Alibre Dimensions change to red

[David George 1Participant @davidgeorge1]

When drawing in Alibre Atom I get dimensions in drawings change to red when I have modified the model. I can be as simple as adding or removing an edge chamfer etc.  Can this be avoided as I have to go through re-dimension some dimensions with same dimension as original.

 

David

[JasonBModerator @jasonb]

Check that when you altered the part that you clicked “generate to last” before savng the alteration.

I find the red dimensions relate to features of the part that were after the alteration and only see them if I forget to generate to last

Here is an example, I created a drawing and dimensioned the 12mm hole and it came out black as it should, saved and closed the drawing.

I then opened the part and moved the slider up so it was above the last item which was the hole and saved the part.

Then opened the drawing and the hole is missing but the red dimension is still there.

Going back to the part and correctly generating to last will bring back the circle and make the dimension black. If I had deleted the extrude cut that formed the circle it would have gone from the drawing together with the dimension

[David JuppParticipant @davidjupp51506]

That can be a surprisingly complex question.

Red dimensions are a warning that something has become disconnected, and hence may not be reliable.

There is now a re-target dimension option for such cases, which can save time, compared to re-doing from scratch.

How you place the dimensions at the beginning can be important.  Some options may be more robust, but if the model topology changes, then the ID of edges in the drawing may not match any longer.

[David JuppParticipant @davidjupp51506]

Dimensioning from end to end is likely to be more robust than dimensioning the long edge of a rectangular block, if you might later add chamfers…

[David George 1Participant @davidgeorge1]

This is a picture of a drawing I am working on where I have just put a 0.010″ chamfer on the model on small hole on top right hand side of the top lefthand side drawing on the page.

 

I tried to stop this by clicking generate to last feature button but no joy.  It is a pain when I have to re dimension swathes of drawing for such a small change to remove red dimension sizes which don’t change only colour.

David

 

[David George 1Participant @davidgeorge1]

 

Not quite finished drawings but getting there just annoying when red dimensions appear.

David

[JasonBModerator @jasonb]

I just replicated the same problem.

Only way seems to be to use “retarget dimensions” but as the dimension was to the ctr of the hole that has not really moved so seems a bit of a bug.

On the other hand it changes the black dimension which was corner to corner when I chamfered the square on the right. The left hand was dimensioned side to side rather than to the corners

[David JuppParticipant @davidjupp51506]

As I said – the red is a warning that the dimension may not be reliable.

Jason has demonstrated that some ways of placing the dimension are more robust to design changes than others (though there is no guaranteed way to avoid dimension dissociation).

Dimensions will update OK as long as topology isn’t changed – size changes should not give any difficulty.

You can mask the problem by simply changing the layer for the red dimension – but that doesn’t fix the cause and it will come back again.

[Author]

Posts