Can't make spline control points coincident in orthogonal planes

[Anonymous]

I am trying to loft an airplane fuselage using the crown and keel lines as the rails, and the cross sections as, well, cross sections.  

Here's the workflow:

Create the crown and keel splines as a sketch on the YZ plane.

Create an offset plane parallel to the XY plane at cross section A (first cross section near the nose)

Create cross section A on the offset plane as a spline.

I am trying to constrain the end points of the cross section A spline to the crown and keel splines. 

I have tried constraining the end points of the cross section A spline to the YZ plane, the side view canvas - anything to get them on the YZ plane, but I can only manipulate the spline in the XY plane - I can't edit the actual 3D point X,Y,Z value or anything.  What am I missing?

Also, when I edit the crown/keel sketch, my cross section A sketch is hidden.  When I edit the cross section A sketch I can still see the crown/keel sketch?  Why the difference?

 

Here's my file:

https://a360.co/2v06hRZ

Thanks!

-JimR

[etfrench · Accepted solution]

Try the Intersect command:

When you edit a sketch, the Timeline marker moves back in time to when the sketch was created.  Items created after that time will not be visible until you stop editing the sketch.  You can move items around in the Timeline, but they can't be moved past something they reference (or vise versa).  One way to overcome this is to create a new sketch, project the needed geometry, break links to all of the projected geometry, stop editing the sketch, move it back in time.

See also Rule #1

[davebYYPCU]

Your file is not accessible….

Just as Ed has shown, the only way to get it done, is with Project > Intersect.

Hints:

When drawing the section view turn off the keel sketch and it's canvass, snap to the purple points, 

Draw all the longerons, keels and other rails you want before the profiles, or Visa Versa, so much easier.

Might help....

[TrippyLighting]

Few tips here from the battle front of surfacing :

1. Use as few spline control points as you can get away with. the name of the game is Curvature and not precision, so don't try to precisely replicate a shape but create a good approximation. Use the spline tangent handles to modify the shape and only ass spline fit points is absolutely necessary. 

2. There are three tools in the inspection menu that help you check the quality of your surfaces, the curvature comb, the zebra stripes and the curvature map. Make frequent use of them. When sketching a spline you can right-click on the curve and toggle the curvature comb display on and off. Again, make frequent use of it! Surfaces are created from curves, so good curves are a prerequisite for good surfaces.

3. Just as with spline points, use as few rails and profiles for lofting as you can get away with. More is less when it comes to lofting.