I stepped up to the challenge on twitter.... designed in NX5. Its a 2.5 mm shell with 8 finger holes on top and two on the bottom. Not sure what kind of noise it will make but I\'ll print one and update the post. Obv going to need support material, I'll try the auto version from skein but if that doesnt work well I will add some in.
The largest overhang on this version is 45 degrees so there should be no need for support material. I followed the instructions from the website 'PrintTo3D' posted so, in theory, it should make some noise. I also increased the diameter from 30mm to 40mm at the widest point, so hopefully the noise that does come out wont be too high pitched.
I included a couple pictures including one just of the sketches I used to create the object.
New pictures show the old version (left) and the new version (right) which got about 65% of the way done and decided to pop off of the build platform after I walked away for approximately 30 seconds. I'm going to change a couple things and will print off a new copy by friday