Clocks, Watches/Grandfather Clock


QUESTION: I have a clock with the Hermle 461-850 movement.  It stops running every morning at exactly 12:27am.  What do you think is the problem?  Could there be some trash in one of the gears?

ANSWER: Les, there are many reasons for a clock stopping.  When it stops at a certain time, the number of causes is decreased.  Most clocks complete a running cycle twice a day.  In other words, from 12 am to 12 pm is one cycle and 12 pm to 12 am is the second cycle.  It is possible that a lever or mechanism is so close to being out of adjustment that a temperature difference, say cooler in the middle of the night, could cause it to fail.  I could only watch it to determine the cause.  However, the first thing to come to mind is that there is one mechanism that cycles once a day.  That is the moon dial.  There are some moon dials that advance twice a day, but I am pretty sure the type of moon dial on your clock is the once a day type.  It could be jamming when it tries to advance.  To test this, use the minute hand to advance the clock 12 hours.  See if it stops at 12:27 in the middle of the day.  If not, as I explained before, it could be another mechanism that is close to being out of adjustment.  Let me know what you find and we'll go from there.

John Newman
Old Prattvillage
Prattville, Alabama

Sorry I assumed the moon dial and went into so much detail.  Try checking the hour hand to see if it is pushed on far enough.  If it isn't, it will interfere with the minute hand and stop the clock.  Also a bent handshaft can cause the problem.  Again, this is one of the situations that a small bit of interference, influenced by temperature change and lifting of the chime lever in preparation for the chim action, can result in the stopping of the clock.  This is one of thoses conditions that is rare but does happen.  Rather like "The Perfect Storm" or the "Alignment of the Planets".  In the clock business we do a lot of diagnostics mixed with educated guessing.

John Newman  

---------- FOLLOW-UP ----------

QUESTION: John  -  I think you have solved my problem.  The clock was stopping at 12:27am and pm.  You said to check to see if the minute hand was interfering with the hour hand. It was the hour hand that was interfering with the seconds hand! I had to look quite closely to see that.  Thank you much for your advice.

Les, I would think that I really didn't solve your problem, but at least set you on the track to see what what was happening.  Good job!  The hour hand interfering with the seconds hand does happen occasionally, but since it was happening only at 12:27 am and not at 12:27 pm, I did not consider that.  But then we find some strange situations with clocks.  Also, if the hour and minute hands are bent toward each other they can interfere with each other at 12:00, 1:05, 2:10, etc.

Glad you solved the problem.

John Newman

Clocks, Watches

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John Newman


As much as I would like to offer values of clocks, I am not a certified appraiser and will not venture into giving an unresearched guess. There is very little published information on what I consider to be the value of "modern production clocks". Considerations are what the clock originally sold for, the condition of the case and movement, and particularly the area in which you live, the demand and the economy. ALSO, WATCHES ARE NOT MY FIELD. However, I can advise the clock owner on proper maintenance of a clock to keep it running, small corrections and adjustments and how to move a clock without damaging it. I can also advise on obtaining parts for clocks. It helps if you can send any information on the clock movement which is usually found on the back plate of the movement. I have been a clockmaker for about 35 years and was plant engineer in the mid 90's and later operations and engineering consultant at Emperor Clock Company in Fairhope, Alabama. I now have my own clock shop.


One of my greatest accomplishments was traveling to China to assist a clock factory in building clocks to the standards which we required. With the proper specifications and quality control, some beautiful clock cases were built. The factory people from the wood carvers to the plant manager were very congenial, friendly and I left a lot of wonderful friends when I returned from my trips.

NAWCC (National Association of Watch and Clock Collectors) 30 years Prattville, Alabama Chamber of Commerce

Horological Times, a publication of the American Watch and Clockmakers Instute. Collaberated column author, with Photos and ideas for clock movement conversion article.

Associate of Science Mechanical Engineering Technology Emperor Introductory Clock Repair (Eventually taught a portion of the class after becoming employee)

Awards and Honors
Small Business of the Quarter (Prattville, Alabama) Leadership Class of 2009 (Autauga County, Alabama)

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