Welcome to the forum. I get the same with your two files, although I'm puzzled by the second test case, what would be the purpose of doing a rounded edge if it's to remove it with Part Thickness? I agree it would be better for FreeCAD not to crash though.
I get that the first file is a very simple test case, but in any case a workaround could be to apply a Part Offset
on the first Cylinder (with a negative value so the shape is offset inward), make a Part Cut between the shapes, and then a new Part Cut between the result and Cylinder001.
DeepSOIC wrote:I've experienced Thickness breaking input shapes, too. That is OpenCascade territory, and there's not much we can do about it.
I was pretty excited when Part Thickness was introduced, but it has proven rather unpredictable... For better or for worse, FreeCAD is built on top of OCC, there is no available alternative anyway.
OS: Ubuntu 14.04.4 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6603 (Git)
Build type: None
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17