Data which is universally understood in 2D or 3D packages is referred to as neutral data.  All companies have their own export and import translators for neutral data therefore there can be differences across packages.

 

Exporting 3D data

Common neutral file formats: STEP, IGES, VRML, STL

Assembly issues – if your assembly is not fully constrained then you may get positioning errors in the translated neutral file.

STEP and IGES maintain the surface geometry and the assembly structure – best for rendering.

 

Exporting an .stl file

Save a copy

Set the file type to .stl

DON’T change the name of the stl file in the Export STL window

The window will give you 2 setting; chord height and angle control.

For maximum resolution input the minimum figure in chord height (input zero, hit enter, the system will set it to the minimum allowable) and enter 1.0 [range 0 to 1.0] in angle control will give the maximum surface quality.

Caution – maximising these figures will also give maximum .stl file size – these can become very big and therefore slower to process.  Export at an appropriate level for the end use of the .stl.

Apply the setting – this will show the facets

Click OK to export the file

Notes:

1. STL – stereolithograghy file – facet file

6400.stl_example

The file consists of a Cartesian point cloud which lie on the original surface.  The points are then joined to form three sided facets.  Each facet has a positive and negative side.

2.  Chord Height – the deviation of the facet surface from the original surface.  The points at the corners of the facets will lie on the original surface but the centre of the planar facet will deviate from the surface – the distance between the three points and the curvature of the surface will dictate the deviation – the chord length.

6400.stl_chordheight

  1. Chord height
  2. Part surface
  3. Facet surface

6400.stl_chordheight_example

Consider the above with reference to 3D printing

3.  Angle control – provides extra improvement on surfaces with a high curvature – small radius.

 

Exporting 2D Geometry

The laser and waterjet cutters need neutral 2D geometry to drive them, the dominant neutral 2D geometry is DXF.  This format needs to be exported from an engineering drawing.

Use a paper size big enough to accommodate your part

Choose empty – no border or table

Generate the planar view at 1:1 scale

Save As and choose the DXF extension > OK

DXF Version > 12

4000.dxf.export.window

 

IDD – Import Data Doctor

Edit and repair imported neutral geometry