We use Include a lot and there is a checkbox "Maintain associatitvity when including geometry from other parts in the assembly"
it is sometimes grayed out, but I don't see why - when and when not.
I have 2 identical occasions and 1 time i am able to check the box, the other time it's grayed out.
You should work with ordered mode to keep "Maintain associatitvity when including geometry from other parts in the assembly" active.
may be other have some other answer
Thanks & Good Luck
Just a guess - is it because one time you are including from a lower level part, other time a higher level part ?
(in terms of assembly structure).
I run into the same thing. Can't ever say why other than sometimes I find a reason down stream that is not obvius at the time.
I suspect this is another vid driver/fresh boot issues sometimes.
Over time I run into it less. So some habbit I have been learning prevents the issues, but I sure can't put my finger on it.
One related learning curve was that includes can't be repaired, but then you just replace the include to an existing sketch with a relation.
My colleague and I stopped using "include" because the relationship can't be trusted.
I think it's in principle better to treat includes between parts as a temporary measure to be deleted at some point when the design is solidified (pun intended) and you no longer benefit. Otherwise you're asking for trouble down the road due to broken links which can be difficult to find and fix. Or you find changing something has unintended consequences in your assembly.
Other than that sometimes when I get that greyed out I'm also baffled as to why.
Includes are the core of my modeling process.
When I can, I do includes from planes rather than objects. But including from the thickness of sheet metal is the only way I know how to make designs tolerant of gage changes.
The one I avoid if at all possible is includes from frame members. Very easily broken.
In general when I start a design, I create assembly planes, then assembly driven ordered sheet metal where the first tab sketch is includes from planes. The last few parts added will have includes from planes and other sheet metal parts to account for thickness changes.
When all done. Planes and gages are in control of the model