CAD-Line > STL Import tab
See also : CAD-Line dialog
Use the CAD-Line dialog > STL Import tab to:
•Import 1 x STL file •Edit the STL File Units to those Linear Units of the STL file that you save in your CAD. •Edit the Edge Angle Limit to remove ghost lines in the CAD-Solid that represents the STL-file |
Use the STL Import tab if you do not have SOLIDWORKS.
Before and when you save an STL file in your CAD:
Rotate the model in your CAD to the correct orientation relative to the XY-Plane of the Mechanism-Editor before you import it. Save the model (in your CAD software) as a Binary STL file-type. Remember the Linear units. If you cannot edit the STL units, they will be SI units - meters (m). |
After you import an STL file:
See Display Options tab to move the STL file in the X, Y, Z-axis directions. |
CAD-Line dialog
STL Import tab
CAD-Line dialog > STL Import tab
|
To import an STL file:
Note: To see the CAD-Solid, enable Visibility toolbar > Show Solids in Mechanisms
Top-Tip I find these options are a good compromise between the quality of the image, accuracy of the CAD-Solid, and the file-size of the STL file. Edge Angle Limit =80 (STL Import tab) Linear Deviation = 0.04 (SOLIDWORKS tab) Angular Deviation =30 (SOLIDWORKS tab) |
||
 Image with too many Facet-Edges |
|||
 Image with Facet-Edges OK |
STL FILE-SIZE
The STL file tessellates the surfaces of the CAD model as a mesh of triangles. Each triangle appears as a small face - which we call a facet. The number of facets is a function of: •the complexity of the original CAD model, and •how accurately you want the STL file to tessellate the original CAD model. To build complex models, and to import many STL files, you want: Small file-size for each STL file - AND each STL file to appear as the original CAD model - AND to see only those facets that define real edges in the CAD model. |
Strategies to reduce the STL file-size.
Strategy 1: Reduce the complexity of the original CAD Model = SMALL file-size Add a new configuration for the CAD model. In the new configuration: •Do a geometry check of the CAD model file to find if it has any small gaps or whiskers. •Suspend small fillets, especially if they do not have a function. •Replace fillets with chamfers, especially along straight edges. •Suspend all fasteners •Suspend fastener holes and hole features. •Suspend all cosmetic details. •Simplify bearing models, and other complex models you may have downloaded from the internet. Strategy 2: Reduce the accuracy of the STL file There parameters are in the SOLIDWORKS tab. Linear Deviation : The maximum Linear deviation (distance) between the surface of the original CAD model and the tessellated surface of the STL file. Angular Deviation : The maximum angular deviation between adjacent facets of the tessellated surface of the STL file. If you do not have SolidWorks, you must find these parameters in your 3D-CAD before you save to the STL file. It is possible they are options in the Save as > STL file-type dialog. Strategy 3: Use the Edge Angle Limit parameter - see Import STL File above STL files will show their facets if the angle in Edge Angle Limit is less than the facet of the CAD-Solid. Experiment. Import the model again each time you edit Edge Angle Limit (80 degrees). Examples Below, the two images are of the same SOLIDWORKS part. They appear to be identical. However, there is a large difference in the number of facets and vertices. |
|
 STL tessellation: Large number of Vertices |
BAD - many facets •Linear Deviation = 0.014mm and •Angular Deviation = 0.4º There are •119132 vertices •~40000 triangles •The STL file size is 3.5 Mega Bytes |
 STL tessellation: Few number of Vertices |
GOOD - few facets •Linear Deviation = 0.5mm and •Angular Deviation = 5º There are: •7533 vertices •2500 triangles •The STL file size is 0.365 Mega Bytes GOOD - few facets •Linear Deviation = 0.05mm •Angular Deviation = 30º •Edge Angle Limit = 80º There are: •7533 vertices •2500 triangles •The STL file size is 0.365 Mega Bytes |