This is another example of Inventor's buggy constraint handling.
I've seen many flexible cylinders loosing their constraints and setting them bad, for no visible reason. This happens often with cylinder/rod combinations with +/- insert constraints. You can open the cylinder sub-assy, move the rod by mouse, and the constraint is back again.
With this excavator, all attempts with the cylinder near the boom were not successful. I only could get it stable, after moving it up into the main assy. Thus, I could get rid of the problems in Main and Free posrep, but not with Max vertical position.
This position simply can't be handled. The four bar linkage at the bucket assy flips and can't be set up, as needed.
As a remedy, I added Begrenzungswinkel and Begrenzungswinkel 2 as limits for the angular position of the bucket and the bucket link. But although the bucket angle was limited as +/- 30°, it's juming to about 105°. This should never happen, and results in flipping of the 4-bar linkage.
You can see this method working well in the minor assy Constraints ok.iam. But Inventor can't handle it in the still rather simple main assy.
I think, this should be improved. I don't need another UI change, but I'll have to do my job with tasks like that.
Walter
Files (only the changes) can be downloaded because of filesize for some time here:
www.holzwarth-cad.net/Joomla/media/download/Excavator_changes.zip
