Deleted Geometry Reappears on Redefined Sketch Plane

[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 !

[jhackney1972]

Your Screencast did not make it to your post.   Also I would be helpful to attach your model so the forum users can troubleshoot it directly.

[Blue_Wings]

Hi @jhackney1972 , many thanks for your reply and for pointing that out. Turns out you need to click insert after selecting the screencast. I am learning new things!

I have included the screencast now.

[Blue_Wings]

I received a solution from Mark @HughesTooling on my Dashboard. Not sure his response was deleted and my original post also deleted so I re-posted the one above. But I could read the solution on my Dashboard (meanwhile this post does not appear in the dashboard!?!). Thanks Mark for your solution. Here is his message:

" 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:  "

[HughesTooling · Accepted solution]

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@Blue_Wings wrote:

I received a solution from Mark @HughesTooling on my Dashboard. Not sure his response was deleted and my original post also deleted so I re-posted the one above. But I could read the solution on my Dashboard (meanwhile this post does not appear in the dashboard!?!). Thanks Mark for your solution. Here is his message:

" 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:  "

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@Blue_Wings  Thanks for the reply and tagging me in on this thread.

Here's the picture I added in my original post for reference.

Also example of a sketch on face with invisible curves.

Mark

[Blue_Wings]

I have unchecked the Auto project geometry on active sketch plane option and it solved it as @HughesTooling suggested. I also found a video explaining auto project: https://www.youtube.com/watch?v=tDYjNDGp1LQ&ab_channel=ATNomad