I suspect that this is a known issue, but at the off-chance that it isn't, I thought it's probably a good idea to report it here. I may open an issue in Github; I haven't found one that looks relevant, but since I wouldn't be surprised to learn that it's a known problem, I thought it's best to wait for input first.
To the issue:
Basically, if you use the offset pattern for the 3d Pocket and use the min travel option, It can jump to deeper cutting depths in areas where there's still material on top.
In the attached file, if you run it through the simulator or export and inspect the code, you can see that it clears the outermost perimeters on all depth levels first and leaves a column of material in the middle, which means it'll cut into thicker and thicker material, which can be bad. I have observed this on other 3d shapes as well, but the half sphere illustrates the issue nicely.
Now, there's obviously a workaround which is simply not combining offset and the min travel option. This is more of a PSA post I guess.
Version:
Code: Select all
OS: Arch Linux (XFCE/xfce)
Word size of FreeCAD: 64-bit
Version: 0.21.30377 (Git) AppImage
Build type: Release
Branch: master
Hash: 2462f4c7a05745488bb9e81ccc7ba0f386f78849
Python 3.10.6, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: English/United States (en_US)
Installed mods:
* Curves.backup1662935656.4450686
* Curves 0.5.8