Help with free form surface error

[cody.wheaton]

I created this by using a form surface.  I started with the flat face in the front then pulled the geometry backward to get the wrap around.    I did the two vertical faces on a side then pilled two of the upper faces back and merged edges to get the clean profile.  I started by just doing half of it to get the profile right then did a mirror to create the other half and checked the weld box.  When I used then thicken feature it created that small hump in the middle.  Why did it do that and how do I fix that self intersecting error the thicken feature seemed to create?

[jhackney1972]

I think you will have to attach your model for anyone to try and diagnose your issue.   If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save to your hard drive. Then use the Attachments section of a forum post to attach it.

[jeff_strater]

one hint:  Switch to Box mode in the Form workspace:

often, it will be apparent in Box mode where the self-intersections are.  But, even better, as @jhackney1972 says, share your model here, and someone will show you on your own model.

[cody.wheaton]

Thanks! Model should not be attached.  Another question on the same topic...sometimes when I'm working on adding some complex curves the model will revert to box mode until it's "fixed."  What exactly does this mean.  Also when I'm selecting points using a tool like 'flatten' some lines are red and some points are highlighted but not actually selected.  What's this telling me?

[mango.freund]

Hello  @cody.wheaton   the error message actually tells you everything. i tried to improve the form with body repair, but it is more difficult than necessary. it is normal to work with a form surface and if the contour is correct to thicken it. this prevents the shape / surfaces from overlapping. greetings mango
please always enter photos directly visible with the camera symbol - thank you

[cody.wheaton]

Thank you for taking a quick look.  Quick question...when I'm using the flatten tools there are a lot of red lines and control points that show up which are not normally visible.  They look like they're some sort of automatic spline handle, but I'm not sure.  What's the purpose of these?

[TrippyLighting · Accepted solution]

Here is a screencast demonstrating how to fix the model:

The "dots" you see are vertices and the red "things" are tangent handles. Don't touch them. 😉

[jeff_strater]

@cody.wheaton - thanks for the model.  I understand the basic problem with the model here.  It looks like it is all connected together, but if you try to edit it, you can see that it is actually not connected over part of its length.  I think I understand how this came to be, in trying to repair it.  I suspect that you modeled half of it, then tried to use Mirror Duplicate symmetry to create the other half.  The idea was good, but because not all of the model's vertices were directly on that plane, it created this gap in the surfaces.  I'm trying now to find the best way to put it all back together again.

[jeff_strater]

oh, it looks like @TrippyLighting got there first.  Do what he says...

[cody.wheaton]

That was extremely helpful and answered a lot of nagging questions I had. Thanks so much for the time and effort.

[cody.wheaton]

Also thank you.  Just seeing you do that with the model gave me another way to try and tackle issues in the future.