Treatise on Staff Making and Pivoting

<h2><SPAN name="CHAPTER_III" id="CHAPTER_III"></SPAN>CHAPTER III.</h2> <p>Our wire has been roughed out into the form of a staff, has been hardened and the temper drawn down to the requisite hardness and we are now ready to proceed with our work. As I said before, we have now arrived at a point where many authorities differ, <i>i. e.</i>, as to whether the finishing of the staff proper, should be performed while the work is held in the chuck, or whether a wax chuck be substituted. We will take it for granted that you have a true chuck and that you prefer to finish all the lower portion of the staff while held in the chuck.</p> <p>Before we proceed with our work it will be necessary for us to make some accurate measurements, as we cannot afford to do any guess work by measuring by means of the old staff. I have used a number of different kinds of calipers and measuring instruments for determining the various measurements for a balance staff, but have met with more success with a very simple little tool which I made myself from drawings and description published some years ago in <span class="smcap">The American Jeweler</span>. This simple little tool is shown in <SPAN href="#f7">Fig. 7</SPAN>, and has been of great service to me. It consists of a brass sleeve A, with a projection at one end as shown at B. This sleeve is threaded, and into it is fitted the screw part C, which<span class="pagenum"><SPAN name="Page_20" id="Page_20">[Pg 20]</SPAN></span> terminates in a pivot D, which is small enough to enter the smallest jewel. The sleeve I made from a solid piece of brass, turning it down in my lathe and finishing the projection by means of a file. The hole was then drilled and threaded with a standard thread. The screw part C, I made of steel and polished carefully.</p> <div class="figcenter"> <SPAN href="images/il20a.jpg"> <ANTIMG id="f7" src="images/il20a-th.jpg" alt="Fig. 7." /></SPAN> <p class="caption">Fig. 7.</p> </div> <div class="figleft"> <SPAN href="images/il20b.jpg"> <ANTIMG id="f8" src="images/il20b-th.jpg" alt="Fig. 8." /></SPAN> <p class="caption">Fig. 8.</p> </div> <p>To ascertain the proper height for the roller, place it upon the tool, allowing it to rest upon the leg B, and set the pivot D in the foot jewel. Now adjust, by means of the screw C until the roller is in its proper position in relation to the lever fork. This may be understood better by consulting <SPAN href="#f8">Fig. 8</SPAN>, where A is the gauge, C is the roller, E is the lever, F is the plate and G is the potance.</p> <p>Now in order to locate the proper place to cut the seat for the roller, remove it from the foot of the gauge and apply the gauge to the work as shown in <SPAN href="#f9">Fig. 9</SPAN>. The foot of the gauge resting against the end of the pivot, the taper end of the gauge will locate accurately the position of the roller seat. In order to locate the proper position for the<span class="pagenum"><SPAN name="Page_21" id="Page_21">[Pg 21]</SPAN></span> seat for the balance, proceed the same as for the roller, except that the foot of the gauge is lowered until it is brought sufficiently below the plate to allow of the proper clearance as indicated by the dotted lines at H. Now apply the gauge to the new staff, as shown in <SPAN href="#f10">Fig. 10</SPAN>, and the taper end will locate the exact position for the balance seat.</p> <div class="figleft"> <SPAN href="images/il21a.jpg"> <ANTIMG id="f9" src="images/il21a-th.jpg" alt="Fig. 9." /></SPAN> <p class="caption">Fig. 9.</p> </div> <div class="figcenter"> <SPAN href="images/il21b.jpg"> <ANTIMG id="f10" src="images/il21b-th.jpg" alt="Fig. 10." /></SPAN> <p class="caption">Fig. 10.</p> </div> <p>As previously stated, I have taken it for granted that you preferred to finish all the lower portion of the staff while the work was held in the chuck. I have assumed that you prefer to work in this way because I have noted the fact that nine watchmakers out of every ten start with, and first finish up, the lower portion of the staff. Where this method of working originated I do not know, but it always has the appearance to me of "placing the cart before the horse." I do not pretend to say that a true staff cannot be made in this way, but it certainly is not the most convenient nor advisable. We all know that the heaviest part of the staff is from the roller seat to the end of the top pivot. Now it seems to me that it is the most natural thing in the world for a mechanic to desire to turn the greater bulk of his work before reversing it. Now if the workman has been educated to turn indifferently with right or left hand, it may make little difference, as far as the actual turning is concerned, whether he starts to work at the upper or lower end of<span class="pagenum"><SPAN name="Page_22" id="Page_22">[Pg 22]</SPAN></span> the staff, but unfortunately there are few among us who are so skilled as to use the graver with equal facility with either hand, and it is therefore an advantage to start with the upper end, as you can thus finish a greater portion of the work more readily. You can readily see that when you come to reverse your staff and use the wax chuck, that by starting at the top of staff your wax has a much larger surface of metal to cling to, and again the shape of the balance seat is such as to secure the work firmly in the wax, while if the reverse method is employed, the larger portion of the balance seat is exposed and the staff is more liable to loosen from the motion of the lathe and pressure of the graver and polishers.</p> <hr style="width: 65%;" /> <p><span class="pagenum"><SPAN name="Page_23" id="Page_23">[Pg 23]</SPAN></span></p> <div style="break-after:column;"></div><br />