Expert: John Newman - 12/28/2010

Question
I was given a clock and none of the weights was noticeably heavier than the others. I marked them when I moved the clock and when I got home I noticed that they had already been marked but differently. The way they were marked wasn't the way they were hanging when I picked up the clock. It keeps good time but the quarter hour chimes don't always strike. the back is marked
                   Erhard Jauch
                    Uhrenfabrik
                     Made For
                   Emperor Clock
Pendell 110 cm     Made in Germany                  204433
If you could tell me how much each weight should actually weigh I could see if that is my problem. The clock came from my mother and was not running when I got it. It had stopped running and my mother sent it out to be repaired, when it came back it would stop about every 12 hours always about 10 till 1 so for years it just sat there. I oiled it using sewing machine oil which I now realize was not the thing to do but is too late to change now. If you could help with locating an owners manual or any information about the weights I would greatly appreciate it.

Answer
Jim, you didn't tell me how long it had been since it was serviced, but by your description of the events I would think that it is probably out of warranty.  A general rule is that oils shouldn't be mixed, but I don't think using sewing machine oil will cause your problems.  There are a few causes for a clock to stop, but you might have narrowed it down by stating that it stops around 12:50.  There can be a bur on a gear or lever such as the strike lift mechanism.  If this is the case, an experienced clockmaker would have to look at it.  One quick check that I can suggest for you is to check to see if there is a bind between the minute and hour hand.  When the clock stops at 12:50, gently grasp the hour hand at the center bushing and see if there is any play as you move it front to back.  Just 1/16th of an inch would be okay.  Also try moving the minute hand backwards and forward a little and see if the hour hand wants to move with it.  If either of these happens, push the hour hand bushing back a little on the shaft.  If this doesn't work, start the pendulum and gently move the minute hand forward about a minute and see if it seems to bind and then click free.  This would indicate that there is a problem with the chime trip function and would have to be worked on.  

As far as the weights are concerned, I will refer to a chain driven Jauch grandfather movement with single Westminster chimes and a 110cm pendulum.  My information shows that all weights are equal at 8.8#.  This will vary sometimes, like if a decorative lyre pendulum is substituted, the center weight might need to be increased to run the time train reliably.  Another reference I have shows the left and center weights being 7.7# and the right weight being 8.8#.  If the movement is a triple chime, then the right weight would be 10.5#

If the clock hasn't been serviced in the last 7 to 10 years, it could be that the lubricants have become gummy and some parts are worn.  However, since the problem happened after being repaired, it could be something the clockmaker missed or caused.  Let me know what you find.

John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama

Good job, Jim.  Choosing the correct weight is usually done at the factory when the movement is designed and tested.  Sometimes we loose the published information on some clock movements and have to choose the weight.  Other factors can enter in, such as using a heavier pendulum.  The whole idea is to choose a weight that is going to run the clock reliably without adding so much weight that it bushings wear out, or the chime and strike functions are over-torqued.  When a movement is new with fresh lubricant, it would most likely work with less weight than specified.  But as the clock wears and lubricants become a little gummy (these conditions are normal#, it should still run between servicing.  When we service a movement that comes in with no weights and there is no data available, such as antique or rare clocks, we will start with a weight that is less than we think it should be.  We keep adding weight until it functions normally #this includes the time, chime and strike functions, if present).  Then we add 10% more to the weight.  With your clock, run it with the weight you have chosen.  But if the chimes seem a little slow, add a little more.  Good luck!

John Newman