Next step in my experiments designing a bird box automata made from paper.

This time I'm driving the bellows from a crank handle via a bell crank linkage.

Instead of the single fold bellows I've gone for a three layer design. This should allow the bellows to open wider.

I've mounted the pipe inside the box. The box is slightly larger than the previous version and is flexing a little in use. It would probably benefit from some stiffening strips.

I've put together this twelve frame stop motion animation so you can see how it works. The crank and bell crank are clearly visible inside the box.
This design works well and is a fun little model. I'll probably be releasing it as a download – let me know if you would be interested in the comments below.
Next step is to link the tuneable pipe to the crank so that the pitch changes as the handle is turned.