This section is from the book "Lathe Design, Construction And Operation, With Practical Examples Of The Lathe Work", by Oscar E. Perrigo. Also available from Amazon: Lathe Design: Construction And Operation.
Setting up a Lathe. Placing the Lathe. Plan of Small Shop. Line Shaft Size and Speed. Power Needed to Drive Lathes. Leveling Lathe. Lubrication of Lathe Parts. When to Oil. Attaching Face Plate or Chuck. Lathe Parts and Their Functions. Headstock. Tail Stock. Carriage. Automatic Apron. Reverse Gear. Compound Rest. Starting the Lathe. Operating Levers. Simple Lathe Accessories. Spur and Screw Centers. Drill Pads. Turning a Steel Shaft. Drilling in the Lathe. Taper Attachment for Lathes. Milling in the Lathe. South Bend Attachment. Barnes Attachment. Motor Driven Attachment. Knurling on the Lathe. Indicators and Their Use. Boring Bar Construction and Use. Adjustable Boring Bar. Boring Bars for Heavy Work. Methods of Holding Work. Special Chuck for Gas Engine Pistons. Increasing Swing of Lathe. Lathes for Heavy Work. Grinding Attachments, Belt Driven. Machining Concave and Convex Surfaces. Grooving Oil Ducts. Combination Lathe Dogs and Their Use. Hacksaw Attachment for Lathes.
If the Lathe is purchased new, it will undoubtedly come crated up in a substantial manner with all auxiliary parts wrapped in burlap with excelsior padding. A list of parts included in the purchase price should be carefully checked against the shipment to insure that all are received. The wrappings should be carefully removed and inspected to see that no small parts are overlooked. It will be noticed that all bright parts are covered with vaseline. This precaution is taken to reduce liability of rusting during shipment. This may be easily removed with a cloth dipped in kerosene, after which the parts are wiped dry. The gears should be cleaned thoroughly and all chips, excelsior shreds or sawdust removed from each tooth separately. This includes change speed gears as well as back gears.
The placing of the lathe in the shop depends upon many conditions such as position of drive shafting, opportunity for countershaft installation, relation to work bench, direction of light, etc. It is claimed by experienced mechanics that the operator can work most efficiently with the light coming from a point over the right shoulder. The floor supporting the lathe should be firm and level. If there is any vibration after the lathe is started, the floor should be suitably braced from underneath, if possible. The lathe should be placed so the operator can readily gain access to all sides as there are many jobs that require the operator to work at all sides of the machine.
Fig. 315. - Plan View of Small Shop Showing Arrangement of Shafting and Location of Lathe.
The general arrangement of the lathe, its countershaft and line shaft to drive it as well as two sources of power that can be used as recommended by the South Bend Lathe Works are clearly shown in Figs. 315 and 316. The plan view shows the location of the machine relative to the bench, as well as the placing of the line shaft so it can be driven by either an electric motor or small gas engine, and drive not only the lathe countershaft but an emery wheel stand as well. The view at Fig. 317 is a front view of the lathe and countershaft and is lettered so the principal dimensions of a lathe may be clearly grasped by the novice machinist. The swing A is twice the radius R, and indicates the diameter of the largest piece that can be turned supported by the centers. The distance between centers B indicates the maximum length that can be turned between these points of support. The length of the bed is indicated by C.
Fig. 316. - View of Small Machine Shop Showing Relation of Lathe to Workbench.
It is said that the countershaft should be placed at least five feet above the spindle in order to secure proper belt tension and that six or seven feet would be even better. The countershaft may be set either side of the line shaft depending upon position of the lathe. The shipper rod actuating lever must be conveniently placed so it may be readily operated by the lathe user. When the lathe location is settled, the countershaft should be permanently installed. For a light lathe, the countershaft hangers can be secured to cross pieces, about 2" x 4", which are attached to the ceiling beams parallel with the lathe ways and sufficiently far apart to make possible the retention of the hanger feet by lag screws. The countershaft support pieces should be secured to the ceiling by substantial fastenings, lag screws being the most common.
The usual method of supporting the line shaft is by the joists which run from the side walls. If the shop is a small one, including only a lathe, emery grinder and perhaps a drill press, a 1 7/16" shaft will be ample. The line shaft hangers should be placed eight feet apart and a shaft speed of 200 to 300 R. P. M. is considered sufficiently fast, the average speed being 250 R. P. M. If electric power is available, a small motor may be secured to a suitable bracket attached to the side wall, care being taken to place the motor high enough so the belt leading from it to the line shaft will not interfere with anyone having occasion to pass under it. If a gas or gasoline engine is used instead of an electric motor the engine may be placed in any convenient location, though usually it is put in a corner where it will be out of the way.
Fig. 317. - View of Lathe Showing Important Dimensions.
If the lathe is not larger than 16" swing, a gas engine of 2 1/2 to 3 H. P. will be ample, while an electric motor of \\ to 2 H. P. will provide sufficient power. The horse power needed to drive a lathe varies with the size and character of the work. Obviously, the motor power should be ample so the lathe can work at full capacity. A 12" swing lathe will take \ H. P. under these conditions, a 13" will take 3/4 H. P. About 1 H. P. should be allowed for a 15" swing, 2 H. P. for a 16" swing lathe while not less than 2 1/2 H. P. should be supplied to turn an 18" swing machine at maximum load. The shafting friction in a small shop of the character indicated at Fig. 315, providing the line shaft is properly aligned and well oiled, would not be any more than \ H. P. This figure must be added to the energy necessary to turn the lathe.
When the countershaft is properly fastened in position, move the lathe over until the driving belt will track properly between spindle cone pulley and countershaft pulley group. The axis of the lathe spindle should be parallel with that of the countershaft. Upon the proper leveling of the lathe much depends, as the way the lathe is erected has much to do with its accuracy. A carpenter's level should be placed across the ways near the head stock. Repeat this operation at various points along the length of the bed, leveling carefully in every direction. If the lathe bed is not plumb, put a shim between the low leg and the floor. Shingles are a favorite shim among millwrights on account of the taper which makes it possible to level very accurately by driving two shingles in opposite directions under the lathe leg to raise it gradually. When properly leveled, as can be easily determined by using the level both parallel to the ways and across them as well, the pads or feet at the bottom of the legs are securely lagged to the floor. If the floor is of cement or concrete, it is necessary to drill out holes and drive in wooden plugs in order to secure anchorage for the lags. Expanding bolts are also sometimes used for this purpose.
In belting up the lathe, most mechanics favor leather belts. The belt nearest the lathe head is usually straight, while the other is generally a crossed belt to give reverse motion. The countershaft belts should be so arranged that when the shipper rod is moved in the direction of the lathe head, the spindle of the lathe should revolve so the top of the spindle cone pulley group turns toward the operator when he is standing in front of the lathe.