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Dec 24, 2012 3:40 pm
Dec 24, 2012 3:40 pm
Subject: Re: Smiths Clock - How to reverse the polarity
Christian - thanks for posting this.
A few small points were over-looked, in your otherwise excellent write up, which is very useful indeed.
1. Given that the clock on your car has not been used in 20 years plus, the pivots and plate pivot-holes will have dried out and there will be congealed oil and dust in them. I would recommend that you get yourself some clock oil and an oiler from "Cousins watch and clock spares". To do this for all pivots; you will need to remove the dial and hands, so you can lube the pivots from both ends of the steel arbors. With clock oil, less is more...
2. Take very, very great care when handling the clock when it’s out of the case, as the balance wheel and hair spring are partially exposed and easily knocked. If you knock the hairspring out of parallel, you will not be able to true it, a watch/clock maker will be required.
[Tweezers and other fine tools are preferred for this work, using a very clean work, tool free surface, with a large sheet of white paper to work on].
3. This clock movement does not have a pendulum, it has a simple balance wheel arrangement. If you made a mark with a small amount of white tipex, when the clock is disconnected from 12 volts at the nominal 12 o'clock position, then reconnect to 12 volts, you will be able to quickly see how "gunged" up the pivots and pivot holes are by the amplitude of the "balance wheel". This is connected to the internal pallets and escape wheel.
When this escapement, is set up properly, you will have a nice clean tick-tock sound. It should beat at around 150 bpm, when correctly set up again after changing polarity.
Do note that a mechanical clock is not self starting, either you set it in motion by hand or when the car starts, the movement will start up. So disconnecting the battery will stop the clock, and it will not always start up when re-connected.
4. if you have been able to get the clock to keep decent time, don't expect quartz accuracy from any cheap mechanical car clock, then all is fine. If not, and having been down this road before, using a suitable capacitor and resistor will set things right. Then fine adjustment can be made via adjuster to front of clock, which will alter the position of curb pins with relation to the balance spring.
5. It’s not a bad idea to put an inline fuse in the power lead when refitting the clock back in the dash to protect all that hard work – 250mA is ample.
Christian - thanks for posting this.
A few small points were over-looked, in your otherwise excellent write up, which is very useful indeed.
1. Given that the clock on your car has not been used in 20 years plus, the pivots and plate pivot-holes will have dried out and there will be congealed oil and dust in them. I would recommend that you get yourself some clock oil and an oiler from "Cousins watch and clock spares". To do this for all pivots; you will need to remove the dial and hands, so you can lube the pivots from both ends of the steel arbors. With clock oil, less is more...
2. Take very, very great care when handling the clock when it’s out of the case, as the balance wheel and hair spring are partially exposed and easily knocked. If you knock the hairspring out of parallel, you will not be able to true it, a watch/clock maker will be required.
[Tweezers and other fine tools are preferred for this work, using a very clean work, tool free surface, with a large sheet of white paper to work on].
3. This clock movement does not have a pendulum, it has a simple balance wheel arrangement. If you made a mark with a small amount of white tipex, when the clock is disconnected from 12 volts at the nominal 12 o'clock position, then reconnect to 12 volts, you will be able to quickly see how "gunged" up the pivots and pivot holes are by the amplitude of the "balance wheel". This is connected to the internal pallets and escape wheel.
When this escapement, is set up properly, you will have a nice clean tick-tock sound. It should beat at around 150 bpm, when correctly set up again after changing polarity.
Do note that a mechanical clock is not self starting, either you set it in motion by hand or when the car starts, the movement will start up. So disconnecting the battery will stop the clock, and it will not always start up when re-connected.
4. if you have been able to get the clock to keep decent time, don't expect quartz accuracy from any cheap mechanical car clock, then all is fine. If not, and having been down this road before, using a suitable capacitor and resistor will set things right. Then fine adjustment can be made via adjuster to front of clock, which will alter the position of curb pins with relation to the balance spring.
5. It’s not a bad idea to put an inline fuse in the power lead when refitting the clock back in the dash to protect all that hard work – 250mA is ample.