Part 18 (2/2)
A CONVENIENT TOOL FOR LENGTH MEASUREMENT
[Illustration: Fig 180]
A pair of coood a pair of calipers for length measure a small screw in one of the blades--the head on the inner side, as shown at _f_, Fig 180 The idea of the tool is, the screw head _f_ rests in the sink of the cap jewel or end stone, while the other blade rests on the cock over the balance After the adjusting screw to the caliper is set, the spring of the blades allows of their removal The top pivot _z_ of the cylinder is next cut to the proper length, as indicated by the space between the screwhead _f_ and the other blade of the pinion caliper The upper pinion _z_ is held in the jaws of the cutting pliers, as shown in Fig 177, the sath between the lines _d v_, Fig 171, is secured, after which the cylinder is put back into the ce 178, except this time the top portion of the cylinder is allowed to protrude so that we can turn the top pivot and the balance collet _D_, Fig 171
The sizes we have now to look to is to fit the pivot _z_ to the top hole jewel in the cock, also the hairspring seat _D_ and balance seat _D'_ These are turned to diameters, and are the most readily secured by the use of the e watchmakers'
tool and supply house In addition to the diaht for the balance, which is represented by the dotted line _b_ The measurement for this can usually be obtained fro it with the new one as it rests in the ceage We havethe pivots, as these points are generally well understood by the trade
REMOVING THE LATHE CEMENT
One point perhaps we ard to re the lathe ce in a copper dish with alcohol But there are several objections to the practice In the first place, it wastes a good deal of alcohol, and also leaves the work stained We can acco the cylinder with the wax on it in a very sht The bottle is then boiled in water, and in a few seconds the shellac is dissolved away The balance to most cylinder watches is of red brass, and in soold; in either case the balance should be repolished To do this dip in a strong solution of cyanide of potassium dissolved in water; one-fourth ounce of cyanide in half pint of water is about the proper strength Dip and rinse, then polish with a cha 181]
In staking on the balance, care should be observed to set the banking pin in the ri said pin so it stands opposite to the opening in the half shell The seat of the balance on the collet _D_ should be undercut so that there is only an edge to rivet down on the balance This will be better understood by inspecting Fig 181, where we show a vertical section of the collet _D_ and cylinder _A_ At _g g_ is shown the undercut edge of the balance seat, which is folded over as the balance is rivetted fast
About all that re it to poise The practice frequently adopted to poise a plain balance is to file it with a half-round file on the inside, in order not to show any detraction when looking at the outer edge of the rim A better and quicker plan is to place the balance in a split chuck, and with a diamond or round-pointed tool scoop out a little piece ofthis, the spindle of the lathe is turned by the hand grasping the pulley between the finger and thumb The so-called dia 182
The idea of this plan of reducing the weight of a balance is, one of the tools _o_ is rested on the T-rest and pressed forward until a chip is started and allowed to enter until sufficientdown on the handle of the tool, the chip is taken out
[Illustration: Fig 182]
[Illustration: Fig 183]
In placing a balance in a step chuck, the banking pin is caused to enter one of the three slots in the chuck, so as not to be bent down on to the rim of the balance It is seldom the depth between the cylinder and escape wheel will need be changed after putting in a new cylinder; if such is the case, however, move the chariot--we mean the cock attached to the lower plate Do not atte the balance cock Fig 183 shows, at _h h_, the for 182