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+ | ====== Information about creating and using STL files for Rapid Prototyping applications ====== | ||
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+ | * [[http:// | ||
+ | * [[http:// | ||
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+ | =====What is an STL?===== | ||
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+ | An STL, or Standard Template Library, is a standardized computer exchange file which contains a 3D model. | ||
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+ | The name STL is taken from its extension, .stl, originally because the files were intended for a rapid prototyping process called Stereolithography. | ||
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+ | =====Mesh models and precision===== | ||
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+ | Mesh representations of objects are faceted, i.e. they are not smooth, but composed of an array of small faces which, if fine enough, can represent smooth surfaces with a given degree of accuracy. | ||
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+ | If the individual facets in a mesh model are too coarse or there is too much of an angle between them, the model appearance will be rough, and it will lack precision. | ||
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+ | If the individual facets in a mesh model are too fine, the surface representation will generally be good, but the model will be data heavy and the file large. This may cause problems with the generating or receiving software, as well as the visual display on the screen. | ||
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+ | In one way, mesh precision may be thought of as the greatest difference allowed between the faceted mesh representation of the surfaces and the smooth surfaces themselves. | ||
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+ | The prototyping process used to create the final object determines the optimum level of precision and tolerance required for the model. | ||
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+ | Since an STL mesh is composed entirely of triangles, it is the simplest form of mesh model format. | ||
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+ | In actual practice, some tolerance is allowed. | ||
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+ | =====Creating STLs from Rhino models===== | ||
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+ | Rhino models are created with mathematically determined smooth curves and surfaces called [[rhino: | ||
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+ | For RP purposes it is very important that the Rhino surface model be a closed volume (closed valid surface or polysurface). | ||
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+ | If there are a few naked edges, you can usually use the V3 bonus mesh tools or V4 mesh tools to fix them. Commands like MatchMeshEdge, | ||
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+ | =====Export mesh settings===== | ||
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+ | We recommend that you use the custom/ | ||
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+ | <color red> | ||
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+ | Stereolithography | ||
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+ | SLS | ||
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+ | FDM (Stratasys) | ||
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+ | Polyjet printer (Objet) | ||
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+ | Z-Corp machine | ||
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+ | [[rhino: | ||
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+ | Invision | ||
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+ | Etc. | ||
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+ | For FDM use, I have found a reasonable group of settings are: | ||
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+ | Max angle: 30 | ||
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+ | Max dist edge to srf 0.01 | ||
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+ | Initial grid quads 16 | ||
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+ | All others 0 | ||
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+ | Refine checked | ||
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+ | All others unchecked. | ||
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+ | // | ||
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+ | For Jewelery (rings) printing on a [[rhino: | ||
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+ | Min Edge length: 0.02 | ||
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+ | Max Edge Length: 0.3 to 0.6 (0.3 takes longer, but is worth it) | ||
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+ | Max dist edge to srf 0.001 to 0.005 (0.001 takes longer, but is also worth it) | ||
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+ | All other settings = 0 | ||
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+ | Refine checked | ||
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+ | All others unchecked | ||
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+ | Later | ||
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+ | Evert | ||
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+ | // | ||
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