A Treatise on Staff Making and Pivoting / Containing Complete Directions for Making and Fitting New Staffs from the Raw Material

by Eugene Edward Hall

When the staff is finished from the lower pivot to the seat of the balance, the upper part should be roughed out nearly to size and then cut off preparatory to finishing the top part.

Attention was previously called to the fact that the majority of watchmakers prefer to finish all the lower portion of the staff first, notwithstanding the fact that there are numerous advantages to be gained by proceeding to first finish up the upper portion. We have now reached the point where the wax chuck must be used, and perhaps these advantages may be now more clearly defined. In order that the two procedures may be more distinctly shown, illustrations of both methods are here given. [Fig. 18] shows the popular method, the lower portion of the staff being all completed and fastened by means of wax, in the wax chuck. [Fig. 19] shows the opposite course of procedure. In both illustrations the lines indicate the amount of wax applied to hold the work. It will be noted that in [Fig. 18] the hub of the staff is enclosed in the wax very much as a cork is fitted into a bottle, while in [Fig. 19] the hub is reversed, just as a cork would appear were the larger portion within the bottle and the smaller portion protruding through the neck. A study of the diagram will readily show that in [Fig. 19] the staff is held more rigidly in place and that a greater bulk of the work is enclosed in the wax than in [Fig. 18], although there is less wax used in the former than in the latter.

Fig. 18.

Fig. 19.

Before proceeding to set the staff in the wax, it is necessary to make some measurements to determine its full length. Remove both cap jewels and screw the balance cock in place. Examine the cock and see if it has at any time been bent up or down or punched to raise or lower it. If so, rectify the error by straightening it and then put it in place. Now with a degree gauge, or calipers, proceed to take the distance between the outer surfaces of the hole jewels and shorten the staff to the required length. Do not remove too much, but leave the staff a little long rather than cut it too short, as the length can be shortened later.

Fig. 20.

A very handy tool for the purpose of making these length measurements can be constructed by adding a stop screw to the common double calipers as shown in [Fig. 20] . The improvement consists in the fact that they can be opened to remove from the work and closed again at exactly the same place, so that an accurate measurement can be made.