Topic: IGES Export Settings tips -- Any CAD System

Technote 82 Date: 06/94 Product: SmartCAM Advanced Milling, SmartCAM Freeform Machining  Version: Up to v11.5

Steps in Conversion Process:

1. Pre-Processing on the CAD System:

Explode subfigures.

Convert offset surfaces to spline surfaces.

Pick only the surfaces you need to export to FFM.

 

2. Export to IGES from CAD system:

Convert all surfaces to IGES entity 128 (B-spline).

Convert all spline curves as IGES entity 126 (B-spline).

Output XYZ data (model space curves) in addition to UV data (parameter space curves) for trimmed surfaces.

Export all surfaces as IGES entities 142/144 (Curve on Parametric Surface/Trimmed Surface). (First Preference)

Export all surfaces as IGES entities 141/143 (Boundary Entity/Bounded Surface). (Second Preference)

 

3. Import into SmartCAM:

FFM Import Settings:

First Preference:
U, V Count = 1, 1
Tolerance = .01 inches


Second Preference:
U, V Count = 0, 0
Tolerance = .01 inches
(Faster, but cannot tell difference between surface patches and picking surfaces may be difficult.


Third Preference:
U, V Count = 3, 3
Tolerance = .005 inches
Slower, but more descriptive on complex surfaces.

Create a log file. Use the log file to review error messages for the import.

 

4. Post-Processing in SmartCAM:

Checking and debugging the model:

Do Dynamic View & see that surfaces look connected or look like your engineering drawing.

Use View--Render Image to see that the image looks like the part or like your engineering drawing.

Look at your log file & check for errors or lost surfaces.

Review the release notes for known limitations in IGES transfers.

Test the surface by doing:

Property Chg--Surfaces to change the number of display grid curves and see if the surface still looks good.

Do a Render Image and see if the surface looks good.

Do a Surface Machine--Straight and check that the toolpath follows the surface.

Replace bad surfaces with new ones or edit surfaces by:

Mesh Edit--Generate Mesh to get a mesh that covers the surface.

Mesh Edit--Extract--Trimming Curves to get wireframe elements at the boundary edges.

Group Trim to trim the mesh back to the trimming curves.

Create--Surface--From Mesh to create the new surface.

Review computer hardware setup in case of a crash or out of memory error. Do you have the minimum RAM and minimum virtual memory?