Bugreport: 'Holding Tags' not working for circles

[maxpautsch]

As https://freecadweb.org/wiki/Help_FreeCAD mentiones to first report possible bug in the forum:

When using the 'Tag Dressup' on a profile based on a circle, there is a problem with the lowes path segment. The path is not calculated correctly and would crash the end mill. This is not only in the preview but also in the generated g code.
While playing around to check what could be the problem, i could find a setting where the path seemed to be ok. However the correct output could not be reproduced!

Is this user trouble or can anybody confirm that this is a bug?

Nightly build installed on 13.01.18 (yesterday)

OS: Ubuntu 17.10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.12920 (Git)
Build type: None
Branch: master
Hash: 8faa9f38bb70a598afc2bc39ea1645d416ab057e
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0
Locale: German/Germany (de_DE)

[chrisb]

Can you upload your file please, preferably in a simplified version showing the issue.

[maxpautsch]

During the generation of the simplified version (see attachment) i found a new dependency:
the problem only occurs, if the 'Step Down' value is smaller than the height of the tag.

I changed the 'Step Down' value by hand. By default it is the tool diameter. I do not know if this is a good default. Perhaps this should be changed.

[herbk]

I made a own model and have a simular problem.

tag_dressup.jpg (57.25 KiB) Viewed 362 times

Edit FC is 0.17 12920 to

Edit Edit: I have this wronk path only as long as the Tag Dressup GUI is open. If i finish the operation by clicking OK, the path gets OK.

tag_dressup_2.jpg (46.54 KiB) Viewed 353 times

[maxpautsch]

The problem only seems to occur if a tool path matches exactly the top of the tag. It is not the last path layer but the one at the height of the tab which is not calculated correctly.

When looking at your screenshots, I guess you use a 3 mm tool and thus 3 mm height increments by default. You should be able to see the problem, if you set your tag height to 3 mm.

Thank you and have a nice evening!

[chrisb]

During the generation of the simplified version (see attachment) i found a new dependency:
the problem only occurs, if the 'Step Down' value is smaller than the height of the tag.

I changed the 'Step Down' value by hand. By default it is the tool diameter. I do not know if this is a good default. Perhaps this should be changed.

Hi Max, thanks for finding out. That's why I asked for a simplification, because it usually helps the developers to track the problem to its source.

I forgot in my last post: Welcome to the forum!