[Solved] Fillet geometry error

[berka]

I think I'm seeing some geometry "improvisation' by the PartDesign fillet tool. I was able to replicate it in a simple model. (Attached.)
Has anyone else noticed this? Is this a bug to report or is there another explanation?
(All pictures are orthographic).

Overview:

Object Overview.png (51.1 KiB) Viewed 559 times

Right View Before Fillet:

Before Fillet Right.png (8.1 KiB) Viewed 559 times

Right View After Fillet:

After Fillet Right.png (9.48 KiB) Viewed 559 times

OS: macOS 10.14
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16117 (Git)
Build type: Release
Branch: (HEAD detached at 0.18.2)
Hash: dbb4cc6415bac848a294f03b80f65e888d531742
Python version: 3.6.7
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)

[openBrain]

This is a display artefact, mainly due to deflection setting.
You can change it at body level (view tab of the property editor) - set it to eg. 1° - then force the whole document to recompute by right-clicking on "filletbug" -> "Mark to recompute" -> F5 key.

dev.png (28.37 KiB) Viewed 553 times

[berka]

Thank you for that explanation. I suspected display-only artifact, but I was thrown off that it looked the same every way I looked.

[Vincent B]

In your file datumplane is not attached, it's not tangent. That gives an error.

[berka]

In your file datumplane is not attached, it's not tangent. That gives an error.

Thanks for taking a look. I intentionally put the datum plane to be slightly below the top of the object. (Z=14.9mm; object has 15mm radius.) That allowed me to show the portion sticking above the plane easily in pictures.

[berka]

This is a display artefact, mainly due to deflection setting.
You can change it at body level (view tab of the property editor)

Tried this morning. This is definitely it. Both Angular deflection and deflection improve the view. More importantly, knowing it's a view artifactly only, and knowing how to affect it are key. It allows me to ignore it or temporarily change it to keep computation faster.

[openBrain]

This artifact is highly seeable here also because your model is at a very small size.
Also be aware that this parameters will have direct effect on the result if you export as mesh (typically STL).