MACHINING OPERATIONS AND MACHINE TOOLS Ch 22
Generating refers to the creation of work geometry due to the feed trajectory of the cutting tool; examples include straight turning, taper turning, and profile milling. Forming involves the creation of work geometry due to the shape of the cutting tool; common examples include form turning and drilling.
22.1 Distinguish between generating and forming when machining work part geometries.
A center holds the work during rotation at the tailstock end of the lathe. A live center is mounted in bearings and rotates with the work, while a dead center does not rotate the work rotates about it.
22.5 What is the difference between a live center and a dead center, when these terms are used in the context of workholding in a lathe?
a tool with multiple teeth moves linearly past a stationary workpart
A broaching operation is best described by which one of the following: (a) a rotating tool moves past a stationary workpart, (b) a tool with multiple teeth moves linearly past a stationary workpart, (c) a workpart is fed past a rotating cutting tool, or (d) a workpart moves linearly past a stationary single-point tool?
Boring, drilling, turning
A lathe can be used to perform which of the following machining operations (three correct answers): (a) boring, (b) broaching, (c) drilling, (d) milling, (e) planing, and (f) turning?
a workpart moves linearly past a single-point tool
A planing operation is best described by which one of the following: (a) a single-point tool moves linearly past a stationary workpart, (b) a tool with multiple teeth moves linearly past a stationary workpart, (c) a workpart is fed linearly past a rotating cutting tool, or (d) a workpart moves linearly past a single-point tool?
In up milling, the cutter speed direction is opposite the feed direction; in down milling, the direction of cutter rotation is the same as the feed direction.
Describe the difference between up milling and down milling?
Turning is a machining process in which a single-point tool removes material from the surface of a rotating cylindrical workpiece, the tool being fed in a direction parallel to the axis of work rotation.
Describe the turning process.
In shaping, the work is stationary during the cut, and the speed motion is performed by the cutting tool; while in planing, the cutting tool is stationary, and the workpart is moved past the tool in the speed motion.
How do shaping and planing differ?
Boring produces an internal cylindrical shape from an existing hole, while turning produces an external cylindrical shape
How does a boring operation differ from a turning operation?
A turret lathe has a toolholding turret in place of a tailstock; the tools in the turret can be brought to work to perform multiple cutting operations on the work without the need to change tools as in operating a conventional engine lathe.
How does a turret lathe differ from an engine lathe?
Methods of holding the work in a lathe include: (1) between centers, (2) chuck, (3) collet, and (4) face plate.
Name the various ways in which a workpart can be held in a lathe.
Knee-and-column
The basic milling machine is which one of the following: (a) bed type, (b) knee and column, (c) profiling mill, (d) ram mill, or (e) universal milling machine?
In peripheral milling, cutting is accomplished by the peripheral teeth of the milling cutter and the tool axis is parallel to the work surface; in face milling, cutting is accomplished by the flat face of the cutter whose axis is perpendicular to the work surface.
What is the difference between peripheral milling and face milling?
Broach
Which one of the following cutting tools cannot be used on a turret lathe: (a) broach, (b) cutoff tool, (c) drill bit, (d) single-point turning tool, or (e) threading tool?
