Selective Laser Sintering By: Tyler Killgore Period 2B 11/11/2008AD
What it does A rapid prototyping technology in which powders are fused layer wise by a laser. The technology produces accurate parts and models in engineering polymers, metals and polymer-coated sand for casting applications. Speed is similar to stereolithography, but material selection is wider.
How It WorksStep 1 • The Selective Laser Sintering (SLS) begins with A 3-D cad machine. Next your file is mathematically processed into 2-D cross sections.
Step 2 • Step 2: The SLS machine starts out with 2 powder magazines on either side of the build chamber. The powder is then heated to just below its melting point. This is done so that the laser will only have to heat the powder a little bit to can cause sintering. Then the leveling roller forces the powder and other material over onto the build area. A CO2 laser beam is then steered by a scanning system draws the 2D cross sections on the surface of the building material, which then sinters the powder. The platform then descends a layer thickness. The leveling roller pushes material from the powder cartridge across the build platform, where the next cross section is sintered to the previous. This continues until the part is completed
Step 3 • After the object is fully formed, the piston is raised to elevate it. Excess powder is brushed away and final manual finishing may be carried out. No supports are required with this method since overhangs and undercuts are supported by the solid powder bed.
Martial Used • Nylonbased substance that creates highly durable and functional plastic prototypes • Flex plastic for elastomeric parts. • Rubber like parts for metal prototypes.
AdvantagesDisadvantages • Cost-effective. Directly manufacture customized short production runs. • Productive. Go from 3-D CAD design to finished part in one step. • Tool-less. Eliminate the time and expense of tooling. • Design for function. No limitation on design complexity. • One disadvantage is that it cannot make really big parts at one time.
Other Information • The Selective Laser Sintering (SLS) was first introduced in 1989 by Dr. Carl Deckard. • It cost about $300.00 per month • The SLS uses a STL file.
Key Terms • Additive: A substance added in small amounts to something else to improve, strengthen, or otherwise alter it. • Subtractive: Capable of or involving subtraction • Compressive: Serving to or able to compress • Slice File: a unique type of file; they contain (or reference) a single piece of sample data, have a list of markers denoting "slices" of the sample, and also have a set of parameters such as tempo and time signature.
Citations http://home.att.net/~castleisland/glos.htm www.dpt-fast.com/rapidprototyping/sls.asp http://www.selecteng.com/sls.htm http://westinghouse.marc.gatech.edu/Members/cwilliams/classes/ME6796.RPMetal.CBW.pdf http://www.westsiderc.org/v/Sample%20SLS%20Category%20A%20Cost%20Statement%20(2).pdf