Sketches get corrupt on parametric changes

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19116
Posts: 3
Joined: Tue May 11, 2021 5:55 am

Sketches get corrupt on parametric changes

Post by 19116 »

Hello,

Im very new to freecad and I have problems with simple sketches, which gets wrong, after I change some sizes in my spreadsheet. I have already read about an issue with dogleg solver flipping geometry constraints https://tracker.freecadweb.org/view.php?id=3348, but maybe there is a way to change my sketches to avoid this issue.

The screenshot shows an external geometry rectangle (pink) and my own geometry rectangle (green). The green one should sit inside the pink one with a border of 0.1mm (spreadsheet / expression value!) between both. The solver does move the green rectangle out of the pink and the contraints are also satisfied. But I did not come up with an idea how to specify the constraints to fix the green rectangle in the pink one, yet.
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25427884-0390-479c-9d07-45153382b525.jpeg
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chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches get corrupt on parametric changes

Post by chrisb »

Please add the information at which values the sketch flips, so that not every helper has to invest the time to find out.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
19116
Posts: 3
Joined: Tue May 11, 2021 5:55 am

Re: Sketches get corrupt on parametric changes

Post by 19116 »

I have two of those pink rectangles in my body and the distance between them is the parameter which changes. This forces the solver to redo the sketches and it ends up putting the green geometry outside of the pink geometry. So no change in the sketch, but in the outer geometry, which is referenced as pink rectangle.
chrisb
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Posts: 53945
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches get corrupt on parametric changes

Post by chrisb »

You can make the sketch flip-safe, if you do the calculations in the spreadsheet.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
19116
Posts: 3
Joined: Tue May 11, 2021 5:55 am

Re: Sketches get corrupt on parametric changes

Post by 19116 »

chrisb wrote: Tue May 11, 2021 7:55 am You can make the sketch flip-safe, if you do the calculations in the spreadsheet.
I think this is a solution I can live with.
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