2017 Thicken/Offset Join unexpected behavior, Intersect, New Solid

[annette.jennings42]

I work on imported solids (I first use shrinkwrap substitute creating separate bodies) and then use the thicken/offset tool to exaggerate the few otherwise tiny features to a 3D-printable size. I often exceed 1000 thickens in a file. Twice now upon resuming work after closing a file for the day, Thicken/Offset behaves unexpectedly. 

Where the "Join" button in the Thicken/Offset dialogue normally works just fine to thicken a solid, when it bugs, it erases the object and an arbitrary portion of adjacent features. It seems to be behaving like Intersect but in a very narrow window/box in close proximity around the feature.

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NOTE I have a work-around - using the "New Solid" button will successfully thicken the feature in question.

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But this is not optimal as I often need to thicken in multiple axes and so having multiple bodies increases the number of steps in the workflow

Is there a known issue with Thicken/Offset JOIN sometimes cutting away portions of a model?

[johnsonshiue]

Hi Annette,

The behavior does not sound right to me. Could you share a simple example here? I would like to understand the behavior better. When you try thickening, did you uncheck "Auto-blending" option?

Many thanks!

[annette.jennings42]

Please reference the images attached for an example of disappearing or cut/trimmed geometry.

Yes, auto-blending is turned off.

[johnsonshiue]

Hi! Purely based on the images, it looks like a geometry specific behavior. Could you attach the part here or send it to me directly (johnson.shiue@autodesk,com)? I would like to understand the behavior better.

Many thanks!

[annette.jennings42]

I cannot duplicate the problem today. I completed all the modifications yesterday using the "new solid" work-around mentioned in the OP.

If this problem comes up with another file, I will email you.