session 5 _ reverse engg & rapid prototyping
TRANSCRIPT
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Reverse Engineering
&
Rapid Prototyping
Session -5
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Session Objectives:
On completion of this session, the student would Know what is Reverse Engineering in CAD.
Understand the techniques used in Scanning, processing thedata and generating CAD models, their applications.
Know what is Rapid Prototyping, how it is integrated withthe CAD systems
Understand the techniques used in RP processes and theirapplications
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Challenges faced by Manufacturers today...
Reduce Manufacturing Cycle time
Increase Productivity
Reduce cost
Improve product quality Better customer service support
Flexible in accepting changes
CAD/CAM is the Major solution for Manysuch issues
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What is Reverse Engineering (RE)?
It is a process of generating engineering design datafrom existing components
CARE Computer Aided Reverse Engineering
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Need of Reverse EngineeringCAD models are often unavailable or unusable for parts
which must be duplicated or modified: CAD not used in original design.
Inadequate documentation on original design.
Original CAD model not sufficient to support modification ormanufacturing using modern methods.
Original supplier unable or unwilling to provide additionalparts.
Shop floor changes to original design.
To reproduce complex free form surface
Broken or obsolete Part
Aesthetics in design
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Application... Tool and Die making
Mould Making
Press tools
Aerospace and Automobile Industry
Jewelry and artistic work Or any where , where there is a need to produce free
form surfaces.
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The objective of reverse engineering is to increase the abilityto maintain a manufacturing capability at its peak rate byimproving documentation for logistically unsupportedequipment and systems
Reverse engineering should not be confused with systemmodernization, which involves technological upgrade of anentire system to eliminate many portions of a currentmanufacturing system
Reverse engineering is targeted at modernizing singularcomponents of a system to maintain or increase system
productivity
Objective of Reverse Engineering
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Typical Design Process
Manufacturing
Finished product
Idea
Concept
design
Detail design
CAD / CAM
CNC programme
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The Reverse Engineering Process
Manufacturing
Finished product
Idea
Concept
design
Detail design
CAD / CAM
CNC programme
Reverse
Engineering
Start
Start
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Reverse Engineering Process
Reverse engineering usually consists of four stages:
Data generation
Data evaluation
Design verification Design implementation
A reverse engineering process identifies and strengthensthe weak links in any system
New documentation support for equipment and improvedsystem maintenance are important byproducts of thereverse engineering processes
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Legality in RE
Patents protect the ideas behind the functioning of a product,
copyright protects only its look and shape. A warning sign to a competitor to discourage competition. If
there is merit in an idea, a competitor will do one of following:
Negotiate a license to use the idea
Claim that the idea is not novel and is an obvious step foranyone experienced in the particular field
Make a subtle change and claim that the changed product is notprotected by the patent
Ethical uses involved in RE
Do not reverse-engineer parts if the procurement contract of thecomponent prohibits reverse engineering.
Remember to perform reverse engineering using only data that
is part of the public domain.
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Reverse Engineering Methods
It is the process of gathering information about an undefined3D surface and digitizing it
Types of Scanning:
Contact Type Non-Contact Type
Scanning
The Physical part is scanned and the cloud point data with millions ofpoints is acquired.
The cloud point Data is converted into a Polyganized data set, of tinyfacets.
NURBS Surfaces are created and the geometry can be exported to anyCAD, CAM and RPT Software.
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Non-contact type 3D laser scanning
PICZA LPX 250 Laser Scanner
Converts scanned data intopolygon and NURBS surfaces
Exports in STL, DXF and IGESfile formats for industry standard3D CAD and solid modelingsoftware
Large scanning area -- up to406.4mm (16") high x 254mm(10") in diameter with a
resolution of 200 microns Dual modes -- offers both rotary
and plane scanning for optimumperformance
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Methodology of Reverse Engineering
A cloud of points taken from scanned datausing a digitizer such as a laser scanner,computed topography
Convert the point cloud to a polygonalmodel. The resultant mesh is cleaned up,smoothed, and sculpted to the required shapeand accuracy.
Draw/create curves on the mesh usingautomated tools such as feature detectiontools or dynamic templates
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Step 4: Create a restructured spring mesh usingtools
Step 5: Fit NURBS surfaces using surfacefitting/editing tools
Step 6: Export the resulting final NURBS surface
that satisfies accuracy and smoothnessrequirements to a CAD package for generatingtool paths for machining
Step 7: Manufacture and analyze the part for
physical, thermal, and electrical properties
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Typical RE Applications Creating data to refurbish/manufacture a part for which there is no
CAD data, or for which the data has become obsolete/lost
Creating 3D data from an individual, model or sculpture forcreating scaling, animation in games/movies, copying artwork
Documentation and/or measurement of cultural objects or artifactsin archaeology, paleontology and other scientific fields
Fitting clothing or footwear to individuals and determining theanthropometry of a population
Generating data to create dental or surgical prosthetics, tissue-engineered body parts, or for surgical planning
Documentation, measurement and reproduction of crime scenes,architectural and construction work
Inspection and/or Quality Control - Comparing a fabricated part toits CAD description or to a standard item
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Stages of RE Applications
Data Collection (Digitizing or Scanning)
Geometry Clean-up (Cleaning or Noise Removal) Data Collection
The process of gathering the requisite data (3D) from an object
Range: Mechanical (slow) - Radiation-based (fast, automated)
Output: Description of physical object in 3D space - point cloud
Point Cloud
Numerous data points of object in terms ofx, y, z coordinates
Typically correspond to point on the surface of object (external &internal view scanning) or inside of object (internal view)
The points on surface can be used to create surface poly-meshgeometric model and interior points for volumetric model
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Data Collection Specifications 3 Key Specs
Volume currently no issues, New RE software can stitch PCs
Accuracy - how precisely the measurements correspond todimensional standards; Resolution the smallest increment ofdistance or volume that the instrument can measure; different foraxis of measurement; other issues repeatability, linearity
Speed range from a few points per minute using manualtechnologies, to more than a million points per second; Thetradeoff for digitizers is time and accuracy
Data Collection Technologies
Contact - Mechanical Touch Probe Systems Non-contact - Laser based Systems
Structured light or Broadband source Systems
Seeing Inside - Internal Viewing Technologies
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Contact Type
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Non-Contact Type
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Mechanical Touch-probe Systems, CMMs Accurate over wide measurement volume, some devices most
affordable, operated manually or automatically in advanced
Usually an articulated arm that allows for multiple DOF ofmovement; position of each section of the arm is determined byencoders, glass scales or potentiometers mounted on joints
Other mechanical arrangements are gantry crane type CMMs
Can distort soft objects such as auto upholstery, and are too slowto digitize parts of human bodies, or may require much labor toscan complex curved surfaces.
Not affected by the color of a surface or if it is transparent orreflective, the way laser & other light-based systems may be.
Faster for simple surfaces & easier for hard to digitize areas of anobject such as narrow slots or pockets.
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Laser Line Systems
Use geometric triangulation to determine surface coordinates
A laser line is scanned on the target object and individualsensors image the line, (simultaneously from each side of line)
The rules of trigonometry are then applied to calculate theposition of the target surface at each point on the laser line
Technology is simple, fast, accurate and gives good resolution;but may affected by color of a surface, transparency, reflective
Although scanning lasers are rated below harmful threshold,reflections on curved surfaces can result harmful focused beam
Color video information can be gathered separately to combinewith surface measurement through laser scan
Color laser scanning: multiplexed arrangement of R G B lasersto simultaneously gather color and geometric data
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Laser-based Systems for long range tracking
Time of flight systems: measure how long it takes for light emittedby a laser to return to a sensor located near its source.
Optical radar systems: similar in operation, measure the return-time of a radio wave
Both don't usually require retro-reflectors on object and canoperate at very high rates to quickly capture entire object
Laser trackers: look for a signal in their field of view from a retro-reflector placed or held on the object
These methods offer good accuracy and capability of makingmeasurements from a long distance away from the subject
These offer a high precision over a large working volume and afrequent use is for aligning large pieces of machinery or verifyingas-built dimensions of large objects
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LED-based Tracking Systems
A probe with LED's is touched to the object to be digitized;Sensors images the LED's in their FOV; Trigonometry is thenused to calculate position of the probe on the surface of object
Encoding schemes ( high-speed modulation of light emitted byLED's) are used to simultaneously track the position of LED's.
Magnetic-based Tracking Systems
Instead of an LED probe, these systems use a small wire coil as atarget. Generally used for digitizing points not within LOS
Features
Have smaller working envelopes than laser-based systems, but
may not be quite as accurate. Gives good accuracy, moderatespeeds and not affected by surface quality or color.
Mainly used in human and other types of motion studies
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Structured-light or Broadband-source Systems
Project a pattern of lines (moire/fringes, structured-color light,polarized-light interferometry) on object to be digitized, whichgets distorted by the objects 3D nature.
Deviation from the original pattern is translated into a surfacemeasurement at each point in the FOV of the instrument.
Triangulation is used to calculate the surface data and nearly allsystems use CCD cameras for sensing.
Very fast and can digitize millions of points per second, dont usea laser. These strongly favored for digitizing human beings.
Somewhat less accurate than laser systems and does smallerscanning volumes. Takes considerable time and effort to scan.
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Seeing Inside - Internal Viewing Technologies
To verify a part with complicated internal features has beenmanufactured correctly, or to survey a fossils internal features
Destructive (CSS) applicable for quality control applications;Non-destructive (X-Ray CT) for valuable or irreplaceable object
X-ray Computed Tomography:beaming an X-ray from manydirections and calculating resulting interior point density;
Offer resolutions but require specialized knowledge to use
Cross-Sectional Scanning:based on a CNC milling machinecombined with optical data-gathering using a CCD camera
A part or other object is embedded in a contrasting color plasticmatrix material. The part and matrix combination is then shaved
by the miller and scanned layer by layer until data for the completeobject has been acquired.
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Data Collection RE Scanner & Digitizer Technology Comparison
Mechanical - Arm/Guided Probe
Accuracy: 0.001 inches, Speed: Manual, Color:Not Applicable
Strength: accuracy; low-cost instruments available; measures deepslots, pockets; not affected by color or transparency
Weakness: manual operation; slow for complex surfaces; can distort
soft objects Tracking - LED Based/Magnetic
Accuracy: 0.02 mm, Speed: 300 points/sec, Color:No
Strength: can digitize hidden points in some cases; can be used to
track motion of many points simultaneously; magnetic devices canmeasure outside line of sight; not affected by color, transparency orsurface quality
Weakness: requires targets or contacting probes; smaller volumes;lower accuracy; slow for complex surfaces
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Coordinate Measuring Machine Granite Base
Cross Bar Probe Mounting
Assembly
Computer Interface
Quality of CMMs
Resolution
Repeatability
Accuracy
Linearity
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DEA Gantry CMMpowered by Virtual DMISsoftware
It provides for the needs ofthe aerospace and
automotive industries withits ability to generateinspection points fromCAD imported part
surfaces
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Scanning Methods
Single 2D profile
Multiple 2D profiles
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Scanning Methods
Grids defined to suit part geometry
User defined stepover Data density automatically controlled
Scanning speed automatically controlled
Unmanned operation
Polygonal boundary
Radial
Y axis
Any angle
X axis
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Some of the Probe Mountings and scanning
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3-D Scanning
3-D Scanner
Dot cloud Model of surface
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Immersion MicroScribe G2XRomer STINGER Digitizer
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Limitations of Contact Type Scanning Probe itself Vibration, Humidity, Heat and other Environmental conditions
Accuracy
Non Contact Methods Machine Vision
Laser Probing
MRI ( For Non Metallic Objets )
ERI ( For For Metallic Objects )
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Scanner
Head
Standard
Tripod
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The Software in RE CopyCAD
HighRES, Inc.
PolyWorks
RevEng
RevWorks Alias|Wavefront
3D RESHAPER
Imageware
RapidForm
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2D and 3D scanning tools Male to Female Inversions
Differential Scaling
Generation of NC Programs Generation of Graphic exchangefiles
[ 2D and 3D DXF, IGES, PDES, STL ]
http://www.tenlinks.com/CAD/products/reverse_eng.htm
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Case Study: Duplication of existing tool withCARE
Tool
Scanned Data
Part
Surface Model
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Mockup of a Fuel Tankfor a sport Vehicle made
in wood and clay
Point Cloud Data
Final Output as a Surface File
given to Customer
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3DP
Rapid Prototyping & itsApplications
SLM LENSEBM
SLA
REPAIR
PROTOTYPESANALYSIS MODELS
TOOLING
ASSEMBLY
MOCKUP
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Rapid Prototyping
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Design Process Overview
Concept
Pre-lim Design Drawings
Testing
Analysis
Physical
Prototype
Iterate
Manufacturing
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Traditional Prototyping - Steps Engineering Drawings
Machine or prototype shop to produce part Part usually machined (Lathe, Mill etc.)
Problems:
Material incompatibility
Shop specialization (Cant perform task you need) Design limited by prototype tools available
Part too complex to produce (curved surfaces are very difficult)
Machine deficiencies (3 axis mill, Need for 5 axes)
Costs of traditional prototyping Skilled Craftsman ($60-70/Hour shop time)
Time to receive model from shop
Time to get model into the public domain
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NC Machining & Rapid Prototyping NC machining requires a skilled operator to set up machine and to specify
tools, speeds, and raw materials.
For this reason, many do not consider NC machining to be a true RapidPrototyping (RP) technique.
True RP should create a part from some model without any assistance.
NC Machining does have some benefits over trueRP NC Machining allows a wide range of materials for prototypes (true
RP techniques often prohibit material for function prototype)
NC Machining allows better accuracy than most true rapid
prototyping techniques (may be needed for fit prototypes) True RP techniques can produce a prototype of a part that is
impossible to manufacture. NC machining often revealsmanufacturing limits in a given design.
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Solid Freeform Manufacturing
Many restrict true Rapid Prototyping to the Solid Freeform
Manufacturing (SFM) procedures (i.e. RP=SFM) All the SFM procedures are based on some layering operation The CAD/CAM program takes the shape and models it as a series of
thin layers stacked upon one another The SFM process then forms the part a layer at a time, starting at
the bottom and working toward the top This can cause trouble with large overhangs-- one must somehow
support the overhang in order to form the next layer
Overhang
Support must be used
to form next layer
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Layer Formation Methods
Solid
Powder Bulk Liquid
Polymerization
Melting &
Solidification
1 ComponentSelective Laser
Sintering
Component& Binder
3D Printing &Gluing
Gluing SheetsLaminated
ObjectManufacturing
PolymerizationFoil
Polymerization
Liquid
Shape Melting
Fused DepositionModeling
Ballistic ParticleManufacturing
LightHeatThermalPolymer-
izationTwofrequencies
Beam Inter-ference
solid
Onefrequency
Lamps
Lasers
Solid Base CuringPhotosolid. Layer at a Time
Stereolithography
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RP Technologies: Introduction
Rapid prototyping processes are a relatively recentdevelopment.
The first machine was released onto the market in late1987.
The term Rapid prototyping is little outdated. A moreaccurate description would be layer manufacturingprocesses.
An alternative term is free-form fabricationprocesses.
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These processes work by building up a component layer by
layer, with one thin layer of material bonded to the previousthin layer.
There are several different processes. The main ones are: Stereolithography
Laser Sintering Fused Deposition Modeling - FDM
Solid Ground Curing
Laminated Object Manufacturing - LOM
In addition there are a number of newer processes, such as
ballistic particle manufacturing and three-dimensionalprinting, and so on
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RP processes are material addition processes where asin conventional manufacturing processes, the materialis removed to get the desired shape from a block ofmaterial.
RP processes are driven by instructions which arederived from three-dimensional computer-aideddesign (CAD) models. CAD technologies aretherefore an essential enabling system for rapid
prototyping.
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The processes use different physical principles, but essentiallythey work either by using lasers to cut, cure or sinter materialinto a layer, or involve ejecting material from a nozzle tocreate a layer.
Many different materials are used, depending upon theparticular process.
Materials include-
Thermopolymers Photopolymers
Other plastics
Paper
Wax Metallic powder, etc.
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The application of these processes
To supporting new product development activities.
To create models
Tooling
Prototypes In some cases to directly produce metal components.
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1st System - 1989 - (accuracy 200m)
Current State -(accuracy 1 m)
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Many rapid prototyping technologies actually producephysical models.
These models are then used to produce tooling using anindirect secondary process such as investment casting.
The resulting tool is then used to manufacture a component.
New processes are beginning to appear that allow the toolingto be manufactured directly from the computer model, thuseliminating the physical model production stage.
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Now RP technologies have potential applicationsspanning the complete product life cycle fromconcept generation, through preparation ofspecifications and detailed design, to manufacture.
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Benefits of RPThe manufacturing business objectives potentially
affected by rapid prototyping technologies are: Throughput time: for example, by helping to eliminate or
speed up bottleneck processes
Flexibility to support product development: for example, bybeing quickly able to develop models, prototypes and tooling
Unit costs: for example, by reducing the costs traditionallyassociated with customizing products
Delivery to schedule: for example, by exploiting timesavings to manufacture products faster to meet due date
promises
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Labor productivity: for example, by eliminating time-
consuming processes involved in making models andtooling
Flexibility to introduce new products: for example, bybeing able to quickly create new tooling for new products
Flexibility to customize products: for example, bydeveloping specific tooling for each customer
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Flexibility to change product specification: for example, by
being able to quickly modify or create new tooling inresponse to specification changes
Flexibility to change production volumes: for example, bybeing able to quickly create additional tooling in response
to increased demand.
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Data Transfer to RP Process
Typical Process of Data Transfer
Layered
Manufa
cturing
Techniq
ues(LMT).
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A 3D CAD system-a surface or solid modeler-is used forcreating the model.
The most common step that follows is faceting the model.
The current de facto data exchange standard for representingfaceted models is called STL.
This format requires significant redundancy and is restricted
to triangles. Normally, each vendor supplies the software tools for
verifying the correctness of the model, generate process-dependent data, and to perform the slicing of faceted models.
The format for representing the slices is proprietary
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Constraints On The Model
Correct Triangulation
In-correct Triangulation
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In a correct STL-file, each triangle has exactly oneneighbor along each edge, and triangles are onlyallowed to intersect at common edges and vertices.Under these conditions, it is possible to distinguishprecisely the inside from the outside of the model
The models can contain gaps due to missing facets,facets may intersect at incorrect locations, the sameedge may be shared by more than two facets, etc.These are not accepted.
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Errors in the model can interfere
with the building process. Forinstance, if a slice contains a gapwhen the internal structure of theslice is built, stray vectors might
be created. The possibility of this happeningis great, due to the fact, that thetool in this case is a laser beam of
small diameter. These strayvectors damage the resulting partand possibly other parts beingbuilt in the same platform.
Correct & Incorrect Slices
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RP T h i
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RP Techniques
Stereo-lithography- photopolymer cured by laser
Photosolidification Layer at a Time- photopolymer cured bylight
Solid Base Curing-photopolymer is cured by UV light
Fused Deposition Modeling - molten plastic is extruded &
solidifies Ballistic Particle Manufacturing- microparticles of moltenplastic
3D Printing Direct Shell Production Casting-powder w/binder
Selective Laser Sintering- fusible powder, fused by laser
Laminated Object Manufacturing- glued layers of sheets
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RP Processes: Stereolithography
Schematic of Stereolithography Apparatus (SLA)
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Stereo-lithography Apparatus(SLA)
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Stereolithography Overview
Laser is focused/shaped throughoptics. A computer controlled
mirror directs laser to appropriatespot on photopolymer surface.Polymer solidifies wherever laserhits it.
When cross sectionis complete, elevator
indexes to preparefor next layer.
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Initially, the elevator is located at a distance from the
surface of the liquid equal to the thickness of the first,bottom-most layer.
The laser beam will scan the surface following thecontours of the slice.
The interior of the contour is then hatched using a hatchpattern.
The liquid is a photopolymer that when exposed to the
ultra-violet (uv) laser beam solidifies or is cured. The elevator is moved downwards, and the subsequent
layers are produced analogously.
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Th l bi d h h Fi ll h i d f
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The layers bind to each other. Finally, the part is removed fromthe vat, and the liquid that is still trapped in the interior isusually cured in a special oven.
A second, HeNe-laser is used to ensure that the surface of theliquid is in the correct location. The sweeper breaks the surfacetension, ensures that a flat surface is obtained, and minimizesthe processing time of each layer.
Scanning time depends on-
The geometry of the contours
Hatch patterns
The speed of the laser
The recoating time (i.e.the time taken to place a layer ofphotopolymer over the last solidified layer).
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h lidifi i i
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Photosolidification Layer at a Time
1) Cross section shape is printed onto a glass mask2) Glass mask is positioned above photopolymer tank3) Another rigid glass plate constrains liquid photopolymer from
above4) UV lamp shines through mask onto photopolymer- light only
can pass through clear part, polymer solidifies there, polymerin masked areas remains liquid
5) Due to contact with glass plate, the cross linking capabilitiesof the photopolymer are preserved- bonds better w/ next layer
6) New coat of photopolymer is applied7) New mask is generated and positioned, and process repeats
8) 12-15 minute postcure is required
Much less warpage than SLA, but still uses photopolymerswhich are toxic.
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F d D i i M d li (FDM)
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Fused Deposition Modeling (FDM)
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F d D i i M d li
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Fused Deposition Modeling
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FDM L F i
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FDM Layer FormationFDM generated
cross section
Notice that the FDM filament cannotcross itself, as this would cause a highspot in the given layer
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Fused Deposition Modeling (FDM)
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Fused Deposition Modeling (FDM)
In this process a plastic filament is unwound from a coil andsupplies material to an extrusion nozzle.
The nozzle is heated to melt the plastic and has a mechanism,which allows the flow of melted plastic to be turned on &off.
The nozzle is mounted to a mechanical platform, which canbe moved in both horizontal and vertical directions.
As the nozzle is moved over the table in the required geometry, it deposits a thin bead of extruded plastic to formeach layer.
The plastic hardens immediately after being squirted from thenozzle and bonds to the layer below.
Several materials are available for the process includinginvestment casting wax.
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STRATASYS Di i SST
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Build size:
Maximum size 203*203*305mm(8*8*12 inches)
Layer thickness:
0.245mm(0.010in) or 0.33mm(0.013in) of precisely deposited ABSand support material
STRATASYS - Dimension SST
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PEMP- AME2501FDM Applications: Functional Models
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FDM Applications: Functional Models
Key Characteristics (cont.)
Good MachinabilityMechanical Joining, Adhesive Bonding, and Welding ArePossibleSnap fit tests
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RP Application - Automotive
PEMP- AME2501Rapid Tooling - RP Patterns for Casting of Gear Box Casing
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Rapid Tooling - RP Patterns for Casting of Gear Box Casing
PEMP- AME2501Functional Design
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Functional Design
Toyota
Click to viewexamples
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Laminated Object Manufacturing (LOM)
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Laminated Object Manufacturing (LOM)
Schematic of Laminated Object Manufacturing (LOM)
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Laminated Object Manufacturing (LOM)
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Laminated Object Manufacturing (LOM)
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Processes Involving Solid Sheets
Laminated Object Manufacture
The Sheet Material is supplied from the roll and it passes on the Part blockPlaced over the Platform. A laminating roller rolls over the Sheet material andthe Laser beam is Impinged over the sheet material and it is cutoff from the
Sheet and Are placed layer by Layer one over another.
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LOM: The Process
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LOM: The Process
Slice thickness depends onmaterial and ranges from0.002" to 0.02". Materialsin use are,
- butcher paper
- plastics
- ceramics
- composites
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Laminated Object
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Laminated Object
Manufacturing
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LOM Applications: Functional Models
Key Characteristics:
Large Size Form and fit
Design verification Joining to form even largermodels/prototypes
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Advantages of LOM:
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1. Materials
LOM uses varieties of thin sheet included paper, plastic and composites. The
sheets are coated with heat sensitive adhesive, which enable the sheet to bebonded layer by layer by hot compression to form the part.
2. Properties
The parts created by LOM system are durable structures, which have a wide varietyof applications. The parts created may be sanded, polished, coated and painted.
3. Post-curing
Since LOM parts use papers, there is no need for post-curing.
4. Cost
There is no need of special polymer or wax to build the part. Thus this reduce the
cost of buying these special polymer.5. Stress
Since the part is bonded layer by layer, there is no induced stress in the
parts.
Advantages of LOM:
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The parts are built surrounded by wax, eliminating the need forsupport structures .
Once a layer has been exposed to the uv-lamp, the un-curedareas-those areas filled with residual, liquid polymer-are replaced
by wax.
This is done by wiping away the residual polymer and applying a
layer of wax. The wax is hardened by a cold metal plate, and subsequently, thelayer is milled to the correct height.
The milling station also allows for layers to be removed, i.e.anundo operation is possible. The new layer of polymer is applied
when the workspace moves from the milling station back to theexposure chamber.
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Selective Laser Sintering
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Selective Laser Sintering
Schematic of Selective Laser Sintering
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Working Principle of SLS
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SLS Functional Models: Nylon-
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S S u ct o a ode s: Ny o
BasedAvailable Materials
DuraForm Polyamide
Nylons
Glass reinforced nylons
Key Part Characteristics
Good Toughness
High Use Temperature = 163 - 188C
(DTUL @ 0.45 MPa)
Good Solvent Resistance
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The 3D Printing Process
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The 3D Printing Process
3D Printing Process
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Laser Engineering Net Shape (LENS)
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Laser Engineering Net Shape (LENS)
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L E i i N t Sh i
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Powder delivery nozzle
X-Y Motion
Focused laser beam
Laser Engineering Net Shaping
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Laser Engineering Net Shape (LENS)
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Laser Engineering Net Shape (LENS)
The most advanced process in terms of achieved mechanical
properties of generated metallic parts among all commercialprocesses based on layered manufacturing build principle.
The process uses a high power laser focused onto a substrateto create a molten puddle on the substrate surface.
Metal powder is then injected into the melt pool to increaseits volume. Powder ejection head moves back and forth inaccording to geometry of the first layer.
After the first layer is completed, new layers are then builtupon it until the entire object represented in the three-
dimensional CAD model is reproduced. Employment of a substrate makes this process different from
another ones, considered in this work.
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Laser Engineering Net Shape (LENS)
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Laser Engineering Net Shape (LENS)
This method can utilize wide range of metals and alloys(including super alloys) as a build material.
Relatively high cost of operation and of produced parts onthe on hand, and very high mechanical properties of
generated by this method objects on the other, do not allowto consider the method as a plain RP technique, or as ameans of visualization.
This technology became efficient only in case of functionalparts or tooling production.
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Comparison of some RP Processes
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Summary
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Summary
The Reverse Engineering concepts have been
discussed.
Various techniques, tools and applications of thereverse engineering have been presented.
An introduction to Rapid Prototyping has beenpresented.
Data transfer to RP and different RP techniques havebeen discussed.
Applications of RP have been discussed with casestudies