Expert: John Newman - 5/2/2010

Question
QUESTION: I bought a grandfather clock at auction in Feb.  It was running but not keeping correct time(slow).  I adjusted the nut at the bottom of the pendlum by turning it to the right. Now it still runs, but stops at 1:45-1:50.  But not ever 12 hr, sometimes it will run longer but still stops around the same time- give to take 5 min. I would appreciate any help you could give with this problem.

ANSWER: Joan, it could be that when you adjusted the regulation nut the clock was knocked out of beat.  That is explained below.  As I do not have the movement number, I do not know if it has the auto-beat function or not.  The clock needs to be in beat or it will stop at some point.  The time it is stopping indicates that maybe there is a bind in a mechanism at that point.  But if he clock is in beat, it might overcome that small bind.  Check out the following and let me know how it goes.

If a clock movement is in operating condition but not working, I would check the stability of the clock in that it doesn't rock or wobble on the floor.  It should be relatively level.  The level is not critical, as setting the beat (below) will correct for this.  

Next, verify that the weights are hung correctly.  On most clocks the weights vary in weight.  The general rule is that if two weights are equal, the third weight, if it is heavier, goes on the right side (as you face the clock).  If the third weight is lighter, it goes on the left.
Is the pendulum hanging configuration correct?  This means that the suspension spring, hanger, verge and pendulum are all connected properly with nothing broken, especially the suspension spring.  When the pendulum swings, it should be "in beat", meaning that when the pendulum swings you hear an even tick....tock....tick....tock.  If it is uneven, like tick..tock......tick..tock, the clock will probably stop.  Most later model movements have an "auto-beat" mechanism.  The beat can be set by holding the pendulum over to one side next to the case and releasing it.  It will automatically correct itself.  If it does not have this feature, the escapement crutch will have to be slipped manually.  If required, I can give you instructions for that.  I will need the model of the movement.  This can usually be determined by all the information found on the back plate of the movement.  Also check to see if the hands are catching on each other or the dial.  Look at the chime and strike hammers to see if they are all in alignment at the rest position.  Sometimes jammed hammers or the drive mechanisms will stall the clock.




John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama
 

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

QUESTION: The clock is level, both ways.  it is in time-tick...tock...tick...tock.  It will run during the day but will stop at night, at 1:45, or close to that time.  Any other thoughts would be helpful.  Thank you for your time.

Answer
Since I still don't know the type of movement, make, model number of the movement, I cannot tell if there are any specific quirks for this movement.  I assume it is a wind up clock either using chains or cables for the weights.   It could be that the hour hand is not pushed on far enough and the minute hand bushing is rubbing just enough at the 1:45 position to bind and stop it.  Or the hand shaft could be bent or a gear could have a burr on it or a bad tooth.  These are some of the things I look for when diagnosing this problem.  You might have to ask an experienced clockmaker to look at it.  

John Newman