Cross-sketch constraints "failed to regenerate"

martin_meinke

Hi everyone!

I am pretty new to onshape and really like it so far!
Still, right now I am struggling with what feels like a trivial problem - introducing a constraint "between sketches".
I have tried to make this work for an hour, but just can not figure out what might be the problem.

I'd highly appreciate if someone could have a quick look:
https://cad.onshape.com/documents/c4d93042f556b439a8561fbf/w/a1dadf21232ad4bb82d6a260/e/a2ea35d7bbaa35b166155245

NeilCooke

Because the feature list is regenerated top to bottom like a recipe and Sketch 2 did not exist when Sketch 1 was created. Or in other words, you can't alter the past.

glen_dewsbury

The rectangle in sketch 2 is over constrained. Because the rectangle is tied to all 4 corners of previous part a dimension is too much. Check show constraints to see.

martin_meinke

Thank you for your response @glen_dewsbury!
Let me try to be more precise:
Why does onshape not increase the width of the rectangle in Sketch1 to accommodate the width constraint in Sketch2? This should be possible without violating any constraints?

NeilCooke

Because the feature list is regenerated top to bottom like a recipe and Sketch 2 did not exist when Sketch 1 was created. Or in other words, you can't alter the past.

martin_meinke

That's the piece that was conceptually missing to me - thanks!

dirk_van_der_vaart

This will be usefull for you
https://cad.onshape.com/help/Content/sketch-tools-use.htm?Highlight=Use