NASF blowing only the 4th harmonic

[Matthew Orifice]

ok i've been making Native american style flutes recently. and had some nice success not going for brilliant instruments just something for me to play and a few for friends, i've been asked to make a few for sale. THAT said, i recently made one from pine that has me baffled. it's a split flute Routed with a round nose bit and then glued, and by all accounts no different from the others I've done successfully but this one seems to want to hit a note an octave and a 4th above it's intended pitch... if i REALLY restrain my breath i get a weak B4 however, any more than that and it hits F#6. This decreases as i open the finger holes stopping after the third one (it's in a pentatonic minor).

anyone got any ideas what i did wrong?

[Jason Rodgers]

Sounds like something funky going on with the fipple. I don't know anything about their construction or adjustment, but if an instrument is over-blowing that easily, then I'd say the air is getting split up wrong. Those intervals, specifically, sound like that's what's going on. If I'm not mistaken, a classical flute head with the end covered will blow A, E, A, E: from bottom to top, that's an octave and a 4th.

[Matthew Orifice]

good thoughts thanks... going to continue on some research then but i'll focus on that for now