When I saw the brief for this month the first thing I thought of was "The Luggage".
The Luggage is a fictional object that appears in several of the Discworld novels by Terry Pratchett. It is a large chest made of Sapient Pearwood (a magical, intelligent plant which is nearly extinct, impervious to magic, and only grows in a few places outside the Agatean Empire, generally on sites of very old magic, such as Indian burial grounds and ancient monolithic sites). It can produce hundreds of little legs protruding from its underside and can move very fast if the need arises. It has been described as "half suitcase, half homicidal maniac" (Sourcery paperback p22).
"Babbages baggage" is my interpretation of this, perhaps Rincewind travelled through a magic portal to England on one of his adventures and taught Babbage how to make his own version of the chest.
For the project I first looked at a range of walking robots. There are loads of these and many you can 3D print yourself. These required a lot of servos but they typically have about 6 legs and that did not seem enough for me.
Then I spotted some giant centipede toys with loads of legs and a remote control. I took a look at the pictures and concluded that it had lots of potential so I ordered one. In parallel to this I got thinking about the chest. I had seen some small "treasure chests" at a recent Pirate Themed party and wonder if I could get hold of one of those. After a lot of searching I eventually found one on my doorstep in the local corner shop.
When the centipede arrived I did a quick test and was very happy. When I started taking it apart I was even happier as it was a complete dream to hack. The centipede was screwed together and came apart really easily. The chest was just the right size for the legs. As suspected the mechanics were all hidden in the head. Two tiny motors with right angled gearboxes drove two wheels, there were LEDs to indicate that it was turned on (bonus). And to my surprise it actually came with the ability to steer and the centipede could be controlled although I kept crashing it into the chairs.
The control circuit consists of a Lipo battery, there's no sign of a charger here but there is a "special" cable that connects to USB so perhaps there's a small charger in that. The switch simply connects the + of the battery to either the control circuit or to the charging socket. There's an IR photo transistor on the top of the board and an 8 pin chip on the bottom. That chip seems to drive a couple of transistors which I'm guessing are connected to the motors. There does not seem to be any markings on the chip other than the silk screen.
I collected together the parts and made some suitable holes in the chest for the LED eyes, power connector, on-off switch and motor wiring. The electronics were nicely housed in the lid of the chest and I used sugru to hold everything in place. A couple of brackets and a meccano wheel were added to the bottom along with the motor and some legs. There's still plenty of space left in the chest to store a range of electronic components such as variable dibbler, high voltage angua or a nanny ogg.
Here's the resulting "Babbages Baggage"