I’m having fun experimenting with various layouts of sound making devices. Here is the latest version as an Instagram animation.
There is a single bellows/pipe suspended from the roof of the box. As the handle is turned a pair of double fingered cams tap repeated on the bellows making the pipe twitter.
There are two cams so that the bellows are pushed up evenly.
Once I have the box layout sorted out I think it will make a rather nice twittering bird model.