At various times I have read articles on position adjusting but I am still at a loss to understand what to do if a watch does not run right in positions. Some writers claim that if a watch is in good mechanical condition, freshly cleaned and oiled, it is bound to perform well in positions. A great portion of my work consists of railroad watches. I use a watch cleaning machine for cleaning and _____ oil for lubrication. Until recent months I used _____ oil. The reason I changed to the present brand is because I had a number of watches which ran well for a little while but started to act up shortly after being put in service. My greatest difficulties are in getting the flat positions to run alike, and no small amount of grief do I experience with the pendant up position, which, as if for spite, always runs slow. Sometimes I question whether the factories do anything to adjusted watches outside of stamping them "Adjusted." The reason for my suspicion is that I have as many difficulties with supposedly new watches as I do with those I repair.
An example of my grief is the case of a trainman, whose old watch I have condemned and recommended the purchase of a new _____ watch. I have been trying to regulate it now for the last three months, and just when I think that I moved the regulator the right amount it comes back the next week with a much greater variation.
Answer: In order to fully cover all of the difficulties pointed out in this letter it would consume the pages of a good size book. Indeed one could go on indefinitely just explaining why a watch may vary in the flat positions only. In the limited space of the Question Box we can touch only briefly on the subjects in question.
The brand of oil you have been using, as well as that which you are using now, is considered to be of good quality. It has already been pointed out in the article "Oiling a Watch" (See August issue of HOROLOGY) that there is just as much in the manner of oiling a watch as there is in the brand of oil.
The statement that "a watch which is in good mechanical condition will have a good position rate" is very true. The difficulty is to be able to recognize when the watch is in such a condition. Just as there is a definite mechanical reason why an automobile engine stops, knocks, or consumes too much gas, so is there a particular cause for every peculiar position rate of a watch. Some of the most common faults which cause variation in the flat positions are as follows: A pitted or out of flat endstone, the end of one pivot may be flat while the other is rounded; one pivot may be freely projecting through the jewel while the other chokes on the cone. A slight burr on one pivot will sometimes also cause a variation in the flat positions, especially if the balance has too much end shake and the pivot hangs up on the burr and prevents the opposite pivot from reaching the endstone. Unequal sizes of hole jewels in the balance or even in the fork will cause a variation in the flat positions, to say nothing about excessive endshake in any escapement member, level of the hairspring and a host of other reasons too numerous to mention here.
Among the common causes for slow pendant positions are open regulator pin. No eye loupe is too powerful for examining regulator pins. All upright positions may be accelerated or retarded by the slightest touch of the regulator pins. Other important points to observe are good poise of the balance and perfection in pivots. When a balance does not seem to come to poise there must be something wrong with its pivots. A balloon chuck for examining and touching up pivots is good enough. The best, however, is the old-fashioned contrivance illustrated in Figure 2. In this tool the pivot rotates on its own cone and by putting the heavy number 8 Dumont tweezer against the parallel section one can easily tell whether it is bent or perfect.
For those who are fortunate enough to own a regular microscope the device illustrated on page 11 of the January 1937 issue of HOROLOGY, is recommended.
The correct pinning point of the inner terminal of the hairspring plays no small part in the good rate of a watch. However, manufacturers of modern railroad watches are fully aware of this fact and the average horologist will do well not to tamper with it, outside of observing whether the hairspring runs true in the flat and the round.
A watch which runs within five or six seconds between the dial up and dial down positions and does not vary over fifteen seconds in all five positions may be considered an excellent commercial timekeeper.
A good book on adjusting is "Rules and Practice for Adjusting Watches" by Walter J. Kleinlein.