Now retuned and with new embouchures. Some conicity has been introduced to tune harmonics, improve response, and facilitate playing high notes softly without warbling, You now have an instrument that is useful throughout its range for lyrical playing. It is a copy of the prototype I have been playing in my youtube videos (username = brilliantcorners).
This is a lightweight 22-tube whole tone panflute for improvising. The scale is D1-E-Gb-Ab-Bb-C-D-E through 3 octaves to Ab4, straddling the range of a flute and a piccolo. The idea of wholetone tuning is to make it equally easy to play in all keys, and be able to switch scales at will. You can see my flash animation to illustrate the principle on http://improvise.free.fr/nai/nai.html.
Semitones are obtained in various ways - by tilting the instrument, by moving it down so that more of the hole is covered by your lip, and coolest (and fastest) of all, by holding it half tilted and thinking "blow up" or "blow down". With practice you can move each note down a halftone without anyone seeing how you do it. There are videos demonstrating this on youtube. I played diatonic panpipe daily for 13 years before I got this idea and changed the tuning to wholetone. It took me 3 weeks to get used to the new system and believe me I have never looked back.
I have made this model because of the difficulties I have had persuading panflute makers to make to my specifications, particularly regarding ideal diameters. I hope you can benefit from my experience, and save money and years of practice. Depending on the finish of this instrument I recommend sanding the surface that rubs against your chin, for extra comfort. Romanians also sand inside the tubes of their bamboo instruments, just around the playing edge to create side flanges which act as resonating surfaces. I have take care of this in the design, so this is ready to play out of the box