Mike Allen Posted December 9, 2009 Share Posted December 9, 2009 (edited) I'm probably just missing something here, but when I apply an angle constraint between two shapes (one is a hole shape, with dimension constraints to keep it's center fixed on the other shape), I'm unable to predict which direction it will rotate when I change the angle. For instance, if I start with the constrained edges at 90 degrees & change the angle to 45 degrees - as often as not, it will rotate 135, or 225, or 315 degrees. What I need is plus or minus 67.5 degrees from the 90 degree position. Any ideas? angle_constraint.7z Edited December 9, 2009 by Mike Allen Quote Link to comment Share on other sites More sharing options...
Mike Allen Posted December 11, 2009 Author Share Posted December 11, 2009 I'm giving this another try as a Structured Part. I need to constrain the center of the cut feature arc at a specific point from the end of the stock. Then I want to drive the angle of rotation through parameters. In the position shown, it's easy enough to put Smart Dimension constraints for X & Y of the center of the cross section arc, then put an angular dimension between the straight edge of the cross section & the bottom edge of the stock. The problem arises when I try to change the angular dimension - all my dimensional constraints go away. Is there another way to make these constraints? Quote Link to comment Share on other sites More sharing options...
Mike Allen Posted December 11, 2009 Author Share Posted December 11, 2009 OK - I think I'm getting very close here. I'm using construction lines in the sketch to provide the position constraints. I can parametrically drive the angle using Design Variations, until I pass 90 degrees - so 22.5 is OK, 45 is OK 90 is OK - and 135 is OK, but it must break something, because after that point, I can no longer drive the angle through Design Variations. ******************* Hold on - now it's working. I changed nothing, but after setting the angle to 135 through Design Variations, I went to edit the cross section - but did not change anything in the sketch or constraints, because it all looked right. So I went back to Design Variations & have no trouble going from 157.5 to 22.5, to 90, to 45, to 140, to 30, etc. I'm still a bit concerned, since I have absolutely no idea why it started to work right. On a side note, I would really appreciate a tutorial on the best way to constrain sketches on structured parts. This trial & error can be quite frustrating, since when the constraints get broken, undo doesn't always set things right & I find myself scrapping the feature so I can start again. Oh yes - was there a reason why we can't use the TriBall to position the grid when creating features on structured parts? It would really come in handy, because I like my sketch to have a direct relationship to 0,0 on the grid. Quote Link to comment Share on other sites More sharing options...
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