In normal operation, the user draws lines and curves in a sketch. Those curves describe the geometry to be manufactured; ultimately, the endmill or the laser or some other tool will cut along those curves.
In some cases, it is useful to draw a line that should not appear on the final part. For example, the user may wish to draw a center line for a symmetric part; but that center line is only a guide, and should not actually get exported with the CAM data. These lines are called construction lines.
To mark an entity as construction-only:
- Choose .
A construction entity will behave just like any other entity, except that it is drawn in green, and does not contribute to the geometry for export (or to the section that will be extruded or lathed or swept).