Lathe, Milling Machine, Planer, and Shaper
A selection of basic machine tools shows a variety of functions and methods of crafting a workpiece. The job at hand usually determines which tool will be used. For instance, a person making a rounded handle would use a lathe, while a person making a breadboard would use a planer. In order to use power tools efficiently and safely, either the workpiece or the actual tool must be stationary. A planer is an example of a stationary machine tool because the workpiece is moved, or fed, into it. To use the shaper, the workpiece must be kept stationary while the tool is moved across it.
Among the basic machine tools are the lathe, the shaper, the planer, and the milling machine. Auxiliary to these are drilling and boring machines, grinders, saws, and various metal-forming machines.
| A | Lathe |
A lathe, the oldest and most common type of turning machine, holds and rotates metal or wood while a cutting tool shapes the material. The tool may be moved parallel to or across the direction of rotation to form parts that have a cylindrical or conical shape or to cut threads. With special attachments, a lathe may also be used to produce flat surfaces, as a milling machine does, or it may drill or bore holes in the workpiece.
| B | Shaper |
The shaper is used primarily to produce flat surfaces. The tool slides against the stationary workpiece and cuts on one stroke, returns to its starting position, and then cuts on the next stroke after a slight lateral displacement. In general, the shaper can produce almost any surface composed of straight-line elements. It uses a single-point tool and is relatively slow, because it depends on reciprocating (alternating forward and return) strokes. For this reason, the shaper is seldom found on a production line. It is, however, valuable for tool and die rooms and for job shops where flexibility is essential and relative slowness is unimportant because few identical pieces are being made.
| C | Planer |
The planer is the largest of the reciprocating machine tools. Unlike the shaper, which moves a tool past a fixed workpiece, the planer moves the workpiece past a fixed tool. After each reciprocating cycle, the workpiece is advanced laterally to expose a new section to the tool. Like the shaper, the planer is intended to produce vertical, horizontal, or diagonal cuts. It is also possible to mount several tools at one time in any or all tool holders of a planer to execute multiple simultaneous cuts.
| D | Milling Machine |
In a milling machine, a workpiece is fed against a circular device with a series of cutting edges on its circumference. The workpiece is held on a table that controls the feed against the cutter. The table conventionally has three possible movements: longitudinal, horizontal, and vertical; in some cases it can also rotate. Milling machines are the most versatile of all machine tools. Flat or contoured surfaces may be machined with excellent finish and accuracy. Angles, slots, gear teeth, and recess cuts can be made by using various cutters.
| E | Drilling and Boring Machines |
