So, I’m trying my hand at flute making. I have started with the design of Mark Shepard’s “Plumber’s Pipe” – which can be found at: http://www.markshep.com/flute/Pipe.html – but I wanted it in D, So I’m using the Flutomat to generate hole positions/sizes.
I have an inner diameter of 1", and a wall thickness of 0.125" (1/8"). It sounds pretty good, and I got all the notes pretty close to correct in both octaves, except for the 2nd hole down from the embouchure hole.
Here’s the problem: When I play a lower-octave B, it is perfect. When I try the high octave B, it comes out a C. I mean exactly a half step from what it should be. I thought this really odd, especially since the rest of the flute is fine.
Does anyone know why this would happen and/or what I can do about it? It seems that if I were to change the hole size/position to fix the upper octave, it would mess up the lower octave. Whatever shall I do?
By “undercutting” do you mean “made the whole too small”?
I don’t know. I would think that if that were the case, the lower octave B would be out of tune too. But I’m going to try widening it and see what that does, just to experiment. I have plenty of PVC if it ruins it…
My stupid ISP disconnected me after I wrote a nice long message…I’ll try to recreate it, but it’s well after midnight so I’m tired.
Undercutting is when the hole is larger inside the bore than the opening on top of the bore.
Cutting the hole larger will only sharpen the note above C. Don’t forget that the hole beneath the note you’re playing is what creates the note so,
XOO OOO is B and the hole that makes the sound is not the X but the O just after the X. The larger it is the sharper the note.
Another possibility is that what’s sharpening the high B is that your cork is too close to the embouchure hole. A cork too close to the embouchure hole will not effect the lower and middle notes, but the upper octave (especially A and above) will get sharper.
Finally, if you roll the flute in when playing that high B, you can flatten the note without doing any cutting on the flute. Almost all wooden flutes have certain notes that are not perfect in intonation that you have to try rolling in/out or lipping up/down.
I’m gonna take a wild guess and say that your embouchure hole is too close to the end of the flute or to the stopper, whichever you have.
In flutes the cork position really starts playing a large effect on tuning at the top of the second octave…right where you are encountering your problem.
–James
P.S. Eric, I didn’t read your whole post first…my bad. Sorry for the duplicate info.
My humble experience is that the hole placing mainly affects the lower range and the hole size mainly affects the upper range. So if you have an ideal placing for the hole which creates the B note, you seem to have got that right, you might want to make the hole smaller, thus flatten it in the second octave but not changing it much in the first. Put some tape on the hole, see if it works and how much smaller the hole should be. Also try to mess with undercutting and stopper placement, as those things also affects the balance of first/second octave. The problem with the stopper issue is that it affects every note of the flute in some way and you say you’ve got pretty much all the other notes right, undercutting and alter size of the second hole (from the head) might be a better idea.
1 inch inner diameter is bit large for a flute. You sure you have that diameter right. 3/4" PVC, (which is not really 3/4" anywhere) will work fine for a flute.
1" is going make hitting high notes very difficult, in fact the might be what is making the flute a bit sharp.
I helped someone once with a homemade flute that was oversized in diameter, he couldn’t even get the highest note to play. I had him take an exacto knife and cut a little more ramp on the underside of the embouchure hole where the stream of air hits. It worked well after that.
Also, between the headjoint and rest of the flute. If you are using any coupling, make sure that you clean the edges of the pipe nice and smooth. Otherwise, the flow through bore will be tripped and do a great number of wierd things that you won’t like.
