W. H. Samelius, Chairman
Science of Horology and Technical Board
Ans: I can see no harm in using water for the first rinse as that will remove the cleaning solution. Then by following with the first and second rinse of naphtha, all water will be removed and drying accomplished without danger of rust. The advantages I see in this would be that you would not have to use such an amount of rinse and the rinsing fluid will remain cleaner for a longer period of time. In any case, rinsing in water the first time would be cheaper than rinsing in regular solution.
]DW: No. I - How is the distance between the end stones and hole jewels measured so as to get an accurate measurement of the oil space.
No. 2 - How can I find correct width of mainspring for any given barrel if the broken sample is missing or incorrect?
No.3 - How can the banking be opened or closed on cheap watches that do not have banking screws without bending the pins?
Ans: I - The watch manufacturers gauge the distance that the jewels are set below the surface of the setting by using a depth gauge. This; is a very fine instrument and measures to one ten thousandth inch, an instrument that the average watchmaker could hardly afford to enjoy. When the watchmaker at the bench sets a balance or cap jewel, the surplus material is cut away until the jewel is approximately .001 inch below the surface of the setting and can be checked very close by eye measurement by laying a straight edge across the setting and observing the space between the straight edge and the top of the jewel. For comparison. the ordinary tissue paper is .001 inch thick.
No. 2 - By using the millimeter slide gauge and setting the gauge to the bottom of the barrel up to the ledge seating the barrel cover. This would give the exact width of space required for mainspring. By deducting about 1/10th millimeter from the full measurement, would give the correct width of spring for that particular barrel.
NO. 3 - In watches that have solid banking pins and alterations must be made without bending the pin, the proper way is to put in new banking pins instead of bending the pins inward, enlarge the holes in the plate and put in larger pins. This would naturally decrease the angular motion of the watch. If the pins have to be bent outward, allowing more room for the lever action, new pins might be inserted that would fit the hole in the plate but the part of pin that extends thru the plate should be turned down smaller in diameter or sometimes the side of the pin could be shaved off with a sharp cutting tool In either case the pins will be left upright
DN: I would like information art how to rebush worn plates, especially wrist watches. How can I rebush these with friction jewels and be certain the train will line up as when it was new? What tools do I need and what methods do I follow?
Answer: The ordinary procedure for setting the friction jewel is to select a reamer of proper diameter for the jewel to be used and then with a friction jeweling tool, press the jewel to place. This sounds as a simple operation however, many workmen take it for granted that it is simple and when reaming the hole, use undue pressure when placing the reamer in the hole and in that way will cut more from one side of the hole than the other, causing the hole to be out of upright. To correct this error, it would be necessary to place the watch plate in a face plate of a lathe and centering the lower jewel accurately. Then screw the bridge fast to the plate, using the slide rest with a fine boring tool, boring the hole so it is concentric and the hole parallel throughout it's length.
Select a jewel of proper size to fit pivot, set the jewel in a brass wire, check hole for truth and if the hole is true, cut the brass 'Wire down to a friction fit, cutting to proper length or thickness of plate when the top of the setting is polished flat and the inside stripped, leaving a bright cut.
The jewel can now be pressed into the plate when the wheel will once more be upright and depthings correct.
CD : Your request for information or advise on how to test for short and long fork, how to find bank or drop position, how to make angular tests, how to swedge the fork when testing the escapement, altering permanent banking pins.
Answer: Space does not permit to cover all these subjects you treat on. May I suggest you obtain a copy of "It's Timing That Counts" covering all these subjects. The book may be procured from your jobber or the American Horologist direct.