Nazlyatul fizar

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Nama : Nazlyatul Fizar bt. Zainuddin

No. Kad Pengenalan : 900530-08-6360

Opsyen : PPISMP RBT/BI/BM 1

Hand Tools Images

Adjustable Spanner

http://www.flickr.com/photos/keith-merriman/353178817/

Hammer

http://www.agrabilityproject.org/search/showpic.cfm?picname=OXO+GRIP+HAMMER.JPG&product

=Oxo+Good+Grips+16+oz.+Hammer

Screwdriver

http://www.flickr.com/photos/axle-13/427515438/

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Wrench

http://www.istockphoto.com/file_closeup.php?id=40650

Chisel

http://www.hcwg.org/howto/Dovetails/FavoriteChisel.htm

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ADJUSTABLE SPANNERhttp://en.wikipedia.org/wiki/Adjustable_spanner

An adjustable spanner, shifting spanner, shifter, crescent wrench oradjustable-

angle head wrench (American English) is a tool which can be used to loosen or

tighten a nut orbolt. It has a "jaw" (the part into which the nut or bolt goes) which isof adjustable size, which allows for different size nuts and bolts to be handled by the

same spanner. Compare this to the ordinary spannerwhich has a fixed size. In France

it is called an "English Key" and in Denmark it is called a "Swedish Key".

There are many forms of adjustable spanners, from the taper locking spanners which

needed a hammer to set the movable jaw to the size of the nut, to the modern screw

adjusted spanner.

There is a class of adjustable that automatically adjust to the size of the nut. The most

modern are digital types that use sheets or feelers to set the size, and other simpler

models that use a serrated edge to lock the movable jaw to size.

It is uncertain who invented the adjustable spanner. Some early spanners were

inventedby Edwin Beard Budding (17951846) using a screw to replace the wedge

that fixed the jaw of a known type of adjustable spanner, and Johan Petter Johansson

of Sweden in 1892 using a screw to adjust and fix the jaw.[1] Monkey wrenches are

another type of adjustable wrench with a long history; the origin of the name is

unclear

Proper Use

The movable jaw should be snugly adjusted to the nut or bolt head in order to prevent

rounding. In addition it's important to ensure that the movable jaw is located on the

side towards which the rotation is to be performed. This reduces the risk of

deformation of the movable jaw or the adjusting mechanism, thus avoiding the

increase of backlash.

This type of wrench should never be used on a rounded off nut, as this can overload

the movable jaw. Nor should the wrench be used "end on" in cramped quarters, where

a socket wrench is more appropriate.

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Hammerhttp://en.wikipedia.org/wiki/Hammer

A hammer is a tool meant to deliver an impact to an object. The most common uses

are for driving nails, fitting parts, and breaking up objects. Hammers are often

designed for a specific purpose, and vary widely in their shape and structure. Usual

features are a handle and a head, with most of the weight in the head. The basicdesign is hand-operated, but there are also many mechanically operated models for

heavier uses.

The hammer is a basic tool of many professions, and can also be used as a weapon.

By analogy, the name hammer has also been used for devices that are designed to

deliver blows, e.g. in the caplock mechanism offirearms.

History

The use of simple tools dates to about 2,400,000 BCE when various shaped stones

were used to strike wood,bone, or other stones to and break them apart and shape

them. Stones attached to sticks with strips of leather or animal sinew were being usedas hammers by about 30,000 BCE during the middle of the Paleolithic Stone Age. Its

archeological record means it is perhaps the oldest human tool known.

Design and Variations

The essential part of a hammer is the head, a compact solid mass that is able to deliver

the blow to the intended target without itself deforming.

The opposite side of a ball as in theball-peen hammerand the cow hammer. Some

upholstery hammers have a magnetized appendage, to pick up tacks. In the hatchet the

hammer head is secondary to the cutting edge of the tool.

In recent years the handles have been made of durable plastic or rubber. The hammer

varies at the top, some are larger than others giving a larger surface area to hit

different sized nails and such,

Popular hand-powered variations include:

carpenter's hammers (used for nailing), such as the framing hammerand the

claw hammer

upholstery hammer construction hammers, including the sledgehammer

drilling hammer - a lightweight, short handled sledgehammer

Ball-peen hammer, or mechanic's hammer

cross-peen hammer, or Warrington hammer

mallets, including the rubber hammer and dead blow hammer.

Splitting maul

stonemason's hammer

Geologist's hammeror rock pick

lump hammer, or club hammer

gavel, used by judges and presiding authorities in general

Tinner's Hammer

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Mechanically-powered hammers often look quite different from the hand tools, but

nevertheless most of them work on the same principle. They include:

jackhammer

steam hammer

trip hammer

hammer drill, that combines a jackhammer-like mechanism with a drill

In professional framingcarpentry, the hammer has almost been completely replaced

by the nail gun. In professional upholstery, its chief competitor is the staple gun.

Tools use in conjuction with hammer.

Woodsplitting wedge - hit with a sledgehammer for splitting wood.

Woodsplitting maul - can be hit with a sledgehammer for splitting wood. Masonry star drill

Chisel

Punch

Anvil

The physics of hammer

Hammer as a force amplifier

A hammer is basically a forceamplifierthat works by converting mechanical work

into kinetic energy and back.

In the swing that precedes each blow, a certain amount of kinetic energy gets stored in

the hammer's head, equal to the lengthD of the swing times the forcefproduced bythe muscles of the arm and by gravity. When the hammer strikes, the head gets

stopped by an opposite force coming from the target; which is equal and opposite to

the force applied by the head to the target. If the target is a hard and heavy object, or if

it is resting on some sort ofanvil, the head can travel only a very short distance d

before stopping. Since the stopping forceFtimes that distance must be equal to thehead's kinetic energy, it follows thatFwill be much greater than the original driving

forcef roughly, by a factorD/d. In this way, great strength is not needed to produce

a force strong enough to bend steel, or crack the hardest stone.

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Effect of the head's mass

The amount of energy delivered to the target by the hammer-blow is equivalent to one

half the mass of the head times the square of the head's speed at the time of impact (

). While the energy delivered to the target increases linearly with mass, it

increases geometrically with the speed (see the effect of the handle, below). High tech

titanium heads are lighter and allow for longer handles, thus increasing velocity and

delivering more energy with less arm fatigue than that of a steel head hammer of the

same weight. As hammers must be used in many circumstances, where the position of

the person using them cannot be taken for granted, trade-offs are made for the sake of

practicality. In areas where one has plenty of room, a long handle with a heavy head

(like a sledge hammer) can deliver the maximum amount of energy to the target. But

clearly, it's unreasonable to use a sledge hammer to drive upholstery tacks. Thus, theoverall design has been modified repeatedly to achieve the optimum utility in a wide

variety of situations.

Effect of the handle

The handle of the hammer helps in several ways. It keeps the user's hands away from

the point of impact. It provides a broad area that is better-suited for gripping by the

hand. Most importantly, it allows the user to maximize the speed of the head on each

blow. The primary constraint on additional handle length is the lack of space in which

to swing the hammer. This is why sledge hammers, largely used in open spaces, can

have handles that are much longer than a standard carpenter's hammer. The secondmost important constraint is more subtle. Even without considering the effects of

fatigue, the longer the handle, the harder it is to guide the head of the hammer to its

target at full speed. Most designs are a compromise between practicality and energy

efficiency. Too long a handle: the hammer is inefficient because it delivers force to the

wrong place, off-target. Too short a handle: the hammer is inefficient because it

doesn't deliver enough force, requiring more blows to complete a given task.

Recently, modifications have also been made with respect to the effect of the hammer

on the user. A titanium head has about 3% recoil and can result in greater efficiency

and less fatigue when compared to a steel head with about 27% recoil. Handles made

of shock-absorbing materials or varying angles attempt to make it easier for the user

to continue to wield this age-old device, even as nail guns and other powered driversencroach on its traditional field of use.

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Screwdriverhttp://en.wikipedia.org/wiki/Screwdriver

The screwdriver is a device specifically designed to insert and tighten, or to loosen

and remove, screws. The screwdriver is made up of a head or tip, which engages with

a screw, a mechanism to apply torque by rotating the tip, and some way to position

and support the screwdriver. A typical hand screwdriver comprises an approximately

cylindrical handle of a size and shape to be held by a human hand, and an axial shaft

fixed to the handle, the tip of which is shaped to fit a particular type of screw. The

handle and shaft allow the screwdriver to be positioned and supported and, when

rotated, to apply torque. Screwdrivers are made in a variety of shapes, and the tip can

be rotated manually or by an electric or othermotor.

A screw has a head with a contour such that an appropriate screwdriver tip can be

engaged in it in such a way that the application of sufficient torque to the screwdriver

will cause the screw to rotate.

History

Gunsmiths still refer to a screwdriver as a "turnscrew", under which name it is an

important part of a set of pistols. The name was common in earlier centuries, used by

cabinet makers and shipwrights and perhaps other trades.

The Cabinet-Maker's screwdriver is one of the longest-established handle forms,

somewhat oval or elipsoid in cross section. This is variously attributed to improving

grip or preventing the tool rolling off the bench, but there is no reason to suppose

these are not rationalisations. The shape has been popular for a couple of hundred

years. It is usually associated with a plain head for slotted screws, but has been used

with many head forms.

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Types and Variations

There are many types of screw heads, of which the most common are the slotted,

Phillips, PoziDriv/SupaDriv (crosspoint), Robertson, TORX, and Allen (hex).

Screwdrivers come in a large variety of sizes to match those of screws, from tiny

jeweler's screwdrivers up.

If a screwdriver that is not the right size and type for the screw is used, it is likely that

the screw will be damaged in the process of tightening it. This is less important for

PoziDriv and SupaDriv, which are designed specifically to be more tolerant of size

mismatch. When tightening a screw with force, it is important to press the head hard

into the screw, again to avoid damaging the screw.

Some manual screwdrivers have a ratchet action whereby the screwdriver blade is

locked to the handle for clockwise rotation, but uncoupled for counterclockwise

rotation when set for tightening screws; and vice versa for loosening.

Many screwdriver designs have a handle with detachable head (the part of the

screwdriver which engages with the screw), called bits as with drill bits, allowing a

set of one handle and several heads to be used for a variety of screw sizes and types.

This kind of design has allowed the development of electrically powered

screwdrivers, which, as the name suggests, use an electric motor to rotate the bit. In

such cases the terminology for power drills is used, e.g. "shank" or "collet". Some

drills can also be fitted with screwdriver heads.

Manual screw drivers with a spiral ratchet mechanism to turn pressure (linear

motion) into rotational motion also exist, and predate electric screwdrivers. The user

pushes the handle toward the workpiece, causing a pawl in a spiral groove to rotate

the shank and the removable bit. The ratchet can be set to rotate left or right with each

push, or can be locked so that the tool can be used like a conventional screwdriver.

Once very popular, these spiral ratchet drivers, using proprietary bits, have been

largely discontinued by manufacturers such as Stanley, although one can still find

them at vintage tool auctions. Companies such as Lara Specialty Tools now offer a

modernized version that uses standard 1/4-inch hex shank power tool bits. Since a

variety of drill bits are available in this format, it allows the tool to do double duty as

apush drill.

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A number of screwdrivers used to remove faulty electronics from a laptop computer

Many modern electrical appliances, if they contain screws at all, use screws with

heads other than the typical slotted or Phillips styles. TORX is one such pattern that

has become very widespread. The main cause of this trend is manufacturing

efficiency: TORX and other types are designed so the driver will not slip out of the

fastener as will a Phillips driver. (Slotted screws are rarely used in mass-produced

devices, since the driver is not inherently centered on the fastener). A

benefit/disadvantage of non-typical fasteners (depending on your point of view) is

that it can be more difficult for users of a device to disassemble it than if more-

common head types were used, but TORX and other drivers are widely available.

Specialized patterns of security screws are also used, such as the Gamebit head style

used in all Nintendo consoles, though drivers for most security heads are, again,

readily available.

While screwdrivers are designed for the above functions, they are commonly also

used as improvised substitutes for pry bars, levers, and hole punches, as well as other

tools.

There is no such thing as a "left-handed screwdriver", as the device can easily be

wielded in either hand. To be sent on an errand to find a left-handed screwdriver is

often a test of stupidity, or is used as a metaphor for something useless. The term

"Birmingham screwdriver" is used jokingly in the UK to denote a hammer or

sledgehammer.

The handle and shaft of screwdrivers have changed considerably over time. The

design is influenced by both purpose and manufacturing requirements. The "Perfect

Handle" screwdriver was first manufactured by HD Smith & Company that operated

from 1850 to 1900. Many manufacturers adopted this handle design world wide. The"Flat Bladed" screwdriver was another design composed of drop forged steel with

riveted wood handles?

Among slotted screwdrivers, there are a couple of major variations at the blade or bit

end involving the profile of the blade as viewed face-on. The more common type is

sometimes referred to as keystone, where the blade profile is slightly flared before

tapering off at the end. To maximize access in space-restricted applications, the same

edges for the cabinet variety, in contrast, are straight and parallel, meeting the end of

the blade at a right angle.

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MACHINES TOOLS IMAGESBandsaw

http://www.flickr.com/photos/steve555/1449696172/

Chainsaw

http://www.lowes.com/lowes/lkn?action=howTo&p=BuyGuide/Chainsaw.html

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BLOW Moulding Machines

http://www.flickr.com/photos/27524969@N07/2567229582/

Laser Cutting

http://www.fedcomfg.com/laser-cutting.php

MILLING Machines

http://www.likest.com/punching-machine

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Blow Mouldinghttp://en.wikipedia.org/wiki/Blow_Moulding

Blow molding, also known as blow forming, is a manufacturing process by which

hollowplastic parts are formed. In general, there are three main types of blow

molding: extrusion blow molding, injection blow molding, and stretch blow molding.

The blow molding process begins with melting down the plastic and forming it into a

parison or preform. The parison is a tube-like piece of plastic with a hole in one end in

which compressed air can pass through.

The parison is then clamped into a mold and air is pumped into it. The air pressure

then pushes the plastic out to match the mold. Once the plastic has cooled and

hardened the mold opens up and the part is ejected.

Extrusion blow moulding

In extrusion blow molding (EBM), plastic is melted and extruded into a hollow tube

(a parison). This parison is then captured by closing it into a cooled metal mold. Air is

then blown into the parison, inflating it into the shape of the hollowbottle,containeror part. After the plastic has cooled sufficiently, the mold is opened and the part is

ejected. Continuous and Intermittent are two variations of Extrusion Blow Molding.

In Continuous Extrusion Blow Molding the parison is extruded continuously and the

individual parts are cut off by the mold. In Intermittent or Accumulator Method, an

accumulator gathers melted plastic and when the previous mold has cooled and

enough plastic has accumulated, a rod pushes the melted plastic and forms the

parison.[1]

EBM processes may be either continuous (constant extrusion of the parison) or

intermittent. Types of EBM equipment may be categorized as follows:

Continuous extrusion equipment

rotary wheel blow molding systems

shuttle machinery

Intermittent extrusion machinery

reciprocating screw machinery

accumulator head machinery

Examples of parts made by the EBM process include dairy containers, shampoo

bottles, hoses/pipes, and hollow industrial parts such as drums.

Injection blow moulding

The process of injection blow molding (IBM) is used for the production of hollow

glass andplastic objects in large quantities. In the IBM process, the polymer is

injection molded onto a core pin; then the core pin is rotated to a blow molding station

to be inflated and cooled. This is the least-used of the three blow molding processes,

and is typically used to make small medical and single serve bottles. The process is

divided into three steps: injection, blowing and ejection

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The injection blow molding machine is based on an extruder barrel and screw

assembly which melts thepolymer. The molten polymer is fed into a manifold where

it is injected through nozzles into a hollow, heated preformmold. The preform mold

forms the external shape and is clamped around a mandrel (the core rod) which forms

the internal shape of the preform. The preform consists of a fully formed bottle/jar

neck with a thick tube of polymer attached, which will form the body.

The preform mold opens and the core rod is rotated and clamped into the hollow,

chilled blow mold. The core rod opens and allows compressed air into the preform,

which inflates it to the finished article shape.

After a cooling period the blow mold opens and the core rod is rotated to the ejection

position. The finished article is stripped off the core rod and leak-tested prior to

packing. The preform and blow mold can have many cavities, typically three to

sixteen depending on the article size and the required output. There are three sets of

core rods, which allow concurrent preform injection, blow molding and ejection.

Strecth blow moulding

In the stretch blow molding (SBM) process, the plastic is first molded into a

"preform" using the injection molded process. These preforms are produced with the

necks of thebottles, including threads (the "finish") on one end. These preforms are

packaged, and fed later (after cooling) into an EBM blow molding machine. In the

SBM process, the preforms are heated (typically using infrared heaters) above their

glass transition temperature, then blown using high pressure air intobottles using

metal blow molds. Usually the preform is stretched with a core rod as part of the

process. The stretching of some polymers, such as PET (Polyethylene terephthalate)

results in strain hardening of the resin, allowing the bottles to resist deforming under

the pressures formed by carbonated beverages, which typically approach 60 psi.The

main applications are bottles, jars and other containers.

Advantages of blow molding include: low tool and die cost; fast production rates;

ability to mold complex part; produces recyclable parts

Disadvantages of blow molding include: limited to hollow parts, wall thickness is

hard to control.

History of blow moulding

There has been evidence found suggesting that Egyptians and Babylonians blew

plastic materials, but Enoch Ferngren and William Kopitke were the first verifiedpeople who used the Blow Molding Process. The process principle comes from the

idea of blowing glass. Ferngren and Kopitke produced a blow molding machine and

sold it to Hartford Empire Company in 1937. This was the beginning of the

commercial blow molding process. During the 1940s the variety and amount of

products were still very limited and therefore blow molding did not take off until later.

Once the variety and production rates went up the amount of products created

followed soon there after. In the United States soft drink industry the amount of

plastic containers went from zero in 1977 to ten Billion in 1999. Today even a greater

amount of products are blown and it is expected to keep increasing.

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Laser Cuttinghttp://en.wikipedia.org/wiki/Laser_cutting

Laser cutting is a technology that uses a laserprogrammed by a computer to cut

materials, which is used in the production line and is typically used for industrial

manufacturing applications. Laser cutting works by directing the output of a high

power laser, by computer, at the material to be cut. The material then either melts,

burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high

quality surface finish. Industrial laser cutters are used to cut flat-sheet material as well

as structural and piping materials.

Comparison to mechanical cutting

Advantages of laser cutting overmechanical cutting vary according to the situation,

but two important factors are the lack of physical contact (since there is no cutting

edge which can become contaminated by the material or contaminate the material),

and to some extent precision (since there is no wear on the laser). There is also a

reduced chance of warping the material that is being cut, as laser systems have a smallheat-affected zone. Some materials are also very difficult or impossible to cut by more

traditional means. One of the disadvantages of laser cutting includes the high energy

required.

Types

Both gaseous CO2 and solid-stateNd:YAG lasers are used for cutting, in addition to

welding, drilling, surface treatment, and marking applications.[2]

Common variants of CO2 lasers include fast axial flow, slow axial flow, transverse

flow, and slab.

CO2 lasers are commonly "pumped" by passing a current through the gas mix (DC

Excited) or using radio frequency energy (RF excited). The RF method is newer and

has become more popular. Since DC designs require electrodes inside the cavity, they

can encounter electrode erosion and plating of electrode material on glassware and

optics. Since RF resonators have external electrodes they are not prone to those

problems.

In addition to the power source, the type of gas flow can affect performance as well.

In a fast axial flow resonator, the mixture of carbon dioxide, helium and nitrogen is

circulated at high velocity by a turbine or blower. Transverse flow lasers circulate the

gas mix at a lower velocity, requiring a simpler blower. Slab or diffusion cooled

resonators have a static gas field that requires no pressurization or glassware, leading

to savings on replacement turbines and glassware.

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Process

Laser cutters usually work much like a milling machinewould for working a sheet in

that the laser (equivalent to the mill) enters through the side of the sheet and cuts it

through the axis of the beam. In order to be able to start cutting from somewhere else

than the edge, a pierce is done before every cut. Piercing usually involves a high

power pulsed laser beam which slowly (taking around 5-15 seconds for half-inch

thickstainless steel, for example) makes a hole in the material.

There are many different methods in cutting using lasers, with different types used to

cut different material. Some of the methods are vaporization, melt and blow, melt

blow and burn, thermal stress cracking, scribing, cold cutting and burning stabilized

laser cutting.

Vaporization cutting

In vaporization cutting the focused beam heats the surface of the material to boilingpoint and generates a keyhole. The keyhole leads to a sudden increase in absorptivity

quickly deepening the hole. As the hole deepens and the material boils, vapor

generated erodes the molten walls blowing ejecta out and further enlarging the hole.

Non melting material such as wood, carbon and thermoset plastics are usually cut by

this method.

Melt and blow

Melt and blow or fusion cutting uses high pressure gas to blow molten material from

the cutting area, greatly decreasing the power requirement. First the material is heated

to melting point then a gas jet blows the molten material out of the kerf avoiding theneed to raise the temperature of the material any further. Materials cut with this

process are usually metals.

Thermal stress cracking

Brittle materials are particularly sensitive to thermal fracture, a feature exploited in

thermal stress cracking. A beam is focused on the surface causing localized heating

and thermal expansion. This results in a crack that can then be guided by moving the

beam. The crack can be moved in order of m/s. It is usually used in cutting of glass.

Burning stabilized laser gas cutting

Burning stabilized laser cutting is essentially oxygen cutting but with a laser beam as

the ignition source. This process can be used to cut very thick steel plates with

relatively little laser power.

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Machine configurations

There are generally three different configurations of industrial laser cutting machines:

Moving material, Hybrid, and Flying Optics systems. These refer to way that the laser

beam is moved over the material to be cut or processed. For all of these, the axes of

motion are typically designated X and Y.axis. If the cutting head may be controlled, itis designated as the Z-axis.

Moving material lasers have a stationary cutting head and move the material under it.

This method provides a constant distance from the laser generator to the workpiece

and a single point from which to remove cutting effluent. It requires fewer optics, but

requires moving the workpiece.

Hybrid lasers provide a table which moves in one axis (usually the X-axis) and move

the head along the shorter (Y) axis. This results in a more constant beam delivery path

length than a flying optic machine and may permit a simpler beam delivery system.

This can result in reduced power loss in the delivery system and more capacity perwatt than flying optics machines.

Flying optics lasers feature a stationary table and a cutting head (with laser beam) that

moves over the work piece in both of the horizontal dimensions. Flying-optics cutters

keep the workpiece stationary during processing, and often don't require material

clamping. The moving mass is constant, so dynamics aren't affected by varying size

and thickness of workpiece. Flying optics machines are the fastest class of machines,

with higher accelerations and peak velocities than hybrid or moving material systems.

Dual Pallet Flying Optics Laser

Flying optic machines must use some method to take

into account the changing beam length from near field

(close to resonator) cutting to far field (far away from

resonator) cutting. Common methods for controlling this include collimation, adaptive

optics or the use of a constant beam length axis.

The above is written about X-Y systems for cutting flat materials. The same

discussion applies to five and six-axis machines, which permit cutting formed

workpieces. In addition, there are various methods of orienting the laser beam to a

shaped workpiece, maintaining a proper focus distance and nozzle standoff, etc.

Milling machines

http://en.wikipedia.org/wiki/Milling_machine

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A milling machine is a machine tool used for the shaping ofmetal and othersolid

materials. Its basic form is that of a rotating cutter which rotates about the spindle axis

(similar to a drill), and a table to which the workpiece is affixed. In contrast to

drilling, where the drill is moved exclusively along its axis, the milling operation

involves movement of the rotating cutter sideways as well as 'in and out'. The cutter

and workpiece move relative to each other, generating a toolpath along which material

is removed. The movement is precisely controlled, usually with slides and leadscrews

or analogous technology. Often the movement is achieved by moving the table while

the cutter rotates in one place, but regardless of how the parts of the machine slide, the

result that matters is the relative motion between cutter and workpiece. Milling

machines may be manually operated, mechanically automated, or digitally automated

via computer numerical control (CNC).

Milling machines can perform a vast number of operations, some of them with quite

complex toolpaths, such as slot cutting, planing, drilling, diesinking, rebating, routing,

etc. Cutting fluid is often pumped to the cutting site to cool and lubricate the cut, and

to sluice away the resulting swarf

Types of milling machinesThere are many ways to classify milling machines, depending on which criteria are

the focus:

CriterionExample classification

schemeComments

Control

Manual;

Mechanically automated via

cams;

Digitally automated via

NC/CNC

In the CNC era, a very basic distinction is manual

versus CNC.

Among manual machines, a worthwhile distinction is

non-DRO-equipped versus DRO-equipped

Control (specificallyamong CNC

machines)

Number of axes (e.g., 3-axis, 4-

axis, or more);Within this scheme, also:

Pallet-changing

versus non-pallet-

changing

Full-auto tool-

changing versus semi-

auto or manual tool-

changing

Spindle axis

orientation

Vertical versus horizontal;

Turret versus non-turret

Among vertical mills, "Bridgeport-style" is a whole

class of mills inspired by the Bridgeport original

Purpose

General-purpose versus

special-purpose or single-

purpose

PurposeToolroom machine versus

production machineOverlaps with above

Purpose "Plain" versus "universal"

A distinction whose meaning evolved over decades as

technology progressed, and overlaps with other purpose

classifications above; more historical interest than

current

Size

Micro, mini, benchtop,

standing on floor, large, very

large, gigantic

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Power source

Line-shaft-driveversusindividual electric motor drive

Most line-shaft-drive machines, ubiquitous circa 1880-

1930, have been scrapped by now

Hand-crank-power versus

electric

Hand-cranked not used in industry but suitable for

hobbyist micromills

Comparing vertical with horizontal

In the vertical mill the spindle axis is vertically oriented. Milling cuttersare held inthe spindle and rotate on its axis. The spindle can generally be extended (or the table

can be raised/lowered, giving the same effect), allowing plunge cuts and drilling.

There are two subcategories of vertical mills: the bedmill and the turret mill. Turret

mills, like the ubiquitous Bridgeport, are generally smaller than bedmills, and are

considered by some to be more versatile. In a turret mill the spindle remains

stationary during cutting operations and the table is moved both perpendicular to and

parallel to the spindle axis to accomplish cutting. In the bedmill, however, the table

moves only perpendicular to the spindle's axis, while the spindle itself moves parallel

to its own axis. Also of note is a lighter machine, called a mill-drill. It is quite popular

with hobbyists, due to its small size and lower price. These are frequently of lower

quality than other types of machines, however.

A horizontal mill has the same sort ofxy table, but the cutters are mounted on a

horizontal arbor across the table. A majority of horizontal mills also feature a +15/-15

degree rotary table that allows milling at shallow angles. While endmills and the other

types of tools available to a vertical mill may be used in a horizontal mill, their real

advantage lies in arbor-mounted cutters, called side and face mills, which have a cross

section rather like a circular saw, but are generally wider and smaller in diameter.

Because the cutters have good support from the arbor, quite heavy cuts can be taken,

enabling rapid material removal rates. These are used to mill grooves and slots. Plain

mills are used to shape flat surfaces. Several cutters may be ganged together on the

arbor to mill a complex shape of slots and planes. Special cutters can also cut grooves,bevels, radii, or indeed any section desired. These specialty cutters tend to be

expensive. Simplex mills have one spindle, and duplex mills have two. It is also easier

tocut gears on a horizontal mill.

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A miniature hobbyist mill plainly showing the basic parts of a mill.

Other milling machine variants and terminology

Box orcolumn mills are very basic hobbyist bench-mounted milling machinesthat feature a head riding up and down on a column or box way.

Turretorvertical ram mills are more commonly referred to as Bridgeport-type

milling machines. The spindle can be aligned in many different positions for a

very versatile, if somewhat less rigid machine.

Knee millorknee-and-column millrefers to any milling machine whose x-y

table rides up and down the column on a vertically adjustable knee. This

includes Bridgeports.

C-Frame mills are larger, industrial production mills. They feature a knee and

fixed spindle head that is only mobile vertically. They are typically much more

powerful than a turret mill, featuring a separate hydraulic motor for integral

hydraulic power feeds in all directions, and a twenty to fifty horsepowermotor. Backlash eliminators are almost always standard equipment. They use

large NMTB 40 or 50 tooling. The tables on C-frame mills are usually 18" by

68" or larger, to allow multiple parts to be machined at the same time.

Planer-style mills are large mills built in the same configuration asplaners

except with a milling spindle instead of a planing head. This term is growing

dated as planers themselves are largely a thing of the past.

Bed mill refers to any milling machine where the spindle is on a pendant that

moves up and down to move the cutter into the work. These are generally

more rigid than a knee mill.

Ram type mill refers to a mill that has a swiveling cutting head mounted on a

sliding ram. The spindle can be oriented either vertically or horizontally, oranywhere in between. Van Norman specialized in ram type mills through most

of the 20th century, but since the advent of CNC machines ram type mills are

no longer made.

Jig borers are vertical mills that are built to bore holes, and very light slot or

face milling. They are typically bed mills with a long spindle throw. The beds

are more accurate, and the handwheels are graduated down to .0001" for

precise hole placement.

Horizontal boring mills are large, accurate bed horizontal mills that

incorporate many features from various machine tools. They are

predominantly used to create large manufacturing jigs, or to modify large, highprecision parts. They have a spindle stroke of several (usually between four

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and six) feet, and many are equipped with a tailstock to perform very long

boring operations without losing accuracy as the bore increases in depth. A

typical bed would have X and Y travel, and be between three and four feet

square with a rotary table or a larger rectangle without said table. The pendant

usually has between four and eight feet in vertical movement. Some mills have

a large (30" or more) integral facing head. Right angle rotary tables and

vertical milling attachments are available to further increase productivity.

Floor mills have a row of rotary tables, and a horizontal pendant spindle

mounted on a set of tracks that runs parallel to the table row. These mills have

predominantly been converted to CNC, but some can still be found (if one can

even find a used machine available) under manual control. The spindle

carriage moves to each individual table, performs the machining operations,

and moves to the next table while the previous table is being set up for the

next operation. Unlike any other kind of mill, floor mills have floor units that

are entirely movable. A crane will drop massive rotary tables , X-Y tables , and

the like into position for machining, allowing the largest and most complex

custom milling operations to take place.

Portical mills It has the spindle mounted in a T structure

Computer numerical control

Thin wall milling ofaluminum using a water based coolant on the milling cutter

Most CNCmilling machines (also called machining centers) are computer controlled

vertical mills with the ability to move the spindle vertically along the Z-axis. This

extra degree of freedom permits their use in diesinking, engraving applications, and

2.5D surfaces such as reliefsculptures. When combined with the use ofconicaltools

or aball nose cutter, it also significantly improves milling precision without

impacting speed, providing a cost-efficient alternative to most flat-surface hand-

engraving work.

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Five-axis machining center with rotating table and computer interface

CNC machines can exist in virtually any of the forms of manual machinery, like

horizontal mills. The most advanced CNC milling-machines, the 5-axis machines, add

two more axes in addition to the three normal axes (XYZ). Horizontal milling

machines also have a C or Q axis, allowing the horizontally mounted workpiece to be

rotated, essentially allowing asymmetric and eccentricturning. The fifth axis (B axis)

controls the tilt of the tool itself. When all of these axes are used in conjunction with

each other, extremely complicated geometries, even organic geometries such as a

human head can be made with relative ease with these machines. But the skill toprogram such geometries is beyond that of most operators. Therefore, 5-axis milling

machines are practically always programmed withCAM.

With the declining price of computers, free operating systems such as Linux, and open

sourceCNC software, the entry price of CNC machines has plummeted. For example,

Sherline, Prazi, and others make desktop CNC milling machines that are affordable by

hobbyists.

High speed steelwith cobalt endmills used for cutting operations in a milling

machine.

Milling machine tooling

There is some degree of standardization of the tooling used with CNC Milling

Machines and to a much lesser degree with manual milling machines.

CNC Milling machines will nearly always use SK (or ISO), CAT, BT or HSK tooling.

SK tooling is the most common in Europe, while CAT tooling, sometimes called V-

Flange Tooling, is the oldest variation and is probably still the most common in the

USA. CAT tooling was invented byCaterpillar Inc. ofPeoria, Illinois in order to

standardize the tooling used on their machinery. CAT tooling comes in a range of

sizes designated as CAT-30, CAT-40, CAT-50, etc. The number refers to the

Association for Manufacturing Technology(formerly the National Machine Tool

Builders Association (NMTB)) Taper size of the tool.

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CAT-40 Toolholder

An improvement on CAT Tooling is BT Tooling, which looks very similar and can

easily be confused with CAT tooling. Like CAT Tooling, BT Tooling comes in a range

of sizes and uses the same NMTB body taper. However, BT tooling is symmetrical

about the spindle axis, which CAT tooling is not. This gives BT tooling greater

stability and balance at high speeds. One other subtle difference between these two

toolholders is the thread used to hold the pull stud. CAT Tooling is all Imperial thread

and BT Tooling is all Metric thread. Note that this affects the pull stud only, it does

not affect the tool that they can hold, both types of tooling are sold to accept both

Imperial and metric sized tools.

SK and HSK tooling, sometimes called "Hollow Shank Tooling", is much more

common in Europe where it was invented than it is in the United States. It is claimed

that HSK tooling is even better than BT Tooling at high speeds. The holding

mechanism for HSK tooling is placed within the (hollow) body of the tool and, asspindle speed increases, it expands, gripping the tool more tightly with increasing

spindle speed. There is no pull stud with this type of tooling.

The situation is quite different for manual milling machines there is little

standardization. Newer and larger manual machines usually use NMTB tooling. This

tooling is somewhat similar to CAT tooling but requires a drawbarwithin the milling

machine. Furthermore, there are a number of variations with NMTB tooling that make

interchangeability troublesome.

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Boring head on Morse Taper Shank

Two other tool holding systems for manual machines are worthy of note: They are the

R8 collet and the Morse Taper#2 collet. Bridgeport Machines ofBridgeport,Connecticut so dominated the milling machine market for such a long time that their

machine "The Bridgeport" is virtually synonymous with "Manual milling machine."

The bulk of the machines that Bridgeport made from about 1965 onward used an R8

collet system. Prior to that, the bulk of the machines used a Morse Taper #2 collet

system.

As an historical footnote: Bridgeport is now owned by Hardinge BrothersofElmira,

New York.

MACHINES

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