd as well). So I’ll be taking nearly a month off and I really need it!
Casey