Rules and Practice for Adjusting Watches.

by Walter J. Kleinlein.

PREFACE

In the early days of horology the apprentice was taught the art of making a complete watch. Production was slow, very few duplicate watches were constructed, and it was necessary that extra material be made individually by hand in the same way that the original part was produced. As time pa.s.sed the value of the repairer was indicated by his ability to make new parts and to replace them so that the watch would again be in running condition. This was the prevailing situation for many years and the repairer was judged according to his skill in making and finishing the various parts.

A similar method of judging ability is still in force among some employers, although the development of the industry into machine and specialized work has made many changes in regard to the most important duties of the repairer.

It is no longer necessary for him to know how to make a complete watch and only on occasional instances is it necessary for him to make a part. Genuine material for modern watches is supplied by the manufacturer at less expense than it can be produced by the individual and in this particular branch of the work the repairer's requirements have been very considerably curtailed.

A more exacting and a higher standard of timekeeping has developed, however, and in this field the requirements of the watchmaker have increased to the extent that it is no longer sufficient to merely restore a good watch to running condition. It must keep time. This development has grown gradually and surely and the past twenty-five years may be a.s.sumed as the period of greatest advance.

It has been made possible by scientific and practical refinements which permit the adjustment of watches so that they will keep time within closely defined allowances under varying conditions.

The larger problem of the successful repairer of today, therefore, is that of understanding the principles governing close time and of knowing how and where to look for the causes of variation, so that the higher standard of timekeeping may be restored in case of damage since the original adjustment.

It is naturally essential to know when material is correct, how to make it fit in its proper place, and how to make and finish some of the individual parts. It is also commendable to be skilful in all cla.s.ses of lathe work, as this at times gains prestige for the workman through restoring old model watches to running condition.

It is, however, a disadvantage to develop one's ability in making parts for watches of a bygone age and neglecting the training that happens to be most essential and of daily advantage in repairing modern watches so that they will keep time as consistently after repairs have been made as they did when new.

The object of this book is to present the essential points of watch adjusting in an elementary and non-technical way that will interest the average watchmaker and to enable him to have a convenient source of information, covering the necessary refinements that are fundamental in repairing, regulating and adjusting the better cla.s.s of watches.

The author trusts that the experienced successful watchmaker will read the book with interest and also with profit and that the novice will be enabled to foresee that there is something more to the art of watchmaking and repairing than that of merely a.s.sembling a watch and making it "tick."

It so happens that the author has had many years of experience in both factories and repair shops and that a considerable part of his duties have been devoted to instruction.

He has for a long time felt the need of a book that would, above all else, be practical in its description of the rules that an adjuster follows and which would prove its value in actual experience by being personal as far as permissible in the same sense that detailed shop instruction would be.

Since writing the article ent.i.tled "The Watch Adjuster and His Work"

several years ago numerous inquiries have been received, for this cla.s.s of information and the present book is an effort to meet this demand in a manner that can be followed without highly technical or theoretical education.

To promote advancement and interest in everyday practical results is the foremost consideration, and to this end definite means are presented for personal development and for obtaining better results from high grade watches than can possibly be obtained without a fair knowledge of the final details which go so far toward a.s.suring close time.

WALTER J. KLEINLEIN, July 21, 1920 Waltham, Ma.s.s.

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 circ.u.mstances 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 bra.s.s and one of steel, with the bra.s.s 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. Bra.s.s 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 bra.s.s, 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 princ.i.p.ally 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 bra.s.s 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._