Clock repair blog

PLATING ON PIVOTS:

The plating on pivots must be removed if it has started to pit or peel. This is
one of the biggest problems the modern german mechanisms have had for 10 or 15
years now. you can tell by the color of the metal if the pivot is plated. The steel in most  pivots has a very slight yellowish color compared to the metal on the inside of the
plating. the herschede clocks have a plating on their pivots and below the plating there
is a copper colored metal that must also be polished. If it is not polished completely
the bushings will wear very quickly, and also severe power loss will result.
GEAR DEPTHING:

It doesn’t take much to stop a clock. The most common problem is failure to
wind the mainsprings up all the way. This is a user/owner problem.
Generally speaking if a clock is stopping after it has been rebuilt check the following:
Check the beat setting
check endshake check for tight bushings
check the position of the impulse arm vs susp rod
check for bent escape wheel teeth
check for bent teeth (even slightly) every where in the gear train
check for a mounting bind (with the mechanism is mounted in the case if one of the
mounting feet is even slightly bent it can cause any one or all of the gear trains to
bind) check for barrell teeth hitting #2 wheel teeth on endshake minimum or maximum.
check for worn gear teeth
check for proper gear depthing
are the mainsprings the correct strength?
is the suspension the correct strength?
possibly the pendulum is the wrong weight
Hands rubbing on the glass at any point in the 360 degree rotation? (put your finger on
the glass over where the minute hand is located and if the hand looks closer to your
finger than the glass is thick then the hand is probably hitting on the glass.)

check for a bushing not oiled
are the hands touching each other at all anywhere?
when the clock stops , very carefully check to determine if there is any power to
the escape wheel; if there is power then be more concerned about pendulum friction,
sympathetic vibration, or suspension problems. If there is absolutely no ; or very
little then there is probably a gear train problem.
is there any air circulation around the pendulum?
are the weights magnetized and is the pendulum brass plated steel?
is the pendulum touching the back of the clock ?
Is the clock;ck sitting on a solid surface?
is the clock hanging plumb on the wall?
Is the hour tube binding?
are the chime or strike levers binding because of lack of oil or rough edges?
check the suspension post to see if the suspension is loose— If it is loose the clock
will probably stop.
check for pallet face wear
check all lubrication points.

WHAT WILL CAUSE TIMEKEEPING PROBLEMS:

There are a number of things that will cause timekeeping problems. Some
are true generally speaking and some are specific to certain clocks. The following is
a list of the generally speaking problems:
set mainspring
improperly lubed mainspring
damaged mainspring— scratched ,rusted or pitted spring : or a spring with lumps
caused from the shape of the spring upon itself being wound for years and years.
worn weight pulley
gummy oil
worn or loose bushings
loose suspension post
incorrect mainspring
sympathetic vibration
damaged threads on the pendulum adjusting nut
\regulator end of key damaged
bent suspension spring
loose verge  worn gear teeth
worn roller pinions and or worn roller pinion bushings
incorrect weight on time gear train
loose hand clutch
scored pivots or pivot
too much play in impulse loop
incorrect gear ratio
incorrect center of gravity on the pendulum bob
incorrect pendulum weight
incorrect suspension spring thickness
mainspring run down
unstable running position
out of beat
mainspring catching on gear teeth or click rivet or click spring hooks
damaged escape wheel teeth
moon dial gear binding
incorrect verge escape wheel depth (shallower depth will generally make the clock
run faster because the swing is reduced making less time between ticks.

FUSEE:

Watch the winding stop; be sure the cable pushes it over far enough to actually
hit the pin. Be sure to take the fusee apart and clean it out. The ratchet is on the
inside not much oil is required to make this part work; too much will cause the ratchet
to eventually gum up and stop working. At the point where the cable comes out of the fusee, check very carefully to be sure there are no sharp edges. If you do not remove
these edges , the cable will break. The pendulums on most fusee clocks have the impulse
loop built into the pendulum rod as an actual cut out slot for the impulse pin to
fit into. The surfaces of these slots are critical. They must be free of rough surfaces.
Check for gouges, wear marks, or hardened oil deposits. Also, of course , check for
looseness of the impulse pin.

ANCHOR ESCAPEMENT(RECOIL ESCAPEMENT)

This type of system does not have a lock action , it is simply impact, slide ,
and release. The recoil escapement is less critical to adjust, and generally speaking ,
is more efficient in that it does not take as much power to run. However this type of
system is less accurate because the motion of the pendulum is less isolated from the
gear train. The escape wheel tends to bounce backwards at each impulse ; and as the
spring runs down the arc of the pend slows causing less bounce or recoil in a nonlinear
manner.The escape wheel/verge depth on this type of escapement in not as critical as
the dead beat escapement. On most cuckoo clocks the depth should be set so that the
escape wheel is 80% of the way from completely missing ; to actually hitting on the
edge of the verge on both sides(binding up).Generally speaking, the lighter the
pendulum, the deeper the setting on this type of system, up to the 80% amount.
Mantle clocks with pendulum lengths of 6 inches or shorter should not be set  deep; between 60% and 70% is normal on most german time and strike types from the late
1800’s to the mid 50’s. If possible the escape wheel should move equally on each
side of the tick. Often the verge has either been bent or replaced and the escape
wheel will impact,slide and release further on one side than the other; and in many
cases the clock will run. My experience has taught me that this is not an extremely
critical adjustment on this type of verge with respect to whether or not the clock will
run.If the goal is just to get it to run ; then don’t be fussy.To charge a customer a
premium price for this kind of work , however is quite another matter.The majority of
clocks (excluding cuckoos) that I have seen over the years have an even release distance
on the impact ,slide , and release. If you want to do accurate, original , restoration;
then set both sides of the sequence equal.
(describe the setting of the depth)

GRAHAM ESCAPEMENT:

The dead beat escapement also known as the graham escapement is
characterized by its action of lock and slide ad it operates. This type of system
can be easily recognized by looking at the verge. Pay particular attention to the
working faces of the verge, there will be a flat edge where the escape wheel tooth
hits upon releasing from the opposite side and a sharp edge that the tooth drops off
from the flat part and an angled surface that the tooth slides along as it gives the
pendulum an extra push until it lets go and the whole thing starts again on the other
side. This type of system is or can be quite accurate because the verge has significant
control over how much power is delivered to the pendulum. If however there is too much lock or not enough lock the accuracy and dependability will be questionable
at best. The depth setting is not the same for all clocks although the principle is the
same. Generally speaking weight drive clocks with heavy pendulums are more
sensitive and require somewhat shallow depth settings keeping in mind not to
completely eliminate the lock segment of the operation.
The following is a list of some of the sensitive clocks:
seth thomas #2 regulators , most vienna regulators
most french clocks
jewelers regulators (large wall clocks and floor clocks with mercury filled pendulums)

REPAIRING ESCAPE WHEEL TEETH

There is a way to repair escape wheel teeth if there are some that are bent
or broken. This is intended at a last resort if there are no other viable options. This
will not always work; only if the teeth aren’t too far gone. Chuck the wheel up in the
lathe and be certain it is spinning as true as possible. Very carefully take a fine file
and file the teeth down until they are of a uniform length. This will work if the amount needed to file off does not exceed the amount of depth adjustment available. After the
teeth have been trimmed reshape them to as close as possible to the original shape.
Spin the wheel at as high a rpm; as possible and be sure that the teeth are trimmed to be
true with respect to the pivots on the front and back. The file must be held firmly on
the steady rest or it will file the inconsistancies of the wheel and the new teeth will
not be true enough to keep the clock in beat; and it will not run.

FLOATING BALANCE:

The floating balance actually hangs from a spring that performs the same
function as a hairspring. There are 2 jewels on each end of the brass tube press fit in.
A common problem is gummy oil stuck inside this tube. On the actual balance wheel there are 4 radii of weights that control the timekeeping , the fourth radii assembly has the adjustable section. The weights are removeable and can be reinstalled if necessary.
It is best to remove weights directly across from each other if possible.

SETH THOMAS COUNT WHEEL SHIPS BELL (ANTIQUE)

The Seth Thomas count wheel ships bell does not use a rack and snail. The count
wheel is the drive gear and the hammer lift wheel is the idler.There are short pins and
long pins on this wheel. there are 2 hammers with lift tabs: one rides on the long pins  only and the other one rides on both the long and short pins. The count wheel travels
half as fast as the hammer lift wheel. One complete rotation or the hammer lift wheel
is equal to 4 hours or running time.