Negative offset for constraints

[ligeris]

I've just upgraded from Inventor 11 to Inventor 2010 and noticed when I place a set of constraints in an assembly I can't actually use negative numbers in the offset to inverse the direction of the constraint. Has this function been eliminated in the latest version(s), or should I be enabling something in my current Inventor 2010 options that I am unaware of.

Thank you,

Lily

[johnsonshiue]

Hi! I cannot seem to reproduce it on my machine. Could you post a screenshot or a dataset?
Thanks!

johnson.shiue@autodesk.com

[ligeris]

I tried it again today with 2 very simple parts and on Inventor 2010 it worked.
But when I get to my assembly, the edges I would like to have spaced in the other direction, the mate doesn't work. (see attached screenshot).

I also tried mating surfaces instead, and I got that to work.
Can the problem be because I was trying to mate edges and not surfaces?

Thank you,

Lily

[JDMather]

>Can the problem be because I was trying to mate edges and not surfaces?

I can mate edges with negative or positive but get same results as negative to edges is not entirely defined.

I'm not sure exactly what your picture was supposed to show, but I am interested in your use of Move Face as I have not found many uses for that command.


Just went back and saw the text in your picture about +/- giving same results. When you pick a face that defines the normal direction for the offset. (Face has a front side and a back side.) An edge is partially ambiguous as normal direction is not defined. Edited by: JDMather on Aug 12, 2009 9:41 AM

[johnsonshiue]

Hi! I do not think there is a change in behavior.On mating two edges, the offset value is absolute. If you enter a value (negative or positive), the constraint solver will move the component to a place keeping the offset distance between the two edges. At that moment, if you change the value from positive to negative or vice versa, the component would not move. This is because, for edge (point) - edge (point) mate, there is no concept of positive distance and negative distance: The offset distance in Edge-Edge mate should allow the moving component to rotate around the stationary component.
Thanks!

johnson.shiue@autodesk.com

[ligeris]

Thank you all the responses, I guess my application for mating edges was the problem. I did not know that mating edges was absolute which explains why I couldn't change my direction.

> I'm not sure exactly what your picture was supposed to show, but I am interested in your use of Move Face as I have not found many uses for that command.
>

I use the move face command when I am using profiles to build a frame.
I make my profile with a certain extruded length. When I place the profiles in an assembly, and mate them to corner pieces, instead of using multiple profiles, I use only one and just move face of the profile in the assembly to make the profiles longer or shorter for my application.