rapid pro to typing- cam

7/31/2019 Rapid Pro to Typing- Cam

1/26

2/9/2012 2007 John Wiley &

RAPIDPROTOTYPING

COMPUTER AIDED MANUFACTURING

ASSIGNMENT

Presented by

S.SAMPATH KUMAR.

M.Tech Ist year.

(Product design and manufacturing)

Pondicherry engineering college.


2/26

2/9/2012 2007 John Wiley &

CONDENT

1.

Definition of Rapid Prototyping.2. Why is Rapid Prototyping Important?

3. Classification of Rapid Prototyping

Technologies.4. Advantages of Rapid Prototyping.

5. Disadvantages of Rapid Prototyping.

6. Applications and Benefits of RapidPrototyping.


3/26

2/9/2012 2007 John Wiley &

INTRODUCTION OFRAPIDPROTOTYPING

Rapid prototype is a process wherein a

working model or prototype is developed

for the purpose of testing the variousproduct features like design, ideas,

features, functionality, performance and

output. This process of development of

working model is quite quick. The user

can ive an earl feedback re ardin theO C O O


4/26

2/9/2012 2007 John Wiley &

INTRODUCTION OF

RAPIDPROTOTYPING cont...The Rapid prototype that is

developed by the process of rapid

prototyping is based on the

performance of earlier designs. Hence,it is possible to correct the defects or

problems in the design by taking

corrective measures. The product can

be produced if the prototype meets the

re uirements of all desi nin ob ectives


5/26

2/9/2012 2007 John Wiley &

Definition of RapidPrototyping (RP)

A family of fabrication processesdeveloped to make engineeringprototypes in minimum lead time

based on a CAD model of the item

Traditional method is machining

Can require significant lead-times several

weeks, depending on part complexity anddifficulty in ordering materials

RP allows a part to be made in hours

or days, given that a computer


6/26

2/9/2012 2007 John Wiley &

Why is Rapid PrototypingImportant?

Product designers want to have aphysical model of a new part orproduct design rather than just a

computer model or line drawing Creating a prototype is an integral step in

design

A virtual prototype (a CAD model of the part)may not be sufficient for the designer tovisualize the part adequately

Using RP to make the prototype, the designer

can see and feel the part and assess its meritsand shortcomin s

l ifi i f


7/26

2/9/2012 2007 John Wiley &

Classification of RPTechnologies

There are various ways to classify theRP techniques that have currentlybeen developed

The RP classification used here isbased on the form of the startingmaterial:

1. Liquid-based

a) Stereolithography

2. Solid-based

a) Fused Deposition Modeling (FDM)

b) Laminated Object Manufacturing (LOM)


8/26

2/9/2012 2007 John Wiley &

Figure 34.2 Stereolithography: (1) at the start of the process, in which theinitial layer is added to the platform; and (2) after several layers have beenadded so that the part geometry gradually takes form.

Stereolithography


9/26

2/9/2012 2007 John Wiley &

Stereolithography (STL)RP process for fabricating a solid plasticpart out of a photosensitive liquidpolymer using a directed laser beam tosolidify the polymer

Part fabrication is accomplished as aseries of layers - each layer is addedonto the previous layer to gradually

build the 3-D geometry The first addition RP technology -

introduced 1988 by 3D Systems Inc.

based on the work of Charles Hull


10/26

2/9/2012 2007 John Wiley &

Figure 34.3 A part produced by stereolithography(photo courtesy of 3D Systems, Inc.).


11/26

2/9/2012 2007 John Wiley &

SLA Video http://www.acucast.com/video.htm
http://www.acucast.com/video.htmhttp://www.acucast.com/video.htmhttp://www.acucast.com/video.htm


12/26

F d D iti M d li


13/26

2/9/2012 2007 John Wiley &

Fused Deposition Modeling(FDM)

RP process in which a long filament ofwax or polymer is extruded onto existingpart surface from a workhead tocomplete each new layer

Workhead is controlled in thex-yplaneduring each layer and then moves upby a distance equal to one layer in the

z-direction Extrudate is solidified and cold welded

to the cooler part surface in about 0.1

s


14/26

2/9/2012 2007 John Wiley &

Stratasys, Eden Prarie, MN

patent 1992

robotically guided fiber extrusion

accuracy 0.005

casting and machinable waxes,

polyolefin, ABS water soluble or wax supports

Fused Deposition Modeling

FDM


15/26

2/9/2012 2007 John Wiley &


16/26

2/9/2012 2007 John Wiley &

FDM material


17/26

2/9/2012 2007 John Wiley &

Figure 34.5 Laminated object manufacturing.

Laminated Object Manufacturing

L i t d Obj t


18/26

2/9/2012 2007 John Wiley &

Laminated ObjectManufacturing (LOM)

Solid physical model made by stackinglayers of sheet stock, each an outline ofthe cross-sectional shape of a CAD modelthat is sliced into layers

Starting sheet stock includes paper,plastic, cellulose, metals, or fiber-reinforced materials

The sheet is usually supplied withadhesive backing as rolls that arespooled between two reels

After cutting, excess material in thelayer remains in place to support the


19/26

2/9/2012 2007 John Wiley &

Logon the website :

www.xpress3d.com

www.acucast.com
http://www.xpress3d.com/http://www.acucast.com/video.htmhttp://www.acucast.com/video.htmhttp://www.xpress3d.com/


20/26

2/9/2012 2007 John Wiley &

ADVANTAGES

High quality product is easilydelivered by way of Rapidprototyping.

Rapid prototyping enablesdevelopment time and costs.

There are many innovative ways inwhich Rapid prototyping can be used.

As the development costs arereduced, Rapid prototyping proves tobe cost effective.


21/26

2/9/2012 2007 John Wiley &

DISADVANTAGES

One more disadvantage of rapid

prototyping is that it may not besuitable for large sized applications.

The user may have very high

expectations about the prototypesperformance and the designer isunable to deliver these.

The producer may produce aninadequate system that is unable tomeet the overall demands of the

organization.


22/26

2/9/2012 2007 John Wiley &

RP Applications

Applications of rapid prototyping canbe classified into three categories:

1. Design

2. Engineering analysis and planning

3. Tooling and manufacturing


23/26

2/9/2012 2007 John Wiley &

Design Applications

Designers are able to confirm theirdesign by building a real physicalmodel in minimum time using RP

Design benefits of RP: Reduced lead times to produce prototypes

Improved ability to visualize part geometry

Early detection of design errors Increased capability to compute mass

properties


24/26

2/9/2012 2007 John Wiley &

Engineering Analysis andPlanning

Existence of part allows certainengineering analysis and planningactivities to be accomplished that

would be more difficult without thephysical entity

Comparison of different shapes and styles to

determine aesthetic appeal Wind tunnel testing of streamline shapes

Stress analysis of physical model

Fabrication of pre-production parts for processplanning and tool design


25/26

2/9/2012 2007 John Wiley &

Tooling Applications

Called rapid tool making (RTM) whenRP is used to fabricate productiontooling

Two approaches for tool-making:

1. Indirect RTM method

2. Direct RTM method


26/26

rapid pro to typing- cam

Documents