Wednesday, August 19, 2009

Gakken Kits: #18 and #20

I'd been holding off on buying more of the Otona no Kagaku (Adult Science) kits for the last couple of months in order to recover from all the spending I'd done on the synth kit and keyboard. I'd also been keeping myself busy with the microprocessor and synth kits so I hadn't needed to get any of the other kits until now. But, the time has come to start back up again. I'm not going to bother with the out-of-print kits because collectors have jacked the prices up so high on them. What's left are kits 18, 20, 22 and 23. And maybe the speaker.

Kit 20: Bird Organ, 2500 yen (about $25 USD). Looking at the picture on the cover, it's easy to think that this is some kind of mechanical music box. It's not. Like the name implies, this is actually a very small pipe organ. The mechanism is very clever, and is based on a French design dating back to at least 1751. The original box used a hand crank to drive a bellows for air flow, while rotating a wooden cylinder covered with little brass pins, The pins would open up stops on the pipes and air from the bellows through the pipes would produce your music. Change the cylinder to play a different song. This is pretty much the concept of the instrument played by organ grinders for trained monkeys to dance to.

The Gakken kit is a simpler approach. First, start with the hand crank, and set up two separate gear chains - one to pull a sheet of paper through the organ, the other connected to a cam. The cam makes a small piston move up and down, creating the air flow through a chamber to the openings in the base leading to the pipes (thus ensuring even air pressure to all pipes). Holes in the paper allow air flow to specific pipes. The pipes are small, so the sounds are high-pitched like a canary, hence the name "bird organ". A small scissors-like punch is included to punch out the holes in the paper, and there are several pages of sheet music in the mook you can cut out and play. Of course, you can make your own sheet music, too.

Music Sheet List:
Tuning Card
Amazing Grace
Kotori no echuudo (Small Bird Etude)
kokyou no hitobito (Hometown Folks)
Ryoshu (Travel Nostalgia)
Tondetta Banana (Flying Banana)

(Closeup of the underside of the base. The gear on the right advances the paper, and the circular shape on the left is the piston that acts as the bellows for air flow.)

The kit consists of about 20 pieces, not including the screws, and took about 40 minutes to assemble. The authors recommend greasing the moving parts, but I didn't have grease at the time and didn't bother with it. The really time-consuming part is punching out the holes in the sheets. The really difficult part (for someone tone-deaf like myself) is moving the rubber stoppers in the pipes to tune them. There's a "tuning sheet" included in the book that runs through the scales, which didn't help at all.

(Assembled, but without the paper. If you turned the crank now, all of the whistles would sound at one time.)

The mook runs through the history of barrel organs, church organs and wind-up metal music boxes, including lots of nice photos and the theory of wind-produced music. There's a story on Kuricorder Quartet and their reactions to the bird organ, and one article on modding the kit (adding a bellows and putting it into a larger wooden case). Another article takes the reader behind the scenes at the clock tower in Bern, Switzerland. Other pieces describe how different birds produce distinctive songs, and the affects of sound on the human brain. Finally, there's a piece on the Golden Gate Bridge and how it relates to the discovery of the structure of DNA by Crick and Watson.

(With the tuning card.)

There are a number of links to other websites:

Roller Canary Club (fans of pipe organs)
Kuricorder Quartet (musician page)
Roland (electronic pipe organ)
Jobin Living Museum
Le Musee CIMA
Musee Baud
Museum fur Musikautomaten
Naoki Wakita Organ Company

This is a very cool kit for anyone that likes wind instruments and church organs, but it's not practical as an instrument. Air escapes from the bellows around the paper sheet. If you hold the pipe section down hard enough to prevent air leakage, you prevent the paper from advancing through the organ. Don't press so hard, and while the paper will advance, the air leaks and the music stops. When you hit a section of the paper that doesn't have holes, the air pressure buildup from the piston makes the crank hard to turn and the paper doesn't advance. If you turn the crank fast enough, the music will play, but it will be unrecognizable. This is another nice idea that lends itself to decoration, but will spend all its time on the shelf because it really doesn't work *at all*. Get the mook just to better understand the theory involved, but you can throw the kit into the trash.

Kit 18: Wind-Powered Generator, 2300 yen (about $23 USD). Back in the world of electron flow, we have a small wind-powered electrical generator, which is good for primarily running a night light, if you need a wind-powered night light.

(Front view. Notice the plastic wrap around the neck of the soda bottle. This is to keep the soda from getting on the pipe stem. For reference, the pipe stem is about 4-5" tall.)

Most people have at least a vague understanding of how DC motors work. Wrap wire around a core, and when you connect the wire to a battery, you make an electromagnet. Have real magnets located in a housing and put the coil on a spindle, and when the coil is connected to power it gets attracted to a magnet, but then the connection gets cut. The momentum of the turning spindle brings the spindle back into contact with the current and the process repeats. In essence. Real motors are more sophisticated than that, but this is the way kit #21, the DC car, works.

(From the back.)

Interestingly, the reverse process also works. Pass a magnet near a coil of wire and electricity gets produced through the coil. Put some magnets in a housing, and the coil back on the spindle, but now attach a prop blade to the spindle and when the wind turns the prop, the motor morphs into an electric generator. The Gakken kit produces about 1.5V at normal wind speeds (maybe 5-10 MPH), just enough to make an LED turn on. The kit supplies 1 red LED, but you can use other colors if you like (with the caveat that LEDs of other colors usually have higher turn-on voltages, so the wind will need to be stronger for them).

This is a very simple kit. I was hoping/dreading that I'd have to wrap the wire to make the coil, but it's provided as a standard commercial AC motor. 15 parts, and a suggested 20 minute assembly time. It took me about 20 minutes, too, because I wanted to tape the prop fins on the backing fingers "just right". Applying the double-sided tape to the prop fins and backing fingers took the most time. Really, it's just a motor wired to an LED inside a housing intended to mount onto a soda bottle. There's a little plastic piece underneath the housing that lets you restrict the housing rotation to just a 90-degree swing, or allow a full 360-degree rotation. Suggested mods include decorating the prop fins, mounting the generator on a small child or Christmas tree, connecting the motor to a music chip from a greeting card, and building a bigger coil. Mounting suggestions include the soda bottle or a PVC pipe, or taking the soda bottle and cutting it up to make a support for taping it to a fence railing.

The mook is "green". At least half of the articles concern alternative energy sources (solar panels, super-massive wind generators, geothermal and beamed energy); the theory behind wind-powered generators; the mechanisms behind green house gas production; and, projected global warming temperature maps. Other articles include suggestions for housings for Gakken's speaker kit; theory of operations for Gakken's vacuum tube amplifier (plus a photo showing it connected to the theremin kit); photos of a "baka-robo" (silly robot) contest; and a short story with the editor learning how to weld his own steel chair.

If you want to learn how to make your own, larger, wind-powered generator, this is a great kit to start from. If you want a wind-powered night light, GET THIS KIT. Otherwise, this kit doesn't do much. You need a pretty stiff wind for it to generate enough electricity to turn the LED on. It's an AC motor, so the LED only stays lit for a fraction of the time. I did test it by holding the generator in front of the air conditioner, and the LED does light up within about a foot of the air vent, but there's a very noticeable flicker; ideal for attracting UFOs.

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