Repair: Lemania 2220 Nuclear Submarine Chronograph

We’ve had one of these before, and quite some time ago… These are quite rare, and were used in the British nuclear submarine fleet. As you can’t have luminous compound there (it would set off all sorts of radiation alarms), they have no luminous compound, but a while dial with black markings and hands, so that the watch can be read nicely in the low light conditions in a submarine.

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BestFit Catalogues scanned and available for download, lots of other technical manuals …

It’s always been a thorn in my side that old BestFit catalogues go for a lot of money (I paid £60 for mine), and that they are hard to get.

Finally, I got around to cut mine up and scan them in. I also ran some ocr software over them, so they are searchable.









I hope you find them useful – feel free to download and store a copy, but please don’t try to sell the pdfs on or claim that they are yours. Click on the links to get to the pdf files, or go to

Probably won’t get a lot of money now if I want to sell my cut-up catalogues 😉

Whilst we are at it, I have also compiled a large amount of technical information sheets, and they are all available at – enjoy.

CNC Update

I’ve been busy with my CNC milling machine, and anything flat (minute recorder springs, setting lever springs, etc.) is no problem at all.

The final frontier are of course wheels and pinions. The fourth axis motor that came with the milling machine wasn’t very accurate, so I had to modify it in order to be usable for watch parts.

A good indicator how small you can machine is making a small pinion. The one in the photo measures 2.5mm across, and has 18 teeth, so that’s not bad for a start. Continue reading

Merry Christmas and a Happy New Year

To all our readers who celebrate the season – we wish you a merry Christmas and a Happy New Year. And for our readers and customers all over the world who celebrate something else, or don’t celebrate at this time of the year, we do of course wish you our finest season’s greetings, and a Happy New Year!

CNC machine saves a Prince!

Brendan sent in this Rolex Prince from the 1930’s complaining that the crown felt detached from the movement when trying to set the hands.

The movement is removed from its case and the dial and hands are taken off to investigate what is causing the problem. I test the keyless works and it is observed that when the crown is turned in hand setting mode the sliding pinion falls below the intermediate winding wheel making setting the hands impossible. Under the microscope it is just possible to see the end of the stem moving about on the other side of the movement.

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