The Shape - or Why does your serpent look different?
When I first thought about making a serpent I knew just one thing ... I wanted to be able to make more than one. Serpents, when you could find them, were terribly expensive and I thought I could provide a good inexpensive instrument to fellow enthusiast and at the same time start a little cottage industry for myself. I started down the road of building a custom CNC wood router to carve the two halves of the serpent. I actually built what has become known at my house as "THE MACHINE", but it proved to have problems carving hard materials. It would carve foam fairly well, but the minute I tried to carve walnut, the machine would begin to chatter and the carbide cutter would break. The machine frame had too much give and only building or buying a better machine would tackle the serpent carving job. In preparing to carve my serpent by machine I had spent hours doing detailed 3D drawings and surface mesh networks of both the interior and exterior of a serpent.
If you look at a lot of serpents, and I have closely studied the photos of about 20 or so, you will notice that the bell end comes up very close to the bottom of the final 180 degree bend. Because I initially planned to carve the serpent by machine, I planned on making the front and back halves of the body perfectly symmetrical. This would limit my engineering since I could do a detailed design on the front half and then flip the design to get the back. Most serpents I have seen are not symmetrical; their backs will lie almost flat against a table. This means that their bells project slightly in front of that final 180 degree curve. If I had kept the original shape of Monk's serpent, my bell would be projecting right into the curve and I was afraid that would block some of the sound.
My compromise was to keep the original dimensions of Monk's serpent on the top, so the finger holes would be in the traditional location, but I rounded out the bottom section to bring the bell down from the final 180 degree bend. The final shape is formed by four straight runs separated by three 180 degree bends, and a final 270 degree swoop with a slight flair at the end. The interior bore shape is shown below. Except for the flair, the bore increases at a constant rate from just past the beginning to the very end.
The Kaiser Serpent Shape