ATECH : Adapting A Spirograph Machine For External Switch Use

The inside of the Spirograph Machine. All three buttons are momentary, so keeping them shorted (pressed) doesn't increase the spin time. You have to keep pressing to trigger a new cycle.

That white blob toward the center is the rotation sensor. That's how it knows how many times it has gone around.

There are unpopulated capacitor install points at C4, C5, and C6. Each corresponds to a button. The easiest to get at it C6, which is also the fewest rotations.

Some sloppy soldering got the job done on this Spirograph.

Drill a hole for the pigtail and feed through first. Small clamps are your friend -- Omnifixo are expensive but worth it. Kapton or other tape can help hold the leads while you solder (or not -- my generic kapton is awful). I use a small (C210) soldering iron for this sort of work. Much much easier to use. For the ground connection, I used an existing point (away from C6) -- because I *knew* I'd mess up the soldering otherwise. 🙂 Double-cable-ties give strain relief.

Watch it spin.