Expert: Martin Meyer - 7/29/2009

Question
My GF clock has, after 23 years, developed a problem with the chimes. I know what broke - have no idea what it is called.  Where can I find a manual on the movement so I can intelligently converse with someone about a replacement part? The movement is an 1161-853BS 94cm.  The part is a brass wheel about 3/8" in dia with a collar of about 3/16" in dia.  It has 2 slotted set screws to secure the collar to the shaft. It also has 1 single pin inserted near the outer perimeter that is the hook point for 2 levers that control the hour strike and the 1/4 hour chimes.  This pin broke off and the chimes never stop.  I have repaired it using a small steel finish nail but I think the original steel part was hardened.  Can you help?

Answer
Hi Rodger,

This is a very common problem with Hermle movements which are quite old. Unfortunately, terminology in the clock profession is far from standardized. This part is variously called the "locking disk", "chime locking cam" and "chime lock piece". First, your repair may turn out to be perfectly adequate. I have successfully replaced the pin on this part with mild steel pins. Replacements for this part are no longer available, because Hermle has changed the design of the part to prevent this problem from occurring. The replacement part which is available requires machining off a small amount of metal to make it fit on the old style movement. You could probably do this adequately with careful hand filing. This part is available from Black Forest Imports (www.blackforestimports.com)

There is no one manual for this particular movement, but there are several publications which might be helpful. They are the "Hermle Service Manual", the "Hermle Movement Catalog", and the "Hermle Spare Parts Catalog". The Spare Parts Catalog has excellent exploded diagrams of all movements, but the parts' names are, unfortunately, only in German. These books are all available from Timesavers (www.timesavers.com).
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