User's Manual

DOC08010 Rev. A (DRAFT 1) 3–3
Stratasys P750K User Guide
Source Files
Objetȱ3DȱprintingȱsystemsȱproduceȱthreeȬdimensionalȱmodelsȱdesignedȱ
withȱmostȱ3DȱCADȱtoolsȱandȱwithȱotherȱjobȬspecificȱ3Dȱapplications.ȱ
Stratasysȱsystemsȱaccept:
STLȱFiles
SLCȱFiles
Stratasysȱsystemsȱfeatureȱtheȱcapabilityȱofȱproducingȱdifferentȱtypesȱofȱ
modelȱfilesȱsimultaneously.
STL Files
STLȱisȱshortȱforȱStandardȱTriangulationȱLanguage.ȱThisȱlanguageȱviewsȱanyȱ
objectȱasȱaȱcollectionȱofȱsurfaces,ȱandȱdescribesȱeachȱsurfaceȱofȱtheȱobjectȱasȱ
aȱcollectionȱofȱtriangles.ȱ
Forȱexample,ȱaȱsquareȱcanȱbeȱdescribedȱasȱtwoȱtriangles;ȱaȱcubeȱ(sixȱ
squares)ȱasȱ12ȱtriangles.ȱCurvedȱsurfacesȱneedȱmoreȱ
trianglesȱtoȱdescribeȱ
them.ȱTheȱhigherȱtheȱtoleranceȱ(forȱsmoothȱsurfaces),ȱtheȱmoreȱtrianglesȱareȱ
needed.ȱTheȱresultȱisȱthatȱhighȬqualityȱobjectȱdescriptionsȱmeanȱveryȱheavyȱ
files.ȱ
MostȱCADȱsoftwareȱcanȱexportȱSTLȱfiles.ȱTheȱStratasysȱsystemȱutilizesȱ
theseȱfilesȱforȱbuildingȱmodelsȱ(rapidȱprototyping),ȱandȱalsoȱforȱdirectlyȱ
making
ȱmoldsȱforȱmassȬproducingȱitems.
STLȱfilesȱcanȱbeȱASCIIȱ(text)ȱfilesȱorȱbinaryȱfiles.ȱTheȱcontentȱofȱtheȱASCIIȱ
fileȱbeginsȱwithȱ“solid”ȱandȱendsȱwithȱ“endȬsolid”ȱ(bothȱlowerȱcase).ȱ
Betweenȱtheseȱkeywordsȱisȱaȱlistȱofȱtheȱtrianglesȱthatȱdescribesȱtheȱfacesȱofȱ
theȱsolidȱmodel.ȱEachȱtriangle
ȱdefinesȱaȱsingleȱnormalȱvectorȱdirectedȱawayȱ
fromȱtheȱsolid’sȱsurface,ȱfollowedȱbyȱitsȱXȬYȬZȱcoordinates.ȱTheseȱareȱ
expressedȱasȱCartesianȱcoordinatesȱandȱareȱfloatingȬpointȱvalues.ȱTheȱ
coordinatesȱofȱallȱtrianglesȱshouldȱbeȱpositiveȱandȱshouldȱfallȱwithinȱtheȱ
volumeȱofȱtheȱmodel.ȱ
SLC Files
SLCȱisȱshortȱforȱStereoȬLithographyȱContour.ȱSLCȱfilesȱdescribeȱtwoȬ
dimensionalȱcontoursȱofȱtheȱthreeȬdimensionalȱmodels.ȱTheseȱcontourȱlinesȱ
areȱpolylines.ȱ
SLCȱfilesȱareȱASCIIȱ(text)ȱfilesȱthatȱsaveȱmodelsȱasȱaȱseriesȱofȱslices.ȱThisȱ
meansȱthatȱmodelsȱbased ȱonȱSLCȱfilesȱcannotȱbeȱorientated;ȱonlyȱtheirȱ
scaleȱ
(size)ȱandȱpositionȱonȱtheȱbuildȱtrayȱcanȱbeȱcontrolled.ȱForȱthisȱreason,ȱtheȱ
model’sȱorientationȱmustȱbeȱsuitableȱforȱproductionȱbeforeȱitȱisȱsavedȱasȱanȱ
SLCȱfile.ȱBecauseȱofȱtheȱnatureȱofȱSLCȱfiles,ȱtheȱappearanceȱofȱmodelsȱinȱ
ObjetȱStudioȱmayȱbeȱdifferentȱthanȱtheȱsolidȬobject
ȱimagesȱdisplayedȱfromȱ
STLȱfiles.