Constraints are not stable.

lloyd_snell

I am always redoing constraints between a casting part model and the related machining part file. I bet I have replaced the same constraints a hundred times. Enough so, I am looking for answers. For instance, I have a revolved surface and the edges of the surface are constrained to a face of the casting. Everytime I add a feature, or change a feature in the model, not even related to the define constraint it is lost. Example two, when adding drilled and tapped holes in the machining model you place points and constrain them to arc and circle that are raised bosses. By simply adding a fillet to the boss in the model the reference is broken. Change, remove the radius the reference is lost. 

Parametric relationships are explosive and easily disrupted it seems. What am I missing? Reference, definitely not as stable as Creo, but Creo has a 25 yr head start. 

NeilCooke

Hi @lloyd_snell

In any parametric modeller, if you remove a reference like adding a fillet to an edge, the edge no longer exists so your hole locations will no longer have a reference. This is the same behaviour in Creo, SolidWorks, etc. If you add the fillet after the hole everything is fine as the hole locations would have been resolved before the edge disappears.

If you can share more detail related to "revolved surface and the edges of the surface are constrained to a face of the casting. Everytime I add a feature, or change a feature in the model, not even related to the define constraint it is lost", I can help to explain why.

Thanks.

lloyd_snell

I did not remove the edge. the boss still has the same top edge, the same construction circle. 

NeilCooke

If you are adding a fillet, it is removing the edge. If this is not the case, please can you make your doc public, or a cut-down version of it (or open a ticket with support)  and we can take a look at it. Thanks.

lloyd_snell

I will try and make a cut down version. But my delivery time for some kind of documentation to suppliers is too tight to spend time solving all of the problems right now. So communications are being added by hand due to deficiencies on my part or new software development needs. 

SquidLord

lloyd_snell said:

I will try and make a cut down version. But my delivery time for some kind of documentation to suppliers is too tight to spend time solving all of the problems right now. So communications are being added by hand due to deficiencies on my part or new software development needs. 

There's never time to do it right. There's always time to do it over.