I posted a flute I made recently for a trade and there was some interest in a build along and I thought I would go ahead and start one. Just a disclaimer though the posts may be a bit sporadic, because that's kind of the way I work
Hopefully when I finish with the builds I will have a Gm flute and a branch flute that I have no idea what key it's going to be, since I've never done one. I don't use any specific formulas just estimates that I have sort of learned to start with depending on the key I am trying to make. The flutes don't always work out, kind of like my bows. I am not determined enough/smart enough to work out a specific formula and at the risk of sounding to spiritual the wood kind of makes me do what it wants me to.
These first few photos are just to show some basic measurements I usually start off with on making my flutes. You may not do it this way and if you've found something that works for you feel free to speak up, cause it may work for someone else too, but this is how I do it.
The most important part in this mock up is the place where the air is going to go from the spot you blow into across air hole. I usually start off by making it a bit longer than 7/16ths of an inch because it's easier to take some off then put it on.Just a close up of my painted ruler and the area I'm talking about.The branch I'm going to try and make into something playableanother shot of the branch after I um... debarked it and the two pieces I cut out of the board I'm using to make the typical flute you see most everywhereThe board is about an 1 1/4" wide for both halves, 1/2 thick and around 24" long.
If you look at the diagram it shows where the air chamber around 5" (the part you blow in) and the flue 7/16" (where the air flows over and hits the sounding edge) this is the area I will be concentrating on the most in these first few steps after I get the bore carved out.
Since I am going to make a G flute for the board I am going to take it to about 3/4" bore. I had a guy, who said he learned how to make them from an Indian in Colorado who lived in a tipi, tell me since I don't carve all of mine out that they aren't genuine Native American flutes. I told him I am NA and I've never met any NA who still lives in a tipi and that if NA would have had access to an electric router they would have used it, because they were primitive not stupid. Anyway if it makes you it feel more "genuine" for you then feel free to carve it out, if your like me then you will route out most of it for the rough shape and maybe do a bit of carving on the bore for the board. The branch flute I will be carving out for sure just because it is a weird shape and I don't want to screw it up with power tools.