Definition
It refers to a process by which digital 3D design data is used to build up a component in layers by depositing material.
"What you see is what you build process "
Difference between rapid prototyping and additive manufacturing
- AM , also known as 3d printing , rapid prototyping and free form fabrication.
- Although the terms 3d printing and rapid prototyping are casually used to discuss additive manufacturing , each process is actually a subset of additive manufacturing .
- Additive manufacturing adds material to create an object .
- By contrast when you create a object by traditional means it is often necessary to remove material through milling , machining , carving , shaping or other means.
How does AM work?
- Objects are digitally designed by computer aided design software that is used to create .stl files that essentially slice the object into ultra thin layer.
- This information guides the path of a nozzle or print head as it precisely deposits material upon the preceding layer.
- Or a laser or a electron beam selectively melts or partially melts in a bed of powdered material . as material cooled down or are cured they fuse together to form a three dimensional object.
Generic AM process
- Cad
- Stl convert
- File transfer to machine
- Machine setup
- Build
- Remove
- Post process
- Application
Cad model into stl format
- Stl uses triangles to describe the surfaces to be build . Each triangle is described as three points and a facet normal vector indicating the outward side of the triangle.
Generation of geometric layer information on single layers
- To produce 3d model by layer oriented additive manufacturing process , the 3d cad solid must be mathematically split into the same layers as those produced physically by the AM machine . This process is known as slicing.
- There are two basic methods of doing this :
- Triangulation which leads to the stl format
- Direct cutting in the cad system , which leads to the CL (SLI) format.
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