Handout 10_Rapid Prototyping-Rapid Tooling

Rapid Prototyping / Rapid ToolingRapid Prototyping / Rapid Tooling

• Rapid Prototyping (RP) refers to the physical modeling of a designusing a special class of machine technology.

• The input to these Rapid Prototyping machine is an output formatfrom a CAD data called *.STL

• Using additive approach to building shapes, RP systems joinliquid, powder or sheets of materials to form physical objects.

CAD DataCAD Data RP SoftwareRP Software RP MachineRP Machine

*.STL file

The model is slicedin Z axis of uniformthickness which creates an SLI file.

*.SLI file

The SLI model is fabricated in layer by layer starting from bottom to top.

The model is createdin any CAD Softwareand saved as STL file.

(The entireprocess isSimple &Automatic)

3D CAD Data3D CAD Data

Paper draw

D2-CAD-Model

CAD-Volume-Model

3D-CAD-Suface-Model

Not Suitable Format

Suitable Format

Major TechnologiesMajor Technologies

Selective Laser Sintering (SLS)Selective Laser Sintering (SLS)

Layer Generation

.SLI format

.STL data

Building ProcessBuilding Process

Recoater

LoosePowder

PlatformLoose Powder

Frame

Part

LaserOpticsScanner

Major TechnologiesMajor TechnologiesSelective Laser Sintering (SLS)Selective Laser Sintering (SLS)

3D-Printing Technique (3DP)• 3D Printing is a Rapid Prototyping technique

• The sectional and solid-drawing of the component constructed using any standard drawing software are acceptable

• The drawing need to be converted to STL (stereo-lithographic) file format

• The process step consists of ‘printing’ the component layer by layer on a bed of finely dispersed powder with intermittent chemical and thermal curing of the formed layer

• Subsequent to each layer being created, the platform supporting the powders bed incrementally moves down, this enables the creation of the second layer.

Unique Features:• A range of complicated shapes can be created (e.g. undercuts, internal cooling channels, conjoined/concentric parts)• Flexibility (one can buildup a cylinder in both vertical as well as horizontal axis position• Prototype Material can be normal strength polymer; a flexible elastomer, or a high strength material.

Potential Application:As an educational and research tool; For prototype component fabricationFor rapid tooling Jobbing

3D-Printer

Cleaning & Recycling Chamber

Miniature gear(80 µm thickness)

being printed

Top-View and Solid Drawing of Gear-1

Top-View and Solid Drawing of Gear-2

Gear-1 and Gear-2 were stacked one on top of another

• A separation of 160 µm was left by leaving the polymer particles uncured so as to facilitate subsequent separation of the two parts

• Total printing time taken [Gear-1 (35 min); Gear-2 (40 min)]

Primary Cleaning of After Part Fabrication

• Subsequent to this the parts were further cleaned in air-blow chamber. The loose powders was collected through air-suction

• The cleaned parts were resin infiltrated (optional step) to impart greater strength to the prototype

40 mm

Prototype Parts

10 mm

Prototype Part

Part thickness: 240 µm

20 mm

Prototypes Fabricated in Engineering Metallurgy Lab

Unassembled• Both components fabricated simultaneously

Assembled

Prototypes Fabricated in Engineering Metallurgy Lab

10 mm