Fusion 360 goes south with overlapping objects

[jpjones2]

Fusion 360 v 2.0.1758

Mac OS X 10.9.5

I am new to Fusion 360 and am pulling my hair out on this one...  Searched the forum and didn't find anything on this.  I created a box by extruding a rectangle up, then the interior of the box by extruding the middle down.   I placed several small circles for button holes on the bottom of the interior.  Concentric with each small circle I added a larger circle.  The small circle was extruded down to the very bottom (all the way through the case).  The larger circles were extruded down about half way through the case bottom, creating a feature like an upside down wedding cake, and I also added various other features.  I test printed and found I needed to adjust the spacing on some of the holes.

If I non-overlapping holes are made overlapping, or already overlapping holes are made non overlapping, Fusion 360 just goes out to lunch.  Things that had been extruded no longer are, or just disappear.  Sometimes areas that weren't extruded are now.  If I save, quit, and reopen, things may appear to be back to normal, or may remain messed up.  Either way, if export to STL, Slic3r finds around 1000 errors and the model is useless.

Perhaps I'm doing something wrong here, but seems like a bug to me - I would expect Fusion 360 to handle this type of object move gracefully and determinately.

Can someone enlighten me on what is happening and how to avoid this issue?

Thanks

[jeff_strater]

It's a little hard to tell exactly what is going on without the model, or at least a picture.  I will try to re-create your problems from the description, but more information would be helpful.

When you say "Fusion 360 just goes out to lunch", do you mean that it hangs, crashes, or just gets the incorrect result?  Some of what you say you see may be as intended behavior, some may be bugs.  Any crashes or hangs, definitely are Fusion problems.

So, if you could share your model, or a screencast of your workflow, it would help us greatly to get to the root of the problems.

Thanks,

Jeff Strater (Fusion development)

[jpjones2]

It is difficult to describe - the symptoms are not always consistent.  I have had hangs (spinning pizza wheel of death), or areas that were extruded are no longer, features completely disappear, etc..  I might think that it this intended behavior because it can't handle the transition, except that it breaks the model and areas not direclty affected are impacted.  When I print to 3D and import into Slic3r, it has sometimes well over 1000 errors.  I've had it look messed up, I quit and reopen the model and it looks ok again, but I still get hundreds of errors when I import into Slic3r.  Or I'll quit and reopen and it will look the same (features missing). 

I would be happy to privately send you the model, just let me know how to do that.  I have a copy saved just where it is intact, and can give you instructions to make it fail.

[jeff_strater]

thanks @jpjones2, yes, definitely it would help to have that copy.  The easiest way to to this is to "share" the model.  In the data panel choose "Share Public Link" from the right-click menu:

Then, in the dialog that comes up, make sure you check the two boxes shown below.

Then, just copy the link and either post it here, or you can send it to me directly via a private message on this forum. 

Autodesk is closed for the holiday season, so the response might not be all that quick, but we'll try to get to it soon.

thanks,

Jeff

[jpjones2]

Ok, dumb question...  How do I send a private message?  The forum documentation says:

    How do I send a private message?

    To send a private message:
    Sign in to your community account.
    Click on the envelope icon next to your Autodesk ID to go to your Private Messages Inbox.
    Click on the Compose New Message tab.

There is no envelope icon.  I see:  id|Edit account|Preferences|Sign Out|Share|Help.  Once I go into Forums, There is only a people icon and "MY PROFILE" at the top, but on the right hand side is "MESSAGES/MY SETTINGS/..."   If I click on MESSAGES, I get an error "You do not have sufficient privileges for this resource or its parent to perform this action."

[jeff_strater]

Here's how I usually do this, although there are more than likely other ways to get there:

Jeff

[TrippyLighting]

To send a private message you click on the image under Jeff's mame on one of his posts. Then somwhere on teh lower right side in the side pnel you'll find "send this user a private message".

Jeff is very responsive, but if you can't wait you can also share the project with other users willing to help.

[jpjones2]

Yep, that's exactly what I was trying to do.  That's matches what is in the forum help text.  There's no envelope icon there for me.  I also had checked your profile for "send private message", which TrippyLighting mentioned.  It seems I do not have sufficient forum permissions to do that.  How do I get that fixed?

[jpjones2]

I created another model from scratch and can duplicate the problem there.

[jpjones2]

Just a short update in case anyone else is having this problem.  Jeff was able to duplicate the issue.  In its simplest form, if you have two overlapping circles (or other objects), there are three areas to be extruded - the two areas unique to each, and the overlap area.  In my case, which is slightly more complex, I selected all areas to extrude as one operation.  If the two are moved such that they are no longer overlapping, Fusion 360 has trouble figuring out what happened to the now missing overlap area and does some very strange things.

Jeff created this screen cast on how to repair:

    https://knowledge.autodesk.com/community/screencast/d8ce2e16-c395-4d80-aec0-3324d472bbfe

In my case, it wasn't quite this simple.  I found extrusions that had to be deleted, including some that I believe were created implicitly.  Although a bit tedious in my case, I was able to repair using this general process.

What I found empirically was that creating multiple extrusions greatly reduced the chances of the problem occuring and the severity of it.  For example, I selected all areas that were a member of circle set 1 as one extrusion.  For the second extrusion, it didn't seem to make much difference if I selected just the unique areas for circle set 2, or all areas that were a part of circle set 2.

For the case of non-overlapping circle sets that might have to be moved such that they overlap, again extruding each one separately seems to lessen the chance or severity of the problem.  This case also seems easier to repair if it does occur.