In reply to Kiteman's comment below (the system wouldn't accept my response or register the captca code): I'm new to instructables: if there's a requirement that the author be the maker, I guess I'm guilty. I took pix while Ray did (most of) the work. (I did some of the assembly on this particular instrument. When I got home, I made another one from a bowl I turned on a foot-powered lathe, but it didn't sound nearly so good.) However, the images are screen shots of a pdf I put together, so it is my material. Please do download the pdf for the entire process, in much greater detail. Mostly I work with wood and mud (adobe, or cob). I have a variety of work up at handprintpress.com/kiko
Step 2: Neck and back
tight grain, strong wood: fir, larch, etc. Most 2x4s should work. The tighter the grain the better. Ideally, orient the grain vertically. See the illustration for dimensions.