The simpler and closer to the player the better in my opinion.
Go ahead with the links by all means, and this post is turning into a bit of a chat anyway. I should put up a new post just on the topic though so that others can find info in one place. Same goes with the flutebuilding resources post I started, for now I just concentrate on where I am at on it, but there are quite a few links I will throw in there later, just odds and ends that might interest or inspire people. It takes ages to find some of these links online sometimes, so to have somewhere where there is a bit more of a curated choice and in one place is a help…at least that is what I find, often footnotes or “further links” give direction to other information that would not otherwise be found.
I know curved extensions are used and work for bass flutes.
So this is an idea to bring toneholes closer for your flutes if you are still in to playing around with design etc. It is a spiral tube (say copper to start, or 3d printed etc… and which I don’t know how to draw as design properly but the idea is simple enough) that fits into a say alu. case. This means flute tube dia. is smaller, but volume can be from embouchure, and toneholes kept large I think also. Length of tube is most responsible for freq. , not diameter.
In 1 it rests on casing and forms emb.
In 2 it opens to form a soundbox.
In 3 I drew how wide toneholes could feasibly be, obviously with tube sealed around to inside of flute. If width is needed for sensitivity to finger placement for getting half hole note then it could be smaller at actual tube maybe and widen towards casing… if it needs lots of venting for half hole then larger hole as shown I guess.
In 4 just straight tonehole.
Smaller tube is going to change the tone a little probably, I don’t know how…I would play with designs like this myself… a 50cm long flute in low A ? … but I’m staying with wood for flutes.
There is an optimal tube diameter for pitch vs tone, and that means any flute is a compromise in that sense for having notes of different pitch. So that is why a larger box at head might help depth of a note and probably volume . Equally simply adding a bit of helix instead of tight full spiral might be enough for finger spacing and allow a larger tube diameter ? I could even imagine a disc flute, made with a flat spiral and held like ocarina. Another question though is if anyone would want to play them…but for those who like making things…
I’m not sure how practical any of these ideas would be in reality to make. I don’t guarantee they will work, and I don’t mean to waste anyone’s time should they not, so better to think it through or read up or calculate if not up to trial and error
Yamaha did something similar with the “Venova” to bring tone holes closer together. I no longer make flutes – at least not at the moment (I might make a few for friends and family but only one person in my family does play the flute and I already gave him 2 ). The design I made works perfectly. And that was more or less my goal – make a great sounding flute that I will play for the rest of my life and on which I can play any type of music I want to from classical to Irish.
Since I decided against making them to sell them (considering you can get flutes 3d-printed nowadays I think the demand for what I do dwindles to zero) – I don’t need to improve tonehole-spacing .
The next step would of course be what you are doing – wooden flutes. But I don’t have the tools and necessary space. Maybe one day … one can always dream.
Considering your ideas – a smaller diameter would change the tone quite a lot but there is one more problem – and it’s a big one: It will change the balancing of the octaves and make it almost impossible to get 2 octaves in tune without further tweaks when using a cylindrical bore.
I tried making a flute from an aluminimum tube with 3mm wall thickness (to simulate wood and the chimney-effect of the holes) and 19mm inner diameter. The octaves are brought in tune with a “trick” I adopted from German marching band flutes – a “tuning rod” on the inside of the head which reduces the diameter – so it more or less simulates a tapered bore in the head. But it weakens the tone quite a bit. The flute plays nicely in tune and easily into the 3rd octave but the tone is just too weak. It’s a similar effect as a Fajardo wedge. I experimented with those, too but was never satisfied with the results.
So I switched to 23mm inner diameter tubes and achieved tuning with a careful balance of size of the tone holes, stopper position and size and shape of the embouchure hole. The “wiggle”-room for changes on the design is rather small however if it should sound like an “Irish” flute with enough oomph in the first octave.
). The design I made works perfectly. And that was more or less my goal – make a great sounding flute that I will play for the rest of my life and on which I can play any type of music I want to from classical to Irish.