Timing and Final Regulation 91
75. Mean Time Screws and Timing Washers.
76. Importance of Properly Fitted Regulator.
77. Effect of the Middle Temperature Error.
78. Some Practical Reasons for Slow Rates.
PART III.--SPECIAL NOTES
CHAPTER XVI
Special Notes 99
79. Efficiency of Execution Analyzed (Two Examples)
80. Truing the Balance.
81. Poising the Balance.
82. Truing Hairsprings.
83. Treating a Rusty Hairspring.
84. Stopping by Escapement Locking when Hands are
set Backward or When Watch Receives a Jar.
85. Essentials and Non-Essentials in Cleaning Watches.
RULES AND PRACTICE FOR ADJUSTING WATCHES
PART I
THE ADJUSTMENT TO TEMPERATURE
CHAPTER I
THE COMPENSATION BALANCE CONTROLLING FACTOR
1. _General Method of Obtaining Results._
Only since the introduction of the compensation balance which received
its most substantial early experiments as recently as the year 1859,
has it been possible to control the variation in pocket timepieces
which is caused by changes in temperature. Previous to this
introduction it was not uncommon for the best watches to vary as much
as two or three minutes with changes of forty or fifty degrees Fahr.
Through experiment and improvement in the quality and application of
balance materials, such advancement has been made, that this variation
has been reduced to seconds and temperature adjusting is now quite
universal in the production of medium and high grade watches.
In the large factories, girls and young men of very little previous
experience are frequently taught to make the alterations and to do the
testing, while men of experience in watchmaking handle only the more
intricate cases such as "stoppers" and radical rates that may require
investigation of the inner workings of the movement. The simplicity of
the adjustment naturally becomes more apparent with experience and the
general alterations consist merely of transferring the balance screws
in opposite pairs, either forward or backward one or more holes,
according to the extent of the correction desired.
As these alterations are quite positive the adjustment can be
undertaken with considerable certainty of obtaining results in every
instance.
The repairer will not find as much daily necessity for understanding
temperature adjusting as he will for being thorough in Position
adjusting. The subject is covered, however, for the benefit of those
who may desire practical experience in this branch of adjusting and
also for those who desire a general knowledge of the details.
2. _How to Place Screws When the Rate is Either Slow or Fast in Heat
Compared to Cold._
If a watch rates slow in heat compared to cold it is necessary to
shift screws in opposite pairs out toward the cut or free end of the
rims; because when the metals expand the hairspring becomes weaker and
produces a loss in time. During this period the free ends of the
balance rims, carrying the transferred weight are forced toward the
center and produce a gaining rate which compensates for the loss
caused by the weakened spring.
As the metals contract in cold the free ends of the balance are drawn
outward from their true form and the concentrated weight of these
screws near the ends reduces the fast rate in cold and in principle
works both ways in its action on the rate.
Should the circumstances be just opposite, or the rate be fast in heat
compared to the rate in cold, it will be necessary to move the screws
away from the free end of the rims. In doing this, less weight will be
carried toward the center as the free ends curl inward and as a
result, the rate in heat will become slower and the slow rate in cold
will be reduced.
3. _Composition of and Distortions of Compensation Balances._
Compensation balances are generally made of one layer of brass and one
of steel, with the brass on the outside consisting of about
three-fifths of the total thickness and the steel on the inside
consisting of about two-fifths. These metals are firmly soldered
together and the distortions in changes of temperature are as follows.
In heat both metals expand, which infers that the rims become longer
as well as wider and thicker. Brass expands more than steel and
because of its attachment to the steel it cannot continue to lengthen
in its true circular form, due to the fact that the steel does not
become enough longer to maintain the true curve, and the result is
that the free ends of the rims are forced inward.
In cold the brass, contracting more than the steel, pulls the rim
outward at the free end which is just in reverse of the operations in
heat.
The end of the rim which is attached to the balance arm always moves
in the opposite direction from the free end, or outward from the
center of balance, when the free end moves in, and inward when the
free end moves out. In comparison, however, this movement is
negligible as will be noted later in the results obtained in moving
screws in that direction.
4. _Tests and Experiments._
It is generally understood that the purpose of the compensation
balance is to act in opposition to the error caused principally by the
hairspring. The steel hairspring having no compensating qualities,
either grows stronger or weaker with changes in temperature. When it
becomes longer, wider and thicker in heat, experiments seem to prove
that the increased width and thickness are not in proportion to the
increased length, for if they were, the spring would actually be
stronger; while timing proves that it is weaker because of the loss in
time. In cold the shortening factor seems to dominate because of a
gain in time.
In a series of tests with steel springs on uncut steel brass balances,
the temperature error in the extremes of 40 degrees and 90 degrees
Fahrenheit was found to be from eighty to one hundred and sixty
seconds. With the same balances cut the error was reduced from seventy
to one hundred and thirty seconds in each instance, without any
correction of the balance screws.
A former test with palladium springs on the same balances, previous to
having been cut, showed a considerably reduced error, indicating that
the steel springs were mainly responsible for the temperature
variations.
The above tests were in actual practice and results are given as
noted, regardless of scientific or established formula relating to the
cubic measurement of metals in changes of temperature.
5. _Effect of Shifting Screws to Different Locations._
As a rule compensation balances generally have five or six pairs of
balance screws in addition to two pairs of mean time screws. High
grade Swiss and some American models do not have mean time screws and
are therefore generally supplied with seven or eight pairs of balance
screws. The mean time screws are never disturbed in making alterations
for temperature, such alterations being confined to the balance screws
only and the mean time screws are reserved for timing.
For appearance sake the balance screws should be evenly distributed,
although it is necessary at times to closely assemble them to obtain
temperature results and they should not be disturbed in making
ordinary repairs, as the adjustment may be destroyed in so doing. With
the larger balances the moving of one pair of screws for a distance of
one hole, generally makes a difference of four or five seconds in the
temperature rate. In the case of smaller balances this alteration does
not make as much difference, although the weight and location of the
screws has considerable influence on the result.
A pair of screws shifted from the second holes from the cuts, to the
holes adjoining the cuts, will generally make a correction four or
five times as great as would be obtained by shifting a pair of screws
from the third to the fourth holes from the arms. The same
proportional difference is obtained in moving a pair of screws from
the center of the rims out to the cut, compared to moving a pair of
screws from the holes nearest the arms out to the center of the rims.
This principle also obtains in moving the screws in the opposite
direction and is due to the fact that while the metals composing the
balance follow the common laws of expansion and contraction, the
balance actually becomes smaller in area during expansion and larger
during contraction. This condition is made possible entirely through
joining the metals in proper proportion and then cutting the rims.
In the factories where large quantities of a particular model having a
standard style balance are handled, tests are usually made to
determine as to just what degree of correction will be obtained by
shifting various pairs of screws certain distances. This information
is then used in making alterations with considerable certainty. The
expert temperature adjuster becomes fully informed as to the
peculiarities of various models and is capable of getting larger
percentages of watches within the limits of allowance, after making
alterations, than he could obtain otherwise.
Through understanding the various models individually, he is also
enabled to furnish information that will cause intelligent arrangement
of the balance screws, for each model, when they are originally
fitted. The production thereby showing a greater yield of good watches
that do not require alterations after the first test.
6. _Permanency of the Temperature Adjustment._
When the original temperature adjustment has been carefully executed
it is quite permanent and unless the screws have been mutilated or
changed in location there will seldom be an occasion for readjusting.
The balance may be retrued and repoised many times and the spring may
be retrued, altered, or even changed, without seriously interfering
with the temperature rating, as long as the screws are not shifted. In
changing the spring, however, it is necessary that the same number of
coils and the same size of spring be used, as otherwise readjusting
would be required.
CHAPTER II
EQUIPMENT FOR TEMPERATURE ADJUSTING
7. _Various Methods Available._
Two boxes are necessary for temperature testing. One fitted up to
maintain a temperature of about 90 deg. Fahr. and the other maintaining
a temperature of about 40 deg. Fahr.
The method employed in obtaining the high temperature varies in
different styles of boxes, while the low temperature is always
obtained through the use of ice. When only an occasional test is made,
any simple method whereby approximately close results in the two
extremes can be obtained, may be used. For instance, the watch may be
enclosed in a tin box and placed in sand that is kept at a temperature
of 90 or 95 degrees F. A thermometer placed in the sand indicates when
the temperature rises too high or falls too low. The ordinary
household refrigerator may be used for testing the cold. Tests by this
method are advisable only for short periods and for an approximate
idea as to the extent of error.
If frequent tests are made and accurate results are expected, it is
quite important that the special boxes be used. Such boxes are often
constructed with a capacity of four or five hundred watches, or they
may be constructed to receive only half a dozen watches. Some are made
with a zinc or copper tank in which warm water is placed and which
surrounds the chamber in which the watches are deposited. The water is
kept at the desired temperature by means of a small adjustable flame.
In other instances electrical arrangements are used, in which case no
water is required.
In either instance a thermostat controls the source of heat.
8. _Electrically Equipped Oven, Description and Dimensions._
A very practical arrangement for testing a few watches at a time in
the higher temperature is shown in Fig. 1. This is electrically
equipped and will maintain an even temperature at all times.
The outside of the box is constructed of about one-half inch lumber
and the inside is lined with asbestos. It is about fourteen inches
high by ten inches wide and eight inches deep.
"A". Is an incandescent lamp set in a porcelain base.
"B". Is a porcelain plug through which the wires "C" enter the box.
"D" and "E". Are metal uprights with a thumbscrew on the top, under
each of which a wire terminates.
"F". Is the compensating bar, one end of which is fastened solidly to
"D" with rivets.
The opposite end is free and rests against the end of a thumbscrew
which passes through "E."
The thumbscrew is to be adjusted so that the free end of "F" will rest
against it in a temperature of 70 deg. Fahr. or any lower temperature.
As the temperature rises the free end of the bar moves away from the
end of thumbscrew, breaking the circuit and extinguishing the light,
which cuts off the source of heat. As the temperature decreases the
bar again comes into contact and creates the circuit.
This bar can be made of various compensating metals, one combination
of which is a strip of zinc about six inches long by three eighths of
an inch wide and one thirty-second of an inch thick. On the outside of
this soft solder a strip of tin six inches or a trifle less in length,
by one fourth inch wide and one thirty-second of an inch thick. Both
metals should be bent to a curved form before they are soldered
together as shown in the cut.
[Illustration: Fig. 1]
It is generally preferable to have the bar taper to a slightly
narrower width at its free end, and near this free end it is necessary
to solder a small strip of platinum at the point where the end of
thumbscrew comes in contact.
"G", "H", "I" and "J" are ventilating holes one inch in diameter and
covered by a swinging slide so that the holes can be opened or closed
as desired for regulating the ventilation. "K". Is a shelf of brass
screen located about five inches from the top and on which the watches
and a thermometer are placed in testing.
"L". Is a handle for the purpose of convenience in carrying the box.
The front is to be enclosed by a door made in two parts, the upper
section of which is glass which will admit of observing the
thermometer. Proper adjustment of the thumbscrew and bar makes the box
ready for use.
9. _The Lower Temperature Box._
Fig. 2 shows a box specially made for testing watches in cold. It is
constructed of wood and stands about twenty-four inches high without
the legs and about eighteen inches square.
A double partition packed with about one inch of sawdust will be most
reliable.
The upper half of the box should contain a watertight zinc tank for
holding cracked ice and about an inch of space should be left above
for circulation of the air.
The chamber for receiving the watches may be about six inches square
and supported by a crosspiece and attachment to the front. It should
be covered above to prevent particles of ice from falling on the
watches which are to be placed on the floor or on a shelf of the
chamber, but the sides may be left partly open to improve the
circulation of cold air. The door may also be filled with sawdust but
does not require glass as the moisture would prevent observation of
the thermometer which should be inside for checking up the temperature
when the door is opened.
[Illustration: Fig. 2]
The bottom of the tank should be slightly higher on one side than on
the other, with a one-half inch drain pipe fitted to the low side. The
inlet end of the pipe should be covered with a fine screen to prevent
dirt from accumulating in the pipe and the outlet may be either at the
extreme bottom or on one of the sides as shown in the cut. The upper
part or cover of box should be made so that it can be easily removed
for filling and cleaning the tank.
CHAPTER III
DIFFERENCE IN OBSERVATORY AND COMMERCIAL SYSTEMS
10. _Observatory System._
In the foreign observatories where watches are generally tested for
competition prize, or certificate purposes, they are subjected to
either three or five day tests in each temperature, preceded by one
intermediate day at normal temperature which is not considered in
making the deductions. The purpose of this is to allow the metals to
assume the natural condition before being placed in, or changed from,
one degree of temperature to another. After the three or five day
test, according to the grade of the watch, the average of the daily
rates in each temperature is considered in making the comparison and
arriving at the total variation. The total error is then considered in
the summary, as a fraction of a second variation per each degree of
temperature. As an example we will consider that the total error
between the two averages is five seconds and that the difference in
the two extremes of temperature was fifty degrees F. The variation
would be given as one-tenth of a second per each degree of
temperature.
11. _Commercial System._
In manufacturing watches for commercial purposes, both foreign and
domestic, the tests are generally made for twenty-four hours in each
temperature and the difference in the rates is considered as the total
error.
Sometimes preliminary tests of four or six hours in each temperature
are made to obtain an estimate as to the extent of error, then
alterations are made, after which the watch is subjected to the
regular twenty-four hour test. There is nothing to be gained by this
in regular work, although for a special rush job a day's time may be
saved. Watches are always expected to be in first-class condition and
such features as close fitting pivots or dirty oil will prevent any
dependable timing. It is also advisable to time them closely before
the test is made, as too great mean time variation may confuse in
estimating the error, especially if the time is not taken in each
temperature exactly at the end of twenty-four hours.
The testing should preferably be done in the dial up position to
eliminate poise errors as much as possible. The first test is made
in heat at 90 deg. Fahr., then in normal temperature of sixty-five
or seventy degrees and finally in the lower extreme of 40 deg. Fahr.
When the watch is removed from the cold box it will be covered with
moisture which will immediately begin to condense. The time should
therefore be quickly noted and the watch replaced in the higher
temperature box for four or five hours to become thoroughly dry and
prevent against rusting of the steel parts.
12. _Rating Card and Method of Calculating Variation._
A card ruled similar to the cut shown in Fig. 3, may be used for
entering the rates and the watch need only be set at the beginning of
each test, as deductions can be made from the entries on the card and
the variation accurately ascertained without resetting or disturbing
the time.
Details as to the methods to be followed would be about as follows:
Wind and set the watch to correct time, place it in the heat box and
at the end of twenty-four hours enter the variation from correct time
in the upper left hand square of the card.
Assuming that the time is four seconds fast, enter this as shown in
the first column Fig. 3, then wind but do not set the watch and place
it in normal temperature and at the end of twenty-four hours enter the
total variation noted in the second square of first column. Assuming
the time to be just correct, place a zero as shown. Next wind the
watch and place it in the cold box, and assuming that the variation is
sixteen seconds fast at the end of twenty-four hours, enter this in
the lower square of the first column as shown in Fig. 3. The watch is
next placed in the heat box to dry and the variation shown in the
three sets of figures in first column are carried out as follows.
Fig. 3
+--------------------------------------------------+
| No. .................... Make................... |
+--------+-----+-----+-----+-----+-----+-----+-----+
| HEAT | + 4 | + 4 | + 2 | + 2 | | | |
+--------+-----+-----+-----+-----+-----+-----+-----+
| NORMAL | 0 | - 4 | + 6 | + 4 | | | |
+--------+-----+-----+-----+-----+-----+-----+-----+
| COLD | +16 | +16 | + 8 | + 2 | | | |
+--------+-----+-----+-----+-----+-----+-----+-----+
12 0
In the upper square we find +4, enter this in upper square of second
column at its full value as shown.
Next we find a "0" in the second square of first column, and as this
is a loss of four seconds from the entry shown in the square above we
carry it out in second column as -4. In the lower square of first
column we find +16 and as this is a gain of sixteen seconds over the
square above, it is necessary to carry this to second column at its
full value as per illustration.
To determine the extent of variation between heat and cold, simply
ignore the normal rate of -4 in the second column and subtract +4,
from +16, which indicates an error of twelve seconds slow in heat
compared to cold.
Or it may be determined as twelve seconds fast in cold compared to
heat. For convenience sake it is advisable to form the habit of using
one of the temperatures as a unit for comparison and wherever large
quantities of watches are adjusted, it is generally the custom to use
the higher temperature for this purpose and the rate is stated as
either slow or fast in heat. In this instance the rate is slow in heat
and it will be necessary to shift one or more pairs of screws toward
the cut as explained in Chapter 1, No. 2.
13. _Value of the Normal Period Rate._
The rate in the normal period cannot be considered as of any value,
its importance consisting only of allowing the metals to return to the
natural form and tension before being placed in the cold box.
This is quite important in obtaining a true estimate of the error,
because of the fact that in transferring the watch immediately from
the extreme of heat to the extreme of cold, there will be a period of
time during which the metals are readjusting themselves to the natural
form, and the variation in time during this period will not be
accounted for, as the real comparative rate will not begin to develop
until after the natural form and tension is reached.
If the limit of time devoted to testing is no object and if a very
fine rate is desired the observatory method is of course to be
preferred. However, by allowing an intermediate day at normal
temperature we have the assurance that the hairspring is at the same
tension and that the balance has the same form concentrically when the
test begins in cold that it had when the test began in heat.
As the object is to find the variation between the two temperature
extremes the estimate will be quite close enough and allows the saving
of many days' time. Some authorities advocate in addition to the five
days required for observatory testing in each temperature that the
watch be subjected to an intermediate day in each, instead of in
normal, before considering the daily rate. This seems very logical, as
the time noted each day would be taken at the actual extremes in both
instances and any outside factor in the timing would be eliminated.
14. _Definition of the Characters Used on Rate Cards for Gain or Loss
in Time._
In making entries on the rate cards and in figuring the variations the
sign + is used as denoting that the watch is running faster than the
standard time and the sign - is used as denoting that it is running
slower than standard time.
This is stated for the reason that in some instances, generally
foreign, the signs are used in reverse, or as indicating that the
watch requires a correction of + or - the number of seconds indicated,
to attain the correct standard of time. When the signs are identical
in a column it is necessary to subtract the lesser from the greater
and the result is the variation. There are often instances however,
when one rate will be + and the other - as shown in second column of
Fig. 4, and in these instances it is necessary to add the figures to
obtain the variation.
The first column is always the progressive rate and the second column
shows the variation carried out. This example shows +8 in heat, the
normal rate in the second square is not considered, for the reason
previously explained and the rate in cold is shown as -1. The total
variation between the extremes is therefore arrived at by adding +8
and -1, which in this instance gives us a total of nine seconds fast
in heat.
Fig. 4
+--------------------------------------------------+
| No. .................... Make................... |
+--------+-----+-----+-----+-----+-----+-----+-----+
| HEAT | + 8 | + 8 | | | | | |
+--------+-----+-----+-----+-----+-----+-----+-----+
| NORMAL | +20 | +12 | | | | | |
+--------+-----+-----+-----+-----+-----+-----+-----+
| COLD | +19 | - 1 | | | | | |
+--------+-----+-----+-----+-----+-----+-----+-----+
9
15. _Increasing or Decreasing the Extremes of Temperature._
The extremes of 40 deg. and 90 deg. Fahr. have been used for the reason
that they are best suited for general purposes. When it is known,
however, that a watch is to be used in a warm climate the extremes may
be raised five or ten degrees to advantage. If the watch is to be used
in a cold climate, the extremes may be lowered this amount. The metals,
however, can only stand the strain of expansion and contraction to a
certain degree, and still maintain the positive qualities. Therefore it
is quite important that the extremes be not raised or lowered very much
beyond these figures.
CHAPTER IV
SOME PRACTICAL METHODS OF CORRECTION
16. _Example of Maintaining a Pleasing Appearance of the Balance._
In altering the location of screws during the temperature adjustment
it is often possible to either mar or improve the appearance of the
balance. As a demonstration of this point the correction made in
regard to Fig. 3 is analyzed. The balance had twelve screw holes in
each rim, with the space between the first and second holes from the
arms equal to double the space between any other two holes. There were
seven screws in each rim, equally divided as per cut Fig. 5, which
indicates screws in the first, second, fourth, sixth, eighth, tenth
and twelfth holes.
[Illustration: Fig. 5]
A correction of the rate could have been obtained by shifting the
screws in either the sixth or eighth holes forward three holes. Or
those in either the first or second holes could have been shifted to
the ninth holes and those in the fourth holes might have been shifted
to the ninth holes with good results possible in either instance.
Moving one pair of screws under any circumstances however would have
caused a massing of three pairs of screws at some point and a vacant
space of three holes at another point which would not present a very
good appearance for high grade work. Therefore the alteration made was
to move the screws from the second to the third holes, fourth to
seventh, and from the eighth to the ninth holes as indicated by the
positions shown in Fig. 6.
[Illustration: Fig. 6]
Examination of the fourth column Fig. 3, which gives the result of the
second test will show that the desired correction was obtained with a
better appearance of the balance than would have been possible if only
one pair of screws had been shifted.
In following the logic of the alterations made we must consider that
the screws moved from the second to third holes made no correction,
due to the fact that the balance rims remain almost stationary at this
point, the alteration being for appearance only, those moved from the
fourth to the seventh holes were estimated for a correction of seven
or eight seconds only, for the reason that the alteration did not
carry them beyond the center of the rims where the greatest curvature
takes place. The screws moved from the eighth to the ninth holes
however were estimated for the full correction of four or five seconds
which is to be expected through shifting a normal pair of screws from
one hole to another beyond the center of the rim on sixteen or
eighteen size balances. In moving a pair of screws one hole between
the first quarter and the center of the rims, a correction of from two
to three seconds can be expected and from the center to the cut the
difference for one hole is generally four or five seconds, while an
alteration between the arm and the first quarter seldom yields any
correction.
The matter of appearance should at all times be respected, for it is
just as easy to obtain results in most instances and also have a
well-appearing balance. There is also less disturbance of the poise
usually in moving several pairs of screws a short distance than there
is in moving one pair a longer distance.
17. _Correction Varies When Screws are Above or Below Normal Size and
Weight._
Normal corrections can only be realized when normal screws are
shifted. Some balances have one half, or quarter head screws which of
course will not produce a correction as great as will be obtained by
shifting regular screws. Sometimes platinum, or other extra heavy
screws will be found in balances and these will produce a correction
almost double that of ordinary screws of the same size.
18. _Over or Under Compensation._
On some occasions it will be found impossible to maintain a pleasing
arrangement of the screws because the temperature variation will make
it necessary to mass all of the screws either in the holes nearest the
cuts or in those nearest the arms.
This is due to either over or under compensation of the balance. Over
compensation is caused by too large a proportion of brass in the rims,
which causes them to curve inward too far at the free ends in heat and
outward too far in cold. When the extent of this error is so great
that the rate is still fast in heat, with the screws massed in the
holes nearest the arm, a correction can be obtained by fitting heavier
screws in the holes adjacent to the arms and lighter screws in the
holes nearer the free ends.
When the rate in heat is slow with the screws massed at the free ends
of rims the balance is under compensated, which is caused by too
large a proportion of steel compared to the proportion of brass in the
rims. This prevents the free ends of rims from curving inward far
enough to carry the weight the proper distance toward the center of
balance. A correction for this can be obtained by fitting heavier
screws in the holes adjacent to the cuts and lighter screws in the
holes toward the center of rims.
In changing the weight of screws as stated above it should be
remembered that the gross weight of all screws must remain the same or
the timing will be seriously affected. It is also important that the
poise be tested whenever a considerable degree of alteration is made,
as this will assist in obtaining an accurate rate.
19. _Special Corrections for Over or Under Compensation._
Balances having the extreme degree of over or under compensation will
seldom be found in high grade watches. In any instance, however, it is
possible to obtain a better distribution of the screws by fitting
either a larger or a smaller hairspring. For instance, we will assume
a case of under compensation in which the screws have all been massed
at the holes nearest the cuts. If the spring has seventeen coils, a
correction of from five to ten seconds can be obtained by selecting
and fitting a spring of the same make that will have eighteen coils,
and the correction obtained will permit of shifting one or two pairs
of screws back toward the arms.
In case of over compensation a spring of the same make, one coil
smaller, will permit of shifting one or two pairs of screws toward the
free ends of rims.
In a series of tests it was demonstrated that by duplicating or
changing springs of the same make and size, on balances that had
previously been compensated, there was very slight difference in the
temperature variation of the watch. Also by changing pinning points or
breaking out one-fourth to one-half of the coil around collet and
adding weight to the balances to correct the mean time the difference
in the variation was almost negligible.
On the other hand it was found that by replacing the springs with
others of larger or smaller size, variations of from three to ten
seconds were noted in all instances.
In selecting and fitting a spring that will be one coil larger or
smaller, it should be noted that the inner coil of the original spring
and that of the new spring are approximately the same distance from
the collet. For if there was considerable space between the collet and
inner coil of the original spring, and the new spring was colleted
quite close, there might be the addition of an extra coil in the
inside only. This was found to produce only a very slight correction,
compared to that obtained by the addition of a complete outer coil.
These tests indicate that the proportion of strength of the spring in
the temperatures varies with any appreciable change in length while
slight changes make practically no difference.
20. _Example Demonstrating that Temperature Variation is not Always
Due to the Balance and Spring._
Fig. 7
+--------------------------------------------------+
| No. .................... Make................... |
+--------+-----+-----+-----+-----+-----+-----+-----+
| HEAT | -10 | -10 | + 4 | + 4 | + 1 | + 1 | |
+--------+-----+-----+-----+-----+-----+-----+-----+
| NORMAL | - 6 | + 4 | + 5 | + 1 | + 4 | + 3 | |
+--------+-----+-----+-----+-----+-----+-----+-----+
| COLD | +12 | +18 | + 1 | - 4 | + 7 | + 3 | |
+--------+-----+-----+-----+-----+-----+-----+-----+
28 8 2
The following example is submitted to show that temperature variation
is not always due to the balance and spring, and that the general
condition of the watch may be responsible. The second column of Fig.
7, indicates an error of twenty-eight seconds slow in heat with all
screws assembled in the holes nearest the free ends of the rims.
Examination proved that the motion of the balance in cold was reduced
to about one-fourth of a turn. In heat the arc of motion was at least
one full turn. This difference in motion was sufficient to prove that
there was some binding in the train.
A very close fitting of the escape pivots was found and this
undoubtedly caused binding of the pivots in heat due to slight
expansion. Expansion of the stone would also tend to close the hole,
and while the degree of temperature would hardly have any bearing on
this point it is sufficient to show in what direction the tendency
would be. The fourth wheel end shake was very close and probably
caused binding of the wheel in cold, due to greater contraction of the
bridge than of the fourth pinion. Furthermore the mainspring was only
0.02 of a millimeter narrower than the space in the barrel box. This
no doubt also caused binding through greater contraction of the barrel
than occurred in the mainspring.
The above defects were remedied and the rate was found to be eight
seconds plus in heat as per third and fourth columns Fig. 7.
This made it necessary to shift several of the screws away from the
cut, in almost the same position in which they were before the
alteration which caused the close assembling of the screws was made.
The final rate was two seconds slow in heat as shown in fifth and
sixth columns.
The variation of thirty-six seconds between the second and fourth
columns was entirely erroneous, and was due to condition of the watch
irrespective of the balance and hairspring. Should the variation with
the screws assembled have been by chance within the limits of
allowance the watch would undoubtedly have been a very unreliable
timepiece. The errors in the watch would no doubt have been corrected
during the position adjustment later, but the large error in
temperature which would have been introduced by wrongly moving the
screws, would have prevented reliable timing until possibly at some
future period a test in temperature would have been made and the
screws replaced in the proper positions.
CHAPTER V
THE MIDDLE TEMPERATURE ERROR
21. _Why This Error Exists and What it Consists Of._
In adjusting watches to temperature it is not always possible nor
expected to obtain a perfect rate between the two extremes,
manufacturers generally allowing from two to ten seconds variation
according to the grade.
Even when the rate obtained is perfect it will only be so at the two
extremes and there will always be a few seconds variation in the
middle or normal temperature.
This variation will always be a gain of from two to four seconds in
the higher grades of steel brass balances and usually more in cheaper
balances.
As there is no possible correction for this irregularity in ordinary
balances it has long been known as the middle temperature error and
for many years was one of the most perplexing problems that the
manufacturer of specially fine timepieces had to deal with.
Various devices were originated from time to time for the purpose of
counteracting the error but they were always too infinitely
complicated to be of commercial or scientific value, and none of them
were ever adopted as a solution of the problem.
In chapter I, No. 3, will be found a description of the distortions of
compensation balances in the extremes of temperature and the cause of
the middle error is due entirely to the fact that these distortions
are not exactly equal in both directions. The free ends of the rims
are drawn outward from the concentric form to a slightly greater
proportional degree as the temperature decreases from normal and they
are not forced inward at an even proportional degree with increase of
temperature.
22. _How Nickel Steel Balances Overcome the Middle Temperature Error._
Through extensive experiment in the foreign laboratories balances
containing nickel steel have been found to almost eliminate the middle
error, which is reduced to one second or less, making it possible to
obtain perfect adjustment in various temperatures.
All highest prize watches passing through the Geneva Observatory are
equipped with these balances and they have been adopted for commercial
use to a large extent by the manufacturers of the finer grades of
watches.
From the same source success has recently been attained in applying
this metal to hairsprings and using them in connection with uncut
balances, but owing to the necessary high cost of production, their
general use may be delayed for some years to come. Their general use
however would revolutionize the present-day methods of adjusting to
temperature as there would be practically no expansion or contraction
to deal with.
Nickel steel balances will always be found to have the cuts about one
eighth of the circle distant from the arms instead of close to the
arms. This is made necessary by the fact that the coefficient of
nickel steel is about ten times less than that of ordinary steel, and
if the cuts were made close to the arms the brass in expansion would
force the free end of the rims to curve inward to such an extent that
it would cause an abnormally fast rate in heat.
By making the cuts more central the length of the segments are
reduced, thereby causing less curvature of the extreme ends and more
nearly equalizing the extent of curvature both ways from the
concentric form. This equalization is what causes the reduction in the
middle error and its absence in ordinary balances is what causes the
larger error.
Non-magnetic or palladium balances are also credited with a smaller
middle temperature error than the ordinary steel brass balance, but
owing to the unstable nature of the metal they have not proved to be
as reliable in other respects and are not used to any large extent.
The middle temperature error is of course a small factor in the larger
sense of obtaining time from commercial watches but its influence is
apparent in timing and it will therefore be considered further in the
section devoted to Final Regulation, Chapter XV, No. 77.
PART II
THE ADJUSTMENT TO ISOCHRONISM AND POSITIONS
CHAPTER VI
GENERAL CONSIDERATION
23. _Optional Allowances for Variation._
The phrase "Adjusted to Isochronism and Positions" does not always
indicate the same high quality or the expense assumed in obtaining
close rating in different kinds of watches.
One particular model may be stamped "Adjusted to Five Positions" and
this may indicate that the manufacturer of this model has tested all
watches of this grade for twenty-four hours in each of five positions
and that the extreme extent of variation from one position to any
other, among any of these watches, did not exceed six seconds. Another
model may be stamped in exactly the same way and it may indicate that
all watches of that particular grade have been tested in exactly the
same way and that the extreme extent of variation from one position to
any other, did not exceed twenty-five seconds.
The statement regarding the number of positions to which the watch has
been adjusted is just as legitimate in the latter instance as it is in
the former, for the watches are really tested in five positions and
required to perform within specified allowances.
The important difference is in the established limits of requirement,
one demanding an extreme of only six seconds variation and the other
allowing twenty-five seconds. Both watches may have the same number of
jewels and there is no way to discern the actual variation except
through a test in positions.
Technically it would be just as legitimate to stamp and advertise
watches as above and have an allowance of fifty or more seconds,
providing that they were actually tested and not allowed to pass with
a variation greater than this limit.
Close limits of allowance require adjusters of greater skill and
material of a finer degree of accuracy, however, than do greater
allowances, but the dealer and consumer are generally not informed in
regard to this particular point. Some watchmakers also do not
understand this feature clearly and the limits of variation to which
watches have been adjusted are seldom considered.
Should the difference in allowances and identical advertising be
interpreted as an injustice to the manufacturer who maintains close
limits for his various grades of watches, it must be remembered that
they speak for themselves after passing over the counter and into the
hands of satisfied customers. His reputation after a period of years
will be more firmly established than will that of his less particular
competitor in the high grade field. A similar situation prevails in
the repair shop, and the fact that many of the leading dealers and
railroad watch inspectors require at least a three position adjustment
in the repairing of high grade watches, is convincing evidence that
position rating demonstrates its importance in actual service when
applied to repair work, as surely as it does when applied to new
watches.
In placing limits of allowance for variation in various grades it is
not intended that all watches of a particular grade will have the
extreme variation. It is possible that an individual watch in the
twenty-five seconds allowance class may have an even better rate than
another watch that is in the six seconds class. It is also possible
for a watch in either class to have a perfect rate, although these
would be rather exceptional instances.
24. _Some Necessary Requirements for Learning Adjusting._
The adjustments to isochronism and positions are not permanent to the
same extent that the temperature adjustment is, and they can be
damaged or destroyed entirely by the average workman in making
ordinary repairs unless he is familiar with the common principles
governing their production and maintenance.
Experienced workmen who are familiar with these principles avoid
unconsciously doing any damage and make practical repairs in a manner
that will maintain or improve the original adjustment and time-keeping
qualities of the watch.
To know and to make use of these principles does not make a "putterer"
of the workman, in fact the consequence is just the reverse, because
the training acquired tends to eliminate guess work and enables him to
determine more readily as to just what the trouble may be, how to
correct it, and as to just what degree of perfection is required in a
particular instance.
Certain practical requirements are necessary in reaching this standard
of workmanship and it would not be profitable to attempt to do
adjusting unless one has first had a reasonable degree of training as
a watchmaker or repairer, especially in such branches of the work as
truing and poising balances; truing, leveling and centering
hairsprings; matching the escapement; finishing pivots, and properly
cleaning and assembling watches.
These mechanical requirements and experiences alone are not
sufficient, however, and a certain amount of study must be
consolidated with them in order to become proficient. This study
should not deal so much with the problems of manufacture of the watch,
or its various parts, as it does with the problems pertaining to the
finished results that are to be obtained through refinement and
intelligent assembly of these parts. The workman's willingness to
indulge in such study is a very large asset among the requirements,
and it only remains for him to obtain the proper class of instruction
and then to conscientiously follow correct methods in his practice and
to make personal experiments, conforming to the instruction, so that
his confidence will become more enduring.
It is further required that he be capable of realizing the difference
between genuine and imitation materials, especially such essentials as
balance staffs, hole jewels, mainsprings and roller jewels, which are
the most frequently changed and most frequently substituted parts of
watches. Imitation materials may be less expensive as a matter of
first cost but staffs may have pivots and shoulders out of line, or
out of true; hole jewels may be rough, out of round or extremely
thick; mainsprings soft, or of improper proportion, and roller jewels
may have sharp edges which cause rubbing in the fork and "hanging up"
when the second hand is reversed. It is most satisfactory to depend
upon the materials supplied by the manufacturer of the watch, as
imitation goods are seldom any better.
25. _Train and Escapement Freedom._
Beyond a general insight of high class watch-work this book is not
intended to meet the requirements of beginners. It is designed
principally for watchmakers of some experience, and cannot presume to
cover details that would be essential for those in early
apprenticeship. It is thought essential, however, to consider some
matters in a general way and among these are the subjects of side
shakes and end shakes, and the escapement, as far as they pertain to
general inspection of the watch without consideration of details that
refer to correction of irregularities which are presumed to have been
acquired in earlier training.
Thoroughness of mechanical ability always demands a system of
inspection and of making corrections and it is quite necessary to
follow some method that will reveal any point or points that may not
be up to standard.
As a rule it is best to begin at either end of the watch, and if it is
to be taken down the best place to begin is usually with the balance
and examine each part as it is removed until the barrel has been
reached. If it is not to be taken down, just as good results will be
obtained by beginning the examination at the barrel and finishing with
the balance. Sometimes watchmakers of considerable ability will demand
as a basic consideration that pivots be fitted with very little side
shake and that end shakes also be quite close if close time is to be
expected.
These presumed to be, wide side shakes and long end shakes, very often
have nothing whatever to do with the absence of a close position rate
and frequently are absolutely necessary for good performance of the
watch and proper space for oil.
The importance of reasonable limits is of course granted, but it is
very detrimental to have pivots too close fitting and more stoppage
and irregular time keeping can be traced to lack of freedom than can
be traced to excessive shakes.
If the repairer is not familiar with accepted standards of side and
end shakes, he can improve his judgment by examining watches of the
higher grades and comparing the results with those found in cheaper
makes of watches.
Such examination will invariably disclose the fact that fine watches
receive very careful consideration in this respect. The center, third
and fourth wheels generally having from 0.03 mm. to 0.05 mm. freedom
for end shake and 0.015 mm. to 0.02 mm. for side shake. The escape
wheel, pallet and balance will be found to run quite uniform at from
0.02 mm. to 0.03 mm. freedom for end shake and from 0.0075 mm. to
0.0125 mm. for side shake. The smaller and thinner watches generally
favoring the lesser figures and the larger and thicker watches
favoring the higher.
This uniformity of freedom will be found absent in cheaper watches;
for instance, a center wheel may have 0.02 mm. end shake and 0.01 mm.
side shake which would be very close fitting for large pivots. The
fourth wheel may have as much as 0.08 mm. end shake and 0.03 mm. side
shake which would be too great. The pallet may have 0.05 mm. end shake
and the balance 0.01 mm. and in this instance the short end shake of
the balance would be more detrimental in most instances than would the
longer end shake of the pallet. The variation will even be found to
exceed these figures and when they are found in connection with thick,
straight hole jewels they often interfere with a close position rate
and with regularity of time in service. The interference in
timekeeping is considerably aggravated in cases where one pivot has
excessive side shake and the opposite pivot is close fitting, as this
tends to cause almost certain binding of the close fitting pivot as
soon as the power of the mainspring is applied.
The end shake and side shake allowance for the barrel depends
considerably upon its style of construction. Safety barrels
constructed so that the arbor revolves with the main wheel, when the
watch is running, may have about the same end shake and side shake as
applied to the center, third and fourth wheels, and if the pivots of
the arbor are quite large they may have a trifle more side shake.
As a rule larger pivots will stand more side shake than smaller
pivots; this, however, does not apply in the case of large bearings,
such as safety main wheels that revolve around a stationary arbor, or
going barrels where the entire barrel revolves around the stationary
arbor when the watch is running.
In such instances the main wheel or barrel should have from 0.03 mm.
to 0.05 mm. end shake on the arbor and should be just free for side
shake.
The arbor which turns only when the watch is wound requires merely
freedom for end shake between the plates, as well as for side shake
where the pivots pass through the plates.
With reference to the escapement, good watchmakers often have
different methods of examining the various points and of making
corrections and it is not of so much importance as to just how
correct conditions are obtained, as it is that they actually be
obtained.
Whatever the method may be it is certain that each escape wheel tooth
must have positive locking on each pallet stone and that there must be
positive space for drop between the back of each stone and the pointed
end of each escape wheel tooth. There must also be sufficient draw
when each tooth and stone are locked to hold the fork against the
bankings.
When the lock, drop and draw are correct it is next necessary to see
that the fork length and guard pin freedom are correct.
There is only one positive method of determining as to when the fork
length is correct, and this is through closing the bankings to drop.
This can be done either before or after placing the balance in the
watch and merely requires turning the banking screws so that the
excentric pins will close in on the fork until the fork arrives at the
pins, at the same instant that the tooth drops on the pallet stone.
This eliminates any slide of the stone on the tooth beyond the actual
locking and in this condition it is required that the roller jewel
pass through the fork slot and out of the fork horn entirely on both
sides with perfect freedom.
Should it touch on both sides of the fork, then the fork is either too
long or the roller jewel is too far forward, and if it touches on one
side only it may require simply equalization of the freedom. The guard
pin length also must be obtained with the bankings closed to drop and
should be just free from the safety roller on both sides.
When the inspection proves that these conditions have been properly
provided for, it is necessary to slightly open the bankings so that
there will be just a trifle of slide of each stone, on each tooth,
after the locking takes place.
Extremely wide side shakes of the escape, pallet or balance pivots
will sometimes cause striking of the roller jewel when conditions are
otherwise correct, and these side shakes should not be very much
beyond the extreme limits mentioned in this number. The fact of this
feature, however, should not be construed as a recommendation that
these pivots be closely fitted, for reasonable freedom is to be
desired because it is positively necessary.
CHAPTER VII
THEORY AND PRACTICE
26. _Theory of Frictional Errors and the Isochronal Hairspring._
Theory teaches us in brief, that the position adjustment is made
necessary principally because of frictional errors. It would therefore
seem that if the watch was mechanically correct there would be little
or no requirement for position alterations.
We are also advised that an isochronal hairspring is one which will
cause the long and short arcs of the balance to be made in equal time
and that to attain this, the center of gravity of the spring must
coincide with the center of gravity of the balance and that a certain
pinning point is necessary in producing this result.
Now if we have a watch of correct mechanical construction and fitted
with an isochronal spring it would seem that a close rating timepiece
would be assured.
27. _How Theory Works Out in Practice and What Isochronism Consists
of._
Practical adjusting, however, proves that such is not the case, for
even when the construction and alterations produce watches as nearly
correct as scientific methods can determine, there is often
considerable variation in the position rates. A twenty-four hour test
in any position may prove that the long and short arcs are made in
equal time showing the spring to be isochronous and yet the position
variations have not been accounted for. In this connection experience
proves that a spring showing a perfect isochronal rate may have its
collet pinning point changed, in relation to the pinning point at the
stud and that through such an alteration, a correction in positions
can be obtained, without in the least disturbing the perfect
isochronal rate.
This indicates that the separation of the two adjustments which is
possible in theory, does not hold good in practice, because a spring
showing a perfect isochronal rate has been altered for the purpose of
counteracting some position error and thereby producing a practical
center of gravity of the balance and spring combined, instead of
separately.
This may be further explained as creating an error in a spring which
is supposed to be theoretically isochronous, with the idea of making
it act in opposition to the position error and the combination thus
obtained produces practical isochronism as well as a corrected
position rate.
It is not suggested that these relative pinning points be altered for
the purpose of overcoming position variation such as may be caused by
dirt and gummy oil, damaged pivots, or balances that are out of poise.
The watch should be in first-class condition and have a good motion in
every position and then the alterations may be safely undertaken in
accordance with the principles.
Adjusted to isochronism indicates that the watch functions uniformly
during the entire twenty-four hours running. It is immaterial as to
whether the rate be perfect or whether it be a gain or a loss, so long
as it is uniform.
The watch is not isochronous if there is both a gain and a loss in the
rate, even though the time be perfect at the expiration of twenty-four
hours.
Experiment will demonstrate that watches carefully adjusted to
positions will also have a very close isochronal rate. These
isochronal experiments can be made by timing watches for twenty-four
hours in any one of the vertical positions and noting the variation
in periods of from four to twelve hours and by comparing the variation
in the first period, during which time the arc of motion is long, with
the variation in the latter period when the mainspring power is weaker
and the arc of motion is short.
28. _Common Causes of Extreme Isochronal Variation._
The most common causes of isochronal variation with which the repairer
has to deal and which are often very destructive to position rates, as
well as to general time keeping, may be found in the factor of, out of
poise and uneven motive force, which is one of the elementary
principles of adjusting. This feature should be thoroughly understood
by all watchmakers, so that as good results as possible may be
obtained from all watches above low grade, even though no test for
adjustment is to be made.
When the balance is slightly out of poise and the motion is exactly
one and one-fourth turn during the twenty-four hours, this out of
poise will not affect the isochronism. When the motion varies and
reaches approximately one and one-half turn during the first few hours
after winding and then drops to one and one-quarter turn and finally
to one turn or less during the latter part of the twenty-four hours,
the poise error will have considerable effect. This factor is not
perceptible in the flat positions, but shows up to the full extent in
the vertical positions and the variation differs according to the
location of the point that is heavy. For example, if the balance is
heavy on the lower side when at rest, the watch will lose during the
hours that the arc of motion is over one and one-fourth turn and will
gain when the motion drops to one turn or less.
Should the heavy point be on the top side of balance the result will
be reversed and the watch will gain when the motion is over one and
one-fourth turn and will lose when it drops to one turn or less.
The total variation may be either seconds or minutes, depending upon
the extent of the poise error and experiments will prove that serious
isochronal variations can be traced to the simple cause of lack of
poise and irregular motion in more instances than to any other cause.
The arc of one and one-fourth turn is the ideal motion, as slight
poise errors are neutralized at this point, but very few watches will
maintain this motion for twenty-four hours, therefore the poise must
be as nearly perfect as possible. The nearest approach to even motion
of modern watches is found in the fine Swiss grades equipped with stop
work, which causes only the best part of the mainspring to be
utilized.
Such watches also receive the most expert attention as to gearings of
wheels and pinions and the train wheels are specially rounded up on
their respective staffs. This latter feature has been adopted by at
least two of the American manufacturers of fine watches during the
past few years with considerable benefit in producing even motion and
the use of lighter mainsprings. It should be definitely understood
that these tests refer to the vertical positions of the watch only and
that the horizontal positions are not affected in the same way by lack
of poise.
CHAPTER VIII
RELATIVE PINNING POINTS OF THE HAIRSPRING
29. _Original Springing of Watches._
Theory and practice agree that different models of watches have
important relative points of attachment of the spring to collet and
stud. In the original springing and adjusting of high grade watches,
these points receive careful consideration, and only a very small
percentage ever require future alterations.
There are instances, however, where the original allowance of position
variation has been considerable, also medium grades where no attention
has been directed to pinning points and in which an occasional
alteration may be required before a close position rate can be
obtained.
30. _How Pinning Point Alterations are Made._
These alterations are generally made by breaking off or letting out a
small section of the inner coil at the collet. In making such
alterations a quarter of a coil broken away at the collet will have
the same effect as will a quarter of a coil broken off at the outer
end and will require less weighting of the balance to correct the mean
time. It will also avoid breaking and remaking the over coil and the
possible necessity of readjustment to temperature. Letting out the
spring can be accomplished by unpinning and repinning the spring at
collet with less of the coil entered in the pinhole. This is not a
positive alteration, however, because very often the segment in the
pinhole is as short as it can be with safety.
A more substantial correction is that of reforming the over coil in a
manner that will cause the end holding the stud to be shifted further
forward.
The method of obtaining this correction is illustrated in Fig. 8. The
broken line shows the original formation of the over coil with the
stud on the line "B". The solid lines show the corrections with the
stud shifted to the line A.
[Illustration: Fig. 8]
When the collet is turned to replace the spring in beat, the stud will
be in its original location on the line "B."
This will cause the pinning point at collet to be shifted from "A" to
"B" and bring it that much nearer to the horizontal line "C."
This alteration has the same effect as that of letting out the spring
at the collet or of moving the stud forward on the over coil, with the
advantage of eliminating any change in the mean time.
It should be definitely understood that the objective in making the
above alterations and as illustrated with the aid of the following
cuts, is the relation of the pinning point at collet to the pinning
point at stud, and that the change in length of the spring has no
bearing on the matter whatever as far as the position rate is
concerned.
31. _Even Coil Hairsprings Very Incorrect for Some Models._
It is often supposed that hairsprings having exactly even coils are
correct for close position and isochronal rating. Such springs do
approximate the nearest correct relation in more instances than any
other relation. They are precisely correct for very few models,
however, and are very incorrect for many models, as will be seen
through study of the following cuts showing the various points of
attachment and the different results obtainable in each.
32. _How to Find the Correct Collet Pinning Point for Any Watch._
A very simple method of locating the proper point of attachment of the
spring to collet is to face the train side of the movement and hold
the balance stationary with a small twig, and with the pallet fork
just midway between the two bankings.
[Illustration: Fig. 9]
Presume the existence of a vertical line through the center of
hairspring and collet as shown at "A B" Fig. 9. Then presume a
horizontal line as shown at "C D" on the same cut.
[Illustration: Fig. 10]
The proper pinning point is at the intersection of the collet and
horizontal line; the spring may be either over or under even coils,
depending entirely upon the location of the stud hole in the balance
bridge as demonstrated by Figures 9, 10, 14, 15.
When the spring develops to the right from collet as shown in Fig. 9,
for example, the proper point of attachment is on the right side of
collet as shown at "E" Fig. 9, and also at "J" Fig. 14.
If it develops to the left as the springs of all fine Swiss watches
do, the proper point of attachment is on the left side of collet as
shown at "F" Fig. 10.
33. _Results in Vertical Position Rates Due to Changing the Pinning
Point._
In either of the above instances the spring will develop upward as it
leaves the collet. These points of attachment always produce a fast
pendant up rate when compared to the opposite, or pendant down rate,
and all high grade watches are originally fitted with springs
conforming to this principle.
If these points of attachment were changed to the opposite side of
collet so that the spring would develop downward as shown at "G" Fig.
11, and "H" Fig. 12, the results would be reversed and the pendant up
rate would be slow in comparison to the pendant down rate.
[Illustration: Fig. 11]
This point of attachment in which the spring develops downward from
the collet is generally known as the slow point among adjusters, and
when a spring is pinned at either the slow or fast point the pendant
right and left positions generally compare quite closely to each other
in timing, provided that the poise and other conditions of the watch
are correct.
If the pinning point was changed to the intersection of the collet and
vertical line as shown in "I" Fig. 13, the pendant up and down rates
would compare nearly equal to each other and the pendant right
position would be slow compared to the pendant left position.
[Illustration: Fig. 12]
If it were pinned at the intersection of the collet and vertical line
just opposite to that shown in Fig. 13, the pendant left position
would be slow compared to the pendant right position.
[Illustration: Fig. 13]
The vertical points of attachment are seldom used, for the reason that
the variation between the pendant right and left positions would be
very difficult to control within close limits, due to the existence of
the natural error. As these positions, together with the pendant up
position are the most important of the four vertical positions, they
are given preference, and the natural error is placed in the pendant
down position where it will be the least detrimental to the
performance of the watch.
34. _The Natural Position Error and Why it Cannot be Eliminated._
[Illustration: Fig. 14]
The natural error generally consists of from twelve to fifteen seconds
in finely constructed watches, and exists because of the fact that it
is impossible to perfectly poise a spiral spring. The location of the
heavy point, however, may be shifted by changing the point of
attachment at collet as described in No. 33, this Chapter. The nearest
approximation of a poised spiral spring is probably attained through
L. Lossier's inner terminal curve. Results are not positive, however,
and any deviation from the required precision makes the curve
valueless. It is possible to obtain perfect adjustment between three
vertical quarter positions and the two horizontal positions, but all
four quarter positions cannot be perfectly adjusted because the
natural error will show up in one of them. Manufacturers of fine
watches do not of course presume to supply perfect adjustment in the
five positions. Some however, have considerably closer limits of
allowance for variation than do others and it is logical to presume
that a line of high grade watches having a five position allowance of
six seconds from one position to any other would show better results
than another line which had even a six position adjustment and an
allowance of fifteen seconds from one position to any other.
35. _Principle of Pinning Point Alterations._
[Illustration: Fig. 15]
When an alteration of any pinning point is necessary, the extent and
direction of the alteration are determined by the rate of the watch.
For instance, if a spring is pinned at the fast point and if a
slightly slower pendant up rate is desired, the spring can be broken
off at the collet and pinned one-eighth above the horizontal line.
If the rate is to be made slightly faster, the spring can be let out a
trifle at the collet, the over coil reformed or the stud moved forward
on the over coil so that the collet point of attachment will come
slightly below the horizontal line when the spring is placed in beat.
The former alteration causes an approach toward the slow point and in
making the latter alteration we assume that the fast point is a trifle
below the horizontal line on that particular watch. When altering
springs from the extreme fast point to the extreme slow point, it is
advisable to remove a trifle less of the inner coil than the extreme
calculation. This will cause the point of attachment to be slightly
above the horizontal line on the slow side and will most always
produce the result desired and if it does not, there is still a
possibility of further alteration. The same principle applies in
making an alteration from the extreme slow to the extreme fast point
and in this case the point of attachment to collet may be just a
trifle below the horizontal line.
The theory of this is that all shortening of the coil from the fast to
the slow point produces a slower rate pendant up, until the extreme
slow point is reached. After passing this extreme slow point the
pendant up rate begins to grow faster until the extreme fast point is
reached. [A]The designations "right" and "left" in regard to pinning
points are used with the explicit understanding that the individual is
facing the train side of the movement. The same designations used as
referring to position rates, or results to be expected in positions
should be interpreted to mean with the individual facing the dial side
of the watch.
36. _Same Principles Apply in Case of American Hunting Models._
The points shown in Figures 14 and 15 refer generally to American
hunting models. In all other high grade watches the location of the
balance and spring will be found either to the right or left of the
center of the watch.
In American hunting models the balance and spring are located in the
lower center of the watch.
This is due to the fact that American manufacturers do not construct
separate models for hunting watches as is done by foreign
manufacturers.
Instead of producing an entirely separate model, the method simply
calls for a change in the construction of the barrel bridge by
reversing the position of the barrel and winding wheels. This places
the winding sleeve at figure three on the dial, which is customary on
hunting watches and causes the entire movement to be shifted by ninety
degrees with the balance just about opposite the pendant.
FOOTNOTES:
[Footnote A: Important Note.]
CHAPTER IX
MANIPULATION OF THE REGULATOR PINS
37. _Altering the Length of Spring by Regulator Pins._
On some occasions when the pinning points seem to be comparatively
close and the watch is in good condition with the balance in poise, it
is possible to obtain corrections by closing or opening the regulator
pins.
This, however, can only be resorted to, to a limited extent, as
otherwise the value of the regulator may be impaired.
The pins should not be closed tight enough to cause "kinking" of the
over coil and they should not be spread apart any more than enough to
make the mean rate about 2 seconds per hour slower.
Some models of watches consistently require that the pins be closed,
while other models require that they be slightly spread, and it is
therefore advisable not to disturb the pins when cleaning watches
unless they have been bent by incompetent hands.
It is better to reserve the majority of pin alterations for such time
as the position rate determines the necessity of an alteration. When
the pins are open, however, it is necessary to adjust the coil so that
its vibration will be equal.
Correct execution in spreading or closing the pins will very often
make it possible to obtain a correction of six or eight seconds
between the vertical and horizontal positions.
38. _Method of Examining Vibration of Over Coil Between the Pins._
The proper method of examining this vibration is to stop the balance
and observe the movement of the coil between the pins.
The vibration should be equal at the slightest oscillation of the
balance as well as during the longer arcs. The coil should not rest
against one or the other of the pins at any time unless they are both
closed. Emphasis is placed upon equal vibration of the coil when the
pins are open because of its importance, and if results are not
obtained (as expected) the examination should be repeated to see if
correct conditions have been attained. Examination of this vibration
should be made from both sides of the pins and usually the best
estimate can be obtained by looking between the pins from the stud
side.
39. _Position Corrections Obtained by Spreading or Closing the
Regulator Pins._
When the regulator pins are tightly closed and the watch has a fast
pendant up position rate, it will be possible to obtain a slower rate
by slightly spreading the pins.
When the pins are spread and vibration of the coil between them can be
discerned, and the pendant up rate is slow, a faster rate can be
obtained by closing them.
In spreading the pins they should be drawn away from the coil equally,
as otherwise the coil will strike one pin with more force than the
other, which will not produce results as expected and will cause
uncertain regulation. In closing the pins they should be drawn
together one at a time until both are in equal contact. They should
not be merely squeezed together, as this causes distortion of the coil
at the point of contact.
CHAPTER X
FACTORY AND REPAIR SHOP ADJUSTING
40. _Routine Varies According to Circumstances._
The principles covering the adjustment of watches are the same in the
repair shop as they are in the factory and they are equally the same
in the various lines of high grade watches regardless as to whether
they are of American or foreign extraction.
The routine covering the work to be done, however, may vary, depending
upon the quantity of watches that are turned out. In the factories
where large numbers of watches are adjusted the adjuster is trained in
the various branches of watch work and eventually devotes his entire
time to adjusting. The watches are generally turned over to him after
they are all assembled and ready for the final balance and spring
work, or after they have been finished and rated, in which instance he
receives only those that are not within the requirements and he then
makes the necessary alterations, after which they are again tested for
results.
In some repair shops where large numbers of fine watches are handled,
a similar system is used and one competent adjuster devotes his time
principally to the work of timing and adjusting.
41. _Considering the Watchmaker in the Small Shop of One or Two
Workmen._
By far the greater number of watchmakers are employed in stores having
only one or two workmen who are required to do the cleaning and to
make all repairs. For this reason an adjuster of equal skill could not
do as much actual adjusting as could be done in either of the two
previous instances, but for the same reason he would not be expected
to do as much.
He can, however, adjust the high grade watches that he repairs just as
closely, and he should not permit himself to feel that time and the
nature of his position prohibits him from doing so. Whether it does,
or does not prevent him from obtaining close rates depends entirely
upon his training and understanding of the necessary details. If he is
skilful and accurate, his output of work in the long run will not be
reduced, his work will give better satisfaction and he will have less
"comebacks" to take up his valuable time.
42. _Advantage of Understanding Adjusting Even Though Watches are Not
Tested in Positions or Isochronism._
To understand position adjusting thoroughly is of the greatest
advantage in obtaining satisfactory time from any medium or high grade
watches even though they are not to be tested in positions because
vital points will receive intelligent observation where they would
otherwise be overlooked.
43. _Concerning Watchmakers of Limited Experience._
The previous notes and rules covering pinning points of the hairspring
as detailed by the cuts and descriptions, together with the concrete
adjusting examples to follow would no doubt be of sufficient note for
watchmakers of considerable experience.
There are, however, many ambitious workmen who have not devoted any
time whatever to the study or practice of adjusting and to whom some
elementary study and practice may be quite indispensable.
To be of service to this class of workmen chapters XI and XII are
devoted to preliminary notes and practice lessons.
The contents of these chapters can be worked out in practice by almost
any workman who is capable of holding a position as watchmaker and it
is substantially necessary that they be mastered before finished
results are to be expected.
CHAPTER XI
PRELIMINARY NOTES AND PRACTICE FOR BEGINNERS
44. _Practical Suggestions._
Experience will eventually prove that most of the variations in
positions are caused by apparently insignificant details. The mistake
made by the average repairer is generally that of failing to detect
these details and to make slight corrections where necessary, as he
proceeds with the ordinary cleaning and repairing of the watch.
This oversight often prevents what would otherwise be excellent
results in timekeeping and makes it necessary to utilize extra time
and labor in the effort to obtain more consistent timekeeping.
45. _The First Point of Consideration in Learning to Adjust._
The first consideration in position adjusting should be directed
toward equalizing the time in the two horizontal positions. This
equalization should be accomplished entirely by attention to details
that can be plainly seen before arriving at the point of actual timing
of the watch. The principal requirement for equal time between dial up
and dial down is equal arc of motion of the balance in each of the two
positions, and the adjuster should become capable of obtaining this
equal arc of motion before attempting to obtain close rating in the
other positions.
46. _Causes of Variation Between Dial Up and Dial Down._
Variations between dial up and dial down may be due to one or more of
the following causes which have been arranged in two groups, the
first group consisting of the most frequent and common causes, while
the second group consists of causes equally detrimental but less
common.
Group No. 1
1. Dirt or thick oil in one or both balance jewels.
2. Burred or marred balance pivots.
3. End of one balance pivot flat or rough and opposite pivot polished.
4. Ends of both balance pivots polished but not same form.
5. Balance pivot bent.
6. Hairspring rubbing balance arm or stud.
7. Hairspring concave or convex in form instead of perfectly level.
8. Over coil rubbing under balance cock.
9. Over coil rubbing center wheel. (Some watches).
Group No. 2