VisualCAM FAQs > System Errors > I'm Getting Geometry-Related Errors, What can I do?

If you suspect that the geometry you are using for CAM operations is causing problems there are a few things you can do.

What to Look For:

•If your toolpaths will not generate.

•If you get geometry related messages such as "Open loops found. Cannot proceed."

•If you import or open a part geometry file and the CAD system slows down noticeably.

•Any other geometry related concerns.

What You Can Do for Curve Related Concerns:

•There may be times when you suspect that your NURBs curve geometry is causing a problem. "NURBs" stand for "Nonuniform Rational B-Splines".

•In the CAD system, there are commands that will simplifying the curve into lines and arcs within a set operational tolerance. Meaning that in most cases, you will not notice a difference in the resulting simplified curve.

In VisualCAD you will find curve editing commands on the Curve Modeling ribbon bar under the Edit Curves section.

•Always merge curves before using them in CAM operations. This will ensure that there are no open loops. The term "open loops" simply means that your geometry is not connected end-to-end when the CAM system needs them to be. If after merging the curves, there is still more than one curve, zoom into the end points and connect them manually, using a small line. Then try merging again until the merge completes and there is only one curve.

•You can export the curve geometry out from the CAD system using a neutral format such as DXF, DWG, or IGES. Then import the neutral file back into the CAD system. This round-trip conversion will redefine the geometry and make it suitable for importing into the CAD system within the CAD system's currently defined operating tolerance.

•Enable Use Visual Indicators: Both Rhino and VisualCAD include commands that enable visual indicators on curves such as the start point and direction. In . In VisualCAD go to Home > Options > Display.

•Look for the Start Point (VisualCAD/CAM & RhinoCAM): After generating a toolpath operation that uses a merged or joined curve as Control Geometry, VisualCAD/CAM will highlight the geometry when the toolpath operation is selected from the Machining Job tree. The start point of the curve is shown with an orange rectangle. If the curves are merged successfully, you will see only one start point.

What You Can Do for Surface Related Concerns:

•If you suspect that you have surfaces that are causing problems, here are some things you can do.

•All CAD surfaces have a "normal" direction. This means that the surface has a front and a back. If you have a surface that is inverted, meaning that the back of the surface is facing outward, then there may be CAD tools available to you to "flip" the normal direction of the surface.

•In the CAD system, there may be commands that will simplifying the surface into multiple surfaces within a set operational tolerance. Meaning that in most cases, you will not notice a difference in the resulting simplified surfaces.

•You can export the surface geometry out from the CAD system using a neutral format such as IGES (*.igs) or STEP (*.stp or *.step). DO NOT USE STL (*.stl or *.sla) for these are faceted mesh formats, unless the original geometry is a mesh, then import the neutral file back into the CAD system within the CAD system's currently defined operating tolerance. This round-trip conversion will redefine the surfaces and may fix many geometry related errors.