raylan rp ppt

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Rapid Prototyping Operations

Presentation by:

Raylan Vaz

1RV07ME082VII B



Introduction

Subtractive processes

Additive process Virtual Prototyping

Applications



Technology which considerably speeds the iterative productdevelopment process

Fig: a) Examples of parts made by rapid prototyping b) Stereolithography model of cellular

phone



CAD data files can be manufactured in hours.

Tool for visualization and concept verification.

Prototype used in subsequent manufacturingoperations to obtain final part

Tooling for manufacturing operations can beproduced



Rapid prototyping is classified to 3-majorgroups

Subtractive ( Removal of material )

Additive ( Adding of material )

Virtual ( Advanced computer basevisualization)



Subtractive process use computer based Prototype technology tospeed the process

Essential Technologies for subtractive prototyping :

Computer ² based drafting packages ( 3-D representation ofparts)

Interpretation software (Translation of cad file to manufacturingsoftware)

Manufacturing Software (Planning Machining operations)

Computer-Numerical Control Machinery



Build parts in layer by layer (slice by slice as stacking a loaf ofbread)

Fig: The computational steps inproducing a

stereolithography file a)

Three dimensional

description of part b)The

part is divides into slices

(only one in 10 is shown)

c)support material isplanned d)A set of tool

directions is determined to

manufacture each slice.

Shown is the extruder path

at section A-A from c) For a

fused-deposition-modeling

operation



Require elaborate software

1 : Obtain cad file

2 : Computer then constructs slices of a 3-dimensionalpart

3 : slice analyzed and compiled to provide the rapidprototyping machine

4 : setup of the proper unattended and provide roughpart after few hours

5 : Finishing operations and sanding and painting

6:labor intensive and production time varies from fewminutes to few hours



A gantry robot controlled extruder

head moves in two principledirections over a table

Table can be raised or lowered asneeded

Thermo plastic or wax filament isextruded through the small orificeof heated die

Initial layer placed on a foamfoundation with a constant rate

Extruder head follows a predetermined path from the file

After first layer the table islowered and subsequent layers areformed

Fig : (a)Fused-deposition-modeling process.

(b)The FDM 5000, a fused-decomposition-

modeling-machine.



Works based on the principle ofcuring liquid photomer intospecific shape

A vat which can be lowered andraised filled with photocurableliquid acrylate polymer

Laser generating U-V beam is

focused in x-y directions

The beam cures the portion ofphoto polymer and produces asolid body

This process is repeated till thelevel b is reached as shown in the

figure

Now the plat form is lowered bydistance ab

Then another portion of thecylinder is shaped till the portionis reached

Fig :Stereolithiography Process



Fig: The selective laser sintering process



SLS based on sintering of nonmetallic powders onto aselective individual objects

Basic elements in this process are bottom of processing

chambers equipped with 2 cylinders

Powder feed cylinder which is raised incrementally tosupply powder to part-build cylinder through a rollermechanism

Part-build cylinder which is lowered incrementally towhere the sintered part is formed.



Set of the proper computer files and the initiation ofthe production processes

Machine operate unattended and provide rough

part after few hours

Finishing operations as sanding and painting

Labor intensive & production time varies from fewminutes to few hours



Layer of powder is first deposited on partbuild cylinders

A laser beam controlled by instruction from3-D file is focused on that layer tracing &sintering a particular cross-section into asolid mass & dust is taken off.

Another layer of powder is now depositedthis cycle is repeated again and dust isshaken off



Also called Solid groundcuring

Entire slices of part aremanufactured at one time

So large throughput isachieved

Most expensive & time

consuming

The entire process isshown

Fig:The solid based curing process



Ballistic particle manufacturing

Stream of material , such as plastic ,ceramic, metal orwax ejected through small orifice at a surface

Mechanism similar to inkjet mechanism ( piezo-electricpump)

Operation repeats similar to other process to form apart with layers of wax deposited on top of each other

Ink jet heat guided by three-axis robot



Similar to ballistic particle manufacturingSimilar to ballistic particle manufacturing

Fig:Three dimensional printing process



Print head deposits an inorganic binder material

Binder directed onto a layer of ceramic metal powder

A piston supporting the powder bed is lower incrementallywith each step a layer is deposited and unified by binder

Commonly used materials ² Aluminum oxide, siliconcarbide,silica and zirconium.

Common part produced by 3-D printing is a ceramic castingshall

Curing around 150 C ² 300 F

Firing ² 1000C ² 1500 C



Laminated implies laying down of layers which areadhesively bonded to one another

Uses layer of paper or plastic sheets with heat activated glueon one side of the product parts

Excess material to be removed manually

Simplified by preparing the laser to burn perforations incross-sectional pattern

LOM uses sheets as thin as 0.05mm

Compressed paper has appearance and strength of soft wood, and often mistaken for elaborate wood carvings.



Fig : (a) Laminated object-manufacturing process (b)Crankshaft-part example made

by LOM



Virtual prototyping (modeling andsimulation of all aspects of a prototype, i.e.mechanical design, kinematics, dynamics,and controls accompanied by a realistic

visualization).

Realizing the best design in the shortestlead-time of complex products/processes

Allows the exotic, unconventional designsbe prototyped, rapidly and cost-effectively



Production of individual parts

Production of tooling by Rapid Prototyping (Rapid Tooling)

Fig: Manufacturing steps for investment casting that uses rapid prototyped wax parts as blanks.



The term Rapid Tooling (RT) is typically used to describe a process which

either uses a Rapid Prototyping (R P) model as a pattern to create a mold

quickly or uses the Rapid Prototyping process directly to fabricate a tool

for a limited volume of prototypes .

a)Tooling time is much shorter than for a conventional tool. Typically, timeto first articles is below one-fifth that of conventional tooling.

b) Tooling cost is much less than for a conventional tool. Cost can be below

five percent of conventional tooling cost.

c) Tool life is considerably less than for a conventional tool.

d) Tolerances are wider than for a conventional tool.



Fig: Manufacturing steps in sand casting that causes that uses rapid-prototyped patterns

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