shears where it will be handy to the operator. Such a press is very useful for small work.

For straightening shafts a special form of press is provided which is superior for that work as it is designed for it. A typical shaft straightener is shown at Fig. 33, B. As will be noticed, it is very similar in construction to an arbor press, except that the base is provided with a slot in which V-blocks are placed to support the shaft. Another V-block is attached to the end of the screw and

bears upon the shaft. In order to ascertain if the shaft is properly straightened, a pair of centers are mounted in front of the press on a long bar attached to its base. As a shaft must be placed on centers a number of times in straightening in order to observe the progress of the work, the combination shown is evidently superior for the purpose. With the usual form of arbor press the shaft must be taken to a lathe and swung between the centers after each pressing operation. The process of shaft straightening is a comparatively simple one, as it is revolved on centers and the high spot indicated by holding a piece of chalk against the shaft surface. The high spot is then placed directly under the press screw and the pressure brought to bear against the shaft will tend to straighten it, owing to its two point support.

Another very good form of press for repair shop use is shown at

Fig. 34. At A, the method of removing gears from a shaft is shown, while at B, the press is depicted straightening a shaft. The press is easily handled, as a small hand wheel is provided on the front of the machine to run the ram quickly up or down. This press has a 36 inch space between uprights, a 12 inch opening under the plate, 26 inch over the plate and 48 inch over the lower plate or table. Being mounted on wheels the press can be easily moved to any portion of the shop to straighten an axle or over a trap hole through which a crank shaft may be placed to remove a flywheel. The auxiliary plate at the bottom of the chamber under the revolving plate has a revolving centre and is very convenient when needed. The centre of this plate is provided with a self-centering surface or a spherical or ball joint which will insure steady pressure on the centre line of the press even if the work is tilted slightly when it is initially placed. With this press one man can exert a pressure of ten tons and two men sixteen tons. With the leverage form, the workman is able to "feel" what he is doing, therefore the danger of applying excessive pressure is avoided.

Special Tool Attachments of Value.-Many special devices can be used to facilitate machine work which should be included in the equipment. In automobile repair work many irregular pieces are handled, and it would seem to the writer that a set of universal angle plates, which could be used with equal facility on the bed of the drill press or shaper or on the face plate of the lathe, would be an excellent investment. Then there are the index heads, which can be mounted on almost any machine tool, and which enable one to cut gear teeth, mill slots, or drill holes at regular intervals around the periphery of a circular piece, without time spent in laying out. The vises for holding work on the drill press or shaper should be a pattern that they can use on the face plate of the lathe, and two or three different sizes can be employed to advantage. Special boring bars, cutters, and grinding wheels should be provided, as needed. A small portable electric motor as shown in Fig. 35 mounted on the lathe tool rest can be used in grinding, both internal and external. For the sharpening of drills, cutting tools, reamers, etc., small universal bench. grinders as at A, Fig. 36, driven directly by small electric motor

or by belt from the line shafting, cna be profitably installed. The equipment of drills, taps, reamers, etc., will depend entirely upon the capital one wishes to invest in special epuipment, but endeavor should be made to have an assortment that will include most of the standard sizes employed in making automobile parts. are fully considered in the following chapter.

These

Another form of bench grinder, provided with straight and angular rests and capable of driving two wheels, is shown at B. This is a slightly heavier form than shown at A, but is not sufficiently heavy to require the use of a special support. The grinder shown at C, is also intended to be mounted directly on the work bench and in contrast to the other forms shown, which are dry grinders, it is provided with a housing and a small water tank for all forms of wet grinding. A very useful appliance for use with a bench grinder is shown in this illustration. This is an adjustable work rest which can be set at any angle, making it especially valuable for tool grinding. The machine illustrated at D is a small twowheeled grinder mounted on a substantial base which incorporates a countershaft beneath the table. The grinders shown at A, B and C, make it necessary to install either a countershaft with tight and loose pulleys or a clutch pulley over them to drive. The grinder shown at D, with integral countershaft can be belted directly to the main drive shaft. A grinding machine for heavy work is shown at E. This is the same in general construction as the lighter forms, except that it is much more substantial. Attention is directed to the surfacing attachment mounted over the grinding wheel. This may be raised or lowered as desired, and as the table is accurately planed and surfaced it is very valuable for grinding work absolutely flat.

In many small shops it is not possible to furnish a very complete assortment of machine tools, and while tools designed for a specific purpose are always best if they can be purchased, it is sometimes possible to do very satisfactory work on simple machines adapted for a variety of work. A small bench machine that can be used either as a lathe, drill press or milling machine is shown at Fig. 37. This may be driven by a small electric motor or can be provided. with a two-speed cone pulley, as shown. At A the machine is set up for use as a drill press, at B, the change of the attachment permits it to be employed for milling. Vertical feed is provided so the milling cutter may be raised up or down, and both cross and lateral feeds of the work are obtained by hand lever. When used as a lathe it is possible to drive the lead screw through gearing so that an automatic lateral feed is obtained, this making possible thread cutting operations. The flat table shown at A, can

be supplemented by an index table for use in milling. When used as a sensitive drill the feed is by hand lever attached to the drill spindle. This tool, which is known as the "bench machinist" is furnished complete with a countershaft milling vise, face plate, dividing head and tool post. When used as a drill press, the spindle may be adjusted to any desired angle and the work brought to the tool if necessary. As a drill its capacity is up to a half inch. The spindle fits a number two standard, Morse taper shank. When

used as a milling machine the open side design permits the operator to do work on long pieces such as cutting keyways, straight, taper or Woodruff; squaring ends of long axle, splining and other work of this nature. The diameter of the arbor is seven-eighths of an inch and the extension arm permits the use of an arbor twelve inches long. This machine will cut small spur gears and bevel gears. It will consume but one-fourth of a horsepower whether used as a lathe, milling machine, or drill. While its capacity is limited it can handle such a variety of work that it will be found a valuable item of equipment in even a machine shop of some pretensions.