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.
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 reformingthe 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.
Fig. 8Fig. 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.
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.
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.
Fig. 9Fig. 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.
Fig. 10Fig. 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.
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.
Fig. 11Fig. 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 intiming, 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.
Fig. 12Fig. 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.
Fig. 13Fig. 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 inthe pendant down position where it will be the least detrimental to the performance of the watch.
Fig. 14Fig. 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.
Fig. 15Fig. 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 thiscase 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.
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:[A]Important Note.
[A]Important Note.
[A]Important Note.
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.
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.
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.
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.
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 bedone 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.
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.
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.
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.
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.
Variations between dial up and dial down may be due to one or more of the following causes whichhave 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
10. Balance pivots fitted too close in jewels.11. One pivot having excessive side shake and the opposite close fitting.12. Escape or pallet pivots bent or damaged.13. Balance end stone pitted or badly out of flat.14. Over coil rubbing outside coil, at point where it curves over spring.15. Balance arm or screw touching pallet bridge.16. Balance screw out too far, touching bridge or train wheel.17. Safety roller rubbing dial plate or jewel setting.18. Fork rubbing impulse roller.19. Guard pin rubbing edge of safety roller.20. Roller jewel long and rubs guard pin.
Any of the above irregularities will cause a variation in motion between dial up and dial down andinvariably the trouble will be found on the side which has the shorter motion. For instance, a pivot that is flat or rough on the end will cause a shorter motion, when it is down, than will the opposite pivot when it is down, provided that its end is slightly rounded and highly polished. The same is true when the oil is gummy or dirty in one jewel and the opposite jewel is clean and freshly oiled.
Capped escape or pallet pivots when flat or rough on one end have the same effect to a lesser degree.
It is never proper to make the end of a pivot flat or rough and thereby shorten and equalize the motion. Neither should the ends of both balance pivots be flattened at any time. On the contrary, the ends of pivots should always be slightly rounded and highly polished: there is no logical reason for having them otherwise.
There are occasionally instances where a poor motion on one pivot is caused by a slight burr on the opposite pivot. This is usually due to the fact that while the burred pivot is running on its own end stone, there is space enough between the end stone and jewel to give the burr clearance, but when the position of the watch is reversed, the balance end shake allowance causes the burr to rub on the top of jewel hole and prevents perfect freedom of motion when the good pivot is downward.
The hairspring may be true and level but it should be carefully examined to see that there is no possibility of touching at any point. The observation should take place during the full arc of motion of the balance, for there are some instances in which no rubbing takes place until the motion accelerates. The watch should be held at different angles andthe space between the balance arm and spring, and the stud and spring, closely scrutinized for possible contact. The space between the spring and over coil at the point where the over coil rises and curves over the spring should be at least equal to the width of the coils and care should be taken to see that the over coil just before the point of rising has the usual space between it and the next coil. Either position in which the hairspring may rub will have a shorter motion and a gain in time compared to the opposite position in which there is no interference.
Invariably the arc of motion which is the shortest will gain time compared to the opposite position which has a longer motion. There are, however, some few instances in which there are exceptions to this rule, and knowledge of these exceptions is quite valuable in preventing confusion and doubtfulness in the certainty of making specific alterations. As an example in the horizontal positions; if both end stones are perfect and the freedom of one pivot in the jewel is correct while the opposite pivot has entirely too much freedom, the motion may be somewhat shorter with the proper fitting pivot downward while the rate may be slower compared to the opposite position. This is caused by the balance describing a larger circle when the large hole jewel is upward, as the pivot is allowed to travel a greater distance from the center of the hole as it wavers from side to side during the oscillations.
When the watch is reversed the weight of the balance prevents the pivot from wobbling in the large hole and eliminates the possibility of compensating for the larger circle described by the balance in the opposite position.
The same results are possible when the freedom of both pivots is correct and when one end stone is pitted, as the pit in the stone causes a short motionwhen downward and prevents the pivot from having any side play whatever, while the opposite pivot enjoys full play to whatever freedom there may be and through this causing a somewhat larger circle to be described by the balance and a slower rate in time.
It should be understood that this does not refer to instances where the end stone surface is merely slightly worn, but to pittings in which the surface of the stone has been actually pierced. In most instances of slight wear the motion will be shorter and the rate fast which conforms to the general rule covering rate and motion.
For preliminary practice in position adjusting, select a watch of about 17 jewels which has just been cleaned and put in order to the best of one's ability.
Regulate it so that it will time within ten seconds in twenty-four hours. Then run it dial up for twenty-four hours and make a notation as to the number of seconds either fast or slow. Next run it dial down for twenty-four hours and make note of the number of seconds fast or slow in this position. If there is a variation in time between the two positions it will be found that the position having the faster rate of the two will also have a shorter arc of motion.[B]
The exact arc of motion in each position can be known by observing the arms of the balance and comparing the extent of the arc with some point on the pallet bridge.
A variation of one-eighth of an inch in motion will generally make a difference of four or five seconds in the rate and greater variations will make corresponding increases in the difference.
When a watch is in good order a correct motion for the horizontal positions is generally considered to be that of one and one-half turn, which consistsof three-quarters of a revolution of the balance in each direction.
Should the motion be very much below this, in both positions, there may be something wrong with the general condition of the watch or possibly there may be a weak mainspring at fault, or an imitation spring that is too long and thick may take up too much room in the barrel and cause poor motion as surely as will one that is two weak.
Assuming, however, that the motion is good in one position and drops off in the other, it is quite probable that only an ordinary position correction will be required and the immediate problem to be considered is that of causing the short arc of motion to accelerate enough to equal the longer arc. The precise correction required will most probably be found among the causes listed in No. 46, this Chapter.
The horizontal position which has the slower rate of the two should be considered as the unit which is correct and it will always have the longer motion of the two, barring the occasional exception as described in No. 50.
This longer arc of motion is universally due to a better condition, while the shorter motion indicates that something is wrong, and it should always be the aim of the adjuster to improve some condition that is below standard, rather than to make some good condition a little worse in order to equalize the rates.
It may be possible to equalize horizontal rates by flattening the ends of pivots, but it does not require much more time to improve the motion in one position than it does to make it a little worse in another. The advantage is all one way and results either good or bad depend entirely upon the viewpoint of the worker and how he applies himself to the situation.
In the examination of pivots, end stones and jewels, it is necessary to use a stronger glass than the one used for ordinary work.
Damaged pivots can often be detected by looking through the end stone with a strong glass while the balance is moving. If imperfect they will appear dark or display a slight waver or flash and if they are in good condition they will appear bright and seem to stand still. They can also be examined in the lathe and a good true enclosed balance chuck is of immense value in detecting burrs, chipped edges, rings on the sides, slight bends and poorly shaped ends. The complete balance and spring can be inserted and the pivots can be refinished without disturbing the roller or hairspring. The chuck should be revolving very slowly when making the examination and moving the belt with the hand will enable one to see more than can be seen when the lathe is running at regular speed. Some watchmakers use small bow lathes for examining and finishing pivots, or the Jacot lathe, which is excellent for this kind of work. An end stone that has been deeply pitted should always be discarded and a new one supplied. If the hole is very slight, however, it can be removed entirely and the surface of the stone re-polished on a lap charged with No. 5 diamond powder, but the stone and setting should be thoroughly cleansed by brushing and pithing before replacement.
Should a slight particle of diamond or any other hard stone powder possibly remain on the stone or in the bezel it might eventually enter the end of pivot and again cause pitting. In case that the end stone is of the type that is flat and highly polished on both sides, such as is usually found on detachable dome foreign watches, it can be punched out with a piece of brass wire or peg wood and replaced in reverse position, after which the bezel can be closedand the stone will be just as serviceable as a new one.
Pivots that have been running on pitted end stones are generally rough on the end which is charged with some hard substance. They require special treatment to remove the cause of the pitting and the following method of refinishing is very good. Place the balance in the lathe and draw a soft Arkansas oil stone over the end of pivot with pressure enough to remove a bit of the metal. This will drag out any hard particles that may be lodged in the end and after this has been done the pivot should be pithed clean and polished with a smooth hard steel burnisher covered with oil.
A hard stone such as sapphire or jasper, or a steel burnisher should not be used on the pivot until the Arkansas stone has first done its work, because a hard instrument of this description will force the small particles that cause the pitting further into the end of the pivot instead of removing them entirely.
A pivot that has been treated in this way will not pit the end stone a second time unless carelessness in the use of hard powder permits additional particles to come in contact with the pivot or end stone.
There are some instances in which the steel is highly carbonized but manufacturers generally use the best steel obtainable for balance staffs and excessive carbon can generally be detected with a magnifying glass. Free use of diamond powder and emery wheel dust are more often responsible. The holes of jewels should never be enlarged or polished with diamond powder after the jewels have once been placed in their permanent settings, as this allows the powder to lodge between the jewel and the setting where it cannot be removed by cleaning but where it will be drawn out by the oil and charge any pivot that may be run in the jewel. The grey powder in such instances may be seen through the top of jewel with a strong glass.
FOOTNOTES:[B]Note Exceptions in No. 50.
[B]Note Exceptions in No. 50.
[B]Note Exceptions in No. 50.
The first of the vertical positions to be considered is that of Pendant Up and to understand the causes of and corrections for variations in this position completes what is known as three position adjusting.
The usual causes of variation in the pendant up position as compared to the horizontal positions are as follows.
Poor Motion Pendant Up.Regulator Pins not properly adjusted.Balance not in poise.Hairspring not in circle.Hairspring not pinned at proper point.
Among these causes that of Poor Motion covers a number of troubles such as roller jewel rubbing in fork, guard pin rubbing roller, strong lock on the escapement, or no lock on some teeth.
Such causes may not prevent close rating between the horizontal positions because of non-interference until the position of the watch is changed.
The pendant up motion should therefore be the first vertical point of investigation and if at fault the cause should be eliminated. In this connection it should not be expected that the arc of motion in the pendant up or any other vertical position will be as long as it will be in the horizontal positions,for when a watch is in excellent condition in every particular the vertical arcs are always approximately one-fourth of a turn shorter than the horizontal.
This is due to frictions and is impossible of correction and therefore should not be confused with a poor motion of greater extent which has removable causes that are practical of execution.
A good motion is to be considered as one of the results to be expected in overhauling and putting a watch in good order and it should not be understood that it is particularly to be associated with adjusting only, nor should any watch be slighted in cleaning and assembling with the idea that adjusting will correct it in a few minutes' time. On the other hand it should be understood as fundamental that no watch can be a close time keeper unless it has a good motion and no good adjuster will attempt to obtain close time in one position or a close rate in different positions until the motion is first what it should be. If it is what it should be, about ninety per cent of the necessary work required for obtaining close position rates will have been completed.
When the watch is in reasonably satisfactory condition and a three position test proves that the pendant up position has a variation of from ten to twenty seconds either fast or slow compared to the horizontal positions, the regulator pins may be the first point of examination. If there is considerable vibration of the coil between them, and the pendant rate is slow, it will be necessary to close the pins and if the rate is fast and the pins are found to be closed so that there is no vibration of the coil, it will be necessary to spread them slightly. Closing the pins will of course make the general timing of the watch faster and spreading them will make it slower and therefore it will be necessary to regulate the watch for one or two seconds per hour beforeagain testing it in positions. The result of either operation, however, will be to cause the rate in the pendant up position to conform more closely to the horizontal rates.
Preliminary and profitable two position experiments can be made between dial up and pendant up, by having the pins closed on most any watch that is in good order and timing it within five or ten seconds in twenty-four hours, then rating it in these two positions. Next spread the pins slightly, re-time the watch and rate it in the same two positions and compare the variations. A few experiments of this description will soon demonstrate as to the extent of correction that can be obtained in this way.[C]The rule of equal vibration of the coil between the pins after they have been spread must be rigidly enforced.
Assuming that the motion and regulator pins seem to be satisfactory, the next point of investigation should be the poise of balance. The hairspring should be removed and the pivots known to be straight and polished before testing. The rollers are of course a part of the balance and are not to be removed. A perfectly poised balance can be stopped at any point on the tool and it should at least remain stationary at each of the four quarters of its circumference. No. 28, Chapter VII, should be consulted for details on poise corrections.
The next point of consideration may be the concentricity of the hairspring, and it is quite important that the spring be centered as nearly perfect as the trained eye can determine. Any unusual pressureof the spring in one direction will cause undue friction and a fast rate compared to the opposite direction.
There are several easy tests for determining as to how nearly the spring may be centered. One of these is to look straight down upon the spring and examine the space between the coils that extend beyond the circumference of the dome. This test may be made in three ways, one with the balance at rest, one with the coils of the spring wound up and the third with the coils unwound. With the balance at rest and the spring centered there will be the same space between the coils all around as though the spring were out of the watch entirely and laying on the bench.
If it is not properly centered there will be more space between the coils on one side than there will be on the opposite. The same conditions will be apparent when the spring is wound up, although the coils will all be nearer to each other than they were with the balance at rest, and when they are unwound the coils will all be farther apart with the same apparent difference on opposite sides when the centering is not correct.
The winding and unwinding of the spring is alternating and almost instantaneous, as the balance oscillates from one extreme to the other. For observation of the spring when it is wound or unwound it is necessary to stop the balance with the finger or camel's hair brush as it reaches its extreme arc of motion, then hold it stationary for a few seconds while the space between the coils is being examined. The balance should then be allowed to swing to the opposite extreme, when it should again be held for examination of the coils. In one of these extremes the coils will be wound and in the other they will be unwound and after a few experiments in stopping and starting the balance it will be found that the entire examination will not require over ten seconds' time.
When the spring is not properly centered thereason is of course found in some curve of the over coil and the most usual point at fault is the section or curve on which the regulator pins act. If the coils open too wide on the side where the regulator pins are located this section of the coil will be too near the center and should be moved outward, possibly equal to one-half or one full space of the coils. If the coils are too close on the side where the pins are it will probably be found that the section requires shifting toward the center slightly. The balance should be removed from the watch in either instance and the coil circled with the over-coiling tweezer, although experienced workmen can frequently make excellent corrections with a fine pointed tweezer without removing the balance.
Finely adjusted watches will always be found to have springs as nearly perfectly centered as it is possible for expert workmen to get them and it is quite interesting and instructive to observe the vibration of a perfect spring by any one interested in the work.
Some watchmakers center the spring on the balance cock before it is staked on the balance and very good results can be obtained in this way. The balance cock is placed on the bench in the inverted position which makes it easy to locate the point or curve requiring alteration.
Should most careful investigation of the condition of the watch indicate that the Motion, Regulator Pins, Poise of Balance and Centering of the Hairspring as well as the general condition of the watch are satisfactory and the rating show that there is still considerable variation between the horizontal positions and the pendant up position there is still one source through which positive correction may be obtained.
This refers to the relative positions of the colletand stud pinning points which is defined with explanatory cuts and formula in Chapter VIII.
In constructing this chapter and the preceding one it has been preferred to go into detail for the purpose of defining the possible corrections and alterations, together with the results to be expected. Not every watch demanding position correction would require the extent of investigation and possible alteration that is pointed out and in most instances the direct cause will be disclosed with very little investigation. In fact, the experienced adjuster can tell almost immediately where to look for trouble by merely observing the position rate as entered on the card.
It should also be clearly understood by the student that when the repairing and cleaning of high grade watches is done by one who understands the details of adjusting, there will be only a very small proportion of the watches requiring position corrections. As a rule among experienced adjusters there will be about seventy per cent of the watches that will have very close rates. If, therefore, one hundred watches are put in order and tested in positions there should be seventy that do not require any correction, while about thirty will require either minor or major alteration. The time required for making alterations on this thirty per cent of the watches will be offset by a smaller percentage of unsatisfactory returns and a better reputation for doing good work.