Manufacturing Processes and Drill Types Quiz

Machining Operations and Part Geometry

• Each machining operation produces a characteristic part geometry due to: (1) relative motions between tool and workpiece - generating (determined by feed trajectory of cutting tool); and (2) shape of cutting tool - forming (created by the shape of cutting tool).
• Turning - a single point cutting tool removes material from a rotating workpiece to generate a cylindrical shape. Variations of turning performed on a lathe include facing, contour turning, chamfering, parting, and threading.
• Center Lathe (Engine Lathe) - a machine tool with a headstock and tailstock for holding the workpiece between centers. Methods of holding work in a lathe include chuck, collet, and face plate.
• Turret Lathe - a machine tool that has a turret which holds up to six tools which can be rapidly indexed into action. Tool post is replaced by a six sided turret to index six tools.
• Bar Machine - a type of centre lathe where a collet replaces a chuck to allow long bar stock to be fed through. Also known as an automatic bar machine. Applications include high production of rotational parts.
• Automatic Screw Machines - similar to automatic bar machines but smaller, used for high volume production of screws and similar items.
• Multiple Spindle Bar Machines - capable of machining more than one part simultaneously; example being a six spindle automatic bar machine which can work on six parts at the same time. Spindles are indexed to the next position in sequence after each machining cycle.
• Boring - used for internal operations on the internal diameter of existing holes. Horizontal and vertical - refers to orientation of axis of rotation on machine spindle.
• Drilling - used for creating round holes in workpieces. Contrasts with boring as it can only enlarge an existing hole. Uses a drill, twist drill, or drill bit.
• Reaming - used to slightly enlarge a hole to provide better tolerance and smooth surface finish.
• Tapping - used to provide internal screw threads on an existing hole using a tap tool.
• Counterboring - creates a stepped hole allowing a larger diameter to follow a smaller diameter partially into the hole.
• Milling - a machining operation in which the workpiece is fed past a rotating tool with multiple cutting edges. Axis of tool rotation is perpendicular to feed direction. Creates a planar surface. Variations include up-cut milling and down-cut milling
• Peripheral Milling - involves a cutter axis parallel to the surface being machined, with cutting edges on the outside periphery of the cutter.
• Face Milling - involves a cutter axis perpendicular to the surface being milled, with cutting edges on both the end and outside periphery of the cutter.
• Slab Milling - a form of peripheral milling in which the cutter width extends beyond the workpiece on both sides.
• Slotting - a milling process used to create a slot in a workpiece where the width of the cutter is less than the workpiece width.
• Conventional Face Milling - a milling process using a cutter that overhangs the workpiece on both sides.
• End Milling - a milling process where the cutter diameter is smaller than the work width, thus creating a slot into the part.
• Profile Milling - a form of end milling used to create an outline of a flat part using the outside periphery of the cutter.
• Pocket Milling (Slot Drilling) - a process involving end milling to create shallow pockets in flat parts.
• Surface Contouring - a process involving a ball-nose cutter used to create a three-dimensional surface form by feeding the cutter back and forth.
• Machining Centers - a highly automated machine tool capable of carrying out multiple machining operations. Typically includes features like automatic tool changing, pallet shuttles, and automatic workpart positioning,
• Shaping and Planing - similar operations using a single point cutting tool which is moved in a linear path relative to the workpiece, resulting in a straight, flat surface. Involves interrupted cutting.
• Broaching - used for cutting various shapes on workpieces by moving the tool in a linear direction to the axis of the part.
• Internal Broaching - performed on internal surfaces of holes using a broach tool.

Machining Operations and Machine Tools

• Milling, Machining Centers and Turning Centers, Other Machining Operations, High Speed Machining.
• Leadscrew Backlash - a clearance or lost motion in a mechanism.