Expert: John Newman - 9/12/2009

Question
QUESTION: I recently completed building an emperor model 120 with a 100M movement that was bought back in 1975 but left in the box. I leveled it according to the instructions and the pendulum doesn't hit the sides when I let it swing with the weights off.  I install the weights and it runs fine for a while then I hear the pendulum hitting the left side of the case.  If I let it continue to run it stops hitting the left side of the case for a while then starts hitting the right side of the case.  After a bit it stops hitting the right side for a while then starts hitting the left side. The beat sounds good to me.  It is on a hardwood floor and isn't being moved to change the level.  Any ideas?


ANSWER: Steve, congratulations on completing the clock!  The 120 was the most popular clock manufactured by Emperor.  I purchase them whenever I have the chance and restore them, usually rebuilding the movements or installing a new one.  These clocks had good solid wood like black walnut, cherry, oak and I believe, some mahogany.  

There can be one of three causes for the pendulum to be hitting the side.  The first is that the wrong weight might be hung on the center chain.  Two of the weights weigh 4.4# (sometimes 4.7#) and one weights 6.6#.  Facing the clock, the heavier weight should be hung on the right, which is the chime weight.  If it is hung in the middle it can cause the pendulum to swing further than normal.  The second cause could be that the pendulum bob is too large in diameter.  The standard ones are 4" and I have seen some that are 4.5".  The third cause is that the verge assembly that is part of the escapement is out of adjustment.  Depending on the positon, the pendulum will swing more or less.  This is a critical adjustment and I would have to give you specific instructions if this is the problem.  The escapement wheel can be damaged if done incorrectly.  Lets go with the weights first.  Let me know what you find.


John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama



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

QUESTION: Thanks for the advice John.  All weights are the same at 6 lbs and this is what the manual that came with it says they should be.  This is a Heinz Jauch 77 875.  The pendulum bob is 4".  When I first set up the clock it would only run a few minutes.  I noticed the strap from the verge assembly that is shaped like a sewing machine foot where it connects to the hanger appeared to be bent up so the weight of the pendulum was riding on it.  I bent it down a little to take the weight of the pendulum off it and the clock has run fine every since except for the occasional bumping against the sides. Is there a critical adjustment in the position of this strap that can cause the pendulum to bump against the sides.  After running three days straight the clock is keeping excellent time.  Also before messing with the verge adjustment, can the suspension spring affect how far the pendulum swings, it appears there may be some rust on the spring.

Answer
Steve, I did not think of the possibility of the suspension spring has been changed out for a thinner one, but you are correct.  This could result in an increased pendulum swing.  I would need to know the size of the suspension spring and the thickness of the spring leaves.  This is the first time I have ever heard of a publication stating that all weights for a Jauch 77 movement being over 4.7#.  There is a larger Jauch grandfather movement that did use larger weights but it would not fit in an Emperor 120 case.  Is it possible that you could send me a scan of the page that states the 6# weight requirements?  And if you have the capability of sending a digital photo, could you send one of the back of the movement showing the pendulum hanging arrangement?  My shop email address is below.

John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama
klokdok@juno.com

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