I work at a movie theatre, and ever since we switched to digital projection (2012), some of the old 35mm projectors have been gathering dust in a dark corner of our projection booth. I’ve always wanted to get one of them working again and use it as a display piece for visitors. Recently I took the plunge and got it in working order again. Here’s the full story:

First of all, I took off one of the panels that houses most of the drive mechanics: belts, pulleys, counterweights etc. I took measurements, and recreated the panel in clear acrylic using the LAYZOR. I used the protective sheet as a template and sandblasted our company logo on it.

Here are some pictures of the finished panel:

After some electronics rerouting, I managed to get the motor spinning again (using the original switches).

It is looking a hell of a lot cooler already, especially when in operation. And it’s perfectly safe for curious fingers, which is kind of important, since we host children’s birthday parties with a behind-the-scenes tour on a regular basis. Here’s a video:

Speaking of children, wouldn’t it be cool to have them solve some kind of integrated escape-room puzzle so they can ‘restore the power’ to the machine and see it turning by their own doing? I certainly thought so, and that’s exactly what I did.

I made a connect-the-wires ‘switchboard’-style game from some old cables and an arduino mini. There’s a diagram they can follow, and there’s different length cables. So there is some strategy involved, but it’s still easy and intuitive enough to have even the youngest ones figure it out by themselves.

The cable rack was made on the Shapeoko. I also provided a ‘bypass’ switch if we just want it to work without the game.

Here’s a video showing the game and bypass mode: