Friday, November 15, 2013

Forty Million Clicks

The clock of "forty million clicks". Once a minute for 55 years.
As a teenager I enjoyed finding and restoring vintage clocks. Or just tinkering and restoring anything old, especially if it was mechanical. I was fortunate to live near my grandfather throughout those years, and he was always ready for an outing to an auction to look for things like that. At a hardware store auction we found a tarnished brass Primus stove, like Sir Edmund Hillary would have used on Everest. Polished up it was used for many meals on backpacking trips, and brewing up roaring pots of tea on cross-country ski outings.

The "forty million click" clock was scored at a county school auction in the late 1950's. It was painted green, and had been a classroom clock, the kind that jumps ahead one minute at a time in response to a signal from the master clock in the principal's office, each jerk of the minute hand intently observed by the class as it crept toward the top of the hour and the end of the period. Suspecting it might be solid copper I turned it over and verified that by making a small scratch on the inside with my car key. We took it home with a $2 bid.
A solenoid, activated by a signal sent at one-minute intervals from the clock in the principal's office, once operated the escapement mechanism.
I removed the solenoid, and in its place installed a 1-rpm electric motor (beneath the aluminum plate). The wheel (from an Erector Set) rotates the attached lever with a bearing on the end once per minute to activate that long lever and in turn the escapement that moves the minute hand ahead. Kinda like the escapement in a typewriter. 

In the workshop I found enough electomechanical odds and ends to produce a pulse with the correct voltage once a minute to operate the solenoid in the clock, which in turn moved it ahead one minute at a time. Basically a "principal's clock simulator". While it worked fine, we only tolerated the racket for a day or so before I had it back down in the workshop. The solution was a small 110 volt motor geared down to 1 rpm obtained from Edmund Scientific Company, and a hand-crafted linkage  to operate the escapement. It had been keeping time for our family ever since.

The bearing is activating the escapement lever ...
That's forty million and one activations. The shape of the tip on the end of the escapement lever is designed to gently and quietly operate the escapement. It was formed from a piece of aluminum by a teenage me 55 years ago, and is still doing its job. 

But some time ago the clock became erratic, and I had to pull the plug. After some forty million clicks. Due to my "typewriter problem" it has taken me a while to finally take it down to find the problem. Which turned out to be a loose screw. Once the clock was operating once again, I was going to strip and re-polish it, then re-coat it with clear lacquer. But my wife wisely suggested that I leave it as is with its forty million click patina. So I cleaned it up a bit, polished the glass, and re-hung it above the wood stove and flat-screen TV. Good to go for another forty million or so.


  1. I never heard of such a clock but it makes perfect sense. It is comforting to visit one's teenage self and discover the part-formed human was capable of sending a message so far into the future. The UK's version of Erector Set was Meccano.

    1. "...a message into the future"; That's it exactly, Rob.

  2. I like your clock! And that's very ingenious! I reckon that means all the classrooms had a clock like that, and all ticked at exactly the same time as the principal's office's, thanks to that signal sent via a cable? Very clever!

    And it IS a big clock! You don't really get a sense of its scale until you see the photo of its face standing next to you on your workbench!

    Congratulations! It was a very good work!

    PS: in Mexico, the Erector Set was called "Mecano"... just like that old Spanish pop music group.

  3. I've never seen a clock like that although we had similar military looking ones in our school. You are fortunate to have such a wonderful looking and still working clock. I did not realize how large the clock was until I saw it on your workbench. The size makes it all the nicer.

  4. Really a beautiful clock! How nice to have it with you for so long, and to be able to keep it running.

  5. Sweet! Thanks for keeping it going and telling us about it.
    == Michael Höhne