Kit #16: Edo-era Tea Carrying Windup Doll (2300 yen). I’m starting to question exactly how good these kits are. Ones like the Stirling engine are good quality and run right after being built. Then there’s the planetarium, with it’s brittle plastic parts. Some of the designs are highly imaginative, such as the tea doll, but the execution isn’t that great and the result takes forever to troubleshoot. Such as is the case with the design of this kit.
The original doll was constructed roughly 200 years ago as a way of carrying tea into the owner’s dining room. It consists of a drive mechanism, and a gearing system to cause the doll to stop when you remove the tray, and to turn around and head back after reaching a particular distance. Kit 16 is a smaller version of that doll, but still incorporates the same features. A counterweight attached to the back of the arms pushes a stopper into the gears to halt them when the tray is removed and the arms raise. A guide along one gear puts a brake on one wheel, causing the doll to turn after traveling about 30 cm. The drive is a coiled spring that you wind up with a key. And here’s where the problem comes in – the counter weight occasionally disconnects the spring from the gears and unspins the spring by accident. I haven’t found a good way to stop this from happening, except to keep the doll leaning forward more. Even then, the system freezes up and requires a push to keep moving.
I like this doll, when it works, because the entire design is so simple yet fascinating. It’s also almost infinitely customizable, from changing the head out, to giving it a wig, replacing the weighted tea cup, and even making the clothing more cosplay-like. Another modification is to connect the feet (initially fixed to the base plate) to a jiggle bar to make it look like the doll is walking as it moves. Some of the pictures in the mook show the doll carrying edamame and a small tea bottle.
The default clothing is an Edo-era 3-layer kimono and hakuma (pleated pants) outfit. The material is made up of heavy paper with foil details. Instead, I decided to use colored origami paper with a floral pattern. It took over an hour to trace out the pattern onto the origami paper, and then another 4 hours to assemble everything. (The doll itself has about 20 pieces and took 1 hour to build, and then a couple hours to unbuild and troubleshoot.) While the final result looks pretty good, the paper is too stiff and bulky and prevents the doll’s arms from moving, locking the thing up. So, I either take the outfit off and have a naked doll that runs, or leave it on and have an attractive art object to place on my shelf that doesn’t actually do anything. Sigh. The hat was my idea, and was made from black construction paper.
The mook is great, though, with stories on old windup dolls; articles featuring Honda’s Asimo robot (Honda is a sponsor of this volume); sections on other wind-up machines, wood carving tools, and robots; and various kinds of Stirling and steam engines. There’s also a how-to for making your own gears and a feature story on an author assembling a 17-jewel wrist watch. This kit is worth getting just because this kind of stuff is really cool (although you’d probably be better off getting the higher-quality 6000 yen ($65) version of the doll if you really want a working version.)