1. RAPID PROTOTYPING
TECHNOLOGIES,APPLICATIONS
&PART DEPOSITION PLANNING
Johnbin johnson
S7 ME
26
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2. CONTENT
•
•
•
•
•
HISTORY
INTRODUCTION
PRINCIPLE & FLOWCHART
WHY RAPID PROTOTYPING?
RP PROCESSES
STEREOLITHOGRAPHY
FUSED DEPOSITION MODELING
LAMINATED OBJECT MANUFACTURING
SELECTIVE LASER SINTERING
•
PART DEPOSITION PLANNING
ACCURACY OF RP PARTS
PART DEPOSITION ORIENTATION
•
•
LIMITATIONS
APPLICATIONS
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3. HISTORY
• First phase-Manual prototyping by skilled craftsman (old
practice)
• Second phase-soft prototype modeled by 3D Curves &
surfaces (mid 1970)
• Third phase-rapid prototyping (1980)
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4. INTRODUCTION
• PROTOTYPE
A prototype is a model used to test and evaluate a design .it is
just a test version of an experiment or machine .Before the start
of full production a prototype is usually fabricated & tested .
• RAPID PROTOTYPING
Rapid Prototyping (RP) can be defined as a group of techniques
used to quickly fabricate a scale model of a part or assembly
using three-dimensional computer aided design (CAD) data.
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5. PRINCIPLE & FLOW CHART
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6. PRINCIPLE & FLOW CHART (con..)
•
•
First process in RP is generation of 3D model of the product
.Commonly used 3D CAD systems for this are
o Pro/E
o
UG
o
CATIA
o
IDEAS
Second process is tessellation of 3D model .Basically it is
generation of layer model .A STL file is created after
tessellation
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7. PRINCIPLE & FLOW CHART (con..)
• In next process slicing of model is done by various slicing
softwares like
MeshLab
openRP
Admesh
• Generated sliced data is stored in standard data formats like
SLC or CLI.
• The next stage of process is making of physical model in
which we use a RP system software.
• RP system software generates laser scanning path in which
material deposition should occur.
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8. PRINCIPLE & FLOW CHART (con..)
• Final stage is post processing or finishing of part in which
following process will occur
o Cleaning
o Polishing
o Painting
o Milling ,grinding etc..
 Prototype is then tested &suggested changes are once
again incorporated during the solid modeling stage.

9. TESSELLATION & SLICING
• Surfaces of CAD model are piecewise approximated by a
series of triangles.

10. TESSELLATION & SLICING
• In slicing the CAD model
is divided into number of
layers .slice thickness is
important thing we should
consider during this
stage.

11. Why Rapid Prototyping?
• The Prototype gives the user a fair idea about the final look of
the product.
• To increase effective communication between user &
designer.
• Decrease development time.
• Increasing number of variants of products.
• It is easier to find the design flaws in the early developmental
stages.
• cost effective.

12. PROCESSES
• One method of classification of RP process is based on state of
aggregation of their original material.

13. STEREOLITHOGRAPHY
• In this process liquid resin which forms a solid polymer is
exposed to UV rays.
• Main parts of SL machine is a build platform (mounted on vat)
& argon ion laser or UV Helium-cadmium laser.
• Laser scans first layer & platform is then lowered equal to one
slice thickness.
• A dip-delay is provided for the liquid polymer to settle to a flat
& even surface.
• Scanning speeds ~ 500 to 2500 mm/s.
• Once complete part is deposited ,it is removed from vat &
excess resin is drained.

14. STEREOLITHOGRAPHY (con)
stereolithography

15. STEREOLITHOGRAPHY (con)
A part produced by sterelithography
SL machine

16. FUSED DEPOSITION MODELING
• Main part of a FDM is a movable (x-y) nozzle.
• Molten polymeric material comes through this nozzle which
gets deposited on the substrate.
• Workhead is controlled in the x-y plane during each layer.
• Build material is heated slightly above its melting point so it
can solidifies easily.
• One layer will cold welds to previous layer.
• Part is fabricated from the base up, using a layer-by-layer
procedure.

17. FUSED DEPOSITION MODELING
(con..)
Fused Deposition Modeling

18. LAMINATED OBJECT
MANUFACTURING
• Profiles of object cross section are cut from paper or another
material by using laser.
• Power full CO2 Laser is used for this purpose.
• Paper is unwound from feed roll.
• It is bonded to previous layer with use of a heated roller.
• Heated roller activates a heat sensitive adhesive .
• Slices are cut by laser.
• Waste paper is wound on a take up roll.
• Once one slice is completed platform is lowered & same
process is repeated.

19. LAMINATED OBJECT
MANUFACTURING
LOM process

20. SELECTIVE LASER SINTERING
• In SLS same process as that in LOM is used.
• But in SLS fine polymeric powder like polycarbonate is used.
• Powder is spread over substrate using a power feed roller.
• CO2 laser beam sinters heat‑fusible powders.
• Grains having direct contact with laser beam fuse with
previous layer.
• Then bed is lowered & In areas not sintered, the powders are
loose and can be poured out of completed part

21. SELECTIVE LASER SINTERING
SLS process

22. PART DEPOSITION PLANNING
• It is very important because it decides
• part accuracy
• surface quality
• building time
• cost of part
• Accuracy of a part depends upon tessellation & slicing.
• Tessellation errors can be reduced by reducing size of
triangles.
• Slicing of CAD model with a very small slice thickness leads
to large build time .
• At the same time if large slice thickness is chosen, the surface
finish is very bad .
• Slicing errors can be reduced by using adaptive slicing

23. PART DEPOSITION ORIENTATION
• Selection of suitable part deposition orientation can reduce
part building time ,cost etc..
• But it is difficult & time consuming because we should
consider various processes.
• A multi objective genetic algorithm is proposed for part
deposition planning.

24. LIMITATION
• Poor surface finish due to Staircase appearance caused due to
layering .
• It may not be suitable for large sized applications.
• Limited strength.
• Some important developmental steps could be omitted to get a
quick and cheap working model.
• Mechanical performance of the fabricated parts is limited by
the materials used in the RP process .
• Shrinkage and distortion of RP parts.

25. APPLICATION
• Applications of rapid prototyping can be classified into three
categories:
1. Design .
2. Engineering analysis and planning .
3. Tooling and manufacturing.
• Designers are able to confirm their design by building a real
physical model in minimum time using RP
• It will help them to visualize the object, Early detection of
design errors , Reduced lead times etc..
• In Engineering analysis and planning we will be able to do
stress analysis ,flow analysis ,mock-up etc..

26. APPLICATION
• In tooling application Pattern is created by RP and the pattern
is used to fabricate the tool.
• RP is commonly used in industries like automotive ,aerospace,
jewelry ,biomedical etc…

27. nk yo u
Tha