Female Centers
American Watchmaker and Jeweler (1892)
These very useful adjuncts to a lathe are easily made by any watchmaker. He should have at least six pairs, the largest being one-fourth of an inch in diameter, which will accommodate as large a piece as you will wish to handle on your watch lathe, viz: winding arbors for clocks. These female centers are made from steel tapers, the same as male centers are made, but instead of turning the end to a sharp point they are countersunk, Fig. 55. First place the taper in a chuck and turn off the outside and end true; drill a small hole in the center of the taper, while the lathe is running, and deep enough so the countersink will not reach the bottom of the hole, or one-eighth of an inch deeper than the counter-sink. Harden the end only, and after tempering polish off the bluing. After you have made all the sizes you require, test all of them in your lathe to make sure they did not get out of true in tempering. These female centers are very useful for holding or suspending any article in the lathe that is too large to be held in the split chucks. Pivots of clocks can be turned and polished very quickly and accurately in these centers. Almost any kind of large work can be done on a medium sized watchmaker's lathe by fitting a face plate to the lathe, say one and three-fourths inches in diameter, with four slots, and fitted to a chuck with a taper hole to receive both male and female centers. The taper hole being standard, the centers are interchangeable, and with two styles of dogs, almost any kind of large clock work can readily be handled. These centers prove very useful for many odd jobs. As an example: It is a very common occurrence to hear an American clock beat irregularly, caused by the 'scape being out of round. Select a pair of female centers that will admit the ends of the pivots of the 'scape wheel snugly; place one center in the taper chuck and the other in the tail stock spindle, and suspend the 'scape pinion in these centers; fasten on a dog, run the lathe at a high speed and hold a fine, sharp file so it will touch the teeth of the 'scape wheel slightly, and in a moment the wheel will be perfectly round, after which sharpen up the teeth that are too thick.
What Has Changed in the Last Century
The workshop method the American Watchmaker described in 1892 is still sound: cup or "female" centers, countersunk instead of pointed, remain the standard way to suspend a wheel and pinion between centers on a watchmaker's lathe, and truing an out-of-round American clock escape wheel with a file at speed is still done exactly that way. What has changed is that few watchmakers now make their own. The 8mm Webster-Whitcomb lathe taper became the trade standard, so hardened cup centers, faceplates and dogs are bought as catalogue items, and the quartz movement's arrival in the 1970s shrank mechanical repair from an everyday trade into a specialist and hobbyist craft served by a handful of suppliers.
Written for this edition, 2026.