Fusion 360 Acting Weird: Resurrection of Deleted Geometry

[Blue_Wings]

Hi Guys,

Just started with Fusion 360 few weeks ago.

Downloaded an STL, converted to BRep and trying to recreate the model because it is not symmetric. Projected one of the model faces on a sketch, deleted all projected lines, and drew new ones on same sketch.

I noticed that my sketch is on the wrong plane and when I try to redefine the sketch plane, most of the projected purple lines that previously deleted, have re-appeared in the sketch on top of my geometry just after I redefined the sketch plane.

I am a complete beginner but it seems to me that this is an unexpected behavior. I would appreciate it if someone can explain to me what is going on. Please check the screencast.

Thanks !

[HughesTooling]

In preferences do you have auto project enabled? The setting Auto Project on active sketch plane will create a set of projected curves from the face you sketch on, they are not visible like curves you create. Personally I think autoproject is more trouble than it's worth and disable it. If I need a projection I press P and create it myself

You can see here the shaded area from sketching on a face, the curves around the edge are invisible until you mouse over them. When you redefine a sketch plane all projections are made into fixed curves without any waning which is pretty bad as well!

Mark