Quote:
Originally Posted by Hedgepig1957
It was always a perfect self-starter, sometimes running backwards before correcting itself, and never lost or gained.
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Same principle as the Smith's Sectric movement - the motor can start in either direction but, if it goes backwards, it winds up a little spring which, when fully wound, flicks it back the right way.
The accuracy is determined by the frequency accuracy of the mains supply which, by law, is 50Hz ±0.5Hz. Furthermore, if the supply runs slow when demand is high, it has to be corrected so that clocks are exactly right by 6am the following day.
Normally, there isn't much variation - as I write this the frequency is 50.053Hz. You can always check it for yourself, if you are interested, at
http://www.gridwatch.templar.co.uk/
Check the coil for continuity but if it is like the Sectric movements it is most likely that the motor has seized. Just trickling a drop of light machine oil -
not WD40! - into the bearings is usually all that is needed.
If the movement is like the Sectric one, the rotor will be very fragile so take care not to apply any force to it. If it shatters, that will almost certainly spell the end for your clock!