Problem with assembly constraints in Creo 2 M030

[Wheelsofsteel]

Hi All

I am having a problem replacing a reference part in a manufacturing assembly, the part is in a family table, so I am selecting from within the parts files family table to replace.

The model is constrained by the A1 center line of the model with the center line of the chuck, and a datumn plane.

Since swapping to creo 2.0, every time I replace a model, I loose the A1 axis constraint, and have to re select every time, this is starting to become a pain.

I can't see anything that could cause this, and it only started with Creo 2.0.

Has anyone else had a simular problem.

Peter

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[TomD.inPDX]

I have seen what you are dealing with but not for a while now. What happens when you choose a cylindrical surface rather than an axis?

[Wheelsofsteel]

I must appolgise for the delay, I been out of the office the last week.

The assembly is constrained to the centreline and datum plane. I have treid to pick the cylindrical surface instead of the axis, now I know it should pick the centreline when you do this, but it aligns to the cylinder surface.

I never had this issue before Creo 2.0, just wondering why now, what has been changed between Creo 1.0 and Creo 2.0

[TomD.inPDX]

Something is weird about what you are experiencing. If I pick coincident cylindrical surfaces they assemble concentric as expected. There must be something the surface that makes Creo think they are not true cylinders.

I am using M040 and it seems to work correctly with native holes and revolves.

But what is interesting, and I wonder if this is working as intended... if you pick a cylinder to mate to an axis, coincident in this case makes the axis tangent to the cylinder. Yep, this is counter-intuitive.

I might just have to report this to get an explanation. Anyone else notice this, and is there any real logic behind it?

I don't really like picking axes for mating when I can help it. All too often there are multiple centerline there. Picking the surface helps assure you are picking the intended feature. But now realizing that an axis must be coincident to another axis is pretty darn important.

[Wheelsofsteel]

What is getting me is we never had a problem before with the method we use, the master file's wheel is constraint to the A1 centre line which is the base componet of the wheel, the model we replace from the family table has the exact same A1 centre line, all the other constraints to datum planes are intact, is just looses the reference to A1 centre line, never happened in Creo1 or earlier

Peter

[TomD.inPDX]

It sounds like this error can be duplicated. If you can submit the file as a support case and have them compare their use in Creo 1 and Creo 2 to show the variance, it will get sent to the development guys.

As I said, I have seen something similar in earlier releases. Not sure which one. I could not reproduce it even make sense of it since I did not have a common basis to judge this behavior.

[Dale_Rosema]

Are you using a mate constraint? Have you tried using an insert constraint and see if that works?