Wednesday, March 18, 2009

Gakken kits: #13 and #16



Kit #13: Kaleidoscope (2100 yen). Not all Gakken kits are made of the same high-quality materials. Or, it might be that some of the materials degrade faster over time than others do. In any case, this kit (and the planetarium) had a part that shattered too easily. The light bulb for this kit also burned out within 12 hours of assembling it, which was about 15 minutes of actual use, but fortunately I could find a grocery store that carried spare bulbs pretty easily. It cost about 120 yen ($1) for a package of 2 replacement bulbs.

Kaleidoscopes are generally very straight-forward things, conceptually - three mirrors facing each other, with bright sparklies at one end and a protected eye piece at the other. Aim at a light source, rotate the container of sparklies, and you get to see very elaborate, complex patterns, regardless of how simple or plain the sparklies themselves might be. Of course, the first step at making the kaleidoscope more interesting is to just fancy up the outer case, adding external design work, or making the case out of brass or other materials. The next step is to change the mirrors, either making them taper to an angle at one end, or form them into a box with the aperture in the middle of one side, and the eye hole in an opposite corner. What Gakken did was to turn their kaleidoscope into a projector, putting batteries and a lamp into the base unit, and adding lenses at the end of the tube to focus the light either on a nearby sheet of paper or on the far wall. There's also an option to look directly into the thing ala a microscope. The kit has about 20 parts and took between 1 and 2 hours to build.

For this kit, the sparklies consist of some small colored beads and glitter placed in a clear plastic tube. The suspension liquid could be plain water, while Gakken suggests adding a little wood glue and sugar syrup as thickeners. I tried their suggestion, and the result was an ugly cloudy mess that I just tossed out right away. Instead, I went with straight artificial sweetener syrup, which works fine. The problem was that when I put the end cap in the tube as instructed, part of the end of the tube broke off. Fortunately, the break wasn't so bad as to make the tube useless; I just wrapped the end up in heavy tape and there's been only a very small amount of leaking. I'm planning on finding more tubes so I can try some of the other suggested sparklies (which include using colorful flowers, cooking ingredients, insulated wire, stone fragments and even small insects). The kit's fairly small and easy to store when not in use.

The mook contains a biography on Sir David Brewster, who wrote the book on kaleidoscopes in 1816, and received a patent for his design in 1817, although the idea was previously known to the ancient Greeks. There are examples of various kaleidoscope designs and products (with plans for making them yourself), plus explanations of optics and how kaleidoscopes work. There's a section on how to build Gakken's 3-vacuum tube radio, as well as a look at Zeno's Paradoxes. Another article shows the construction of Tokyo Tower, and part of the city's skyline, while there's also a story on Niels Bohr (who visited Japan in 1937). There aren't as many DIY projects this time, but some of the examples of combining art with physics are easy to replicate (such as the anamorphic paintings, which are woefully under-appreciated). Both the kit and mook are worth getting if you like bright sparkly things.



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 and lamination that threatens to delaminate as you build it. 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.)

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