Flutes a simple fingering system, similar to a penny-whistle, in tune over two octaves. The tenor size is my attempt at a traditional Irish flute. The tenor and soprano are in D, while the alto is in G. These have ranges one octave above the corresponding singing voice. The bore is tapered. As these flutes are larger than most 3D printers can print, they are provided in segments that if printed in ABS plastic can be welded together with acetone. Version 2, December 2013: Thicker end so flutes balance better in the hands. Larger embouchure holes for soprano and alto sizes. Socketed as well as weldable versions.You have a choice of three sizes of instrument: tenor in D, alto in G, or soprano in D. These have ranges one octave above the corresponding singing voice. Each zip-file contains the instrument segmented into 2, 3, 4, or 5 pieces. Choose a segmentation with pieces small enough for your printer to print. When printing the wall thickness and/or fill percentage should be quite high. A stiff wall is necessary for the instrument to sound loudly and without needing excessive air flow. If you can feel the wall vibrating as you play, that is energy being lost. Having printed the pieces, they need to be connected together. In ABS plastic, this is easily achieved by dipping the ends of pieces you wish to join in acetone for 15-20 seconds, then holding them firmly together. The model includes guide prongs that will ensure the correct orientation of the pieces. Use appropriate safety equipment when using acetone (gloves, goggles, good ventilation, etc)! I am not sure if a similar solvent is available for PLA plastic. If not I would suggest trying cyanoacrylate glue in gel form, or epoxy. The join must have absolutely no leaks. This system of attaching the pieces seems to work much more reliably than the sockets I've used in previous flutes. Socketed versions are now included as well in version 2 of the flutes. See the file fingering.pdf for fingering system. These instruments were designed using Demakein, version 0.13. You could use Demakein to design flutes in different keys, and with more or less tapering. Less tapering produces a brighter tone. The tone can be painfully bright in the soprano size, but could be worthwhile in larger sizes, depending on the sound you want. Demakein can also be used to design a variety of other woodwind instruments.