I received this cane flute from a dealer and when I got it instead of Key G it was Key G# but very sharp. None of the notes were correct so I decided since he did not want it back it was probably because to him it was useless. I figured since I had it I might as well experimenting with it. I first had to add a 14mm piece of cane to it to get it into the key of G. Then I filled all the holes except for the embouchure to close off any air leaks. The G note sounds so good it is awesome but I am trying to figure out where to drill the holes. I am wondering if I should use a ratio of tube length measuring from the center of the embouchure to the tube end for each hole after figuring out the ratio on another whistle or flute with a near similar 18mm id and 2.2mm wall thickness. This is what I am starting with. I know it may be a little difficult but figured I have nothing to loose. Any advice would be appreciated. I have tried some online flutomat calculators and find them useless.
https://flic.kr/p/2jPkVg8