Westclox car clock runs fast

Posted: Tue Sep 30, 2008 11:11 pm     Post subject: Westclox car clock runs fast

Hi,

I don't know if anyone remembers, I was here a while back about a late 1800s Lenzkirch in a Meissen case that I took to be serviced.

Now I've got a clock that's a lot less unique than that: the dash clock for a 1980 Malibu. It's a non-quartz Westclox. I had bought it from a guy that said he had it apart to oil (with correct clock oil). It has been running okay for months, but way too fast. Overnight it will gain 45 minutes. About 2 minutes in an hour.

There is no speed adjustment on the face of the clock. The car manual says that turning the time-set knob back more than 5 minutes will automatically slow the clock down. But, I've been setting it back over an hour every other day, it never slows. Is there an adjustment I can make internally? Or better yet, a service manual for this type of clock? I don't mind taking this one apart to see if I can fix it, not quite as delicate as the Lenzkirch!

Thanks,
-Michael

Posted: Thu Oct 02, 2008 8:00 pm     Post subject:

Could it be that the voltage is not proper. It is designed to run at one revolution per minute at 12 volts input, probably. If the input voltage varies, it could possibly affect the rpm of the motor. Just a hunch!

Posted: Thu Oct 02, 2008 8:50 pm     Post subject:

That would be an easy fix, but unfortunately these clocks don't depend on the voltage for time keeping. Of course being DC, it has no frequency, so can't run the motor off the 60Hz like an AC clock. It has a set of points that close ever minute or so, which winds a spring, to keep the movement running.

I've seen inside similar clocks before, and I know they have adjustments on the hair spring, but I don't know much else. I don't know why the clock doesn't slow down with normal adjustment, the way it is supposed to.