Expert: John Newman - 9/27/2010

Question
QUESTION: I recently purchased a grandmother clock at a yardsale with a 451-050 movement from Emporer Clock Company (94 cm/66, handshaft, 8 hammer back, chain driven, westminster). It is missing all of the weights, and from what I have read online, it looks like I need one 6.6 lb weight and two 4.7 lb weights. How important is it to match these weights exactly? I found some weights I could buy that are the following weights: 6.41 pounds, 4.42 pounds, and 4.34 pounds. Are these weights close enough? Thank you,
Jessica

ANSWER: Jessica, the weights you mention MIGHT work okay.  Here is the problem.  The weights chosen for a movement are such that they will work properly for a new movement and then after the movement has worn a little or the lubricants have become old.  This is called overdesign for reliability.  Of course if they are in excess of the designed weight, the clock will run longer to overcome other problems, but the movement will also wear faster.  It's like an automobile engine.  You almost never use the full power.  It is for reserve.  If you drove full power all the time, the engine would have a very short life.  When I work on a weight driven movement, I always use the factory specified weights.  If I use weights that are less and it doesn't run, then I don't know if the problem is in the reduced weights or in the movement itself.  Being that you purchased the clock not knowing if it ran or not, using reduced weights might not get it running.  Or it could be that the movement will need to be serviced.  I would start with the proper weights.  Weights included the shells and iron or lead weight fillers.  The fillers can be increased with additional weight.  Give me the diameter and length of the weights and I can determine if they are the required original dimensions (if they are too big, they will interfere with each other). Then I can give you information on the fillers.  I have them or can direct you to a supplier from which you can order them.

John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama



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

QUESTION: The weights came from a Barwick by Howard Miller grandfather clock using an Urgos UW32/1 movement and they are approximately 1 1/2 inches in diameter and 10 inches long.

Answer
Jessica, there are a lot of calculations involved in determining the substitution of weights.  The Urgos movement weigh requirements are 4.5#,4.5# and 6.6#.  So, I would say they are about right for the Urgos movement.  I cannot guarantee they would work okay for the Hermle, but they might.  The 1-1/2" (38mm) diameter weights are not as common as some of the others which start around  1-7/8" (48mm).  Those are the ones that are usually used for the Hermle 451 movements.  If you do have to add weight to the 38mm shells, there might not be enough space left.  Then you would be stuck with weights yo could not use.  I would keep looking around for the correct weights.  

John Newman



If you will contact me at my shop email address, I will give you some additional details on the weights as far as availability.

John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama

klokdok@juno.com

(Due to the number of Allexperts questions and
the workload I have at my clock shop, I regret
that I cannot answer personal email questions on a timely basis
other than Allexperts follow ups.)