It is made from the protective case for a 12 cc hypodermic syringe, which can be purchased from a pet store or veterinary supply store. I use the syringes as tools for extruding silicone rubber in making silicone rubber sculptures. This is a good way to recycle the protective cases.
The needle cover (pink) is sanded down to make the mouthpiece. The reed is cut from a piece of scrap plastic that I recovered from a junked flat screen monitor. Electrical tape holds it all together.
To protect it in my pocket, I made a carrying case out of PVC pipe.
To hear how the hypotooter sounds, listen to the .mp3 audio file in the last step.
Step 1: The Syringe
Step 2: Forming the Mouthpiece
To sand the curve, use a forward and backward motion, with a little extra wrist action. Make sure the curve has no flat spots and that both sides are sanded with the same curve. Once you get the arm and wrist motion down, it becomes almost automatic.
Use course sandpaper first, then medium, and then fine. Remove edge burrs with a very sharp X-acto craft knife, or something similarly precise.
Step 3: The Reed
I usually do a whole slew of mouthpieces, with variations of curvature and reed material and then select my favorite out of the bunch.
I find that cutting the reed right at the end of the mouthpiece, after the reed is taped in place, is better than having it extend beyond the mouthpiece. Sometimes, I cut it a little shorter, but you don't want it to be so short that it ends on air and not on the plastic of the mouthpiece.
Step 4: The Carrying Case
One nice thing about the hypotooter is that it is so small and easy to carry. It fits in a pocket.
To protect the reed, I cut a piece of 3/4" PVC pipe (appropriate to the diameter of the hypotooter body), and then cut some fingers in it that expand a little and grab the hypotooter.
I made a special spreading tool for opening up the fingers during manufacture, so I could clean up the cuts with a file and an X-acto knife.
I drilled a hole in the PVC for hanging it all from a nail.
Step 5: Playing Tips
There are a lot of variables and they all get easier with practice.
Step 6: Hear the Hypotooter
It sounds remarkably trumpet-like sometimes. It's great for chasing those high notes.