Mechanical clocks are designed to last for generations, or even centuries if
properly serviced. Just like a car that you take in for its thousand mile or
three thousand mile oil change, a mechanical clock needs to be serviced. A clock
runs 24 hours a day, stopping and starting as many times as 184,000 times a day.
The tic toc of a clock is actually the starting and stopping of the mechanism. Some clocks
use a balance wheel for the escapement and other clocks use a pendulum escapement but
both stop and release the escape wheel each time you hear a tic. The mechanism with
its gears and power source would run down almost instantly if it were not for the escapement.
The gears or wheels of a clock each work to gear down the power of a clock power train. The
final wheel of a power train is designed in such a way to allow the locking and unlocking
of the power. Each of the pivots or axles of a gear have oil sinks that are designed to
hold the clock's oil in place. Continuous operation causes different things to happen to
the clock's oil. Some of the oil will simply evaporate. The remaining oil attracts particles from
the air, and those particales mix with metal particles created as the metals wear. The combination
forms an abrasive substance. If the old oil is not removed and replaced with new oil, the pivots
use that abrasive substance and friction to grind away the bushings and pivots.
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Bushing wear
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New bushing installed
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The torque of the power source will cause the plates or bushings to wear to an egg shaped
hole when a clock is operated with dry or contaminated oil. When this happens, it is necessary to
enlarge the pivot hole or bushing area so that a bushing can be installed. The pivot point must
be restored to its original position or the gears will develope wear so that the gears can no longer
roll against each other and can cause the gears to lock. A mechanical clock should be cleaned and
oiled every 3 to 5 years unless it is in an extremely dry or hot envirement. In a dry location the
clock should be serviced more frequently. If there is bushing wear, the clock needs to be completely
disassembled so the pivots can be polished and bushings installed.
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Spring Barrel
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Open Spring Barrel
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Spring Removed From Barrel
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With spring powered clocks such as the one displayed on this page, there is another issue. On modern
clocks, the springs are installed inside of spring barrels. The springs are coated with a grease. Over time
the grease becomes dry and gummy causing each layer of the spring to grip the next layer. When this
happens the springs must be removed from the barrel, the spring must be re-stretched. Then the spring
must be cleaned, have new grease applied, and then the spring must be re-installed into the barrel.
Spring work can be very dangerous. If a clock is disassembled while the clock still has power applied,
this can allow gears to spin out of control and act just like little saws. If plates are unlocked
and the power springs are not contained, the springs can unwind and act just like a knife. Clocks
should only be disassembled by a trained expert.
