Cad Cam Cae

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Introduction to CAD/CAM/CAE/CAPP

Dr. Viboon Sangveraphunsiri

Center of High Precision Manufacturing Systems CHULALONGKORN UNIVERSITY

Chulalongkorn University

CAD CAM

Information Flow

Information Flow

•Knowledge (proprietary)•Reduce Cycle Time•Automate Tasks• Improve Quality

Product

Improve Quality•Reduced Cost• Increase Innovation

Knowledge capture and Reuse


CAE

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What is Design, really?

Which of the following is design and which is analysis?

A. Given that the customer wishes to fasten together two steel plates, select appropriate sizes for the bolt, nut and washer.

B. Given the cross-section geometry of a new airplane wing we determine the lift it produces by conducting wind tunnel experiments


experiments.

Design Analysis

Form is the solution to a design problem.

Form ever follows Function

Function

ControlHoldMoveProtectSt

Design

Form

Store

Decision-making processes

ShapeConfigurationSizeMaterialManufacturing processes


Manufacturing processes

Design is the set of decision-making processes used to determine the form of an object given the functions desired by the customer

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Product Engineering Cycle

• Product need or requirement

• Design Specifications

• Conceptual Design

• Configuration Design

• Parametric Design– Formulate

– Alternated Design

– Analytical Design

– Evaluate

– Refine Optimize

Preliminary Design Embodiment

Design


– Refine Optimize

• Detailed Design

• Manufacturing

• Marketing

Information needed before investment

Production Volume

Product Life Cycle

Sales price (Customer satisfaction)

Product Complication

Development time

Internal development team


External development team

Development cost

Production investment

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Measuring The Design Process

• Product cost

• Product quality

Ti k• Time to market


Example of Ford Motor

The effect of the quality of the design on the manufacturing cost is much greater than 5 percent

The effect of design on manufacturing cost

1 4

1.6

The decisions made during the design process have a great effect on the cost of a product but cost very little.

0 2

0.4

0.6

0.8

1

1.2

1.4IneffieientManufacturing

Average manufacturing

EfficiencyManufacturin

Man

ufac

turin

g co

st


Coffee Maker ManufacturingData reduced from “Assessing the Importance of Design through Product Archaeology, “Management Science, Vol. 44, No. 3, pp 352-369, March 1998 by K. Ulrich and S.A. Pearson.

0

0.2

Poor Design Average Design Good Design

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Manufacturing Cost Commitment During Design

icat

ion

opm

ent

ept

ual

si

gn

ed

Spe

cif

dev

elo

Con

cede

s

Cost in

curre

d

ge

of p

rodu

ct c

ost c

omm

itte

Pro

duct

D

esig

n


C

Per

cent

ag

What determined quality?

Essential Not essential Not sure

Quality cannot be manufactured into a product unless it is designed into it

Works as it should 98 1 1

Last a long time 95 3 2

Is easy to maintain 93 6 1

Looks attractive 58 39 3

Incorporates latest technology 57 39 4

Has many features 48 47 5


Has many features 48 47 5

Quality is a composite of factors that are the responsibility of the design engineer

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Engineering Changes

Company A

Company B

esig

n C

han

ge


Time

De

Release For Production

Engineering Change is Expensive

100

Relative Cost of Change40

60

80


Design Testing Process Planning Production

0

20

7

Product Cycle

Salesand

Profit

Time1 2 3 4

Sales

Profit


1. Introduction or Development2. Growth3. Maturity or Saturation4. Decline

Example of Industrial Design (DESIGN EDGE)


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Industrial Design

Reverse EngineeringHigh Speed Machining

Engineering Analysis

5-Axis Machining


Client MarketingDesignManufacturing

Working in 2D and 3D for Design and Modelling Method



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2D Sketching for Design

• Design often started by 2D sketch or profile

• Profiles consist of wireframe entities• Line

• Arc

• Circle

• Spline


Spline

• Profiles then used to develop 3D geometric model

Creation of data and drawingNC part-programming

Basic Integrated CAD/CAM/CAE System in Mechanical Engineering

Graphics display

Automatic Drafting

Tool and Fixture design

Inspection

Inventory control

COMMONDATABASE


Design Analysis(Finite Element Analysis)

Scheduling

Costing

Finite Element Modeling

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Aims of 3D Modelling

• To define the component geometry in an biunambiguous way

• For the geometric model to be suitable for use in downstream activities, i.e., Finite Element analysis, NC programming.


Geometric Modelling

• You create a full size 3D model of the t hi h ll h b ttcomponent which allows a much better

visualization of it

• Interference detecting may be automatic which is impossible in 2D


• Automatic mass calculations can be performed

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Interference detecting


Automatic mass calculations


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Which 3D Modelling Method?

• WireframeWireframe

• Surface modelling

• Solid modelling


3‐D Modeling System

• 3-D Wire Frame

Surface Modeling Solid Modeling


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1. 3D Wire Frame2. Surface Modeling3. Solid Modeling

3D Modeling System

1. 3D Wire Frame

Wire Frame Model


Possible Interpretation

Visual Ambiguity of Wire Frame

1. Wire Frame Model

Wire Frame model


Which Solid

Incompleteness of the Wire Frame

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TABULATED CYLINDER SURFACE

SURFACE OF REVOLUTION

Surface Modeling

SCULPTURED OR DOUBLY CURVED SURFACE


RULED SURFACE

WEDGE

Solid Modeling

Primitive Solid Objects Element

TORUS


BOXSPHERE

CONE

CYLINDER

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Surface Design


Solid Modeling1) Pure premitive instancing schemes2) Spatial occupancy enumeration3) Cell Decomposition

) S i S

Solid Modeling

4) Sweep representation Schemes5) Constructive solid geometry (CSG)6) Boundary representation schemes (B-rep)


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Solid Modelling – Boundary Representation (B‐Rep)

A b d i (B )A boundary representation (B-rep) modeller represents a solid model by describing its boundaries by faces



• Faces represented by bounding edges and tivertices

• How the faces, edges and vertices are connected is the topology of the solid

• Topological entities are related to geometric


information, i.e. vertices to co‐ordinate points, edges to curve equations.

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Explicit and Parametric Geometry

• Explicit Model Geometry – Geometry specifically defined so that it cannot be modified

• Parametric Model Geometry – Geometry implicitly defined so that it can be modified


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Feature Based Modelling

• Feature based modelling deals with creating t i d l b i f f ta geometric model by using form features

• Essentially, a CAD/CAM system provides a form feature library to build a model

– Standard Featured


– User defined Features

Typical Commands for Solid Modeling

• Protrusion

• Swept

• Spun or revolving

• Loft

• Cutout


• Swept cutout

• Spun cutout

• Loft cutout>>

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Basic Modelling and Feature‐Based ConceptFeature Based Concept

Dr. Viboon SangveraphunsiriCenter of High Precision Manufacturing Lab

Center of High Precision Manufacturing Systems CHULALONGKORN UNIVERSITY37

Base Feature using Pad

Fillet

Pad orBosses


Modeling Process38

Pocket orCuts Thin wall

or Shell

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Example

Center of High Precision Manufacturing Systems CHULALONGKORN UNIVERSITY39

Computer Aided Process Planning(CAPP)



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CAD/CAM For Product Engineering

• Design

– CAD

• Process Planning

– CAPP


• Production

– CAM/CAPP

Introduction

Process planning translates design information into the process steps and p pinstructions to efficiently and effectively manufacture products. As the design process is supported by many computer-aided tools, computer-aided process planning (CAPP) has evolved to simplify and improve process


evolved to simplify and improve process planning and achieve more effective use of manufacturing resources.

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Process Planning

• Process Planning refers to the product design d d id h t f t it ithi thand decides how to manufacture it within the

resource constraints

• Process planning can be seen as an activity which integrates knowledge about products and resources


and resources

• Efficient utilization of resources

Production System

Manufacturing support

Ordering materials, moving work through the factory, and ensuring that products meet quality standards

Systems

Facilities:

quality standards. Include Product Design and certain business functions

Product Related Information(Technical Information Flow)

Order Related Information Flow(Planning Information Flow)

Material Flow


Factory Equipment

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Function in Manufacturing

Factory Operation

•Processing•Assembly•Material Handling•Inspection and test

Raw Material Finished Product


Control

Manufacturing Process Model

Manufacturing Process

Raw Materials

Equipment

Tooling, fixtures

Electrical energy

Labor

Completed workpiece

(How to build parts)


Scrap and waste

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The Need of Process Planning

Product Development

Concept

Product Design

Process Planning

Production Planning

Production

Manufacturing step

Production Schedule


Process Planning

Design dataIN

OU

Process Planning

Design data

Material data

Equipment data

Quality data

Production data

Process plan(plan sheet or route sheet)

NPUT

TPUT


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Scope of Process Planning

• Interpretation of design drawing

• Process and sequence

• Equipment selection

• Tools, dies, molds, fixtures, and gages

• Methods analysis


• Work standards

• Cutting tools and cutting conditions

Typical Route Sheet


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Process Plan Creation

• Creation of new plan

– Detailed knowledge of companies facilities

– Detailed knowledge of sub‐contractors facilities

– Knowledge of manufacturing methods

– Knowledge of manufacturing data – speeds, feeds, etc.


Process Plan Creation

• Modification of existing plan

– Altered for design changes

– Altered for plant changes

– New component is similar to past component

– Good filing and referencing system needed


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Different Approaches of Process Planning

Manually

Traditional

Workbook

Approaches to process planning

Computerized

Variant

Semi-generative


Generative

Computer aided process planning using classification systems (retrieval or variant systems)


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GT Implementation

GT approaches have been developed to decomposed a large manufacturing system into smaller, manageable

t b d i il iti f d i tt ib t dsystems based on similarities of design attributes and part features.

These approaches can be broadly categorized into two classes: Classification approaches using coding


two classes: Classification approaches using coding systems and cell formation approaches using production flow information.

Classification Methods

1 Vi l I i h d1. Visual Inspection method

2. Coding method


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A Set of Parts with Dissimilar features


Grouping Parts

Part family 1: Prismatic parts

Part family 2: Rotational parts


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Monocode

Total partspopulation

SheetMetal parts

0

AllMachined parts

1

PurchasedComponents

3

Raw Materials

9

RotationalMachined parts

0

Nonrotational machined parts

1


0 < L/D < 0.50

0.5 < L/D < 11

L/D > 109

0 < L/W < 10

1 < L/W < 31

L/W > 89

Number of characteristics stored in a monocode = 101 + 102 + 103 = 1110

Polycode

1 2 3 4 5 6 7

PositionPosition

MaterialMaterial shapeMaterial chemistryProduction quantitySurface finishTolerance

Code alphabet

defines the position

value


Machined element orientation

Numbers of characteristics stored in a polycode = 10 + 10 + 10 + 10 + 10 + 10 + 10 = 70

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Generative CAPP

• No process plans are predefined or stored

• Process plans are automatically generated from the part design information

• Process plans are generated by means of component geometry based reasoning, decision logic formula and technology


decision logic, formula and technology algorithms

Generative process planning


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Feature Mapping

Volume to be removed

The part Raw material block

Volume to be removed 1

Volume to

A feature mapping module compares the raw material form to the finished part design form and derives the volume of


be remove 2design form and derives the volume of material to be removed. The manufacturing features are thus derived

Generative CAPP

Process database contains knowledge about the processes, sub-processes and operations used, for example:

• Drilling

• Milling

– Slot milling

• Roughing cut


• Finishing cut

– Surface milling

– Profile milling

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Generative CAPP

• Resource database contains information b t th h fl i thabout the shop floor resources, i.e. the process information about each tool

• This varies between companies


Generative CAPP

The decision support module relates manufacturing features to specific manufacturing operations

• Determines appropriate process operations

• Selects the machine for each operation

• Determines operational details such as plans of cutting


• Calculate setup and cycle times

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CAPP SoftwareCS/CAPP

CIMx1001 Ford Circle

Cincinnati, OH 45150513-248-7700

http:///www.cimx.com

MetCAPPTechnology Answers, Inc.

1190 Coleman Avenue, #2BSan Jose, CA 95110Tel: 408-486-0970

http://wwwcimplex com/metcapp htmpCimplan

Gerber Systems Corp.83 Gerber Road

Windsor, CT 06074 USA203-644-1551

HMS-CAPPHMS Software Inc.1620 Sudbury RoadConcord, MA 01742

781-890-2811http://www hmssoftware com/pages/prodcapp html

http://www.cimplex.com/metcapp.htmCOSTIMATOR 3MTI Systems, Inc.59 Interstate Drive

West Springfield, MA 01089800-644-4388413-733-1972

http://www.mtisystems.com/costimator.htmPARAGON (for PCB Assembly)

Technomatix Technologies4000 Barranca Parkway, Suite 250


http://www.hmssoftware.com/pages/prodcapp.html LOCAM

LSC GroupConcept HouseVictoria Road

TamworthStaffordshire B79 7HL

United KingdomTel: +44 (0)1827 708000

http://www.lsc.co.uk/leansupply/locam.html

Irvine, CA 92714(714) 262-3258

Interlex CAPP (For PCB assembly)Interlex Systems

11423 Almazon St.San Diego, CA 92129

http://www.millennianet.com/interlex

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