As the following describes, I've found a bug in Fusion 360.
I apply the loft to the following profiles, and so far the preview looks fine.
But when I hit OK, immediately a deformation appears!
I'm sure that this wasn't caused by any other feature, as this results immediately from the loft itself.
Is anyone aware of lofts breaking like this?
EDIT: Scroll down to see sample file.
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John Hackney, Retired
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In your Loft preview, the rectangular notch, below the loft, is retained. I did what I saw but if that area is to be filled, simply Extrude the bottom of the Loft feature "To" the groove depth. I created both conditions. Model(s) is attached.
John Hackney, Retired
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NOTE: STILL BROKEN SCROLL DOWN FOR DETAILS
So I've tried to implement what you've suggested, slicing the faces using a plane.
Previously I performed it with projections onto the faces, but now deleted those projections to slice the faces with the plane instead.
Turns out that the problem persists regardless of if I use your solution involving splitting faces or my own solution using projections (though I will continue using your face-splitting technique, since it's neater and a similar solution to what I did for another loft in the project. Thanks for that!)
But... it turns out the fix was as simple as:
- Opening the loft...
- And sliding that weird blue dot to the corner.
And it's fixed!
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(And on a side note, moving the blue dot back to its original place breaks the loft... so this is DEFINITELY a bug in Fusion 360.)
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So yeah
Thanks again for your suggestion and sharing your technique! I'll keep note of it for next time!
NEVERMIND IT'S STILL BROKEN
(What the heck is going on)
The issue seems to persist after trying to move the blue dots to the proper positions.
this is definitely a bug that Fusion needs to fix.
@maula006 wrote:
NEVERMIND IT'S STILL BROKEN
this is definitely a bug that Fusion needs to fix.
In the majority of cases this means that you are trying yo create geometry that is at the technical limit for the loft tool. In the majority of cases that should yield a different modeling approach.
While Autodesk has a tendency to "fix" problems like this and still allow the user to create often absolutely horrendous geometry (it isn't horrendous in this case, but it isn't good either) I would still recommend changing the modeling approach.
You might get past this hurdle with the current modeling approach, but often once bad geometry is created problems start compounding and so does frustration!
Let me see take a look at the model and provide feedback ...
I might have one or more questions.
So here is one better workflow:
I rolled the timeline back to before the loft in questions and unhid sketch "Front/Rear Supp Sketch"
I then use a line in that sketch with the "Split Face" command/feature to split the two selected faces:
I end up with this split line highlighted in red:
Then I extrude the lower of the 2 faces "To Object" to the upper surface:
and end up with this:
This provides 2 faces for a simple solid loft.:
With no holes on the other side:
@maula006 - yes, this is a bug. I created bug FUS-96623 for this. As @TrippyLighting says, though, this is not a recommended modeling technique. I would never recommend using a loft where one of the profiles is essentially co-planar with one of the lofted faces:
So, I would recommend some of the techniques discussed here instead.
However... If you really do want to use the profiles as you have them, the usual way to avoid these kinds of "point mapping" errors is to create rail curves. Create another sketch, Include the points from the two profiles, and create a 3D line between them. Use that line as a rail curve:
One last question:
As part of the solution I had to split some aditional faces temporarily in case the split for the front/rear supports overlap to a different part of the model somehow.
Now I'm done with the lofts... how do I stich these faces back together?
I can't seem to find a command for it; stitch doesn't seem to put split faces back together ~_~
