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Objectives. The development of tools throughout history The standard types of machine tools used in shops The newly developed space-age machines and processes. History of Machine Tools. Began during stone age (<50,000 years ago) Hand tools of wood, animal bones, or stone
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Objectives • The development of tools throughout history • The standard types of machine tools used in shops • The newly developed space-age machines and processes
History of Machine Tools • Began during stone age (<50,000 years ago) • Hand tools of wood, animal bones, or stone • Bronze age (4500 to 4000 b.c.) • Copper and bronze implements • Power-operated (animal power) • Iron age (1000 b.c.) • Iron replaced bronze • Domesticated animals provided power • Commodities handmade by skilled craftspeople
History of Machine Tools • Machine age (~300 years ago) • Explored new sources of energy (water) • Industrial age began when James Watt produced first steam engine (1776) • Steam engine provided power to other areas • Machines improved • Steam/steel in ships, railroads, steam tractors • New power – electricity produced by generators • Diesel and gasoline engines
History of Machine Tools • Progress continued slowly during first part of 20th century • Spurts during the two world wars • Since 1950s, progress rapid • Now in space age • Atom harnessed: nuclear power • Journey to moon and outer space • Calculators, computers, robots commonplace • Can mass produce parts to millionths of an inch
Improved Production • Constant improvement made modern machine tools more accurate and efficient • Improved production and accuracy
Common Machine Tools • Generally power-driven metal-cutting or -forming machines used to shape metals • The removal of chips • Pressing, drawing, or shearing • Controlled electrical machining processes
Machine Tool Capabilities • Holding and supporting the workpiece • Holding and supporting a cutting tool • Imparting a suitable movement (rotating or reciprocating) to the cutting tool or the work • Feeding the cutting tool or the work so that the desired cutting action and accuracy will be achieved
Machine Tool Categories • Four broad categories • Chip-producing machines • Non-chip-producing machines • New-generation machines • Multi-tasking machines
Chip-producing Machine • Form metal to size and shape by cutting away unwanted sections • Generally alter shape of steel-produced products • Casting • Forging • Rolling
Non-chip-producing Machines • Form metal to size and shape by pressing, drawing, punching, or shearing • Produce parts by compressing granular or powdered metallic materials
New-Generation Machines • Perform operations that cannot be done on chip- or non-chip-producing machines • Use either electrical or chemical energy
Multi-tasking Machines • Combined machining and turning center • Can produce virtually any shape part from rough to finish • Consists of turning center with two independent spindles and vertical machining center with rotary tool spindle • Combine Information Technology (IT) and Manufacturing Technology (MT)
Machine Tool Performance • Metal-removal rate • Depends upon cutting speed, feed rate, and depth of cut • Accuracy • How precisely machine can position cutting tool to given location once • Repeatability • Ability of machine to position cutting tool consistently to any given position
General Machine Shop Tools • Tools basic to production of metal components • Operations most commonly performed: turning, boring, threading, drilling, reaming, sawing, milling, filing, and grinding • Basic Machine tools • Drill press, engine lathe, power saw, milling machine and grinder
Drill Press • First mechanical device developed • Used primarily to produce round holes • Function to grip and revolve cutting tool • Common operations • Drilling, reaming, spot facing, countersinking, counterboring, and tapping
Engine Lathe • Used to produce round work • Workpiece held and mounted on lathe spindle which is revolved against cutting tool • Common operations • Straight turning, tapering, facing, drilling, boring, reaming, and thread cutting
Material in vise and saw blade brought into contact with work Material on table and brought into contact with continuous-cutting saw blade Two Types of Metal Saw • Reciprocating cutoff saw • Used to cut work to length only • Bandsaw • Horizontal • Used to cut work to length • Vertical • Used to cut work to length and shape
Milling Machine • Two types: horizontal and vertical milling • Use one or more rotating milling cutters with single or multiple cutting edges • Workpiece fed into revolving cutter • Accessories allow wide variety of operations • Drilling, reaming, boring, counterboring and spot facing
Grinder • Use abrasive cutting tool on workpiece • Bring to accurate size • Produce high surface finish • Surface of work brought into contact with revolving grinding wheel
Common Types of Grinders • Surface • Used to produce flat, angular, or contoured surfaces • Cylindrical • Used to produce internal and external diameters • Cutter and Tool • Used to sharpen milling machine cutters • Bench or Pedestal • Used for offhand grinding and sharpening
Special Machine Tools • Designed to perform all operations necessary to produce single component • Include • Gear-generating machines • Centerless, cam and thread grinders • Turret lathes • Automatic screw machines
CNC Equivalent of Engine Lathe • Capable of machining round parts in one sixth time of skilled machinist • Two centers • Chucking • Designed to machine parts in a chuck (holding and driving device) • Turning • Designed mainly for shaft-type workpieces supported by some type of tailstock center
Robotics • One of fastest-growing areas of manufacturing industry • Numerical control applied to robots • Capable of handling materials and changing machine tool accessories easily and efficiently
Lasers • Used increasingly for cutting and welding • Used in sensing devices for extremely accurate measuring and surveying • Used for many materials beyond metals