Taking Things Apart

Lately, whenever some mechanical or electrical object in our house dies, I put it downstairs in the basement until we can take it apart. The boys like to dismantle things to see what’s inside.

M and I took apart an old nightlight he’s had in his room for several years – it has a light inside, and outside are some rotating plastic scenes of underwater life. When it’s running, it looks a little like an aquarium. During the process of taking it apart, we saw how a light socket delivers electricity to a light bulb, how an on/off switch works (using a continuity tester), and how the gears connected to a motor rotated the two underwater scenes in opposite directions of each other. We also took the motor, the switch, and the gears out and put them into a bin of used parts so we can use them for some other project in the future . I’m trying to get M to think of something we can make, maybe a decoration for Halloween.

We took apart an old boom box a while back, and M extracted the cassette player – the buttons with long arms on them, and the mechanical gears, etc. that are used to control the magnetic heads and the motor. This is a neat component because most of it is mechanical – pushing the Stop button down might pop another button up, and some buttons can only be pushed down if you’re pushing a second button down simultaneously (Record and Play). The pause button stays down if you press it once, then returns to the top position when you press it again. If you push the Stop/Eject button and none of the other buttons are down, the tape will eject. It’s all mechanical – there’s no computer driving it.

A while back K and I took apart a remote control unit for a remote control car. It had two rocker switches in it – one for forward/back and one for right/left. We figured out how many different combinations of settings there could be using the two switches. We could also see the path the signals took from the switches to the transmitter by following wires and/or circuit board connections. We turned off all the lights, but we couldn’t see the radio waves going from the remote to the car.

We have a few more things on tap to take apart - a small vacuum cleaner, a couple of broken CD ROM drives, an ink jet printer that stopped working, and another remote control. That should keep us busy for a while.

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I'm intrigued by mechanical things as much as digital things. A clock that runs on gears is a lot more interesting to look at and take apart than a clock that runs off a chip. A clock that runs on gears does something, whereas a clock that runs off a chip just sits there.

The earliest computers were actually ingeniously-designed gear-based mechanical objects. They could be quite sophisticated. It would be fun to build one, and people have built reproductions, but you'd have to know a lot about metalworking.

Similarly, it would be fun to build a car that didn't rely on microchips and on-board computers, like some of the first cars that were built. Not similarly, it would be fun to turn mechanical operations, like steering a car or pressing the brake pedal, into computerized operations.

Mechanical controls like a brake or accelerator pedal in a car can be replaced with electronic equivalents – consider a car equipped with hand controls for someone who can’t use his legs when driving. A steering wheel controls the rack and pinion gears to some extent, but with power-assisted steering, it seems like it wouldn’t be too hard to eliminate the steering wheel and put in a few buttons – maybe a remote control you could hold in your hand to go right or left. How about a Wii controller? Or a cell phone - since people like to talk on the phone while they drive, you could put in voice-activated steering and kill two birds (or pedestrians) with one stone. For example, if you say “Car Left” your car will turn left. That would be handy. So you could talk on your phone to your friend while you’re driving and still steer your car: “I’ll be home from the store in about 10 minutes - CAR RIGHT, CAR RIGHT, CAR STRAIGHT - but I have to tell you about this guy who was blocking the seafood counter with AAAAGH! CAR LEFT CAR LEFT CAR LEFT CAR STOP CAR STOP CAR STOP CAR LEFT CAR LEFT AAAAAGH!”

Maybe it's not such a good idea.