Expert: Martin Meyer - 6/14/2008

Question
Hello - I have a Cornwall wall clock with a Franz Hermle movement (#131-030, I think).  It was built in 1978. We received it as a gift 2 years ago. It ran slow (losing about 5 min every 3-4 days) for the first six months, then stopped altogether. I think we may have been over winding it.  We took it to a repair shop and $80 later it's running again, but now it does not always chime and it stops alot.  I've also noticed that when it does not chime, a very light tap near the left winder, and it starts to chime. We've taken it to the shop twice, but it still stops pretty regularly (usually not long after it misses a chime).  Any suggestions that you may have would be greatly appreciated. - Thanks, Taylor

Answer
Hi Taylor,

First, overwinding is probably the most common misconception about clocks. There is really no such thing as overwinding, other than winding so hard that one breaks the mainspring, an event that you can't miss due to the loud sound and vibration that it makes.

Your clock's stopping could be due to the pendulum being "out of beat", a need for lubrication, or wear in the movement's bearings. Please browse my previous answers for information on checking and setting the beat on wall clocks. When a clock is out of beat it usually runs for a couple to a few minutes, then stops. Wear in the bearings is more likely to cause the clock to stop erratically, perhaps running for a day one time, then for only an hour another time. As far as lubrication, I would guess that this was done by the repair shop, as that is usually a standard part of service.

Thirty years old is about twice the expected lifespan of this small movement. Unless it has been overhauled and all worn bearings rebushed, it is highly likely that the movement is worn out. The fact that the hour strike will start with a tap on the clock tends to confirm this. This indicates that the strike is not jammed, but stalled, that is, the cumulative friction of worn bearings (or lack of lubrication) prevents the clock from striking, and a slight push (or tap) gets it moving again. The best repair for a worn out movement is to replace it with a new movement, rather than overhaul the old movement. The Hermle 131-030 movement is still in production and available. http://www.clockmasteronline.com