Stratasys P750K, User Manual

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DOC08010 Rev. A (DRAFT 1)
3–3
Stratasys P750K User Guide
Source Files
Objet ȱ 3D ȱ printing ȱ systems ȱ produce ȱ three Ȭ dimensional ȱ models ȱ designed ȱ
with ȱ most ȱ 3D ȱ CAD ȱ tools ȱ and ȱ with ȱ other ȱ job Ȭ specific ȱ 3D ȱ applications. ȱ
Stratasys ȱ systems ȱ accept:
•
STL ȱ Files
•
SLC ȱ Files
Stratasys ȱ systems ȱ feature ȱ the ȱ capability ȱ of ȱ producing ȱ different ȱ types ȱ of ȱ
model ȱ files ȱ simultaneously.
STL Files
STL ȱ is ȱ short ȱ for ȱ Standard ȱ Triangulation ȱ Language. ȱ This ȱ language ȱ views ȱ any ȱ
object ȱ as ȱ a ȱ collection ȱ of ȱ surfaces, ȱ and ȱ describes ȱ each ȱ surface ȱ of ȱ the ȱ object ȱ as ȱ
a ȱ collection ȱ of ȱ triangles. ȱ
For ȱ example, ȱ a ȱ square ȱ can ȱ be ȱ described ȱ as ȱ two ȱ triangles; ȱ a ȱ cube ȱ (six ȱ
squares) ȱ as ȱ 12 ȱ triangles. ȱ Curved ȱ surfaces ȱ need ȱ more ȱ triangles ȱ to ȱ describe ȱ
them. ȱ The ȱ higher ȱ the ȱ tolerance ȱ (for ȱ smooth ȱ surfaces), ȱ the ȱ more ȱ triangles ȱ are ȱ
needed. ȱ The ȱ result ȱ is ȱ that ȱ high Ȭ quality ȱ object ȱ descriptions ȱ mean ȱ very ȱ heavy ȱ
files. ȱ
Most ȱ CAD ȱ software ȱ can ȱ export ȱ STL ȱ files. ȱ The ȱ Stratasys ȱ system ȱ utilizes ȱ
these ȱ files ȱ for ȱ building ȱ models ȱ (rapid ȱ prototyping), ȱ and ȱ also ȱ for ȱ directly ȱ
making ȱ molds ȱ for ȱ mass Ȭ producing ȱ items.
STL ȱ files ȱ can ȱ be ȱ ASCII ȱ (text) ȱ files ȱ or ȱ binary ȱ files. ȱ The ȱ content ȱ of ȱ the ȱ ASCII ȱ
file ȱ begins ȱ with ȱ “solid” ȱ and ȱ ends ȱ with ȱ “end Ȭ solid” ȱ (both ȱ lower ȱ case). ȱ
Between ȱ these ȱ keywords ȱ is ȱ a ȱ list ȱ of ȱ the ȱ triangles ȱ that ȱ describes ȱ the ȱ faces ȱ of ȱ
the ȱ solid ȱ model. ȱ Each ȱ triangle ȱ defines ȱ a ȱ single ȱ normal ȱ vector ȱ directed ȱ away ȱ
from ȱ the ȱ solid’s ȱ surface, ȱ followed ȱ by ȱ its ȱ X Ȭ Y Ȭ Z ȱ coordinates. ȱ These ȱ are ȱ
expressed ȱ as ȱ Cartesian ȱ coordinates ȱ and ȱ are ȱ floating Ȭ point ȱ values. ȱ The ȱ
coordinates ȱ of ȱ all ȱ triangles ȱ should ȱ be ȱ positive ȱ and ȱ should ȱ fall ȱ within ȱ the ȱ
volume ȱ of ȱ the ȱ model. ȱ
SLC Files
SLC ȱ is ȱ short ȱ for ȱ Stereo Ȭ Lithography ȱ Contour. ȱ SLC ȱ files ȱ describe ȱ two Ȭ
dimensional ȱ contours ȱ of ȱ the ȱ three Ȭ dimensional ȱ models. ȱ These ȱ contour ȱ lines ȱ
are ȱ polylines. ȱ
SLC ȱ files ȱ are ȱ ASCII ȱ (text) ȱ files ȱ that ȱ save ȱ models ȱ as ȱ a ȱ series ȱ of ȱ slices. ȱ This ȱ
means ȱ that ȱ models ȱ based ȱ on ȱ SLC ȱ files ȱ cannot ȱ be ȱ orientated; ȱ only ȱ their ȱ scale ȱ
(size) ȱ and ȱ position ȱ on ȱ the ȱ build ȱ tray ȱ can ȱ be ȱ controlled. ȱ For ȱ this ȱ reason, ȱ the ȱ
model’s ȱ orientation ȱ must ȱ be ȱ suitable ȱ for ȱ production ȱ before ȱ it ȱ is ȱ saved ȱ as ȱ an ȱ
SLC ȱ file. ȱ Because ȱ of ȱ the ȱ nature ȱ of ȱ SLC ȱ files, ȱ the ȱ appearance ȱ of ȱ models ȱ in ȱ
Objet ȱ Studio ȱ may ȱ be ȱ different ȱ than ȱ the ȱ solid Ȭ object ȱ images ȱ displayed ȱ from ȱ
STL ȱ files.