Curves
Projected onto Faces 
Insert 
Wireframe Curves
(Part Level)
Use this command to project curves or a sketch
onto faces and/or datum planes. By default, the curve is projected normal
to the faces or planes. Use the Direction option to select a different
project direction.
You can also choose to limit the projected curve to the face's trim boundaries. If more than one curve is created, they become a single feature. If the Options Form is displayed, middle-click to execute the command.
Curves - Select a sketch, curves, or middle-click to Create a Feature Sketch.
Faces - Select faces or datum planes to project curves onto.
Restrict face to trim boundary - Use this option to project only to the trim boundaries of a face. If you are projecting onto a trimmed face, selecting not checking this box will produce a curve that extends to the entire untrimmed boundary of the face.
Bi-directional
projection - 
Use
this option to project the curves in both the positive and the negative
directions relative to the direction of projection.
