RP-RAJAT.ppt

8/10/2019 RP-RAJAT.ppt

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Rapid Prototyping (RP)


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What is Rapid Prototyping (RP)?

Rapid Prototyping (RP) refers to a class of technologiesthat can automatically construct physical model from

Computer Aided Design data

A family of fabrication processes to makeengineering prototypes in minimum lead time basedon a CAD model of the item

OR


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What is Rapid Prototyping ?

Rapid Prototyping is being widely used in the

automotive, aerospace, medical and consumer

products industries

Rapid Prototyping (RP) allows a part to be made in

hours or days, given that computer model of the parthas been generated on a CAD system


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History of RP

Rapid prototyping is the automatic construction of

physical objects using additive manufacturing

technologies

The first techniques for rapid prototyping becameavailable in the late 1980s and were used to produce

models and prototype parts

Today, they are used for a much wider range ofapplications and are even used to manufacture

production-quality parts in relatively small numbers


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Why is Rapid Prototyping Important?

Product designers want to have a physical model of

a new part or product design rather than just acomputer model or line drawing

Creating a prototype is an integral step in designprocess

A virtual prototype (a CAD model of the part) maynot be sufficient for the designer to visualize the partadequately

Using RP to make the prototype, the designer cansee and feel the part and assess its merits andshortcomings


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A 3-D representation of the object is created

using CAD software

A computer software program slices the 3-D

model into 2-D layers

A Process control software interprets the sliced

model to determine the appropriate processing

conditions for the deposition

The object is then built layer by layer

Steps in RP


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Illustration of RP Process


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CAD3-D Modeling

STL file conversion

RP SystemComputer

Slicing

RP Fabrication Layer-by-layer

buildup

Post Processing

Cleaning Finishing

3-D Physical Part

Typical RP process chain


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Examples of parts made by rapid-prototyping processes: (a) selection of parts

from fused-deposition modeling; (b) stereo lithography model of cellular phone;

and (c) selection of parts from three-dimensional printing.

Example of Parts Made by RP


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Classification of RP Technologies

RP Technologies are generally classifiedbased on the form of the starting material

Liquid-based

Powder-based Solid-based


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Liquid-Based Rapid Prototyping Systems

Starting material is a liquid

About a dozen RP technologies are in this

category

Includes the following processes:

Stereolithography Solid Ground Curing


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Powder-Based RP Systems

Starting material is a powder

Powder-based RP systems include the

following:

Laser-Engineered Net Shaping (LENS)

Three Dimensional Printing


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Laser Engineered Net Shaping (LENSTM)


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Examples of Parts Created by LENS Process


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Solid-Based Rapid Prototyping Systems

Starting material is a solid

Solid-based RP systems include the following

processes:

Fused deposition modeling

Laminated object manufacturing


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Fused Deposition Modeling


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Advantages of RPRP allows Designers to make products faster and

less expensively

Rapidly Prototyped parts show great time, cost and

material savings

Quick product testing is possible

Expeditious design improvements

Fast error elimination from design


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Advantages of RP (Continued)

Fast error elimination from design

Increased product sales

The speed of system development is increased

Rapid manufacturing is possible


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Disadvantages of RP

Part accuracy:

Staircase appearance for a sloping part surface due

to layering

Shrinkage and distortion of RP parts

Limited variety of materials in RP:

Mechanical performance of the fabricated parts islimited by the materials that must be used in the RP

process


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RP Applications

Applications of rapid prototyping can beclassified into three categories:

Design

Engineering analysis and planning

Tooling and manufacturing


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Laboratory Demo

onSolid-Based Rapid Prototyping


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The computational steps in producing a stereo lithography (STL) file. (a) Three-

dimensional description of part. (b) The part is divided into slices. (c) Support

material is planned. (d) A set of tool directions is determined to manufacture each

slice.


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Fused Deposition Modeling (FDM)

Solid model or closed surface model required


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Slicing the File

Series of closely spaced horizontal planes

are mathematically passed through the .stl

file

Generate a .stl file : a series of closely

spaced 2D cross-sections of the 3D object


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Final Build File

Model part

Support part RP technology parameters set

Send file to RP machine


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Fabrication of Part

Model part built on platform.

Model and support shown attached to platform.


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FDM Material


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Post-processing

Removal of model from platform

Removal of supports from part

Cleaning of part Finishing part (curing, sanding, polishing, )


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YOU!

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RP-RAJAT.ppt