Transcriber’s notes:

Some minor typographical errors have been corrected.
The author’s spelling has been retained.

A TREATISE

ON

STAFF MAKING

AND

PIVOTING

CONTAINING COMPLETE DIRECTIONS FOR MAKING
AND FITTING NEW STAFFS FROM
THE RAW MATERIAL

EUGENE E. HALL

WITH NUMEROUS ILLUSTRATIONS

CONTENTS.

[Pg 5]

STAFF MAKING AND PIVOTING.

CHAPTER I.

To produce a good balance staff requires more skill
than to produce any other turned portion of a watch,
and your success will depend not alone on your knowledge
of its proper shape and measurements, nor the
tools at your command, but rather upon your skill with
the graver and your success in hardening and tempering.
There are many points worthy of consideration in the
making of a balance staff that are too often neglected.
I have seen staffs that were models as regards execution
and finish, that were nearly worthless from a practical
standpoint, simply because the maker had devoted all
his time and energy to the execution of a beautiful piece
of lathe work, and had given no thought or study to the
form and size of the pivots. On the other hand, one
often sees staffs whose pivots are faultless in shape, but
the execution and finish so bungling as to offset all the
good qualities as regards shape. To have good tools and
the right ideas is one thing, and to use these tools properly
and make a practical demonstration of your theory
is another.

I shall endeavor to take up every point in connection
with the balance staff, from the steel to the jewels, and[Pg 6]
their relation to the pivots, and I believe this will then
convey to the reader all the necessary points, not only as
regards staffs, but pivots also, whether applied to a balance
or a pinion staff.

It may be argued, and we often do hear material
dealers advance the theory, that to-day, with our interchangeable
parts and the cheapness of all material, it is a
waste of time to make a balance staff. To the reader
who takes this view of the situation I simply want to say,
kindly follow me to the end of this paragraph, and if you
are still of the same opinion, then you are wasting your
time in following me farther. For a material dealer to
advance this theory I can find some excuse; he is an interested
party, and the selling of material is his bread and
butter; but the other fellow, well I never could understand
him and possibly never shall. When we seriously consider
the various styles and series in “old model” and
“new model,” of only one of the leading manufacturers
of watches in this country, to say nothing of the legion of
small and large concerns who are manufacturing or have
manufactured in the past, and then think of carrying
these staffs in stock, all ready for use, we then begin to
realize how utterly absurd the idea is, to say nothing of
how expensive! On the other hand, if you reside in a
large city and propose to rely on the stock of your
material dealer, you will find yourself in an embarrasing
situation very often, for as likely as not the movement
requiring a new staff was made by a company that
went out of business back in the ’80s, or it is a new[Pg 7]
movement, the material for which has not yet been placed
on the market. This state of affairs leads to makeshifts,
and they in turn lead to botch work. The watchmaker
who does not possess the experience or necessary qualifications
to make a new balance staff and make it in a neat
and workmanlike manner, is never certain of having
exactly what is needed, and cannot hope to long retain
the confidence of his customers. In fact, he is not a
watchmaker at all, but simply an apprentice or student,
even though he be working for a salary or be his own
master. There are undoubtedly many worthy members
of the trade, who are not familiar with the making of a
balance staff, who will take exceptions to this statement;
but it is nevertheless true. They may be good workmen
as far as they go; they may be painstaking; but they cannot
be classed as watchmakers.

This article is intended for the benefit of that large class
whose opportunities for obtaining instruction are limited,
and who are ready and willing to learn,
and for that still larger class of practical
workmen who can make a new
staff in a creditable manner, but who
are always glad to read others people’s
ideas on any subject connected with
the trade and who are not yet too old to learn new tricks
should they find any such.

Fig. 1.

Good tools, in good condition, are the most essential
requisites in making a new staff. I would not advise any
particular make of lathe, as the most expensive lathe in[Pg 8]
the world will not produce a true staff if the workman
cannot center his work accurately and does not know
how to handle his graver, while on the other hand fine
work can be done on the simplest and cheapest lathe by
a workman possessing the requisite skill. I will take it
for granted that you use an American-made lathe of some
kind, or a foreign-made lathe manufactured on American
lines. It is advisable, though not absolutely necessary, to
have three gravers similar to those illustrated in Fig. 1,
A being used for turning the staff down in the rough; B
for the conical pivots and square shoulders and C for the
under-cutting. The other tools and attachments needed
will be described as I come to them in use.

The balance staff should be made of the best steel,
tempered to such a degree as to give the longest service
and yet not so hard as to endanger the breakage of the
pivots. Select a piece of Stubb’s steel wire, say No. 46,
or a little larger than the largest part of the finished staff
is to be, and center it in a split chuck of your lathe. Be
careful in selecting your chuck that you pick one that fits
the wire fairly close. The chuck holds the work truest
that comes the nearest to fitting it. If you try to use a
chuck that is too large or too small for the work, you
will only ruin the chuck for truth. Turn the wire to the
form of a rough staff, as shown in Fig. 2, leaving on a
small part of the original wire, as shown at A. After the
wire is roughed out to this general form, remove from
the chuck and get ready to harden and temper it. The
hardening and tempering may be effected in various[Pg 9]
ways, and I am scarcely prepared to say which method
is the best, as there are several which give about the
same general results. One method of hardening is to
smear the blank with common yellow soap, heat it to a
cherry red, and drop endwise into linseed oil. Petroleum
is preferred by some to linseed oil, but, to tell the truth, I
can see no difference in the action of linseed, petroleum
or olive oil. Be sure and have enough oil to thoroughly
cool the blank, and a deep vessel, such as a large-mouthed
vial, is preferable to a saucer. The blank will now be
found too hard to work easily with the graver, and we
must therefore draw the temper down to that of fine
spring steel. Before doing this the blank should be
brightened, in order that we may see to just what color
we are drawing it. The main object in using the soap in
hardening is that it may form a scale
upon the blank, and if the heating is
effected gradually the soap will melt and
form a practically air-tight case around the blank. This
scale, if the hardening is carefully and properly done,
will generally chip and fall off when the blank is plunged
in the oil, particularly if the oil is cool, and if it does not
fall off of its own accord, it can easily be removed by
rolling the blank upon the bench. If it does not come
out clean, or if soap is not used, it may be brightened by
again inserting in the lathe and bringing it in contact with
a piece of fine emery paper or cloth.

Fig. 2.

I draw the temper in the following manner: Place some
fine brass filings in a boiling-out cup or bluing pan and lay[Pg 10]
the blank upon these filings, holding the pan over the flame
of an alcohol lamp until the blank assumes a dark purple
color, which it will reach when the heat gets to about 500°
F. This I consider the right hardness for a balance staff,
as it is not too hard to work well under the graver nor too
soft for the pivots. At this degree of hardness steel will
assume an exquisite polish if properly treated. Another
method of tempering is to place the staff on a piece of
sheet iron or copper (say 1 inch wide by 4 long), having
previously bent it into a small angle, for the reception of
the staff, as shown in Fig. 3. This piece of metal, when
nicely fitted into a file handle, will answer all the purposes
of the bluing pan and presents
quite a neat appearance. Having placed
the blank in the angle, lay on it a piece
of yellow wax about the size of a bean,
and heat it over your lamp until the wax takes fire and
burns. Blow out the flame and allow the staff to cool,
and it will be found to be of about the right hardness.

Fig. 3.

We have now arrived at an important station in staff
making, a junction, we may term it, where many lines
branch off from the main road. At this particular spot is
where authorities differ. I have no hesitation in saying
that at this particular point the split chuck should be
removed from the lathe head and carefully placed in the
chuck box and the cement chuck put in its place. I
believe that all of the remaining work upon a staff should
be executed while it is held in a cement chuck. On the
other hand I have seen good workmen who turned and[Pg 11]
finished all the lower part of a staff while in a split chuck,
cut it off and turned and finished the upper part in a
cement chuck. All I have got to say is that they had
more confidence in the truth of their chucks than I have
in mine. I have even read of watchmakers who made
the entire staff in a split chuck, but I must confess I am
somewhat curious to examine a staff made in that way,
and must have the privilege of examining it before I will
admit that a true staff can be so made.

We will suppose that the workman has a moderately
true chuck, and that he prefers to turn and finish all the
lower portions in this way. Of course the directions for
using a cement chuck on the upper part of a staff are
equally applicable to the lower. Before going further I
think it advisable to consider the requirements of a pivot,
but will reserve this for another chapter.

[Pg 13]

CHAPTER II.

The chief requirements of a pivot are that it shall
be round and well polished. Avoid the burnish file
at all hazards; it will not leave the pivot round, for the
pressure is unequal at various points in the revolution.
A pivot that was not perfectly round might act fairly well
in a jewel hole that was round, but unfortunately the
greater proportion of jewel holes are not as they should
be, and we must therefore take every precaution to guard
against untrue pivots. Let us examine just what the
effect will be if an imperfect pivot is fitted into an unround
hole jewel, and to demonstrate its action more clearly let
us exaggerate the defects. Suppose we pick a perfectly
round jewel and insert into the opening a three-cornered
piece of steel wire, in shape somewhat resembling the
taper of a triangular file. We find that this triangular
piece of steel will turn in the jewel with the same ease
that the most perfect cylindrical pivot will. Now suppose
we change the jewel for one that is out of round and
repeat the experiment. We now find that the triangular
steel soon finds the hollow spots in the jewel hole and
comes to a stand-still as it is inserted in the hole. The
action of a pivot that is not true, when in contact with a
jewel whose hole is out of round, is very similar, though[Pg 14]
in a less marked degree. If the pivot inclines toward the
elliptical and the jewel hole has a like failing, which is
often the case, it is very evident that this want of truth
in both the pivot and hole is very detrimental to the good
going of a watch.

Fig. 4.

Fig. 5.

There are two kinds of pivots, known respectively as
straight and conical pivots, but for the balance staff there
is but one kind and that is the conical, which is illustrated
in Fig. 4. The conical pivot has at least one advantage
over the straight one, i. e., it can be made much smaller
than a straight pivot, as it is much stronger in proportion,
owing to its shape. All pivots have a tendency to draw
the oil away from the jewels, and particularly the conically
formed variety, which develops a strong capillary
attraction. To prevent this capillary
attraction of the oil, the
back-slope is formed next to the
shoulder, although many persons seem to think that this
back-slope is merely added by way of ornament, to make
the pivot more graceful in appearance. It is very essential,
however, for if too much oil is applied the staff
would certainly draw it away if its thickness
were not reduced, by means of the
back-slope. Before leaving the subject of
capillarity let us examine the enlarged jewel
in Fig. 5; c is an enlarged pivot, b is the
hole jewel and a is the end stone. We
observe that the hole jewel on the side towards the end
stone is convex. It is so made that through capillarity the[Pg 15]
oil is retained at the end of the pivot where it is most
wanted. It is, in my opinion, very necessary that the
young watchmaker should have at least a fair understanding
of capillarity, and should understand why the end
stone is made convex and the pivot with a back slope.
For this reason I will try and make clear this point before
proceeding further. We all know that it is essential to
apply oil to all surfaces coming in contact, in order to
reduce the friction as much as possible, and if the application
of oil is necessary to any part of the mechanism of a
watch, that part is the pivot. Saunier very aptly puts it
thus: “A liquid is subject to the action of three forces:
gravity, adhesion (the mutual attraction between the
liquid and the substance of the vessel containing it), and
cohesion (the attractive force existing among the molecules
of the liquid and opposing the subdivision of the
mass.)”

We all know that if we place a small drop of oil upon
a piece of flat glass or steel and then invert the same the
oil will cling to the glass, owing to the adhesion of the
particles; if we then add a little more to the drop and
again invert, it will still cling, although the drop may be
elongated to a certain degree. This is owing to the
cohesion of the molecules of the oil, which refuse to be
separated from one another. If, however, we again add
to the drop of oil and invert the plate the drop will elongate
and finally part, one portion dropping while the
other portion clings to the main body of the liquid. The
fall of the drop is occasioned by gravity overcoming the[Pg 16]
cohesion of the molecules. Now take a perfectly clean
and polished needle and place a drop of oil upon its point
and we will see that the oil very rapidly ascends towards
the thicker portion of the needle. Now if we heat and
hammer out the point of the needle into the form of a
small drill and repeat the operation we find that the oil no
longer ascends. It rises from the point to the extreme
width of the drill portion, but refuses to go beyond. It clings
to that portion of the needle which would correspond to
the ridge just back of the slope in a conical pivot. Water,
oil, etc., when placed in a clean wine glass, do not exhibit
a perfectly level surface, but raise at the edges as
shown at a in Fig. 6. If a tube is now inserted, we find
that the liquid not only rises around the outside of the
tube and the edges of the vessel, but also rises in the tube
far beyond its mean level, as shown at b. These various
effects are caused by one of the forces above described,
i. e., the adhesion, or mutual attraction existing between
the liquid and the substance of the vessel and rod. The
word capillarity is of Latin derivation, and signifies hair-like
slenderness. The smaller the tube, or the nearer the
edges of a vessel are brought together, the higher in proportion
will the liquid rise above the level. An ascent of[Pg 17]
a liquid, due to capillarity, also takes place, where the
liquid is placed between two separate bodies, as oil placed
between two pieces of flat glass. If the plates are parallel
to one another and perpendicular to the surface of the
liquid it will ascend to the same height between the plates,
as shown at c in Fig. 6. If the plates were united at the
back like a book and spread somewhat at the front, the
oil would ascend the higher as the two sides approach
one another, as shown at d, Fig. 6. If a drop is placed
somewhat away from the intersecting point, of the
glasses, as shown at m it will, if not too far away, gradually
work its way to the junction, providing the glasses are
level. If, however, the glasses are inclined to a certain
extent, the drop will remain stationary, since it is drawn in
one direction by gravity and in the other by capillarity.
When a drop of oil is placed between two surfaces, both
of which are convex, or one convex and the other plain,
as shown at g, it will collect at the point n, at which
the surfaces nearest approach one another. We now see
very clearly why the hole jewel is made convex on the
side towards the end-stone and concave on the side
towards the pivot.

Fig. 6.

Particular pains should be taken to polish those portions
of the pivots which actually enter the jewel hole and
to see that all marks of the graver be thoroughly removed,
because if any grooves, no matter how small, are
left, they act as minute capillary tubes to convey the oil.

If the hole jewel be of the proper shape, the end-stone not
too far from the hole jewel and too much oil is not applied[Pg 18]
at one time, the oil will not spread nor run down the staff,
but a small portion will be retained at the acting surface
of pivot and jewel, and this supply will be gradually fed to
these parts from the reservoir between the jewel and end-stone,
by the action of capillarity.

Having examined into the requirements of the pivot
and its jewel and having gained an insight into what their
forms should be, we are the better able to perform that
portion of the work in an intelligent manner.

[Pg 19]

CHAPTER III.

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. e., 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.

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 The American Jeweler.
This simple little tool is shown in Fig. 7, 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[Pg 20]
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.

Fig. 7.

Fig. 8.

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 Fig. 8, where A is the gauge, C is the roller,
E is the lever, F is the plate and G is the potance.

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 Fig. 9. 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[Pg 21]
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 Fig. 10, and
the taper end will locate the exact position for the
balance seat.

Fig. 9.

Fig. 10.

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[Pg 22]
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.

[Pg 23]

CHAPTER IV.

By the aid of the pinion calipers and the old staff, the
diameter of the roller seat and the balance and hair-spring
collet seats may be readily taken, but it is perhaps
better to gauge the holes, as the old staff may not have
been perfect in this respect. A round broach will answer
admirably for this purpose, and the size may be taken
from the broach by means of the calipers. In fitting our
pivots, we can not be too exact; and as yet no instrument
has been placed upon the market for this purpose which
is moderate in price and yet thoroughly reliable. The
majority of watchmakers use what is termed the pivot-gauge,
a neat little instrument which accompanies the
Jacot lathe, and which may be obtained from any material
house. This tool, which is shown in Fig. 11, is, however,
open to one objection in the measurement of pivots, and
that is that it may be pressed down at one time with
greater force than at another, and consequently will show
a variation in two measurements of the same pivot.
Some of my readers may think that I am over-particular
on this point, and that the difference in measurement on
two occasions is too trivial to be worthy of attention, but
I do not think that too much care can be bestowed upon
this part of the work, and neglect in this particular is, I[Pg 24]
think, the cause of poor performance in many otherwise
good timepieces. The ordinarily accepted rule among
watchmakers is that a pivot should be made 1/2500 of an
inch smaller than the hole in the jewel to allow for the
proper lubrication. I am acquainted with watchmakers,
and men who are termed good workmen, too, who
invariably allow 1/2500 of an inch side shake, no matter
whether the pivot is 12/2500 or 16/2500 of an inch in diameter.
Now if 1/2500 of an inch is the proper side shake for a
pivot measuring 12/2500 of an inch in diameter, it is certainly
not sufficient for a pivot which is one-third larger.
Of course it is understood that side shakes
do not increase in proportion according
as the pivot increases in size, for if they
did a six-inch shaft would require at this
rate a side shake of 1/2 inch, or 1/4 inch
on each side, which would be ridiculously
out of all proportion, as the 1/64 of an inch
would be ample under any circumstances.
Neither can we arrive at the proper end
shake for a pivot by reducing in proportion from the end
shake allowed on a six-inch shaft, because if we followed
out the same course of reasoning we would arrive at a
point where a pivot measuring 12/2500 of an inch would
require an end shake so infinitely small that it would
require six figures to express the denominator of the
fraction, and the most minute measuring instrument yet
invented would be incapable of recording the measurement.
We must leave sufficient side shake, however, on[Pg 25]
the smallest pivot and jewel for the globules of the oil
to move freely, and experiments have shown conclusively
that 1/2500 of an inch or 1/5000 on each side of the pivot,
is as little space as it is desirable to leave for that purpose,
as the globules of the best chronometer oil will refuse
to enter spaces that are very much more minute. But
to return to our pivot gauge.

Fig. 11.

Fig. 12.

Each division on the gauge represents 1/2500 of an inch,
which is all that we require. The diameter that the pivot
should be, can be ascertained by inserting a round pivot
broach into the jewel and taking the measurement with
the pivot gauge, and then making the necessary deduction
for side shake. Slip the jewel on the broach as far
as it will go, as shown in Fig. 12, and then with the pivot
gauge, take the size of the broach, as close up to the
jewel as you can measure, and the taper of the broach
will be about right for the side shake of the pivot. If,
however, you prefer to make the measurement still more
accurate, you can do so by dipping the broach into rouge
before slipping on the jewel and then remove the jewel
and the place which is occupied on the broach can be
plainly discerned and the exact measurement taken and
an allowance of 1/2500 of an inch made for the side shake.
Another method, and one which is particularly applicable
to Swiss watches, where the jewel is burnished into the
cock or plate, is to first slip on to the broach a small flat
piece of cork and as the broach enters the jewel the cork
is forced farther on to the broach, and when the jewel is
removed it marks the place on the broach which its inner[Pg 26]
side occupied, and the measurement can then be taken
with the gauge. If care is used in the selection of a
broach, that it be as nearly perfect in round and taper as
possible, by a little experiment you can soon ascertain just
what part of the length of the broach corresponds to one
degree on the gauge and by a repetition of the experiment
the broach can then be divided accurately, by very
minute rings turned with a fine-pointed graver, into sections,
each representing one degree, or 1/2500 of an inch,
and the measurement will thus be simplified greatly.

Fig. 13.

As before stated, much depends upon the condition of
your gravers and the manner of using them. It is of the
utmost importance that they be kept sharp, and as soon
as they begin to show the slightest sign of losing their
keenness, you should sharpen them. The proper shape
for balance pivots was shown in Fig. 4.
Now let us examine into the best positions
for holding the gravers. In Fig. 13 two
ways of holding the graver are shown, A
representing the right and B representing
the wrong way. If the graver is applied to the work as
shown at A, it will cut a clean shaving, while if applied as
shown at B it will simply scrape the side of the pivot and
ruin the point of the graver without materially forwarding
the work. Again, the holding of the graver as indicated
at A has its advantages, because the force of the cut is
towards the hand holding it, and should it catch from any
cause the jar of the obstruction will be conveyed immediately
to the hand, and it will naturally give and no harm[Pg 27]
will be done. If, on the other hand, the graver should
meet with an obstruction while held in the position indicated
at B, the force of the cut will be in the direction of
the arrow, downward and toward the rest, and the rest
being unlike the hand, or rather being rigid, it cannot
give, and the result is that the work, or graver, or both,
are ruined. In Fig. 14 two other methods of holding the
graver are shown. The general
roughing out of a staff should
be done with the graver held
about as shown at A, Fig. 13; but in finishing, the graver
should be held so that the cut is
made diagonally, as indicated at
A, Fig. 14. It is rather dificult
to explain in print just how the
graver should be held, but a little experiment will suffice
to teach the proper position. The best indication that a
graver is doing its work properly, is the fact that the chips
come away in long spiral coils. Aim to see how light a cut
you can make rather than how heavy. Never use force
in removing the material, but depend entirely upon the
keenness of the cutting edges. Never use the point of
the graver, except where you are compelled to, but rather
use the right or left hand cutting edges. By following
out this rule you will find that your work, when left by
the graver, requires little or no finishing up, except at the
pivots.

Fig. 14.

At B, Fig. 14, is shown the correct manner of
applying the graver when turning a pivot. Hold the[Pg 28]
graver nearly on a line with the axis of the lathe and
catching a chip at the extreme end of the pivot with the
back edge of the graver, push slightly forward and at the
same time roll the graver towards you and it will give the
pivot the desired conical form. By keeping the graver
on a line with the length of the pivot, all the force applied
is simply exerted in the direction of the chuck, and
does not tend to spring the pivot, as it would were the
extreme point applied, as in Fig. 13. When we come to
such places as the shoulder of the back slope, the seat for
the roller, balance, etc., we must necessarily use the point
of the graver.

[Pg 29]

CHAPTER V.

In chapter IV I called attention to the right and wrong
way of holding the graver while using the extreme
point, and also the correct manner of applying the graver
in turning conical pivots.

Fig. 15.

I also called attention to the
fact that it was well to only use the point of the graver
where positively necessary, as in the back slope of the
pivot, etc. In turning the seat for the balance, as
indicated at A, Fig. 15, the graver A, Fig. 1, or a similar
one as shown at B, Fig. 15, should be used. The
slope at C should now be turned. In turning the pivot
and seat for the roller, you should leave them slightly
larger than required, to allow for the grinding and polishing
which is to follow. No definite amount can be left
for this purpose, because the amount left for polishing
depends entirely on how smoothly your turning has been
done. If it has been done indifferently, you may have to
allow considerable for grinding and polishing before all[Pg 30]
the graver marks are removed, while, on the contrary, if
the work has been performed with care, very little will
have to be removed. Avoid the use of the pivot file by
performing your work properly to start with.

Fig. 16.

For grinding, bell-metal or soft iron slips are desirable,
and the grinding is effected by means of oil stone powder
and oil. Two slips of metal similar in shape to A and B,
Fig. 16, are easily made, and will be found very useful.
A is for square pivots, etc., while B is used for conical
pivots. These slips should be dressed with a dead smooth
file, the filing to be done crosswise, to hold the oil stone
powder and oil. During the operation of grinding, the
lathe should be run at a high speed and the slips applied to
the work lightly, squarely and carefully. The polishing is
effected by means of diamantine and alcohol. After the
work is brought to a smooth gray surface, slips of boxwood
of the shape shown in Fig. 16 should be substituted
for the metal slips. Oil stone slips are sometimes used in
lieu of metal ones, but they soon get out of shape and are
troublesome to care for on this account. All things considered,
there is nothing better for polishing than a slip
or file made of agate, say one inch long, one-quarter inch
wide and one-eighth inch thick. A slip of this kind can
be obtained from any lapidary, and after grinding with
emery and water until the surface has a very fine grain,
it should be mounted by fastening with cement into a[Pg 31]
brass socket and this is then inserted into a small wooden
handle, as shown in Fig. 17. The agate slip should be
ground to about the shape of B, Fig. 16, so that one side
can be used for square corners and the other for conical
pivots. The final polish can soon be imparted by means
of a small boxwood slip, or flattened peg-wood, and diamantine
and alcohol. Never try to bring out the final
polish until you are satisfied that all graver marks have
been ground out, otherwise you will simply have to go all
over the work again.

Fig. 17.

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[Pg 32]
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[Pg 33]
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.

Fig. 21.

The all-important point in the use of wax
chucks is to get a perfect center. If you are not careful
you are liable to leave a small projection in the center
as shown at A, Fig. 21. The ordinary wax chuck cannot be
unscrewed from the spindle and restored to its proper
place again with anything like a certainty of its being exactly
true, and if you insist on doing this there is no remedy
left but finding a new center each time. It will be found
more satisfactory and economical in the long run to have
a permanent chuck for a wax chuck and you will then
have no necessity for removing the brass chuck.

The center, or cone for the reception of the pivot, should
be turned out with the graver at an angle of about 60°
and such a graver as is shown at B, Fig. 1, will answer[Pg 34]
admirably for this purpose. After you have carefully
centered your wax chuck, place a small alcohol lamp under
the chuck and heat it until the wax will just become fluid
and yet not be hot enough to burn the wax. Revolve the
lathe slowly and insert the staff so that the pivot rests
squarely and firmly in the center. Now re-heat the chuck
carefully in order that the wax may adhere firmly to the
staff, keeping the lathe revolving meanwhile, but not so
fast that the wax will be drawn from the center, and at
the same time apply the forefinger to the end of the staff,
as shown in Fig. 18 and 19, and gently press it squarely
into place in the wax chuck. The lines in Fig. 18 and 19
designate about the right amount of wax after
the work is ready, but it is well to add a little more than
is shown in those figures, and you should be careful to
keep the wax of equal bulk all around, or when it cools it
will have a tendency to draw the staff to one side. Now
remove the lamp and keep the lathe revolving until the
wax is quite cool, when it should be removed, by means
of a graver, down to the dimensions designated by the
lines in Fig. 18 and 19. When this is accomplished
re-heat a little, but only enough to make it soft, but not
liquid, and placing a sharpened peg-wood on the tool rest
proceed to the final truing up, by resting the pointed
end against the hub.

[Pg 35]

CHAPTER VI.

I have described above one of the methods in vogue
for holding a staff by means of wax. It is the common
method employed by most watch repairers, the popular
method so to speak. The method which I am now
about to describe may seem awkward at first to those
who have not practiced it, but once you have fairly tried
it, you will never be contented to work in any other way.

The first requisite is a true taper chuck; and it is well
to purchase an extra one to be used solely for this purpose,
so that you will be prepared at all times for staff
work. Select a good steel taper, and having placed your
chuck in the lathe, see if your taper fits well by inserting
it in the chuck while running slowly. If it fits well, it will
be marked almost throughout its length. Insert again in
the chuck, and with a few light taps of the hammer set it
firmly in place, so that you know that there is no danger
of its working loose. The taper will then project about
three-quarters of an inch from the face of the chuck. By
means of a sharp graver, make the face of the taper
smooth and straight, and cut off the taper end. Now
mark a point on the taper about one-fourth of an inch
from the end, and proceed to turn down the diameter
from this point to the end, leaving that portion of the
taper about two-thirds of its original diameter, and finish[Pg 36]
with a nice square shoulder. Now with a long-pointed
sharp graver proceed to cut a nice V-shaped center with
an angle of about 60°. When you have proceeded thus
far you will find that you have an implement resembling
that shown in Fig. 22.

Fig. 22.

Care must be taken that the center is quite true, and
that no projection is left like that illustrated in Fig. 21, no
matter how minute it may be. Now examine the center
by the aid of a strong glass, and after you are satisfied
with its appearance proceed to test it. Take a large sized
pin with a good point, and placing the point in the center,
maintain it in position by pressing upon the head, and
while revolving the lathe slowly proceed to examine by
means of your glass. If the center is a good one there
will be no perceptible vibration of the pin.

Now procure a piece of small brass tubing with an
internal diameter a little less than that of the turned down
portion of your taper. If the brass tubing cannot be procured
readily, you can substitute a piece of brass wire a
little larger than the taper, and by means of a drill a little
smaller in diameter than the turned down portion you can
readily make a small tube about one-half inch long. Now
by means of a broach proceed to open the tube to a point
one-quarter inch from one end, and carefully fit it on the[Pg 37]
turned down portion of your taper. After fitting tightly
to the shoulder of the taper, proceed to turn out the other
end until it will take in the hub of your staff easily and
leave a little room to spare. Now turn your tube down
in length until a little of the hub is exposed either way you
put the staff in. Turn the outside of the tube smooth and
to correspond with the outline of the taper, so you will
have a nice looking job when completed. Just below
where the hub will come drill a small hole in the tube and
remove all burr, both inside and out, that may have been
made in drilling, so that the shellac or wax will not adhere
to it. This little hole acts as an outlet for the air in the
tube; and as the hot shellac enters at the end of the
tube the air is expelled through this vent. It also helps
to hold the cement firmly in place. Now try your staff
in the tube again, and be sure that it is quite free, and that
you will be able to work on the portions of it above and
below the hub, according as one end or the other is
inserted.

You are now ready to insert your staff and proceed
with your work. Hold your shellac in the flame of your
lamp a moment until it is quite liquid, and then smear both
the inside and outside of the tube with it. Heat the shell
or tube gently by means of the lamp, keeping the lathe
revolving slowly all the while, and taking the staff in your
tweezers proceed to insert it carefully into the tube.
Press firmly back, making sure that it has reached the
bottom of the V-shaped center. Pack the cement well
in around the staff, and while centering remove the lamp[Pg 38]
and allow the whole to cool, keeping the whole revolving
until quite cool. Now remove the superfluous cement by
means of the graver, and heating the tube again slightly,
proceed to center exactly by means of a pointed peg-wood,
resting on your T rest to steady it. Turn slowly
in the lathe and examine with glass to see that it is quite
true. Your completed instrument will resemble Fig. 23.

Fig. 23.

The advantage of the device is that your center is
always ready, and all you have to do is to insert your
chuck in the lathe, warm it, and you are ready to insert
your staff and proceed to work. As I said in the first
place, it is well to employ a taper chuck exclusively for
this work, and not attempt to use it for any other, for
if you try to remove your taper and replace it again, you
will surely find that your work is out of center, and you
will be compelled to remove the brass shell and find a
new center each time you use it. You can avoid all this
trouble, however, by purchasing an extra chuck and
devoting it exclusively to wax work. Of course, the
brass shell can be removed and placed in position again
without in any way affecting the truth of the center,
and any number, shape and size of shells can be made to
fit the one taper, and these shells will be found very useful
for holding a variety of work, aside from balance staffs.

[Pg 39]

CHAPTER VII.

The two popular methods of holding a balance staff in
wax have been described and illustrated; the reader
may take his choice. The turning and finishing of the
other end of the staff is performed as previously described.
That portion on which the hair-spring collet goes should
be turned to nearly the proper size, making due allowance
for the grinding and polishing that is to come. The
balance seat should be slightly undercut, so that the balance
can be driven on tightly and all riveting dispensed
with. The size for the pivot can be determined from its
jewel, as previously described. Finish the ends of the
pivots flat and round the corners off slightly; and right
here comes a point worthy of consideration in all watch
work. Leave no absolutely square corners in any of
your work, but round them off very slightly. This may
seem a very little thing, but it is one of the small things
that go to make up first-class work. You can judge
pretty accurately of a watchmaker by the corners he
leaves on his work, as well as by the appearance of his
gravers and screw-drivers.

When your staff is completed and nicely polished,
remove from the wax and boil in alcohol to clean, and
when dried it is ready for the balance. Great care must
be exercised in removing the balance from the old staff,[Pg 40]
especially if it be a compensation balance, that you do not
distort it any way. If the balance has been riveted on
extra care will have to be exercised. The riveting may
be cut by means of a graver, or a hollow drill made from
Stubb’s steel wire. The recess in the drill should just fit
over the shoulder left for the reception of the hair-spring
collet. The edge of the hollow drill has small teeth
formed upon it similar to a fine file, and will cut quite
rapidly.

After removing the balance, if it appears to be sprung
in the arms, the result of removal or previous bad treatment,
proceed to bend them straight, and then to true
up the rim carefully, and stake on with a flat end punch.
Now put on your roller and drive it down to the hub and
see that the roller is free from the fork. See that jewel pin
reaches fork properly and that the guard pin also reaches
the roller. See that your balance is free from the plate and
the bridge. If the balance is true and all right, you are
ready to put on your hair-spring. See that it is in beat.
It is well to make a mark on the balance before taking
off the old staff, showing positions of hair-spring stud and
jewel pin.

Three-quarter plate English lever and Swiss lever balance
staffs differ only in detail, except that they are
sprung under balances. The general operations for making,
however, are similar to those described.

I have not described the method of poising the balance
for two reasons; first, the mere poising of a balance for a
cheap movement is so simple that it needs no explanation;[Pg 41]
and second, to describe the poising of the balance of a
fine watch is a lengthy task, and can hardly be included
under the heading of staffing and pivoting. The ground
has been thoroughly and conscientiously covered by Mr.
J. L. Finn, in a little volume entitled Poising the Balance,[A]
and I would advise all watchmakers, both young and old,
to read what he has to say.

Good pivoting is an art in itself, and although there are
many who undertake to do this work, there are but few
who can pivot a staff in such a manner that it will bear
close inspection under the glass. We often hear watchmakers
brag of the secrets they possess for hardening
pivot drills, but I fancy they would be somewhat surprised
if they traveled around a little, to find how many
watchmakers harden their drills in exactly the same way
that they do. The great secret, so-called, of making
good drills, is to first secure good steel, and then use
care to see that you do not burn it in the subsequent
operations. The fewer times the steel is heated the better.
My experience teaches me that you can do no better
than to select some nice pieces of Stubb’s steel for your
pivot drills. Many watchmakers make their drills from
sewing needles, say No. 3 or 4, sharps. The steel in
these needles is usually of good quality, but the great
drawback is that a drill made from a needle will not resist
any great pressure, and is liable to break just at the time
that you have arrived at the most important point. If[Pg 42]
your drill is made from a piece of Stubb’s steel wire, or an
old French or Swiss graver, you not only know that the
material in it is first-class, but you can leave the base of
the drill solid and substantial, with enough metal in it to
resist considerable pressure. The part of the drill which
actually enters the pivot is very short, and the end can be
turned down to the desired diameter. Turn or reduce
your wire by means of a pivot file so as to be smooth and
conical, as shown at A, Fig. 24.

Fig. 24.

The conical form is given to the drill for exactly the same
reason that it is given to the balance pivots, because
it gives additional strength. Heat
to a very pale red for about one-half
inch from the end, and then spread
the point, as shown at B, Fig. 24, by
a slight blow of the hammer. We
are now ready to temper our drill,
and we must exercise a little care
that the steel is not burnt and that the drill is not bent
or warped when hardening. The flame of the alcohol
lamp should be reduced as small as possible, or otherwise
the steel may become overheated and lose all its
good qualities. If needles are used for making drills
there is a great liability of their warping when hardening,
but when a larger piece of wire is used there is not much
danger, if care is exercised in introducing the drill that it
goes into the compound straight and point foremost. If
a needle is used, it is well to construct a shield for it, to
be used when heating and hardening. This shield can[Pg 43]
be made from a small piece of metal tubing, broached
out to fit loosely over the shank and point of the drill.
The drill is introduced into this shield as shown in Fig.
25, and a little soap may be introduced into the end a
before plunging. Various hardening devices are used,
but in my experience beeswax or sealing wax will be
found as good as any. Heat the drill (or if a needle, the
drill and shield both), to a pale red and plunge straight
into the wax. In the latter case,
where the shield is used, the shield,
on striking the wax, will run up
the shank of the drill, allowing
the point to pierce the wax. Some watchmakers introduce
the extreme point of the drill into mercury first and
then plunge into the wax. This hardens the extreme
point of the drill very hard, so hard, in fact, that it
will penetrate the hardest steel, but care must be
exercised with such a drill because the mercury makes
it not only very hard but very brittle. C, Fig. 24,
shows a drill after it has been finished on the Arkansas
stone. This shape of drill will withstand the pressure
necessary to drill into hard steel. Many watchmakers
reduce the temper of every staff before drilling. This, I
think, is quite unnecessary. There are very few cases
in which it is necessary to reduce the temper of the staff,
and even then it should only be reduced as far as it is to
be drilled, and then not in excess of a good spring temper.

Fig. 25.

The centering of a staff in wax has been thoroughly
described and in pivoting the proceeding is the same as[Pg 44]
in staffing. After accurately centering your work, make
a small cut in the center for the reception of the drill and
make this mark deep enough to take the entire cutting
head of the drill. Keep the drill firmly pressed into this
center and kept wet constantly with turpentine. Do not
revolve the work all one way, but give the lathe an alternating
motion. At first give but a third or a half revolution
each way, until the drill begins to bite into the staff,
when you can then safely give it a full revolution each
way. Care must be exercised, however, not to give the
work too rapid a motion, for if you do the friction is apt
to draw down the temper of your drill. Many watchmakers
find that their drills cut well for a certain distance
and then refuse to work altogether, and one of the chief
reasons is that they are in too great a hurry with their
drilling.

If you find it absolutely necessary to reduce the hardness
of your staff before drilling, do so by drilling a hole
in the end of a small piece of copper wire that will just fit
over the part to be softened, and apply the heat to this
copper wire, say one-fourth of an inch from the staff.
The heat will run down the copper wire and heat the
staff just where you wish to draw the temper. Be careful
and do not draw the temper too much, nor let it
extend down the staff too far.

The plug for the new pivot should be carefully made,
perfectly round, with a very little taper, and should be
draw-filed before being driven in. Some workmen dip
the plug in acid before driving in, as they declare that the[Pg 45]
pivot is less liable to be loosened while turning, if so treated.
The acid simply rusts the pivot and the hole, but I cannot
see that this will hold it any more firmly in place
while finishing. If the taper is a gradual one and the
pivot a good close fit, there will be little danger of it
loosening while dressing to shape. If too great a taper
is given to the plug, there is danger of splitting the end
of the staff, and this involves the making of an entire new
staff.

The turning up of a new pivot does not differ in any
way from the instructions given for turning pivots on a
new staff. With a little care both in turning and finishing,
a new pivot can be put in so nicely that only the
initiated can tell it, and then only with the aid of a strong
glass.

In pivoting cylinders there is some danger of breaking
them. To avoid this, select a piece of joint wire, the
opening of which is slightly larger than the diameter of
the cylinder at the lower end, and cut off a piece the
length of the cylinder proper, leaving the pivot projecting.
Now fill the cylinder with lathe wax, and while the
wax is warm, slip on the joint wire. You can now proceed
to true up the pivot in the usual manner, and when
the wax is quite cold, proceed to turn and polish the pivot
before removing from the lathe. If the joint wire is
properly cemented on the cylinder, it is almost impossible
to break it. After all the work is done, the wax can be
dissolved in alcohol. In pivoting pinions to cylinder
escape-wheels and third wheels, it is not necessary to[Pg 46]
remove the wheels, but great care should be used in
handling. In the latter case use plenty of wax. Do all
your centering by the outside of the pinion. Perfect
centering and sharp tools are requisite to good pivoting.
Do not try to rush your work, especially while drilling.
Proceed deliberately with your work and aim to restore
the watch to the condition it was in originally, and you
will find staffing and pivoting is not half as hard as some
workmen would have you believe.