There is a book "[SIZE=+1]The Amateur Wind Instrument Maker[/SIZE]" Robinson, The Amateur Wind Instrument Maker I used that as my basic template. There is also a handy spread sheet for calculating tone hole placement. ftp://www.mimf.com/pub/cornetto.zip I ended up making my own equations based on the measured frequencies and lengths of my cornetto, but they turned out to be remarkably close to the ones in the spread sheet. I found that getting the tone holes in the right place to be the most nerve wracking part, especially since mine didn't seem to behave as a perfect cone or cylinder. The carving was easy. One tricky part is that the range of the cornetto is G-d''', and the tone holes are like a G recorder, but the fundamental is an A which they lip down to a G, so there is no A tone hole, still getting the hang of that, which is why the spread sheet and book plans are both for an A cornetto, but the range is still G-d''' like a violin.