In Sketcher, I get an invalid constraint error when making a horizontal or vertical line symmetric about an axis and then trying to dimension it.
However, if I dimension the line first and then apply the symmetry constraint, all is good.
Steps to reproduce:
1) create new drawing, select Part Design workbench
2) Task Tab->Start Part->Create body
3) Task Tab->Start Body->Create Sketch
4) Select Plane (I chose XY)
5) Draw a horizontal or vertical line
6) Select the vertices of the line, then the axis it would intersect (X for vertical line, Y for horizontal)
7) apply the symmetry constraint
8) Select appropriate vertical or horizontal dimension constraint (or the general length constraint) and apply to the line
9) Enter length, e.g. 20mm and click OK
10) Dimensional Constraint Error Dialog appears ("Datum 20.0 mm for the constraint with index 3 is invalid"):
If you delete the symmetry constraint, dimension the line first and then apply the symmetry constraint, it works perfectly. Also, with a non-horizontal or non-vertical line, it doesn't happen.
Is this a known issue? It seems like a very common operation and I'm seeing it in both 0.19 and 0.20. FWIW, I did try to search for it, but the terms involved are so generic that I got too many hits to sort.
Should I learn how to file a bug and report this?
Thanks
Sketcher: Invalid Constraint error when dimensioning a line, after applying symmetry constraint
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Re: Sketcher: Invalid Constraint error when dimensioning a line, after applying symmetry constraint
Try fixing the redundant error first.
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
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Re: Sketcher: Invalid Constraint error when dimensioning a line, after applying symmetry constraint
Yep, that did it.. thanks
Re: Sketcher: Invalid Constraint error when dimensioning a line, after applying symmetry constraint
This is one of the cases where "Auto remove redundants" is meant to make your life easier.
Line endpoint symmetry to a horizontal line implies the line itself must be vertical.
Line endpoint symmetry to a horizontal line implies the line itself must be vertical.
Cheers,
Markus
Markus
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Re: Sketcher: Invalid Constraint error when dimensioning a line, after applying symmetry constraint
At this step, you should have a "Redundant constraints" message in the Solver messages window because symmetry implies verticality.7) apply the symmetry constraint
You should use "Auto remove redundants". It's not a bug but a correct behavior of the Sketcher solver.