1. Set the works Level to get the beat right.
The beat of a pendulum clock is the time between the Tick - Tock - Tick - Tock. It should be even. Not like
Tick-Tock - Tick-Tock. Clocks will not run correctly and may stop often if not set with an even beat.
Level side to side - the beat of the clock can be adjusted by leveling the mechanism with coins or other shims. Lift one side, then the other, and listen. Most round French style clocks will turn in the case if care is not taken when they are wound. The works can be loosened and rotated in the case until the beat is even and the 12-3-6-9 are positioned correctly. A very small degree of rotation will make the difference between running and not running. If the case must be way out of level for the clock to have an even beat, a small adjustment can correct it. The problem is caused by the clock being moved with the pendulum mounted and it is fixed by repositioning the crutch. The crutch is the part which has an open slot for the pendulum to ride within and which gives an impulse to the pendulum at each end of its swing to keep the pendulum going back and forth. The center of motion of the crutch must be in the center of the clock. Sometimes the crutch gets bent or rotated on its shaft causing the clock not to run. To determine which way to adjust the crutch, get the beat even by picking up one side, or the other, of the case. Push the crutch carefully so it rotates ( or bends ) a little around its shaft to the side that is raised. Repeat until it runs when level. ( or until it runs in the spot you have selected for the clock )
Anniversary clocks capable of running a year require precise leveling. The rotation of the pendulum causes a small, two prong fork to move back and forth. The beat is correct when the free rotation (the run) of the pendulum beyond the sound of the Tick and Tock is the same for both directions.
2. Time rate adjustment - Lower the pendulum bob to go slower, raise it to go faster. Many clocks have time adjust shafts which lower and raise the bob from the front. With time adjust shafts, turn in the direction indicated about one turn each try. Do not force. All of these clocks can be adjusted to keep accurate time.
3. Set hands to correct time.
The minute hand is fixed firmly on a rectangular shaft and geared to turn the hour hand which is a friction fit. The hour hand can be turned to be the correct hour. Do not push the minute hand counter-clockwise, except for certain conditions as explained below. If a clock is ahead of time, stop it until it can be adjusted by moving the hands forward.
One of the popular types of count mechanism for French clocks is called " Rack and Snail" It has the advantage of keeping the hour hand and the strike count synchronized. For the hands of the clock to move from 12:00 to 1:00 the twelve chime must run. If not, the "Count Lever" gets caught on the "Snail". If this happens and the clock stops between 12:00 and 1:00, ease the minute hand counter clock-wise to the 12 and wind the chime spring. The clock will chime twelve and the "Rack" will lift the "Count Lever" clear of the "Snail" and the hands can be moved forward.
Many French clocks have count wheel in the back called a "locking plate" which with the "knife edge lifting lever" control the strike. To get the strike to correspond to the time do the following: 1. Advance the minute hand until the clock strikes; 2. Raise the lever about 1/8" and release, this will cause the strike to go through another cycle; 3. Repeat until it is correct to the hands. An alternative is to advance the minute hand until to clock strikes and, while it is striking one cycle, advance the minute hand quickly until the hour hand agrees with the strike count, then advance both the time and strike to the correct time.
The hour strike of some wall clocks can be advanced by lifting a wire that hangs down to the left of center.
Set the strike of a Westminster Chime by locating the trip wires in the back inside of the works or with some moving the minute hand while the clock is chiming and stopping at the correct interval. All clock are not the same. Some chiming clocks can advance the chime by moving the minute hand counter-clockwise from the 12 to the 9 and back to the 12.
4. Common Problems.
minute hand catching on the hour hand, dial, or speed adjust shaft
clock moved in case from winding
not set up level with even beat
damage caused by winding too tight
5. Marble Clock Cases: Do not lay them down on the back or sides. Marble cases are cemented together with reinforcing wires similar to a building and are designed to be erect. The large cases must be handled carefully. Do not take chances.
copyright : 10/10/95 "Care of old Clocks" HFZ
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