stereo lithography presentation
TRANSCRIPT
A SEMINAR ON
GUIDED BY, PROF. PETER A R
PRESENTED BY, SOORAJ P N S7MB ROLL NO: 127
CONTENTS Prototyping Rapid prototyping process Stereo lithography
Machine Process Material used
Benefits Application Problems with RP Conclusion
PROTOTYPING
1. Subtractive (conventional process) Milling Grinding Turning
2. Compressive3. Additive
Photopolymer Thermoplastic Adhesives
Why Rapid Prototyping
Reduce product development time and cost
Get products to market sooner Enhance communications between
marketing, engineering, manufacturing, and purchasing
Present physical model at critical design reviews
Generate precise production tooling
Rapid Prototype Process You create a 3-D model of your object in a CAD program
Computer Aided Design (CAD)
Rapid Prototyping Device
3-D Object
BASIC PROCESS
Create CAD model of the design Conversion to STL format Slice the STL file Layer by layer construction Cleaning and finishing
Slices
Conversion of a solid model of an object into layers (only one layer is shown)
Software chops your CAD model up into thin layers -- typically five to 10 layers/millimeter
SLA Interface
Stereolithograpy was first commercial Solid Freeform Manufacturing process, released in 80’s by 3-D Systems
3-D Systems developed interface between CAD systems and their machine
STL files (*.stl) allow CAD systems to interface with 3-D system machines
Many CAD programs now can export the *.stl file for easy conversion from CAD to part
A typical Stereo lithography apparatus.
PARTS OF A SLA MACHINE Tank filled with several gallons of liquid
photopolymer. The photopolymer is a clear, liquid plastic. A perforated platform immersed in the tank. The platform can move up and down in the tank as the printing process proceeds. An ultraviolet laser A computer that drives the laser and the platform
INSIDE OF SLA MACHINE
SLA PLATFORM
MODELS ON PLATFORM
Polymer solidifies when struck by the laser’s intense UV light
Elevator lowers hardened cross section below liquid surface
Laser prints the next cross section directly on top of previous
After entire 3-d part is formed it is post-cured (UV light)
STEREO LIHOGRAPHY PROCESS
SLA MODEL BUILDS….
Stereolithography: (1) at the start of the process, in which the initial layer is added to the platform; and (2) after several layers have been added so that the part geometry gradually takes form
Stereo lithography Overview
LaserOpticsMirror Elevator
Laser is focused/shaped through optics. A computer controlledmirror directs laser to appropriatespot on photopolymer surface.Polymer solidifies wherever laserhits it.
When cross sectionis complete, elevatorindexes to prepare for next layer.
SLA MACHINE-OBJECT CURING PART
SLA Materials
Applications of SLA Technology
Aesthetic & conceptual models
Parts requiring detail & accuracy
Master patterns for castings
Benefits of SLA
Crisp, highly-detailed pieces
Speed of delivery (usually 2-3 days)
Tolerances within .005"/inch
Save Money Save Time
Test Product Catch Errors Improve Design Rapid
Manufacturing
Problems with Rapid Prototyping
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 is limited by the materials that is used in the RP process
Conclusions
Stereolithography is fast and effective. Stereolithography can be applied to
almost every industry, including oil refining, petrochemical, power and marine.
Stereolithography saves time, money, allows speed delivery, and improve designs
A MODEL..