Mechanical Foamcore Models

I’ve been asked a lot about how to get started building mechanical contraptions and I always mention Keisuke Saka’s excellent book Karakuri, how to make mechanical paper models that move. The book has actual printed template pages that are meant to be torn out and used as building materials. The first time I encountered this book it was on loan from a friend that had built most of the models already, so I set out to replicate the basic mechanisms using materials that I was comfortable with, and that were quick and easy. Foam core, paper clips, skewers, paper, and plastic bits from yogurt containers.

I like this approach because paper craft can be intimidating for new makers as it requires patience an precision, and when it comes to working mechanical models it is sometimes easier to take a more forgiving approach.

These pieces are not new work. They were the precursors to the one month of small machines project so I wanted to document them even though they aren’t pretty. Page 6 of the books offers a summary of the basic mechanisms:

Most of the models are built on a foam core base that is roughly 2.75″ x 2.75″ by 2″. And for the completists out there, I didn’t build a Crank B.