Project to Surface Mystery Error

[patmat2350]

F360 keeps throwing a warning on this operation I need to use all the time. The process seems to work, data is usable, but it loses associativity. See picture.

1. Create a curve on plane.

2. Create a curve and an offset on perp plane; extrude both as surfaces.

3. Project Curve 1 to surface along Z axis;

4. Project that curve along another vector to 2nd surface. 

5. Use the 2 projected curves as path and rail in a sweep.

As mentioned, the steps work and produce usable geometry, but I get the warnings and the projections lose associativity, not too helpful!

TIA, Patrick

[jeff_strater]

I will take a look at this issue to see if I can reproduce it.  If not, I may come back and ask for you to post your design.  Thanks for taking the time to report this.

[patmat2350]

Thanks; here's my example:

[patmat2350]

And you might see where I need to use this:

[mango.freund]

hello @patmat2350 i solved your projections and the yellow sketches were easy to use without errors.

I think that's it. greetings mango

[wersy]

[patmat2350]

OK, thanks Mango & Wersy... I see your files, but I don't know what you did, as there is no history inside the sketches. 

[jeff_strater]

Thanks, @patmat2350 - I'm interested in how you created these projections, and then maybe what modifications you made after initial creation.  I tried to create a similar case myself, and it seemed to work OK.  If I do Manage Lost Projections on the failed sketches:

It shows "Edge1" as missing.  I'm not certain if it is missing the input curve, or the projection vector.  It does not appear to be missing the surface, FWIW.  But, nothing I select seems to fix it.  Not sure if that is a bug in Manage Lost Projections or what.  Anyway, if you remember what you selected for the curve to project (I think it's obvious, but worth asking), and the vector, that would help.  Also, do you remember what edits, if any, you made when you first saw this error?  Also helpful.  Thanks.

[jeff_strater]

OK, so I think I discovered the problem, @patmat2350 - did you by any chance select a sketch curve as a vector?  I was able to get a very similar failure selecting a sketch curve.  I will create a bug on this.  Thanks for reporting it.

[patmat2350]

Thanks. Nothing more than what is there. In Sketch3, the spline from Sketch1 was projected to Body1 along either Z axis or that vertical stub in Sketch2. In Sketch4, the projection in Sketch3 was projected along the angled line to Body2.

For both those sketches, the geometry was created but yellow warnings were immediately thrown. As the geometry "stuck", I was able to use it in the sweep to create Body3. 

[jeff_strater · Accepted solution]

thanks, @patmat2350 - the key here was "Sketch4, the projection in Sketch3 was projected along the angled line to Body2."  Choosing a sketch curve as the axis seems to fail immediately.  This seems a bad bug, and we will prioritize a fix, though we currently have no expected date for that fix.  Created Fusion bug FUS-86241 to track this

[patmat2350]

Thanks!
In the meantime, are there other types of entities I should try to use instead of sketch lines for the projection vector?

[mango.freund]

hi @patmat2350  -- it's my way to go along.                               greetings mango

[mango.freund]

oops ods shows not the windows, sorry. https://autode.sk/2V9ID61

[wersy]

Apart from the bug that Fusion produces in your case, I would like to show another simple method that does not produce an error message.

In sketch 1, I copied the outer contour and moved it in the x direction by 0.39.

In sketch 5 both 3D curves were created with intersection.

For the surface I used the loft tool.

By the way, I like your ship very much. A lot of work went into it and the hull was certainly not easy to create. I would be glad if you share the finished project.

[patmat2350]

Thanks Wersy. Your method is simple and it works.

I do share my projects (a recent development): https://grabcad.com/patrick.matthews-1

[TrippyLighting]

I would advise against using projected or intersection curves. Their curvature is almost always broken.

[wersy]

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@TrippyLighting  schrieb:

I would advise against using projected or intersection curves. Their curvature is almost always broken.

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That's right, we've already had this issue with an airplane fuselage.
It's better to use surfaces for this.