My blog post about the development of this whistle.

I wanted to make a quick-printing whistle that used as little plastic as possible. I'm pretty happy with this version, redesigned from the great emergency whistles by DarkAlchemist and muddtt.

I removed the loop at the end, but created a hole in the whistle for putting a cord through - doubly removing plastic.

Print at 0.1mm / layer for best results. Thicker layers than this and you'll probably end up with gaps in the plastic that will prevent it from working. It uses about 0.4 grams of plastic - a great and utilitarian way to run out a nearly empty coil of plastic.

MakerBot

MakerBot Replicator 1

Doesn't Matter

Doesn't Matter

0.1mm / layer

10%

Redesigned from the ground up in OpenSCAD to use as little plastic as possible.