Part 13 (1/2)

CHAPTER XVI

SPECIAL NOTES

79. _Efficiency of Execution a.n.a.lyzed (Two Examples)._

In performance of the various alterations and corrections that have been touched upon in the chapters devoted to position adjusting there are some points that deserve special note. This refers to positive execution of the correction which the watchmaker sets out to make.

As an example we may a.n.a.lyze the simple feature of polis.h.i.+ng a pivot and cleaning and reoiling a jewel to improve the motion in one of the horizontal positions. Ordinarily this would seem to be a very simple proceeding requiring no additional remarks.

It is, however, quite possible to go through all of the operations of removing, cleaning and reoiling the jewel and polis.h.i.+ng the pivot and then find that no improvement has been made in the motion.

Invariably the workman of moderate experience will say that he has just cleaned and reoiled the jewel and polished the pivot and that it must be all right.

Investigation, however, will sometimes show that the pivot has again been marred or that a particle of dirt has found its way into the jewel hole during replacement either through dust in the oil or through clinging to the end of the pivot when the balance was laying on the bench.

This experience is one that comes occasionally to the best and most careful adjusters and if it is found that results have not been obtained the first time it will be necessary to go over the operations a second time.

It is possible to almost entirely eliminate this duplication of work if proper care is exercised in examining the pivot and jewel with a good gla.s.s before replacing and in using oil from a closed receptacle in which it has not been possible for dust to collect.

The point raised in this instance is that the improvement desired is not a.s.sured because of merely going through the operations of doing the work.

It is necessary to actually remove the cause and then keep it removed.

The proof is found in the improved motion and it would hardly be worth while to retest in positions until this improvement was obtained.

Proper curvature of the over coil within the range of the regulator pins is another feature that may be corrected and the correction unconsciously destroyed in replacing the balance or in centering the spring.

A slight kink in the coil close to the regulator pins may cause the spring to be forced out of center when the regulator is moved, or it may cause the coil to lay against one pin and cease vibrating between the pins. This would cause a gain of some seconds per day when the regulator had actually been moved to cause a slower rate.

These two examples are introduced to convey the idea that it is necessary to actually produce the corrections or alterations in any instance and that close timing and close position rates depend more upon this practical execution and understanding as displayed by the watch repairer than they do upon a high degree of technical knowledge.

Personal instruction of watchmakers in adjusting has demonstrated in most instances that the refinements are not considered seriously enough at first, but that consistent practice and reference to the rules soon make the proper impression, after which results are attained in less time than was at first required for faulty execution.

80. _Truing the Balance._

The balance should invariably be true in the round and flat and always in poise before it is placed in the watch.

It is at times pardonable to pa.s.s a balance that is not perfectly true in the round, especially when the watch has been repaired on several occasions and it is noted that the rims have a tendency to become set slightly inward or outward after having been perfectly trued. This shows a natural tendency of the metals to find a permanent position which may be slightly away from the true concentric form. A balance of this description may be poised as it is and often will produce better timing results than would be gained by perfect truing and subsequent regulation during readjustment of the metals.

It is advisable to always have the flat true as by doing so any slightly bent pivots will be detected through wavering of the balance and the flat is not very frequently affected by setting of the metals.

Balances should generally be trued and poised in normal or slightly above normal temperature. If they are trued in a low temperature they will be out of true and possibly out of poise in the temperature to which they are mostly subjected. Compensation balances are not presumed to be true in the round under variations of temperature and therefore inspection for true is necessary in somewhere near the same temperature in which they are trued.

81. _Poising the Balance._

In poising balances it is necessary to consider the mean rate of the watch and several details in connection therewith.

If the rate is known to be fast, weight should be added to the light side, and if it is known to be slow weight may be removed from the heavy side.