fundamentals of cam (1)

8/12/2019 Fundamentals of CAM (1)

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undamentals of Manufacturing


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Course Agenda

Historical Overview

Manufacturing Process Classification

Primary Processes

Secondary ProcessesPrimary Processes

Forging

Casting

Powder Metallurgy

Secondary Processes

Drilling

Milling

Turning

Developing a Process Plan


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Historical Overview

Manufacturingis the production of goods for use or saleusing:

Labor and Machines

Tools

Chemical and biological processing

Formulation

Evolution of Manufacturing:

Concept of Lean Manufacturing:

Reducing Waste

Increasing Efficiency

Seeking Employee Input

Without Breaks

Shift Changes

Pays or Benefits


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Primary Process - Casting

Castingis a manufacturing process by which a liquid material is usually poured into

a mold, which contains a hollow cavity of the desired shape, and then allowed to

solidify. The solidified part is also known as a casting, which is ejected or broken out of

the mold to complete the process.

Casting is most often used for making complex shapes that would be otherwise

difficult or uneconomical to make by other methods.


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Primary Process - Forging

Forgingis a manufacturing process involving the shaping of metal using localized

compressive forces. Forging is often classified according to the temperature at which

it is performed: "cold or "hot" forging.


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Why use Castings?

We use castings for a wide range of wear parts and components that are too large, complicated,

or otherwise unsuitable for the forging process. We can forge parts up to 50kgs but the sheer

energy required to forge larger items make casting a much more viable alternative.

The casting process better lends itself to making parts where internal cavities are required.

The advantages of casting include:

No real upper size limit in casting weight.

Large range of alloy choices.

As forgings remain solid, custom alloys are far more difficult to get

into production whereas with casting, alloys including Chrome,Nickel and Moly can be added at the molten stage.

Tooling is often less expensive than forge dies.

Smaller production runs required.

Complicated/complex parts are no problem.


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Why use Forgings?

Forging offers uniformity of composition and structure. Forging results in metallurgical re-

crystallisation and grain refinement as a result of the thermal cycle and deformation process.

This strengthens the resulting steel product particularly in terms of impact and shear strength.

Forged steel is generally stronger and more reliable than castings and plate steel due to the fact

that the grain flows of the steel are altered, conforming to the shape of the part.

The advantages of forging include:

Generally tougher than alternatives

Will handle impact better than castings

The nature of forging excludes the occurrence of porosity, shrinkage, cavities and cold

pour issues.

The tight grain structure of forgings making it mechanically strong. There is less need forexpensive alloys to attain high strength components.

The tight grain structure offers great wear resistance without the need to make products

super hard We have found that, on a blank HRC 38-42 forged grinder insert wear/wash

is about the same as a high alloy HRC 46-50 cast grinder insert. The difference being a

HRC 46-50 casting does not have the ductility to handle high impact grinding.


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Primary Process Powder Metallurgy

Powder metallurgyis the process of blending fine powdered materials, pressing theminto a desired shape or form (compacting), and then heating the compressed material

in a controlled atmosphere to bond the material (sintering).

The powder metallurgy process generally consists of four basic steps: powder

manufacture, powder blending, compacting, and sintering. Compacting is generally

performed at room temperature, and the elevated-temperature process of sintering is

usually conducted at atmospheric pressure


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Secondary Process - Drilling

Drillingis a cutting process that uses a drill bit to cut or enlarge a

hole of circular cross-section in solid materials. The drill bit is arotary cutting tool, often multipoint.

The bit is pressed against the workpiece and rotated at rates

from hundreds to thousands of revolutions per minute. This

forces the cutting edge against the workpiece, cutting off chips

from what will become the hole being drilled.


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Spot drilling:

The purpose of spot drilling is to drill a hole that will act as a

guide for drilling the final hole. The hole is only drilled part way

into the workpiece because it is only used to guide the beginning

of the next drilling process.


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Drilling Deep Holes:When the depth of the hole being drilled is four times the diameter of the drill itself, remove the

drill at frequent intervals and clean the chips from the flutes of the drill and

from the hole being drilled.

Peck drilling, or the practice of drilling a short distance,

then withdrawing the drill, will reduce the chip packing.

The deeper the hole, the more will be the machining time.

Used when depth of drill is greater than 3 times the drill

diameter.

Breakchip Drilling or high speed peck drilling,

similar to peck drilling but in this case the tool does

not retrieve completely out of the workpiece.


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Counterboring This process creates a stepped hole in

which a larger diameter follows a smaller diameter

partially into a hole.

Countersinking This process is similar to

counterboring but the step in the hole is cone-

shaped.


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Spot Facing: This process is used for cleaning the top of a

surface so that a fastener can sit on it. This process is

usually done on casting or forging which has uneven top

surface

TappingThis process is used to create internal

threads on a circular hole.


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Drilling Tools: Twist Drills

Twist drills are the most common cutting tools used with drilling machines. Twist

drills are designed to make round holes quickly and accurately in all materials.

They are called twist drills mainly because of the helical flutes or grooves that

wind around the body from the point to the neck of the drill and appear to betwisted (Figure 1). Twist drills are simply constructed but designed very tough to

withstand the high torque of turning, the downward pressure on the drill, and the

high heat generated by friction.


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Countersink tools:

Are special angled cutters used to countersink holes

for flathead screws so they are flush with pilot to

guide the cutting action to enlarge a portion of a hole.

Counterbore tools:

Are special cutters that use a pilot to guide the cutting

action to enlarge a portion of a hole. Common uses are for

enlarging a hole to make a bolt head fit flush with the

surface.

Reamers:Reamers are cutting tools that are used to enlarge a drilled

hole by a few thousandths of an inch for a precise fit.


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Some Useful tips:The drilling process, or complete operation, involves selecting the proper twist drill or cutter forthe job, properly installing the drill into the machine spindle, setting the speed and feed, starting

the hole on center, and drilling the hole to specifications within the prescribed tolerance.

Selecting the Drill:

Proper selection of drill depends on the following

parameters:

The material to be drilled,

The size of that material, andThe size of the drilled hole


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Selection of Drill Speed:Correct speeds are essential for satisfactory drilling. The speed at which a drill turns and

cuts is called the peripheral speed. Peripheral speed is the speed of a drill at its

circumference expressed in surface feet per minute (SFPM). This speed is related to the

distance a drill would travel if rolled on its side.

As a general rule, the harder the material, the slower should be the speed used.

It has been determined through experience and experiment that various metals machine

best at certain speeds; this best speed for any given metal is what is known as its cutting

speed (CS).

If the cutting speed of a material is known, then a simple formula can be used to

find the recommended RPM of the twist drill.

RPM=CSx4/D (Imperial), RPM=CSX320/D (Metric)

RPM = drill speed in revolution per minute

CS = recommended cutting speed

D = diameter of the drill


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Selection of Drill Feed:Feed is the distance a drill travels into the workpiece during each revolution of the spindle.

It is expressed in thousandths of an inch or in millimeters. Hand-feed drilling machines have

the feed regulated by the hand pressure of the operator; thus, the skill of the operator will

determine the best feeds for drilling. Power feed drilling machines have the ability to feed

the drill into the work at a preset depth of cut per spindle revolution, so the best feeding

rate can be determined.

The selection of the best feed depends upon the size of the drill, the material to be drilled,

and the condition of the drilling machine. Feed should increase as the size of the drill

increases.

The feed rate must be reduced when drilling into curved or sloped surfaces, drilling across

another hole or enlarging an already drilled hole.

Excessive feed rate can cause chipping or fracture of the cutting edge as well as splitting of

the drills web.

Overtime the cutting edge of the drill becomes blunt this could result in over sizing of the

drilled hole.


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Recommended average feedrates for 2 flutes HSS Drills

Recommended HSS Speeds for common materials

Note:

Remember that the speed and feed calculated using the

manufacturers empirical data (i.e. Tables 1 & 2) are the

optimum parameters. In other words, these are the

maximum speed and feedrate that could be used underperfect conditions.

Running a tool too slow will only decrease

productivity; however, running a tool too fast with

regard to speed or feedrate will result in accelerated

tool wear or outright failure.


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Tool Path Optimization:

Used for a more efficient tool path generation.

Dwell:

You can set the tool delay at depth of cut by number of seconds or revolutions

For the Peck Drill and Break Chip simulated cycles, if you specify a dwell value in seconds or

revolutions, the software generates a DELAY/t or DELAY/REV, r command statement to activate

the desired dwell after the tool has been fed to depth.


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Secondary Process - Turning

Lathes:

A lathe is a machine tool that rotates the workpiece against a tool. The spindle is the part of the

lathe that rotates. It is driven by an electric motor through a system of belt drives

and gear trains. Its rotational speed is controlled by varying the geometry of the drive train.

Lathe Specifications

A lathe is generally specified by:

Its swing, the maximum diameter of the

workpiece that can be machined.

The maximum distance between the

headstock and tailstock centres.

The length of the bed.


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Engine Lathes:

It is the basic, simplest and most versatile lathe. The

machine tool is manually operated that is why it

requires skilled operators. Used for low and medium

production and floor repair works.

Turret Lathes:These machines are capable of carrying out multiple

cutting operations on the same workpiece.

Several cutting tools are mounted on a tetra-, penta-, or

hexag tailstock. These tools can be rapidly brought into

action against the workpiece one by one by indexing

the turret.


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Special Purpose Lathes:

These lathe machines are used for applications

such as railroad wheels, gun barrel and rolling

mill rolls. The size of the workpiece is usually large in

these machines.

Automatic Lathes:In fully automatic lathes, parts are fed and removed

automatically, whereas in semiautomatic

lathes these functions are performed by the operator.

These machines may have horizontal or

vertical spindle and are suitable for medium to high

volume production.


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Work Holding Devices

A 3 jaw self-centering chuck is used for most operations oncylindrical work-parts. For parts with high length-to-diameter

ratio the part is supported by center on the other end.

Between two centres. The workpiece is driven by a device

called a dog; this method is suitable for parts with high length-

to-diameter ratio.

Collet consists of tubular bushing with longitudinal slits.

Collets are used to grasp and hold bar stock. A collet of exactdiameter is required to match any bar stock diameter.

A face plate is a device used to grasp parts with irregular

shapes.


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Lathe Chucks


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Lathe Chucks

Four Jaw Independent Chuck:

The independent chuck has four jaws which are adjusted

individually on the chuck face by means of adjusting screws. The

chuck face is scribed with concentric circles which are used for

rough alignment of the jaws when chucking round workpieces. The

final adjustment is made by turning the workpiece slowly and using

dial indicators to determine its concentricity and to the desired

tolerances.


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Lathe Chucks

Universal Scrol 3 Jaw Chuck

The advantage of the universal scroll chuck is its ease of

operation in centering the work for concentric turning. This

chuck is not as accurate as the independent chuck but, when in

good condition, it will centre the work automatically within0.003 of an inch of complete accuracy

Collet (Collet Chuck)

The collet chuck is the most accurate means of holding small

workpieces in the lathe. The collet chuck consists of a springmachine collet and a collet attachment which secures and

regulates the collet on the headstock spindle of the lathe. The

spring machine collet is a thin metal bushing with an accurately

machined bore and a tapered exterior. The collet has three

lengthwise slots to permit its sides to be sprung slightly inward

to grip the workpiece.


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Face Plates

Face Plate:

For turning, facing, boring, threading and similar operations,

jobs of odd shape and size are usually mounted on large face

plate (instead of chuck) being fitted on the spindle nose as

shown in Fig.The job may be (b) directly clamped on the face plate or (c) in

case of batch or small lot production, in a fixture which is

clamped on the face plate.


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Cutting Tools


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NX CAM Turning benefits

Automatic Detection of Cut Regions for roughing and finishing lets you obtain results morequickly, especially for successive operations.

Teachmode operations allow for maximum flexibility when you want to manually control the

tool to position.

Animation capabilities like material removal display in toolpath replay and 3D display of the In

Process Workpiece.

Better support in creating turning, milling and drilling operations in one programming sessionand for one machine tool.

Allows the creation of NC programs for multiple spindle setups. The system enables you to

successively plan your machining process for each individual subspindle group and then to

rearrange the order of operations.


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NX CAM Turning terminology

Geometry Containment:

Geometry Containment allows you to delimit machining to a

specific area of a part. The containment setting influences the

automatic cut region detection to prevent machining beyondthe specified limits. You can define containment using radial or

axial trim planes, trim points and trim angles.

Avoidance:

Avoidance geometry allows you to specify, activate or cancel

geometry that is used for non-cutting moves before or after a

tool path to avoid collisions with part or clamping devices


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Secondary Process - Milling

Milling:Milling is the process of machining flat, curved, or irregular surfaces by feeding the workpiece

against a rotating cutter containing a number of cutting edges.

Most Commonly used milling machines are Horizontal machining centre(HMC) and Vertical

Machining Centre (VMC).

Vertical Machining Centre:The plain vertical machines are characterized by a

spindle located vertically, parallel to the column face,and mounted in a sliding head that can be fed up and

down by hand or power. Modern vertical milling

machines are designed so the entire head can also

swivel to permit working on angular surfaces.


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Horizontal Machining Centre:The plain horizontal milling machines column contains

the drive motor and gearing and a fixed position

horizontal milling machine spindle.


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Conventional Milling (feed movement opposite

to tool rotation):is preferred when milling casting

or forging with rough surfaces.

Characteristics of Conventional Milling:

Width of chip starts from zero and increases.Tooth meets the workpiece at the bottom of

the cut.

Upward force tends to lift up workpiece.

More power requiredrubbing provoked by

chip beginning at minimum width.Surface finish spoiled due to chips being carried

up by the tooth.

Chips fall in front of cutterchip disposal

difficult.

Faster wear on tool than climb milling.

Cutting Methods


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Climb or Down Milling(feed movement and tool

rotation in same direction):is preferred when milling

heat treated alloys, stainless steel - reduces work

hardening. Climb milling way cause chipping in milling

hot rolled materials due to hardened layer on thesurface.

Characteristics of Climb Milling:

Width of chip starts at maximum and decreases.

Tooth meets workpiece at top of cut.

Easier chip disposal - chips removed behind cutter.Less wear - increases tool life up to 50%.

Improved surface finish - chips less like to be carried

by the tooth.

Less power required - cutter with high rake angle can

be used.

Cutting Methods


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Milling that uses entire

cutting edge

Cuts faces parallel to tool

axis

Cuts faces perpendicular to

tool axis

Planar Milling

Planar Milling Profile

Face Milling

Face Milling Area

Milling that cuts in Planar

Levels

Roughing Operation

Finishing Operation

For cutting Steep Walls

Cavity Milling

Rest Milling

Z - Level Milling

Surface Contouring with

Fixed Axis

Surface Contouring with

Variable Axis


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Planar Milling:Plain milling, also called surface milling or slab milling, is

milling flat surfaces with the milling cutter axis parallel to

the surface being milled. Generally, plain milling is done

with the workpiece surface mounted parallel to the surface

of the milling machine table and the milling cutter mounted

on a standard milling machine arbor.


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Face Milling:

Face milling is the milling of surfaces that are perpendicular

to the cutter axis, as shown in Figure 8-30. Face milling

produces flat surfaces and machines work to the required

length. In face milling, the feed can be either horizontal orvertical.

In face milling, the teeth on the periphery of the cutter do

practically all of the cutting. However, when the cutter is

properly ground, the face teeth actually remove a small

amount of stock which is left as a result of the springing of

the workpiece or cutter, thereby producing a finer finish.

It is important in face milling to have the cutter securely

mounted and to see that all end play or sloppiness in the

machine spindle is eliminated.


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Angular Milling:

Angular milling, or angle milling, is milling flat surfaces

which are neither parallel nor perpendicular to the axis of

the milling cutter. A single angle milling cutter is used for

angular surfaces, such as chamfers, serrations, and grooves.

Milling dovetails is a typical example of angular milling.

Straddle Milling:

When two or more parallel vertical surfaces are machinedat a single cut, the operation is called straddle milling.

Straddle milling is accomplished by mounting two side

milling cutters on the same arbor, set apart at an exact

spacing. Two sides of the workpiece are machined

simultaneously and final width dimensions are exactly

controlled.


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Gang Milling:Gang milling is the term applied to an operation in which

two or more milling cutters are mounted on the same arbor

and used when cutting horizontal surfaces. All cutters may

perform the same type of operation or each cutter may

perform a different type of operation. For example, several

workplaces need a slot, a flat surface, and an angular

groove.

The best method to cut these would be gang milling as

shown in Figure. All the completed workplaces would be the

same. Remember to check the cutters carefully for proper

size


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Form Milling:Form milling is the process of machining special contours

composed of curves and straight lines, or entirely of curves,

at a single cut. This is done with formed milling cutters,shaped to the contour to be cut. The more common form

milling operations involve milling half-round recesses and

beads and

quarter-round radii on workplaces . This operation is

accomplished by using convex, concave, and corner

rounding milling cutters ground to the desired circlediameter.


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Cavity Milling:Use Cavity Milloperations to remove large volumes of material.

Cavity Mill is ideal for rough-cutting parts, such as dies, castings,

and forgings. Cavity Mill removes material in planar levels that

are perpendicular to a fixed tool axis. Part Geometry can be

planar or contoured.


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Z-Level Milling:Use Z-Level Milling for fixed-axis semi-finishing and finishing. Z-Level Milling

maintains a near constant scallop height and chip load on steep walls and can be

especially effective for high speed machining:

With Z-Level Milling, you can do the following:

Profile the entire part, or specify Steep Containmentso that only areas with a

steepness greater than the specified angle are profiled.

Cut multiple levels in one operation.

Cut multiple features (regions) in one operation.

Cut by level (waterline) for thin-walled parts.

Maintain the tool in constant contact with the material. The following options let

you cut an entire region without lifting the cutter.

Level to LevelMixed Cut Direction

The steepness of the part at any given point is defined by the angle between the tool

axis and the normal of the face. When you specify Steep Containmentonly areas

with a steepness greater than the specified angle are profiled.


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Multi Blade Milling:

In Turbomachinery Milling, you use Multi Blade operations

to machine multiple blade parts, such as impellers orblisks, with or without splitters. Multi Blade Milling

operations are designed specifically for machining blade

type parts. They are the most efficient operations for

machining these types of parts.


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Cut patterns that remove material in parallel linear passes are:

Zig

Zig - Zag

Zig with Contour

Cut Pattern Categories

Cut patterns that remove a volume of material with a sequence of concentric

cutting passes that can progress inward or outward are:

Follow periphery

Follow Part

Thochoidal

Cut patterns that create one or more finish passes that follow the part walls

within open or closed regions:

Profile

Standard Drive


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Zig Cut Pattern:

The Zigcut pattern always cuts in one direction. The tool retracts

at the end of each cut, then moves to the start position for the

next cutting pass. Climb (or Conventional) cutting is maintained.

Cut Pattern details

Zig - Zag Cut Pattern:

The Zig Zagcut pattern machines in a series of parallel straight line

passes that cut in opposite directions while stepping over in one

direction. This cut pattern allows the tool to remain continually

engaged during stepovers.


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Zig with Contour Cut Pattern:

The Zig with Contourcut pattern machines with cuts going in one

direction. Contouring moves along the boundary are addedbefore and after the linear passes. At then end of the cutting

pass, the tool retracts and re-engages at the start of the

contouring move for the next cut. Climb (or Conventional) cutting

is maintained.

Cut Pattern details


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Follow Periphery Cut Pattern:

The Follow Peripherycut pattern cuts along offsets from the

outermost edge that is defined by part or blank geometry.

Internal islands and cavities require Island Cleanupor a clean upprofile pass. Climb (or Conventional) cutting is maintained.

Cut Pattern details

Follow Part Cut Pattern:

The Follow Partcut pattern cuts along concentric offsets from all

specified Part geometry. The outermost edge and all interior islands

and cavities are used to compute the tool path. This eliminates the

need for an island cleanup pass. Climb (or Conventional) cutting is

maintained.


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Trochoidal Cut Pattern:

Limit excess stepover to prevent tool breakage when the tool is fully embedded into a cut.

Avoid embedding the tool. Most cut patterns generate embedded regions between islands and

parts during the engage as well as in narrow areas.

Cut Pattern details


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The Profile Cut Pattern:

The Profilecut pattern machines along part walls with the side of

the tool to create a finishing pass. The tool follows the boundary

direction.

Cut Order

Cavity Milling and Planar Milling operations order cut traces by

cut region. Islands are treated as a single region, and all islands

are cut at the same level before proceeding to the next level.

Cut Pattern details

Standard Drive Cut Pattern:

The Standard Drivecut pattern creates profiling cuts along the

specified boundaries without automatic boundary trimming or

gouge checking. You can specify whether or not the tool path is

allowed to cross itself. This cut pattern is available in Planar Milling

only.


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Selecting Milling Cutter

In selecting a milling cutter for a particular job, choose one large enough to span the entire work

surface so the job can be done with a single pass. If this cannot be done, remember that a small

diameter cutter will pass over a surface in a shorter time than a large diameter cutter which is

fed at the same speed.

Selecting Speeds for Milling Cutter

The spindle RPM necessary to give a

desired peripheral speed depends on

the size of the milling cutter. The best

speed is determined by the kind of

material being cut and the size and typeof cutter used, width and depth of cut,

finish required, type of cutting fluid and

method of application, and power and

speed

available are factors relating to cutter

speed.


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Basic steps involved in developing a Process Plan

The development of a process plan involves a number of

activities :

Analysis of part requirements.

Selection of raw workpiece/material.

Determination of manufacturing operations and theirsequences.

Selection of machine tools.

Selection of tools, work-holding devices and inspection

equipment.

Determination of machining conditions (cutting speed,

feed and depth of cut) andmanufacturing times (setup time,processing time and lead time).



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Analysis of Part Requirements:At the engineering design level, the part

requirements are expressed through and as the

part features, dimensions and tolerance

specifications. These, in turn, dictate the

processing requirements. The analysis of the

finished part requirements is therefore the first

step in process planning. First, the design or

geometric features of the parts are analyzed.

Examples of these features are plane, cylinder,

cone, step, edge and fillet. Then, these common

features have to be translated into manufacturing

features, or machining features as in this case.



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Selection of Workpiece:Selection of raw workpiece is an important element of process planning. It

involves such attributes as shape, size (dimensions and weight) and material.

Determining manufacturing operations and their sequences:



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Selection of Machine tools: Workpiece-related attributes such as the material, kinds of features to be made,

dimensions of the workpiece, its dimensional tolerances and raw material form;

Machine tool-related attributes such as process capability, size, mode of

operation (e.g. manual, semiautomatic, automatic and numerically controlled),

the type of operation (e.g. turning, milling and grinding), tooling capabilities (e.g.

size and type of the tool magazine) and automatic tool-changing capabilities.Chapter VIII gives a detailed account of different types of machine tools.

Production volume-related information such as the production quantity and

order frequency.

On the whole, there are three basic criteria for evaluating

the suitability of a machine tool to accomplish an

operation. They are

Unit cost of productionManufacturing leadtimeQuality.



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Selecting Cutting Conditions:The first step in establishing the cutting conditions is to select the depth of cut.

The depth of cut will be limited by the amount of metal that is to be machined

from the workpiece, by the power available on the machine tool, by the rigidity of

the workpiece and the cutting tool, and by the rigidity of the setup. The depth of

cut has the least effect upon the tool life, so the heaviest possible depth of cutshould always be used.

The second step is to select the feed. The available power must be sufficient to

make the required depth of cut at the selected feed. The maximum feed possible

that will produce an acceptable surface finish should be selected.

The third step is to select the cutting speed. Most machining operations are

conducted on machine tools having a rotating spindle. Cutting speeds are usuallygiven in feet or metres per minute and these speeds must be converted to spindle

speeds, in rpm, to operate the machine.



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Some Basics of CNC Coding

Each block, or program line, contains addresseswhich appear in this order :

N , G , X , Y , Z , F , M , S , T ;

This order should be maintained throughout every

block in the program, although individual blocks may

not necessarily contain all these addresses.


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Preparatory FunctionsG Codes:

Preparatory functions, called G codes, are used to determine the geometry of tool

movements and operating state of the machine controller; functions such as linear

cutting movements, drilling operations and specifying the units of measurement.

Defining Units:G20Imperial

G21Metric

Coordinate System:

G90Absolute zero command

G91Incremental Command

Tool Movement:

Feed Function:

Miscellaneous Function: used as an On/Off command

Spindle Speed Function: The spindle speed value specified must fall between

the machine tool RPM range for the command to be effective.

Tool Function:


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G00

Non Linear InterpolationThe G00 code executes a non cutting

movement, at a rapid feedrate, to a specific

co-ordinate position in the working area.

NOTE 1.

The rate of movement is set by the manufacturer of the machine tool. The rateof movement can be reduced from 100% to 0%, but only in increments of 10%,

by using the feed override controls.


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G01

Linear Interpolation:

The G01 code executes a cutting movement

following a straight line, at a set feedrate.

A G01 command is written in the following

format:


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G02 & G03

Circular Interpolation:

G02 Clockwise interpolation

G03 Anti Clockwise direction

Used with G90 code

G01 X100 Y40 F125 ;

G03 X80 Y60 R-20 ;

G01 X60 ;

G02 X40 Y40 R-20 ;


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G04 - DwellThe G04 code is used to enter a set time delay into

the program (called a "dwell").

A G04 command is written in the following format:

G04 X _ _ _ _ ;

or G04 P _ _ _ _ ;

where the dwell value is programmed using the address letters X (time in seconds)

or P (time in 1/1000 seconds), followed by a number indicating this

dwell value.

For example :

G04 X1.5 ;

This command is read perform a dwell of 1.5 secondsduration.

G04 P2500 ;

This command is read perform a dwell of 2.5 seconds

duration.


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Defining Units:G20Imperial

G21Metric

The unit systems of the following items are changed

depending on whether G20 or G21 is set.

1) Positioning commands (X, Y and Z).

2) Incremental movement distances.3) Feedrates commanded by the F code.

4) Offset values.

G83 - Peck Drilling

G73High Speed Peck Drilling

G84

Taping

G94Feed per minute

G95Feed per Revolution


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Miscellaneous Codes

M00Program Stop

M02Program reset

M03Spindle Reset

M04Spindle Reverse

M05

Spindle Stop

M06Automatic Tool Change

M08Coolant Off

M09Coolant On

M13Spindle Forward Coolant On

M14

Spindle Reverse Coolant On

fundamentals of cam (1)

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