Clock repair blog

KEYS:
One of the biggest problems that customers have with clocks is winding them. Many times the keys that are available do not properly fit the arbors, and the customer ends up with a trashed clock and in some cases a very sore finger. Be absolutely that the clock you are working on has the correct key.

LORENZE FURTWANGFLER and SHONE:

The initials on the back of this mechanism are l w s inscribed in a circle on
the back of the mechanism. This is a westminster chime mechanism with some
unusual sequencing levers. The drive gear shaft through the front plate serving also
as the clutch is not so unusual. The trip lever is attached to the front plate on a post
and held on position by a coil spring attached directly above it. The lock and warning
lever are held in place by a coil spring also. The trip lever and the lock / warning lever
works with the trip lever to keep it in place. If the hands get forced ahead one of the
places that are affected is point a. It will get bent too far to the right and then the
lift pins on the minute wheel will not be able to lift the lock/warning lever far enough
to release the warning pin in the chime gear train. Pay close attention to the roller:
it should move freely and when it drops into the shutoff areas it should do so almost
immediately and at the same time the gear train should shut off.The roller is attached
to a plate that is fastened with screws to the trip/lock lever: this allows for adjustment

of the position of the roller as far as up and down is concerned (the holes in the
roller plate are slotted) . When the gear train starts moving for the next chime sequence;
be sure that the shutoff pin on the wheel does not catch the lock lever on the second
time around.This will happen if the position of the roller is set too close to the next
lobe on the sequence cam. The trip lever will hang up if the trip pin and the working
face of the lock/warning lever gets worn. The mechanism that I worked on had
that problem. the chime would trip but the lever would hang up. the working
face at B had a groove worn in it and the trip pin had a flat spot in it. The trip pin
can be twisted so a new working face can be utilized and face b can be filed and
polished. If the pin can’t be turned, it will have to be replaced if the mechanism
will not work. the self correct pin does its job by moving the trip lever into position so
the front pin can reach the front partition of the trip lever. It works on the high lift
principal, its just that the lever A pushes the trip cam back farther back when the
lock /warning lever drops into the deeper area on the ¾ hour position.

JAPENESE MECHANISMS:

One that says crown on the front of the mechanism; it has a rack and snail, and
a clutch system hooked to the hour hand. The mainsprings hook around retainer rids that
make it almost impossible to disassemble and assemble the mechanism by clamping the
mainsprings in the usual manner. The secret here is to repair the mechanism without
clamping the mainsprings . Let them all the way down ; there will be about 8 or 9
feet of loose floppy mainspring dangling about the bench. take the centerpost cam off

if possible before separating the plates; it will be much easier to disassemble. If you
make a jig to hold the springs ,and steady the mechanism, it will be feasible to do
the work this way. Be sure to double and triple check the bushings before the final
assembly is done; its a long procedure to pre-disassemble this particular mechanism.
It’s cumbersome but is easier to get it back together without bending or breaking pivots.
Be sure that the mainsprings are inside the retaining pins as the mechanism is
disassembled; its too late to move them after the mechanism is reassembled.

SETH THOMAS #2 REGULATOR:

The Seth Thomas #2 regulator pendulum cannot be put on the stick upside down
or the clock will run slow. The pendulum is not symmetrical. Be sure to check this.
Some times there will be a clock that comes to you with a cam attached
to a shaft with a set screw that has been broken off making it almost impossible to get the
cam off. ;Most of the time this cam can be removed by cutting a slot on the screw where it
sits flush with the surface of the cam. Be sure to cut the slot deep enough so that maximum torque can be applied to the broken screw on the first try; you will usually only get one
chance so make it count. To reposition the minute hand after removing the centerpost cam use the square end of an old file . Insert it in the hand hub bushing hold the end of the file with a pair
of pliers and slide the hand forward or backward as needed until it matches the trip point
at 12 0;clock . To loosen up the hub hit over a punch / anvil that just fits the edge of the
hand bushing. This will loosen up the bushing enough to allow it to be moved.

HUBERT HERR CUCKOOS:

These mechanisms have a shutoff system that depends entirely on gravity to
operate. Do not oil this system or it will not work.Looking at the mechanism from
the front: the shutoff lever reaches across the outside and drops down on the rod
with the little brass weight that looks like a bushing and pops it out of the way of
the locking lever on the inside of the plate. The angles here are critical. Do not change
them. Be sure the position of the 3rd wheel does not change ; if it is rebushed the lock
will not set and hold if this wheel position changes.Oiling this causes the thing to
hang up fr9om the surface tension of the oil. If it is hanging up , polish it carefully
but do not oil the hook or the rod.
some of the older cuckoos do not have an inspection hole in the back to
allow access to the gong and hammer for adjustment. There are several ways
around this. The least desirable is to drill a hole near the center of the gong.
The reason I say least desirable is this : you may very well end up with a very
angry customer when they see the hole you drilled in their prized 100 year old
family heirloom that great grampa brought from germany during world war 1.
Do not ever alter someone’s clock unless you have a very good understanding
with them; and even then you are taking a big chance. The best way is to adjust
the hammer/gong clearance before the bellows are installed. The hammer and
gong can be seen through the hole for the bellow. It is possible to reach the hammer with an adjustment tool. Bend the hammer not the gong. I am remembering
here the time I was adjusting a cuckoo for a customer at the counter ; and just a slight
adjustment on the gong and ……….. OH NO!!!!!!!! Guess what happened ? the gong
broke off in my hand. Unbeknownst to me and the customer the last person to work on
the clock had taken the fatal short cut and bent the gong several times just enough.
Hubert herr roof mount music mechanism : trip lever has to be absolutely free to move or
the clock will not cuckoo because there is no return spring.
Just enough to weaken it and now it was my turn to break it. Bend the hammer ,
not the gong.
The 1 day regula cuckoo clock movements with 77mm x 75mm plates
(stamped with 35) have common pendulum lengths of 28.5 cm and 20.5cm. The smaller
regula movement 73mm x 63mm usually is available in 23.5cm pendulum length. These
are the same chain size. 61links per foot and a wire diameter of .035in.. The pendulum
length is measured from the suspension post to the center of the pendulum, bob or leaf.
SESSIONS 2 SPRING W/C:
Set the hour trip position on the front cam and coordinate with cam on the
back of the centerpost: cam on back of centerpost should move the pin on the hammer
lift assembly into sequence hole before the quarter hour trip and them drop off edge
n the half hour . Be sure the idler gear on the front plate is tight. The cam on the back
of the centerpost must be tight . Set the hammer sequence at the ¼ after position.

CUCKOO CLOCKS:

The modern cuckoo clock is available in musical and non musical
versions. The musical version has several variations. The music mechanism
can be mounted on the side of the case (usually on the right looking in the back)
or on the top inside just below the roof.
All of these versions are available with count wheel mechanisms in one
day or eight day versions. Most of these (with count wheels) that are musical have
a worm gear drive governor with a large vertical fan mounted on the movement. be
cautious of these , they tend to bind up often and won’t tolerate much wear. The
music sounding part is mounted on the side usually and has only brass drum and
the steel fingers there being no need for a governor assembly.
Commonly the roof mount mechanisms are 1 day units. There are 2 basic
types of shutoffs: one that simply moves in and out of a hole in the side of the drive
gear on the melody sounding drum, and another that has a graduated slot that the shutoff lever is moved out of and above a ridge on the drive gear so it holds the shutoff
open until the valley comes back around and the shutoff lever drops in and the tab
hooks the fan. On this type the secret is that the lock lever must snap out and up from
the shutoff hole to keep it going. These are usually either 22 note or 18 note units.
All of the music mechanisms have small dampers cemented to the bottom
of the fingers on the sounding bar. These dampers must come in contact with the small
pins on the brass drum the instant before the pin comes in contact with small finger
on the sounding bar as the music mechanism is in operation. The purpose of this is
to prevent a squeaking sound from occurring as the pin contacts the finger while it is
still vibrating from the last stroke. If these dampers are missing or defective they
must be replaced or the music mechanism will squeak. That is it. There is no other
way, Do not attempt to oil the sounding fingers ; this will not stop the squeak without
causing the sound to deaden, and will eventually thoroughly gum up the mechanism
and ruin it.

Time and Strike AMERICAN CLOCKS:

Most time and strike (hour /half hour) american clocks work on similar
theory. Most of them use a count wheel with count arm and trip levers on the
inside of the plate. Keep in mind that the bushings that the shutoff and trip levers
ride on must not be too loose.
Be sure that the trip lever moves far enough before releasing the lock lever so
that the warning pin on the 4th wheel will be hooked by enough of the warning
lever so that the action will be dependable.Keep in mind that because of the nature
of the american time and strike clocks there must always be some play in the bushings ,
particularly the shutoff and locking lever bushings.Any tighter than .002in. will
cause intermittent problems that may be impossible to find; any looser than .005in.
will also cause intermittent problems.
Some of the new haven mechanisms will have a shutoff that uses the
actual lever hooking on the 3rd wheel (a slot in the plane attached to the 3rd wheel)
o shutoff the gear train. The shutoff will usually be spring loaded. They are very
tricky because the angle must be such that a minimum of drag is put on the gear train.
The shutoff end must be at 0 degrees to a line drawn through it and the shaft of the
3rd wheel. Do not under any circumstances change this angle. Do, however, be
sure that the surface of the slot and the lever are polished.
Be sure to check the lantern pinions on all the wheels for wear. Also
be sure to check the mainsprings; take them off the arbor , unwind them and
check for cracks or distorted areas. They must be replaced if there is a problem.
On the units that have a trip lever that is just an L shaped piece of wire
be absolutely sure, when it is apart, that the wire is tight. If it is not the trip position will be off: it will either strike before the 12 or after it: and it will have   to be disassembled to fix this tiny little problem.
There are some of the american Time and strike clocks that have alarms that are
set by a brass or silver colored ring in the center of the dial. The ring will usually
have roman numerals on it (1 through 12). There will usually be a small movement
at the bottom of the case with a separate size key and a small mainspring and a verge
and a very heavy duty escape wheel that runs on it. To set these alarms first be sure
the alarm is wound. (THESE ALARMS ARE VERY LOUD , BE PREPARED
FOR LOTS OF NOISE!!!) Then, line up the XII on the alarm ring with the hour
hand. Then, set the strike sequence and bring the clock around to the 12 o’clock
position to check if the XII is indeed at the 12 o’clock position when the alarm
trip lever drops and the alarm sounds; if so, then line up the hour hand with the
roman numeral of the desired hour that alarm is to go off by turning the small
ring with the numerals clockwise. (it is friction fit on the hour tube and can be
turned with a slight effort)Be sure to not disturb the hour hand.
The trip/lock lever setup on the 8 and 1 day time and strike american clocks
must be watched closely on th lock position. The pin n the warning wheel(usually the 4th
wheel) must catch and hold on the lever edge solidly and must have at least the diameter
of the pin over and above when all the slack is backed off the hands and the
bushings on the levers must be reasonably tight or the clock will not stay in sequence.
The fact to remember here is that the clock may work ok for a while but then after
he customer gets the clock home and runs it for a while then it will act up. this is
critical: check this out very carefully. If you get a return and don’t check it out you
may get bit by a mad customer.

JAUCH MECHANISM CHIME CAM:
The chime cam , and the chime hammer drive gear, are held in place by
setscrews that have very sharp points on the end that is inside. When they are
tightened up , they make a disruptive gouge in the shaft; which is ok until you try
to resequence. Often the cam or the gear will slip back into those gouges when the  setscrews are tightened. You will fight it for hours unless you find some way around
the gouges. Grind off the end of the set screws or replace them, and smooth the
shaft, then tighten the setscrews and the wheel or cam will stay where you put it.
Things to be aware of on specific types of clocks:

PUTTING A CLOCK IN BEAT:
All clocks must have maximum power transfer to the pendulum or they will
not run dependably. This means they must be in beat. Try to imagine the pendulum and
verge as a swing and the person pushing as the escape wheel. When the clock is in beat
the escape wheel gives the pendulum a push at just the right time in the same way as a
person gives the swing a push just as it arrives back and at the instant it starts back
on its return trip.

The verge clutch will usually allow the beat to be set by adjusting the position
of the impulse arm until it is at the true center at rest with the mechanism and case set
level and plumb. Be very careful when setting the beat; sometimes the verge clutch is
set so tight that the escape wheel teeth can be bent without realizing it.
If the beat is set, but the clock gets in beat ant they out of beat; check for
bent escape wheel teeth if the the in beat and out of beat: has a regular repeating
pattern. If there is not a regular pattern then the problem is probably a loose verge.
The clutch can be ok but the verge can be loose on the shaft.
when setting the beat on a clock if possible do it by sight and sound.
Setting the beat on a balance wheel is just as important as the beat on the
pendulum units. The hairspring collar can usually be moved if need be, it is a delicate
operation. Practice on spare parts!
CENTERPOST CAM REMOVAL:

Quite often it becomes necessary to remove the centerpost cam so that the
hand end of the centerpost can be rebushed.Be sure the plate is adequately braced and
supply solid surface for the support. The surface must be as solid as a cement floor.
In fact I have had to use the cement floor as a support many times. If the support
surface has any give you will end up destroying the shaft , and possibly the cam also.
If the collar is made correctly and the punches are used and made correctly , it
will be possible to remove almost any center post cam. When the centerpost is
off be sure to taper it with emery paper before reinstalling the cam. Remember
it will only take a few minutes to do. remember if the centerpost bushing is worn
it will have to bee rebushed or the clock will not work. I have observed many
repairs come back to haunt those who thought they could get by with a fast job
and a quick buck. This end remember usually has the chime trip cam if it wiggles
up and down or side to side the trip position will be erratic and too the self
correct will not work.
Another word about cam removal in general: sometimes they will pop
off when you are not ready , go flying somewhere out of sight and you will not
be able to find them. One good way to avoid loosing them is to put a rag over the
cam when you are working it loose: this will hold it if it pops loose before you expect.