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Lathe (Mechanical device used)

A mechanical device used for shaping articles by causing them to revolve while being brought into contact with cutting tools. Those who contemplate buying a lathe will do well to avoid the cheap imitations of the American pattern, which are made by irresponsible makers in foreign countries, and foisted upon an unsuspecting public, and guaranteed true and "as good as the American." They are usually nicely finished, but inferior both in material and workmanship, their greatest failure being their untruth. If an untrue American lathe, by any possibility is allowed to escape the inspector and finds its way upon the market, the manufacturer is only too glad to exchange it for a perfect article, for his reputation is at stake; but who are you going back on in the event of one of these cheap imitations proving untrue? There are American made lathes upon the market that are as inferior in many respects as the imitations, and the watchmaker will do well to do without a lathe until such time as he can afford to purchase one of known reputation. Among the first class American lathes upon the market may be mentioned the Webster-Whitcomb, Fig. 191; the Moseley, Fig. 192; the Hopkins, Fig. 193, and the Rivett, Fig. 194.

An excellent lathe for the heavier work of watchmakers and jewelers, such as cannot be performed with satisfaction on the watchmaker's lathe, is the No. 4 Barnes, which is shown in Fig. 195.

It is manufactured by the W. F. & John Barnes Company, Rockford, Ill. For screw cutting, the manufacture of watchmaker's tools, fishing reels, repairs on tower clocks, in fact, all the heavier work of the trade, it is admirably fitted.

The American lathe of to-day is a marvel of completeness in its parts, and how many hours, yea months, of study and experiment have been bestowed upon it by its projectors and makers to acquire these points of utility and excellency. What a vast amount of care has been exercised for the production of a perfect lathe! Must this care cease at the moment the lathe passes into the hands of the watchmaker?

It is a very easy matter at any time to wipe off the dust and oil that may accumulate, but does this alone constitute due care? There may be a nice glass case to cover it and keep off the dust, and a very good idea it is, if faithfully used; but if a counter shaft is on the bench, or much lathe work is to be done, it soon falls into blissful desuetude, or finishes its usefulness by being broken. Then, often, a cloth is wrapped about the lathe, which soon gets soiled and looks badly, let alone the poor protection it affords. Dust is omnipresent and the greatest enemy to all active machinery; it insidiously makes its way into every crease and crevice, and if not promptly removed will cause untold damage. We cannot get rid of it and must (like the industrious housewife) wage a constant warfare against it. The care necessary to be given to a fine lathe differs from most other tools; it is not confined alone to the removal of dust and keeping clean, but the fitting properly of the several parts as used. There should be no overstraining when tightening screws, chucks, etc., or when fitting articles in both wire and wheel chucks, and so on through the list. The face of the lathe bed when it comes from the makers is (or should be) perfectly true from end to end, in order that head and tail stocks will meet on a direct line of centers, even should they be changed end for end, and a good lathe will meet those requirements. Now, it is obvious to any thinking mind that if this face becomes injured by neglect, whereby the nickling is removed in spots or portions, they will, in all probability become rusty; this rust will then eat away and throw off more, and soon the face presents an uneven surface, which will tend to destroy the line of centers between head and tail stocks.

The head stock, usually occupying one position, causes less wear at this point or place, while the hand-rest and tail stock are constantly being shifted, so where there is more motion or action there must be more wear, especially if dust, chips, or grit be allowed to accumulate beneath them, and though the wear is seemingly imperceptible, it nevertheless is there, and will sooner or later manifest itself, and this is a signal that the level of the bed is becoming impaired, and, necessarily, the truth. Thus too much care and attention cannot be exercised in guarding against chips and dust when sliding hand rest back and forth on the bed.

At the end of the bed, where the tail stock takes position, many watchmakers have the tail stock off, and this portion is more exposed to atmospheric action, also receiving perspiration from the hands when they come in contact. Again, others let the tail stock remain in position, only removing when it comes in the way. In the former case, it is well to devise some means for the protection of the bed; this is easily done by making a sheath of chamois skin to slip tightly over the bed; it can be removed and replaced readily, and when it becomes soiled, can be washed.

This sheath should be fully two-thirds the length of bed, or reaching from tail end up to hand rest when it is close to head stock. It preserves the bed from dampness, which is considerable in some climates, also the perspiration of the hand and flying chips and dust. In the second case, if the tail stock is allowed to remain on lathe, or, if removed and placed on the bench, it is subjected to all the evils the bed is in the former. Our opinion is, the tail stock should be kept in its compartment in a tight fitting drawer, away from dust and accidental knocks of other tools on the bench; the tail spindle not being nickeled, is more liable to rust if left exposed, and should be kept wrapped in a sheath of oiled paper. This may seem superfluous and too much bother, yet it is taking proper care which tells in the end. The bottom of tail stock should always be brushed off before placing in position, not only for its protection, but for fear some particle of grit may be adhering, thereby throwing it out of truth, and screwing it down tight only adds injury to the lathe if allowed to remain.

The head stock demands close attention; the spindle should run freely without end shake, and about once a week should be speeded, meanwhile administering oil until it leaves the bearings clean, and then wiped off. A little oil should be added every day. See that the mouth of the spindle is kept bright and clean; thrust a strip of cloth clear through spindle every now and then, that all dust and dirt may be removed.

Wire and wheel chucks should often be washed in gasoline to remove gummy dirt and oil which is constantly adhering, and it is even well each time a chuck is used, to wash off first, then wipe dry. A little dirt on mouth of spindle, or on chuck, often throws it out of truth, and consequently the article fastened therein also.

When fitting head or tail stocks, or in fact any attachment, do so carefully. Do not bang it in place as if you held a grudge against it, and when in position see that they are tightly screwed in place. Having too much end shake on live spindle, especially in soft lathes, causes uneven wear in its bearings, besides not being reliable for true pivoting or any such work.

When the cost of a lathe is taken into consideration, it goes to prove that it is not easily replaced. Where is the jeweler with a stock of goods who would retire without first seeing his valuables were in the safe, but how many are there who think of giving this protection to their lathes? Some do, but the greater per cent do not. "It is a "pious plan" to see that the head stock, tail stock, and attachments are in the safe, and should a fire break out that endangers the store, and no chance to save it, the feeling of satisfaction is great to know the lathe is safe, that is, the more expensive parts, for the bed can be purchased at a nominal cost compared to the attachments. A word about chuck blocks or stands. The best kinds are those made to fit in a drawer of the bench and the holes sunk deep enough to let the chuck (wire) drop full length, or to the head, the hole being counter-sunk to admit the bevel portion. They can easily be picked out with the finger nail. Have the block thoroughly soaked with oil.

To prevent rusting of tools, and especially if the bed shows signs of rust spots, here is a good old remedy: Procure some blue ointment, spread it on a cloth and rub the tools or lathe briskly, then wipe off with a clean cloth, and wipe dry. This ointment leaves a thin coating of mercury which prevents the action of dampness on the tools. This cure need not be resorted to more than once a month, and keep ointment away from gold cases and watch movements. If you find your lathe bed has got in such a condition as to destroy its truth, send it at once to the makers and have it put in first-class condition. Do not trust it, for the sake of saving a little, to some irresponsible firm for repairs.

LEPAUTE, J. A. One of the most celebrated of French horologists. He did much to improve his art, especially in regard to turret clocks. He was the author of a volume on horology, which in its time was a standard authority. He was born at Montmedi in 1709 and died in 1789.