Make: Volume 95

in a similar manner, but are a bit more efficient.)

That was really the big moment — the first motor

spinning — because now it’s just a matter of scale.

On weekends, Hilary and I would go to

secondhand stores to buy anything that moved.

We would take things apart and try to understand

how they functioned. I started working with little

DC motors with pinion gears. (I didn’t know what

that was called at the time, but I do now.) I took a

practice pad, a kind of a pretend drum, and taped

two DC motors to the side. I drilled holes in two

pencils, stuck them onto the pinion gears, and

then just had the pencils tap by turning the motors

on and off ...