I’m just finding # 1 and # 2 are quite sensitive to size on the cylindrical flute I am making. Particularly # 1, which apart from being known on many flutes as being louder than the rest and so needing a little less pressure to play evenly, also sounds much more easily (on the flute I am making at least) when on the small side (which would also correct volume). That moves it north though, so it is all something to balance out with the two neighbouring toneholes.
That’s another prototype essentially finished, and the holes are very close to how I want them. I didn’t dare to push holes #3 ad #6 quite as far down the tube as would have been ideal, but that’ll probably come right on the next one: another 2mm down for #3 and 4mm for #6 should be about right. Hole #1 is bigger than would be ideal, but it feels as if it would be okay to push it north by up to 2mm without losing the exceptional comfort that my spacings provide, so it’ll likely migrate that way on future prototypes.
Unfortunately, again it got harder to play the lowest note the more holes I made. Maybe they’re causing too much disruption due to the way I’m making them: I file material away around them underneath, so it may be left too rough in the resulting dents which are hard to reach to sand, if the dents themselves aren’t the problem. As with the last prototype, I’ve regained the ability to play the lowest note reliably by filing the inside of the tube at the mouth end to make the opening wider - there’s a distinct reduction in the range of positions to get your lips into that produce good low notes, and you have to get closer to the wedge, making it harder to vary the power. Maybe I should cut deeper chamfers around the holes instead to get my fingers closer to the bore that way.
Edit (a day later): it’s working better after drying out, and after making a few adjustments to the roughest places in the bore around the holes, to the point that it’s now my most playable quena. The lowest note is reasonable and can be pushed with a wider range of force, while I’m getting better notes out of it in the third octave than my best bought) bamboo one, though lowest three notes aren’t as clean. Maybe that’s to be expected when comparing a quena with a 16mm bore against one with a bore of 22mm though. I’ll have to try to find wider wooden rods and have a go at 18mm and 20mm bores to compare them, but I also need to sand the bore of this one properly and then soak some yacht varnish into it.
Update:-
It’s been tough, but I’m finally getting where I wanted to with these prototype quenas. The fourth and sixth ones are the best, and I’ve been able to switch between them by modifying the inferior one to make it more like the better one, and sometimes it becomes better than the previous better one during that process, so they’ve gradually evolved towards higher and higher quality sound as I homed in on the best shape for the wedge (about 40°) and window length. I now have the sixth prototype sounding readily with good tone, and it can be played quietly too while using little air. So, my best quena is now the one made from the worst wooden rod with ruddy great cracks in it which run half the length of the instrument on the underside: I had to fill them in with superglue before drilling the bore. (The fifth prototype, using the best wood, had gone wrong with tiny adjustments to the lowest three hole locations leading to them being too big to be able to cover reliably, but I still learned a lot from it, and particularly when it came to carving the holes without making mistakes that scar the tube - I do most of this work with a knife as drill bits make too much of a mess when they break through, but I’ve also bought a set of Chinese burrs designed for wood carving with a Dremel which I now use to make the initial holes, and again later to finish the holes neatly once the knife has got them approximately right, although I’m using them in an unwieldy full-size drill which allows them to jump easily, so I have to protect the tube nearby by wrapping plastic round it.) Anyway, I now have a good quena which I should be able to copy again and again, and I can now make one in a day, so I might try to sell a few at a modest price to see if I can get back the money I put into this, but it’s been worthwhile regardless as I finally have a quena that’s comfortable to play and which sounds acceptably good. I might yet have a go at doing an ebonite one at some point just to see what difference that makes (once I’ve maxed out the quality I can produce), but birch actually sounds okay, once you get the design right. And as for making a quena with paper maché using International yacht varnish as the glue, I will certainly try that experiment, but it needs to wait for summer so that I can leave a window open to deal with the fumes.