A Treatise on Staff Making and Pivoting | Page 8

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. At B, Fig. 14, is shown the
correct manner of applying the graver when turning a pivot. Hold the
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.
[Illustration: Fig. 14.]
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. 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 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.
[Illustration: Fig. 15.]
[Illustration: 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