Expert: Martin Meyer - 7/22/2008

Question
QUESTION: Our mantel clock was running 10 minutes fast.  I have turned the small screw counter-clockwise 3 full turns over the period of a week trying to slow it down and now the clock is running 25 minutes faster than before.  Any ideas as what to do next?  We do not have anyone locally that works on clocks, the closest is 120 miles.

ANSWER: Hi Mary Jo,

The markings at the regulating unit of the 340-020 are somewhat confusing. If your clock is running fast, you should turn the regulating screw CLOCKWISE to make it run slower.

Additionally, there is an arc scribed at the regulating markings, with "10 S/d" stamped inside the arc. This is a 60 degree arc, and the stamping means "10 seconds per day". As 60 degrees is 1/6 of a full circle, this means that a full 360 degree turn of the screw is supposed to change the rate of the clock by 1 minute per day. This is only a rough starting point, and I have not found it to be extremely accurate.

I'm not sure what is the time period in which your clock gained 10 minutes, and now gains 35 minutes, but it sounds like you mean one week. As this amount is 5 minutes per day, I would start by turning the regulating screw 5 full turns CLOCKWISE. You will probably need to make further small adjustments to get the clock to its maximum accuracy.

Don't forget to wind the clock fully, as far as it will go, then reset it to the correct time, after each adjustment. The let the clock run the full week before noting the error and making the next adjustment.  http://www.clockmasteronline.com

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

QUESTION: Thank you for responding so quickly.  I read where you can reset the clock by backing the minute hand back to the correct time. Is this right or should I move the minute hand forward to the correct time?

Answer
Hi Mary Jo,

The 340-020 can be set by turning the minute hand forward or backward. This is not true of all clocks, especially antiques. The one rule that you should observe is, if the clock begins chiming while turning the hands either way, stop immediately and let the chiming finish before turning farther.  http://www.clockmasteronline.com