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MEPCO SCHLENK ENGINEERING COLLEGE, SIVAKASI

DEPARTMENT OF MECHANICAL ENGINEERING

V SEMESTER MECHANICAL ENGINEERING

July 2010 to Nov 2010

SUBJECT: ME59 – CAD/CAM LAB

LABORATORY MANUAL

Prepared by Approved by

Dr.T.Prabaharan

Professor / Mech.

Dr.R.Rajkumar HOD/Mech.

Professor / Mech.

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SYLLABUS

ME59 CAD/CAM LAB L T P C 0 0 3 2

OBJECTIVES:

- To be able to understand and handle design problems in a systematic manner.

- To gain practical experience in handling 2D drafting and 3D modeling software

systems.

- To be able to apply CAD in real life applications.

- To understand the concepts G and M codes and manual part programming.

- To expose students to modern control systems (Fanuc, Siemens etc)

- To know the application of various CNC machines

- To expose students to modern CNC application machines EDM, EDM wire cut and

Rapid Prototyping

UNIT I 3D GEOMETRIC MODELING

Creation of 3D Models - Wire Frame, Surface, Solid modeling Techniques Using CAD

Packages – CSG, B-Rep Approaches in Solid Modeling - Feature Based Modeling Technique

– Assembly – Detailing - Exposure to Industrial Components – Application of GD&T

UNIT II STL FILE GENERATION – REVERSE ENGINEERING

Manual CNC Part Programming Manual CNC Part Programming Using Standard G and M

Codes - Tool Path Simulation – Exposure to Various Standard Control Systems- Machining

simple components by Using CNC machines.

UNIT III COMPUTER AIDED PART PROGRAMMING

CL Data Generation by Using CAM Software– Post Process Generation for Different Control

System – Machining of Computer Generated Part Program by Using Machining Center and

Turning Center.

UNIT IV STUDY OF EXPERIMENTS

Multi-axial Machining in CNC Machining Center –EDM – EDM Wire Cut – Rapid

Prototyping

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LIST OF EXPERIMENTS

CAD

1. 3D – Part modeling of a component

2. 3D – Part modeling of a component

3. Assembly of Flange coupling in 3D using Solidworks modeling

software

4. Assembly of Plummer block in 3D using Solidworks modeling

software

CAM

1. Milling simulation using CAPSMILL software

2. Turing simulation using CAPSTURN software

3. Turning exercise in Production lathe using single tool

4. Milling exercise in Trainer Milling machine

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TENTATIVE SCHEDULE FOR CAD LAB

Experiment

Number

A1BATCH A2BATCH B1BATCH B2BATCH

Date of Date of Date of Date of

Experiment Record

Submission

Experiment Record

Submission

Experiment Record

Submission

Experiment Record

Submission

1 04-Aug-10 01-Sep-10 11-Aug-10 08-Sep-10 02-Aug-10 30-Aug-10 09-Aug-10 06-Sep-10

2 01-Sep-10 29-Sep-10 08-Sep-10 06-Oct-10 30-Aug-10 27-Sep-10 06-Sep-10 04-Oct-10

3 29-Sep-10 13-Oct-10 06-Oct-10 20-Oct-10 27-Sep-10 11-Oct-10 04-Oct-10 18-Oct-10

4 13-Oct-10 27-oct-10 20-Oct-10 03-Nov-10 11-Oct-10 25-Oct-10 18-Oct-10 01-Nov-10

TENTATIVE SCHEDULE FOR CAM LAB

Experiment

Number

A1BATCH A2BATCH B1BATCH B2BATCH

Date of Date of Date of Date of

Experiment Record

Submission

Experiment Record

Submission

Experiment Record

Submission

Experiment Record

Submission

1 11-Aug-10 08-Sep-10 04-Aug-10 01-Sep-10 09-Aug-10 06-Sep-10 02-Aug-10 30-Aug-10

2 08-Sep-10 06-Oct-10 01-Sep-10 29-Sep-10 06-Sep-10 04-Oct-10 30-Aug-10 27-Sep-10

3 06-Oct-10 20-Oct-10 29-Sep-10 13-Oct-10 04-Oct-10 18-Oct-10 27-Sep-10 11-Oct-10

4 20-Oct-10 03-Nov-10 13-Oct-10 27-Oct-10 18-Oct-10 01-Nov-10 11-Oct-10 25-Oct-10

Batch Roll Number

A1BATCH 08M01 – 08M16

A2BATCH 08M17 – 08M33

B1BATCH 08M34 – 08M49

B2BATCH 08M50 – 08M60 and 08ML01 - 08ML06

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INSTRUCTIONS TO STUDENTS

1. Students are required to remove their footwear outside the center and keep it in the box

provided for the same.

2. Students should leave their belongings outside the lab except their observation note

book, the concerned books/manuals and calculators.

3. Students are requested not to place their legs on the wall or on the table.

4. Students should refrain from leaning on the table and sitting on it.

5. Before logging in to a particular terminal, if there is something wrong in the terminal,

the student should report the same immediately to the concerned staff.

6. Students should not use any disks brought from outside without prior permission from

the concerned staff.

7. Students can get the required manual or disks from the staff after signing in the

appropriate register.

8. Students should collect their printouts before leaving the lab for that particular session.

9. Before leaving the Terminal, the students should logout properly and leave their chairs

in position.

10. Students are not allowed to take any manual outside the center.

11. Edibles are strictly prohibited in the center.

12. No internet browsing allowed during the lab hours.

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IMPORTANT INSTRUCTIONS TO HANDLE CNC MACHINES

1. Get permission from the concerned staff before switch ON the CNC machines.

2. Ensure the proper power supply for the system and machine.

3. Handle the CNC machines very carefully.

4. If any problem occurs in the system or machine immediately inform to the concerned

staff. Don’t try to rectify the problem by yourself.

5. Your batch is responsible for the CNC machine and its system while doing the lab

exercise assigned to your batch.

******

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CONTENTS

Sl. No. ITEMS Page No.

A) COMPUTER AIDED DESIGN (CAD)

1. Design process and Role of CAD 7

2. Solid modeling 8

3. Requirements for Modeling Assembly 8

4. CADCAE/CAM Data Exchange 9

5. Solid Works software overview 10

6. Exercises in 3D Part Modeling 23

7. Exercises in Assembly 26

8. Additional Exercises in Part Modeling and Assembly 28

B) COMPUTER AIDED MANUFACTURING (CAM)

Manual Part Programming in CNC Lathe

9. Programming in CNC 250 Production Lathe 30

10. Exercise in Production Lathe using Single Tool 32

11. Exercise in Production Lathe using Multi Tool 33

Manual Part Programming in CNC Milling

12. Linear, Circular Interpolation and Pocketing 34

13. Exercises in Linear, Circular Interpolation and Pocketing 35

C) SIMULATION AND NC CODE GENERATION

14. LATHE SIMULATION – CL and NC Code generation using

CAPSTURN software 37

15. MILLING SIMULATION – CL and NC Code generation using

CAPSMILL software 38

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A) COMPUTER AIDED DESIGN (CAD)

1. DESIGN PROCESS AND ROLE OF CAD

According to Shigley, the design process is an iterative procedure involving the following six

phases:

1. Recognition of need

2. Definition of problem

3. Synthesis

4. Analysis and optimization

5. Evaluation

6. Presentation

Phase 3 (synthesis) includes defining the design problem, design conceptualization, searching for

design information, modeling and simulation.

Phase 4 (analysis and optimization) may includes parameter study, finite element analysis, etc.

Although computers are being utilized more and more in the design process, their use is still

limited to the last four steps in the design and they are mainly used as a tool that helps the

designer, rather than as a replacement for the designer.

Benefits of Using CAD:

(1) Increasing productivity

(2) Improving quality of design

(3) Improving communications

(4) Creating data-base for manufacturing

The Design Process and Computer-Aided Design

Design Process

Computer Aided Design

Fig. 1.1 – Role of computers in design process

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Geometric Modeling

The term geometric modeling (or representation) means a method of describing commonly used

curves and surfaces in terms of values of a few parameters.

Three Types of Geometric Models

Wireframe Model : connect 3D vertex points, sometimes ambiguous.

Surface Model : define surface to form an object.

Solid Model : various representation schemes are used to describe a solid object

2. SOLID MODELING

A solid modeling system is usually an interactive computer graphics system that is intended to

create true three-dimensional components and assemblies. Recent advances in CAD software,

computers, and graphical displays have made it possible to use solid representations of

components being considered in the design process. These solid models can be employed in

numerous ways.

Advantages of Solid Modeling

A realistic visual display: By producing a shaded visible surface image of the solid, solid

modeling allows a designer to see exactly what has been created.

Easy to deal with different views: Once a part has been created, we have the ability to rotate,

shade, section, or produce almost any view required by a designer.

Single associated model database: The solid modeler provides the only database suitable for all

CAD operations. Almost all information needed for part generation is contained in the solid

model.

The algorithm should be able to ensure that it represents physically possible shape that is

complete and unambiguous Applications. e.g., automatic generation of a mesh for a finite

element analysis.

3. REQUIREMENTS FOR MODELING ASSEMBLING

1. Part modeling and analysis

The part analysis include the material type, mass and inertial properties, functional properties of

the faces, etc.

2. Hierarchical relationships

An assemble tree and assemble sequence must be given.

3. Mating conditions.

There are two methods for specifying mating conditions:

Specify the location and orientation of each part in the assembly, together with the representation

of the part itself, by providing a 4 x 4 homogeneous transformation matrix. (i.e., transformation

from MCS to WCS)

Specify the spatial relationships between its individual parts as mating conditions.

For example, a mating condition can consist of planar faces butting up against one another or

requiring centerlines of individual parts to be collinear (―fits‖ condition).

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4. CADCAE/CAM Data Exchange

Computer databases are now replacing paper blueprints in defining product geometry and

non-geometry for all phases of product design, analysis, and manufacturing. It becomes

increasingly important to find effective procedures for transferring data among CAD/CAE/CAM

systems.

The need to exchange modeling data is directly motivated by the need to integrate and automate

the design and manufacturing process to obtain the maximum benefits from CAD/CAE/CAM

systems.

Four Types of Modeling Data to be Transferred:

(1) Shape

(2) Nonshape

(3) Design

(4) Manufacturing

(1) Shape data consists of both geometrical and topological information as well as part features.

Entity attributes such as font, color, and layer as well as annotation are considered part of the

entity geometrical information. Topological information applies only to products described via

solid modeling. Features allow high-level concept communication about parts.

Examples are hole, flange, web, pocket, chamfer, etc.

(2) Nonshape data includes graphics data such as shaded images, and model global data as

measuring units of the database and the resolution of storing the database numerical values.

(3) Design data has to do with the information that designers generate from geometric models for

analysis purposes. e.g., mass property and finite element mesh data.

(4) Manufacturing data consists of information such as tooling, NC tool paths, tolerancing,

process planning, tool design, and bill of materials.

Commonly Used CAD Data Exchange Format

IGES (Initial Graphics Exchange Specification)

PDES (Product Data Exchange Using STEP)

IGES is focused on CAD-to-CAD exchange where primarily shape and nonshape data were to be

transferred from one system to another. PDES is previous called Product Data Exchange

Standard. It is for the exchange of complete product descriptions which covers the four types of

modeling data (i.e., shape, nonshape, design and manufacturing).

Other data exchange interfaces include: STL, Neutral, SET, ECAD, VDA, STEP, PDGS,

CATIA, Render, CGM, VRML, PATRAN, TIFF, etc.

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5. SOLID WORKS SOFTWARE OVERVIEW

Solid Works is a computer-aided design (CAD) system for mechanical assembly, part modeling,

and drawing production. Developed with STREAM technology, Solid Works is designed to

increase software performance with an interface that ensures maximized user productivity and

return on investment.

Solid Works STREAM technology boosts essential CAD user productivity by capturing

engineers' solid modeling design intentions through inference logic and decision-management

concepts. STREAM technology makes Solid Works easy to learn, easy to use, and more

productive than any other mid-range CAD system on the market.

The Part Environment:

The Solid Works part modeling environment allows you to construct 3-D solid models with true

features. The part modeling process starts with a base feature, such as a block or cylinder, which

you build upon with part features to create a part model. Part features include protrusions and

cutouts (extruded, revolved, swept, and lofted), holes, ribs, thin-walled solids, rounds, draft

angles, and chamfers. You can also construct rectangular and circular feature patterns and mirror

copies.

When you design parts in Solid Works, all geometry is created in the context of constructing

features. The software keeps track of construction elements for you, making them available when

you edit the feature but hiding them from view while you work on other parts of the design. You

can also add your own construction geometry, such as extruded, lofted, and swept surfaces,

intersection curves, projected curves, and intersection points.

The Assembly Environment:

Solid Works can manage large, complex assemblies containing many parts and subassemblies.

The Assembly environment contains commands for fitting parts together with natural assembly

techniques such as mate and aligns. Solid Works accommodates the fact that most parts are

designed in the context of an assembly. To support this workflow, Solid Works provides tight

integration with the part modeling environment, visualization tools, data management tools, and

part-to-part relationship management tools. Solid Works makes it easy to manage assembly data

from the earliest phases of project planning, through revision cycles, manufacturing, project

maintenance, and archival.

The Draft Environment:

Solid Works provides a separate drafting environment for producing engineering drawings

directly from 3-D part or assembly models. Solid Works drawings are associated with the 3-D

model, so that the drawing reflects changes in the model as the design progresses. These model-

to-drawing links minimize drawing maintenance in response to engineering changes, so that you

can easily keep drawings up-to-date with the part or assembly model. Hidden line

representations are properties of the drawing view—they do not affect your view of the solid

model in the Part or Assembly environments.

You can create drawings that display various views, sections, details, dimensions, notes, and

annotations. You can also add feature control frames, datum frames, weld symbols, and surface

texture symbols to your drawings. Ensuring that the dimensions and annotations on your

drawings conform to your company’s standards or international standards is easy—as in

Microsoft Office products, you can capture these settings in styles and templates.

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Base Features in Part Modeling

Extrude: Extension in third axis of the profile

Fig. 5.1

Revolve : Revolve the profile about axis of symmetry

Fig. 5.2

Sweep : Extrusion of a cross section along a path

Fig. 5.3

Blend / Loft : Blending of different cross sections along a path

Fig. 5.4

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Editing & Engineering Features in Part Modeling

Round : Modify the sharp edge to curved edge

Chamfer : Modify the sharp edge to flat edge

Shell : Removes a surface or surfaces from the solid then hollows out the

inside of the solid, leaving a shell of a specified wall thickness.

Rib : Special type of protrusion to create a thin fin or web

Cut : Remove the undesirable portion from the basic part

Fig. 5.5

Hole : Remove cylindrical portion from the basic part

Fig. 5.6

Pattern : Create instances of the selected feature by varying some specified

dimensions

Fig. 5.7

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6. PART MODELING AND ASSEMBLY IN SOLID WORKS

Important steps 1. Choose the best profile for sketching.

2. Choose the proper sketch plane.

3. Create a new part.

4. Create a sketch.

5. Extrude a sketch as a boss.

6. Extrude a sketch as a cut.

7. Create Hole Wizard holes.

8. Insert fillets on a solid.

9. Make a basic drawing of a part.

10. Make a change to a dimension.

11. Demonstrate the associatively between the model and its drawings.

Terminology

Moving to 3D requires some new terminology. The SolidWorks software employs many

terms that you will become familiar with through using the product. Many are terms that you will

recognize from design and manufacturing such as cuts and bosses.

Feature

All cuts, bosses, planes and sketches that you create are considered Features. Sketched

features are those based on sketches (boss and cut), applied features are based on edges or faces

(fillet).

Plane

Planes are flat and infinite. They are represented on the screen with visible edges. They

are used as the primary sketch surface for creating boss and cut features.

Parallel Plane

Creates a reference plane parallel to a part face or reference plane at an offset value you

define. You can define the offset value using the cursor or by typing a value in the Distance box

on the ribbon bar.

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Sketch

In the SolidWorks system, the name used to describe a 2D profile is sketch. Sketches are

created on flat faces and planes within the model. They are generally used as the basis for bosses

and cuts, although they can exist independently.

Extrusion Boss/ Base

Although there are many ways to create features and shape the solid, for this lesson, only

extrusions will be discussed. An extrusion will extend a profile along a path normal to

the profile plane for some distance. The movement along that path becomes the solid model.

Extruded cutout

A Cut is used to remove material from the model. This is the opposite of the boss. Like

the boss, cuts begin as 2D sketches and remove material by extrusion, revolution, or other

methods.

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Revolved Boss/ Base

Constructs a protrusion by revolving a profile

To create a revolve feature:

1. Create a sketch that contains one or more profiles and a centerline, line, or edge to use as

the axis around which the feature revolves.

2. Click one of the following revolve tools:

Revolved Boss/Base on the Features toolbar, or Insert, Boss/Base, Revolve

Revolved Surface on the Surfaces toolbar, or Insert, Surface, Revolve

3. In the Property Manager, set the options.

4. Click OK.

Lofted Boss/ Base

Constructs a protrusion by fitting through a series of cross sections. You can define the

cross sections using profiles drawn within the command, sketches, or edges of existing features.

The cross sections must be closed, planar elements.

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View Options

SolidWorks gives you the option of representing your solid models in one of several

different ways. They are listed below, with their icons:

Symbol Description

Shaded

Shaded with Edges

Hidden Lines Removed

Hidden Lines Visible

Wireframe

Examples of each are shown in the illustration below

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BASIC FEATURES

Extrude : Extension in third axis of the profile

Revolve : Revolve the profile about axis of symmetry

Sweep : Extrusion of a cross section along a path

Blend / Loft : Blending of different cross sections along a path

CREATION OF BASIC SOLID FEATURES EXTRUDE

Insert (from menu bar) > Select Extrude > Click Sketcher icon (from dash board) > Select a

plane (from main window) > Click Sketch (from section dialogue box) > Select References

(check reference status fully placed) > Close (reference dialogue box) > Sketch a figure (edit

dimensions if required) > Click (blue color to continue) > Enter depth value (at prompt in

dash board) > click preview (at dash board) > click (green color on dash board) > file > save >

click (green color)

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REVOLVE

Insert > Revolve > Select Sketcher (icon from dash board) > Select plane for sketching >

Click sketch > Select References > Close reference > Draw figure > Draw centre line as axis

(along which it should revolve) > Click (blue color) > Specify angle (in dash board upto

which it should rotate) > preview > click (green color)

SWEEP

Insert > Sweep > Protrusion > Click Sketch Trajectory (from sweep trajectory menu

manager) > Select a Plane > Okay (for direction) > Default (sketch view) > Select References >

Close (reference dialogue box) > Draw Trajectory > Click (blue color) > Sketch Cross section

(at the intersection of two yellow color axes) > Click (blue color) > Preview > OK (to accept)

BLEND

Insert > Blend > Protrusion > (from blend options) Select Parallel > Regular section > Sketch

section > Done > (from Attributes) Select Straight > Done > (from Set up plane) Select a Plane >

Okay (direction) > Default (sketch view) > Select References (check whether it is fully placed) >

Close (reference dialogue box) > Draw section 1 > Right click mouse and select Toggle section

> Draw section 2 > Click (blue color to continue) > Enter depth value at prompt (between

section 1 and 2) and click (green color) > Preview (from Protrusion dialogue box) > OK (to

accept drawing)

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EDITING & ENGINEERING FEATURES

Round : Modify the sharp edge to curved edge

Chamfer : Modify the sharp edge to flat edge

Cut : Remove the undesirable portion from the basic part

Hole : Remove cylindrical portion from the basic part

Pattern : Create instances of the selected feature by varying some specified

dimensions

Shell : Removes a surface or surfaces from the solid then hollows out the inside

of the solid, leaving a shell of a specified wall thickness.

Rib : Special type of protrusion to create a thin fin or web

Round

Inserting Round in Corners:

Create a basic feature > Insert > Round > Select an edge or a chain of edges with ctrl key pressed

> Enter radius (at prompt in dash board) > Preview > Click (green color to accept)

CHAMFER

Edge Chamfer:

Create a basic feature > Insert > Chamfer > Edge Chamfer > Select Sets option (from dash

board) > Select edges (as reference for chamfering with ctrl key pressed) > select one option

from dash board (for example D x D) > Enter value for D at prompt) > Preview > Click (green

color to accept)

CUT

Create a basic feature > Insert > extrude > select sketcher icon > select sketch plane (to insert

cut) > click sketch > select references > close (reference dialogue box) > draw a figure > click

(blue color) > select type of depth (from dash board) > enter depth value > flip in required >

click remove material icon (on the dash board) > click flip direction if required > preview > click

(green color on dash board to accept)

HOLE

Create a basic feature > Insert > Hole > (from dash board) Select

Simple > Click Placement > Select a surface (for primary

reference) > Select linear > Click No Items under secondary

reference > Select 2 edges (with ctrl key pressed) > Enter edge

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offset values > (In dash board) Enter diameter of hole > Select type of dept > Enter depth value >

Preview > Click (green color to accept)

PATTERN

Create a basic feature (for example with hold included) > select a part

from model tree (example – hole, to be patterned and which is having

reference dimensions) > right click mouse on it > select pattern >

select dimension option (from dash board) > select 1st reference

dimension (from main window by placing cursor on dimension for

direction 1) > enter increment value > select 2nd reference dimension

(for direction 2) > enter increment value > enter number of items (for

direction 1 & 2 at dash board) > click (green color to accept pattern)

SHELL

Create a basic feature > insert > shell > select surfaces with ctrl key pressed (which are to be

shelled) > enter thickness at the prompt > click (green color to accept)

RIB

Create a basic feature > insert > rib > click sketcher icon > select a plane (along with rib should

form) > click sketch > select references > close (reference dialogue box) > draw an open section

for rib formation > click (blue color to continue) > specify thickness of the rib (at prompt) >

flip direction (if required at prompt and also flip direction on screen to face inside) > preview >

click (green color to accept drawing)

ASSEMBLY OPERATION

ASSEMBLY CONSTRAINTS

Mate

Mate constraint two surfaces touch one another, coincident and facing each other shown

in fig.

Mate Offset

Mate offset constraint makes two planar surfaces parallel and facing each other. The

offset value determines the distance between two surfaces shown in fig.

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Align

Align constraint makes two planes coplanar, coincident and facing in the same direction.

It also aligns revolved surfaces or axes to make them coaxial shown in fig.

Align Offset

This constraint aligns two planar surfaces at an offset, parallel and facing in the same

direction shown in fig.

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Insert

Insert constraint inserts a male revolved surface into a female revolved surface, align axes

shown in fig. 1.17.

Orient

The orient constraint orients two planar surfaces so that they are parallel and facing in the

same direction, offset is not specified. See fig. 1.18.

Coord Sys

The coordinate system constraint places a component in an assembly by aligning its

coordinate system with a coordinate system in the assembly shown in fig.

Tangent

The Tangent, pnt on line, pnt on surface and Edge on srf constraints are used to

control the contact of a surface at the tangency of another surface, at a point or at an edge. In

most cases, a combination of the constraints will be required.

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6. EXERCISES IN 3D PART MODELING

Fig. 6.1 Fig. 6.2

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Fig. 6.3 Fig. 6.4

Fig. 6.5 Fig. 6.6

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Fig. 6.7 Fig. 6.8

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7. EXERCISES IN ASSEMBLY

Fig. 7.1

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Fig. 7.2

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8. ADDITIONAL EXERCISES IN PART MODELING

Fig. 8.1

Fig. 8.2

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ADDITIONAL EXERCISE IN ASSEMBLY MODELING

Fig. 8.3

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B) COMPUTER AIDED MANUFACTURING (CAM)

Manual Part Programming in CNC Lathe

9. PROGRAMMING IN CNC 250 PRODUCTION LATHE

Preparatory Functions

G00 – Rapid Traverse

G01 – Linear Interpolation (Cutting feed)

G02 – Circular Interpolation (Clockwise)

G03 – Circular Interpolation (Counter Clockwise)

G04 – Dwell

G28 – Return to Machine reference position

G40 – Tool nose radius compensation cancel

G41 – Tool nose radius compensation left

G42 – Tool nose radius compensation right

G50 – Maximum spindle speed setting / Coordinate system setting

G70 – Finishing cycle

G71 – Turning cycle (Rough)

G72 – Facing cycle

G73 – Pattern repeating cycle

G74 – End face peck drilling

G75 – Outer diameter / Internal diameter drilling

G76 – Multiple thread cutting

G96 – Constant surface speed

G97 – Constant surface speed cancel (constant rpm)

G98 – Feed per minute

G99 – Feed per revolution

Miscellaneous functions

M00 – Program stop

M01 – Optional stop

M03 – Spindle clockwise

M04 – Spindle counter clockwise

M05 – Spindle halt

M08 – Coolant on

M09 – Coolant off

M10 – Chuck or collet close

M11 – Chuck or collet open

M30 – Program End

M40 – Chuck outer clamping

M41 – Chuck inner clamping

Syntax

G00 X Z ;

G01 X Z F ;

G02 X Z R F ;

G03 X Z R F ;

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G04 X ; (Time in seconds)

G28 U W ;

G70 P Q F ;

P – Start sequence

Q – End sequence

F – Feed

G71 U R ;

G71 P Q u w F ;

U – Depth of cut

R – Relief in X direction

P – Start sequence

Q – End sequence

u – Stock amount for finish – X axis

w – Stock amount for finish – Z axis

F – Feed

G72 W R ;

G72 P Q W F ;

G73 U W R ;

G73 P Q u w F ;

U – Depth of cut

W – Relief in Z direction

R – Number of passes

P – Start sequence

Q – End sequence

u – Stock amount for finish – X axis

w – Stock amount for finish – Z axis

F – Feed

G74 R ;

G74 Z Q F ;

G75 R ;

G75 X Z P Q F ;

G76 P Q R ;

G76 X Z q p F ;

P – Number of idle passes

Q – First pass depth of cut

R – Relief

X – Thread minor dia

Z – Thread Length

q – Second pass depth of cut

p – Thread height

F – Pitch

Finishing allowance

Finishing allowance

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10. EXERCISE IN PRODUCTION LATHE USING SINGLE TOOL

AIM:

To write, simulate and execute a CNC program for the job of given dimensions as

shown in the figure using CNC 250 – Production lathe.

PROCEDURE:

- Initially draw the rough diagram with required dimensions

- Write a CNC program with preparatory and miscellaneous codes

- Provide proper tolerances to protect the tool

- Select appropriate tool

- Enter the program using software

- Simulation of tool path

- Do manual setting

- Enable work piece reference and carryout machining

RESULT:

- Verify the tool path generation and actual dimensions obtained.

Fig. 10.1

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11. EXERCISE IN PRODUCTION LATHE USING MULTI TOOL

AIM:

To write, simulate and execute a CNC program for the job of given dimensions as

shown in the figure using CNC 250 – Production lathe.

PROCEDURE:

- Initially draw the rough diagram with required dimensions

- Write a CNC program with preparatory and miscellaneous codes

- Provide proper tolerances to protect the tool

- Select appropriate tool

- Enter the program using software

- Simulation of tool path

- Do manual setting

- Enable work piece reference and carryout machining

RESULT:

- Verify the tool path generation and actual dimensions obtained.

Fig. 11.1

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Manual Part Programming in CNC Milling

12. LINEAR, CIRCULAR INTERPOLATION AND POCKETING

Machine Configuration

Model : Star Mill with ATC

Make : MTAB

Working Table Size : 360mm x 130mm

Longitudinal Traverse [X] : 160mm

Cross Traverse [Y] : 90mm

Head Traverse [Z] : 115mm

Accuracy : 0.001mm

Directives

[BILLET - Define Billet Size

[EDGEMOVE - Offset from the program zero to the lower left corner of the billet

[TOOLDEF - Define diameter and length of a tool

[STEP - Step by step execution of program

[NOSTEP - Cancel step by step execution of program

[SHOW - Show the operation being simulated

[NOSHOW - Stop the operation being simulated

!TUTORIAL - To display user interactive message at the bottom

[CLEAR - It will clear the interactive message display

General Notations

X X coordinate value

Y Y coordinate value

Z Z coordinate value

D Diameter of tool

T Tool Number

F Feed rate

S Spindle speed

R Radius of arc

G functions

Function Operation

G00 Positioning (Rapid traverse)

G01 Linear interpolation (Cutting feed)

G02 Circular interpolation / Helical CW

G03 Circular interpolation / Helical CCW

G04 Dwell Exact stop

G20 Imperial units (inches)

G21 Metric units (mm)

G28 Return to reference point

G40 Tool radius compensation cancel

G41 Left hand radius compensation

G42 Right hand radius compensation

G49 Tool length compensation cancel

G90 Absolute command

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Function Operation

G91 Incremental command

G92 Set datum

G94 Feed per minute

G95 Feed per rotation

G170-G171 Circular Pocketing

G172-G173 Rectangular Pocketing

M functions

Function Operation

M00 Program Stop

M02 Program End

M03 Spindle Forward

M04 Spindle Reverse

M05 Spindle Stop

M06 Tool Change

M70 X Mirror on

M71 Y Mirror on

M80 X Mirror Off

M81 Y Mirror Off

M98 Subprogram Call

M99 Subprogram Exit

13. EXERCISES IN LINEAR, CIRCULAR INTERPOLATION AND POCKETING

Aim

1. Writing a NC program for the given profile as shown in the figure.

2. Simulating and executing the program using FANUC Milling software.

Procedure

- Identify the required coordinates of the profile based on profile origin.

- Provide proper tolerances to protect the tool

- Select appropriate tool, speed, feed rate for the operations

- Write the NC program using appropriate Preparatory and miscellaneous codes.

- Enter the program

- Analyse the program

- ensure the program should be free from errors using check syntax and dry run

- Simulate the program

- Do manual setting carefully

- Carryout machining

Result

The dimensions of machined part are verified with drawing.

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Fig. 13.1

Fig. 13.2

c

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C) SIMULATION AND NC CODE GENERATION

14. LATHE SIMULATION – CL AND NC CODE GENERATION USING

CAPSTURN SOFTWARE

Fig. 14.1

Aim

To generate NC code for the given profile using CAPSTURN software.

Procedure

Work setup

Draw the Part

Define the Part

Draw the Blank

Define the Blank

Machine the Part

View tool path

Select a machine

Generate NC Program

Result

Thus the NC code was generated for the given profile using the CAPSTURN

software.

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15. MILLING SIMULATION – CL and NC Code generation using CAPSMILL

software

All dimensions are in mm

Fig. 15.1

Aim

To generate NC code for the given profile using CAPSMILL software.

Procedure

Work setup

Draw the Part

Define the Part

Draw the Blank

Define the Blank

Machine the Part

View tool path

Select a machine

Generate NC Program

Result

Thus the NC code was generated for the given profile using the CAPSMILL software.