The Jolly Popup Challenge

For a couple of years, Emily has been suggesting that we incorporate a popup book into our Christmas exhibition and this is the year that I've finally found a really good excuse to make one.

But not just any old popup book (and "any old" is pretty complex anyway), oh no, we're going large. Think big, add a bit, and you're probably there. We're creating a "book" with 8 foot / 2.4 metre high pages, with a mechanism that will open and close the book when a visitor presses a button.

We're in the planning stages now. There are a few challenges to overcome: learning the dark art of "paper engineering" so we can design and build the contents of the book, the creation of a fool-proof mechanism to power it all, and then the actual build.

This bit has always been an entertaining succession of last-minute panics, late nights, changes of plan, running out of supplies at the 11th hour and crucially, LOTS of fun.

There's been a reasonable amount of kitchen table fiddling to prove that the general idea is workable. I just have to work out how to scale it up from a folded sheet of A4 card...



For now, I'm concentrating on the mechanics. The idea is to make the book open using a device called a linear actuator. This is basically an electric motor that drives a worm gear, converting rotary motion into linear motion. That's simple: bought one on eBay for a few pounds.

We want visitors to experience the book opening and closing, so it needs control. This is coming from a micro-controller which can control a series of relays. At the touch of a button / pull of a tab, this will turn on power for long enough for the "book" to open, wait for a while, and then reverse the power so the book closes. Then it goes into a zen-like trance while it waits for another nudge.

The weird contraption below is the prototype mech. If it looks vaguely familiar in shape, then you've spent too much time watching JCBs in action.



Simple, eh?