Expert: Martin Meyer - 2/27/2008

Question
QUESTION: Hello, I recently acquired a Schmeckebecher mantle clock, that has not worked for years. The movement is stamped '340-020' and there is also a '74' just above the previous number..I believe that the '74' may be the YOM (1974).
     A family member had it, and gave it to me. It seems to have been over-wound. All three winding mechanisms are wound completely tight..they can't wind any more. It's been this way for years, and I wonder if there might be an easy fix.The clock will run for a minute or more whenever I start the balance wheel?, but the wheel gradually starts slowing down and decreasing it's swing until the clock stops. The chimes wotk, both for the hour and the quarter hours.
   Is there any way to release the spring for running the clock? or does that particular winding mechanism now have to be replaced? I should also mention that there is a clock repair shop in town...but I hate to sink any money into this clock until I find out if it might be better to just buy a different clock.
    BTW, what would be the proper method for winding this clock's three mechanisms? There was no manual or other paperwork with it, and I've ha dno prior experience with one of these.  Thank you for your time.

ANSWER: Hi Bernie,
    The idea of "overwinding" is probably the most common myth in clockmaking. A clock cannot be wound too tight, unless it is wound so hard that the mainspring breaks, in which case the spring becomes completely unwound and will not wind up again. What has actually happened is that the clock is fully wound, but does not unwind because it is not running for some other reason. Letting down the mainspring would have no benefit.
    You're correct that the clock was made in 1974. This is far beyond the expected lifespan of the clock. It is possible that lubrication by a qualified clock repairer could get the clock running again, but considering its age, it may be more likely that the movement is worn out, dirty or corroded and needs replacement.
    The three keys should be wound all the way, as far as they will go,  once a week. This clock should be self-starting when wound, so the fact that it has been sitting wound without running for years indicates a previous problem that prevented the clock from starting and running the mainspring down on its own.


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

QUESTION: HI,
  Thank you for replying to my initial question. I managed get the clock to continue running, by lubricating it's constantly moving parts with Tri-Flow lubricant.
  Although it's 'keeping time' for the most part, it loses about 5 minutes every twelve hours. I looked into past questions concerning this particular movement (Hermie 340-20) , and I found where someone had asked about adjusting the movement for speed.
     The question and answer were posted on 01/08/2008. After reading the reply to the question, I opened up the back of the clock and I was able to find the '-' & '+' symbols, about 2" apart from each other, just to the left and right sides of the balance wheel, near the top of the movement. However, I can't see any adjustment screw or any other marks (ie: 10 S/d) as described in the answer to the question. Is there any way for me to adjust this 1974 movement?
      Due to your answer regarding my initial question,I realize that I may be 'beating a dead horse' on this one. In light of the fact that the clock is now running and the chimes are working properly, it would be great if I can 'get past the final hurdle' and adjust the movement to keep proper time.
Could you possibly give me some idea of what it should cost to have the movement replaced? This clock was given to me in non-working condition, and it's mantle clock. It's style doesn't fit the decor of our home, and we would actually prefer to have wall clock...but then again,the Westminister chimes do sound awfully nice.
Thank you for your time.


Answer
Hi Again Bernie,
    A loss of 10 minutes per day is quite a bit; it may or not be correctable by adjusting the regulating unit.
    Your movement is an older type of 340-020, a true "floating balance" movement, rather than a hairspring balance movement. The adjustment method for this movement is different.
    When you look at the balance wheel, you will see a smaller wheel above it, with three prongs pressing down onto the balance wheel. You regulate the clock by moving (rotating) the prongs on this wheel toward the "+" to go faster. As a very rough starting point, I would rotate the prongs about 1/4 inch around the circumference of the balance wheel. You must carefully hold the balance wheel when you do this, so that it does not get pushed down or up or twisted sideways.
    Costs for clock repairs vary widely by region, so I can't give you a typical price. If you like, you can contact me at my website, www.clockmasteronline.com , and I can quote you the price that I would charge for this repair.