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Clocks, Watches/how to set moon dial on Emperor grandfather clock


We recently came into possession from a family member of an Emperor grandfather clock. The movement has the markings Erhard Jauch Uhrenfabrik and the numbers 20019, and 110 5 73. The clock chimes and strikes properly, and seems to run just fine, but the instructions on how to set the moon phase dial have been lost. Is there a way to obtain a copy, or would you be able to provide instructions? Thanks!

Sue, the moon dial rotates and keeps in alignment with the phases of the moon.  The numbers, from 1 to 29-1/2 are the days of the phases, not the days of the month.  Looking in the back of the clock, the moon dial looks like a circular saw blade.  You reach in and turn it clockwise to set it.  Sometimes the moon dials can be turned from the front by gently pushing and turning the dial with a pencil eraser.  When trying to turn the moon dial, if seems jammed, it is probably in the middle of advancing and you should wait an hour or so before trying again.  There are two ways to set the moon dial.  First, check the newspaper weather page, Weather Channel or any source showing the phases of the moon.  Wait until the day of the full moon and turn the moon dial until the full moon is in the center.  Or wait until the day of the new moon and turn the moon dial until no moon is showing.  That's all you have to do.  The second method is to set it on any day.  This is a little more complicated, as there are two types of moon dial drives.  One is the lever drive which advances the moon dial twice a day.  The teeth on the moon dial are about 1/8" apart.  This results in two clicks per day.  The other type uses a set of gears and advances the moon dial once a day, therefore, one click per day.  Another way to tell is to look at the back of the moon dial.  It's a little hard to see, but the lever drive you can see the lever to your right above the movement and on the gear drive, you can see one of the gears near the center.  To set it, look at the last day of the full or new moon.  For example, the last full moon was on December 28, 2012.  Today is January 2, 2013, or 4 days past the full moon.  Turn the moon dial until it shows the full moon.  If the moon dial is the gear drive, advance it clockwise 4 clicks.  If the moon dial is a lever drive, advance it 8 clicks.  This will put the moon dial in alignment and it will continue to be correct unless the clock stops again.

I hope this helps.  If you have any more questions, get back with me.

John Newman
Old Prattvillage
Prattville, Alabama  

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John Newman


As I am not a certified appraiser I do not give values of clocks over the Internet. There is very little published information on what I consider to be the value of "modern production clocks". However, 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. As clock case model label numbers are difficult to relate to the movements, it is helpful if you can give me the information usually found on the movements themselves. Modern clock movements usually have the information on the back plate of the movement. I have been a clockmaker for about 40 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 in Prattville, Alabama.


One of my greatest accomplishments was traveling to China to assist a clock factory in building clocks to the standards which we required at Emperor. 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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