Redefining the Splines Click Centerline (Sketch toolbar), and do the following: Sketch two vertical lines coincident to the end points of the splines. Sketch a vertical line coincident to the sketch origin. Click Add Relation (Dimensions/Relations toolbar). In the graphics area, select the centerline coincident to the sketch origin, and one of the other centerlines. In the PropertyManager, under Add Relations, click Parallel , then click . Repeat steps 2 through 4 with the other centerline as shown. Parent topic3D Sketching with Planes Previous topic Creating the First Splines Next topic Adding Curvature to Splines