Often times this change has to be made for simple economic reasons; if the old mechanical movement is worn out, the price of a new German made mechanical movement can be very high. Sometimes it’s also just for less work and maintenance. Either way, some considerations have to be made when changing a spring wound or weight driven movement for a battery operated movement. If you think your clock may have any value, keep the original mechanical movement lightly oiled in a plastic bag and store safely.
First remove the clock hands. If you have a second hand it will normally just pull off. The minute hand (the longer one) is usually held in place by a small round nut that needs to be unscrewed, or a tapered pin which must be removed. After this minute hand hardware is removed, pull the minute hand off. The hour hand (the shorter one) is normally just pressed on and can be pulled off. Mechanical movements are usually fastened to the clock dial or the back or front of the clock case by four metal “feet”.(see drawing) If you unscrew the nut holding each foot in place you will be able to remove the mechanical movement from the case. Every clock case is different, but these suggestions will work in most situations.
Once the old mechanical movement has been removed, you can measure the depth, or dial thickness at the mounting hole. It can either be just a metal clock dial, or a metal clock dial on a 1/8″ – 1/4″ piece of plywood. This thickness will help to determine what shaft length of a battery operated movement would be best.
Clock hands are rarely interchangeable between mechanical and battery operated movements. The good news is that you have over 40 pairs to pick from:
If your clock movement has a pendulum you can see, then do not assume that your pendulum will operate on a new battery operated quartz movement. It may be too heavy. If your pendulum is 16″ long or less, then all of our pendulum movements will normally operate at this length, or shorter, using one of our 16″ adjustable pendulums. Just tell us which pendulum Bob (the round disc at the bottom of a pendulum) and clock hands you would like when ordering.
If you have a 16″ to 25″pendulum then you can use the PD200:
And one of these 25″ ADJUSTABLE pendulums:
If your pendulum is in the 25″ to 41″ range, then you need to use a separate pendulum drive that will operate a pendulum up to 8 ounces. See the PHDPD:
Taking out an old mechanical movement and replacing it with a battery operated movement can often be done in a hour or less, just get a good ruler or tape measure, a pair of needle nosed pliers and you should be “good to go” to get the battery operated movement you need. Just let us know how we can help.