Push-box (toy soundbox)

Modeled after an existing one, designed in SketchUp.
Untested design, but in theory it should work. Suggestions are very welcome!

Edit: It comes out fairly well, it just needs some adjustments and fine tuning.

You'll need three AG13/LR44 batteries, a spring and a metal plate to make contact in the battery compartment and four 5x20mm springs.

You should use a 28mm speaker, but other sizes might fit.

Fix electronics to the bottom part, and the speaker into the ring in the top part.