Instrument is 225mm high. It can be printed in two sections, maximum height 134mm high. It may be possible to print in 4 sections, maximum height 74mm (this requires holes overlapping joints, which might not work).
The generously large holes help with expressive techniques such as sliding, cutting, and tapping. The trick with this kind of instrument is to never stop blowing. It's meant to be raw and wild, it's all about analogue glitch.
In order not to cause pain to people of a delicate disposition, this instrument should be played outdoors.
The joints have 0.35mm clearance all around. They need to form a tight seal. Blue teflon plumbing tape appears to work quite well for this.
Even tiny holes can cause an instrument not to produce sound, or to only produce high muffled sounds. If it isn't working, this is one likely reason.
It is also possible to make this instrument by milling wooden pieces and gluing them together. This is a little more involved than 3D printing, so email me if you are interested in doing this.
I expect to refine this design. The pitch may be slightly off A440. I also expect that various parameters of the whistle shape can be improved on.
This instrument was designed using a software package called "demakein", more information here: http://www.logarithmic.net/pfh/design