I had built a time-keeping clock from Meccano parts in 1960(*), but that was "easy" because Meccano had all the characteristics I needed. In 1982 I had wanted to build a Lego clock from Technic parts just to see if it could be done.
Lego poses some challenges:
- you cannot put a gear wheel on an axle and let it turn free from the axle's own rotation. This freedom is needed to turn the hour hand and the minute hand independently of each other: only one of them can be fixed to the common axle, the other has to be driven in another way. So you have to find a special wheel with a round hole.
- there are only very few gear ratios possible, would the ones I needed be present?
In 1982 there was no other way than to drill a 5mm hole in one gear wheel to solve the first problem. The second problem proved to be fairly easy.
But I never got further than proving to Lego that a hole was needed, and did not build more than the hour-minute hands assembly.
In February 2003, looking for a moment of unusual relaxation, I undertook to build a complete pendulum clock, because I wanted to learn how an escape mechanism works.
I completed a working version in a few evenings of tinkering. It ran well and did everything a chronometer should do (but of course it was not as precise in timekeeping!). Then it occurred to me that maybe others had done this before and published their works on the web. Not surprisingly some had:
- Zef Damen in the Netherlands,
- Eric Harshbarger (in the UK?)
- Leo Wins in the Netherlands,
- ...
Seeing their brilliant models, and corresponding with them via e-mail, I found that nevertheless my clock had two characteristics that none of the others possessed:
- wind up without stopping the timekeeping,
- running for more than an entire day.
I also believe my escape mechanism is more robust than any I found. My clock was definitely better, but it did not look nice at all.
Therefore, I reworked my model to make it look better before publishing it. The result is what you see here; it still is not very nice perhaps, but it works well.
There is a list of Lego clocks by Amnon Silverstein
(*) and some do a lot better: Antonio Valero for example.
