This is an alto sized flute with folk fingering system (like a penny-whistle). Consists of three sections, which slide together. The bore shape and hole parameters have been designed using Python package "demakein" so that the flute is in tune over two octaves.
Thanks to John Boshua for the excellent print in ABS plastic.
The joints have 0.3mm clearance all around. If the print turns out too tight, a little sanding should loosen it sufficiently.
The joints need to form a tight seal. A little wax or grease should achieve this. To identify leaks, try covering all the holes and blowing into the instrument as if giving mouth-to-mouth resuscitation, first with just the head, then the first two segments, then all three segments.
See the file "folk-flute-fingering.pdf" for the fingering chart.
You can adjust the design by installing the Python package "demakein". For example you can use demakein to design a flute in the key that you want, or that has a tapered rather than straight bore, or with a different joint clearance. Demakein can also produce shapes for CNC-milling in wood.
If you can program in Python, demakein can be extended to produce designs for other woodwind instruments. I will be adding further built-in designs over the coming weeks.