Why the change from Mating Conditions to Assembly Constraints?

[mander66]

As and old school UG user, I was very comfortable using assembly mating conditions. In NX6 now and I am still feeling uncomfortable using the new Assembly Constraints option. Will mating conditions come back? or do I have to force this old dog the new assy constraints trick? anyone else feel the same way? any recommendations? will mating conditions just disapear in future releases?

 

[tomstickland]

The new system is slightly better than the old system in my experience.
One thing that took me a while to get used to was making constraints visible.

You don't actually need the constraints to be visible, because if you select them then the constrained features light up Red.

The easiest way to find the constraints is to use the object dependancy viewer in the part navigator (magnifying glass icon).

 

[hudson888]

I've been told that mating conditions will always be supported, but creating new ones is being phased out.

The main improvement with assembly constraints is that degrees of freedom exist across assemblies and sub assemblies in a the way that wasn't possible with the older mating conditions. There are a few more capable types and once familiar with them you're able to do more with a little greater easy and intuitiveness.

That said reportedly for really large assemblies having all of the mating alive all of the time can affect system performance.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[JohnRBaker]

First, legacy Mating Conditions in existing files will be maintained as far into the future as we can foresee, however, as of NX 7.5 you will no longer be able to edit or create new Mating Conditions.

Second, Assembly Constraints are based on newer architectural principles which have fewer 'constraints' (if you'll excuse the pun) such as with mating conditions you can only have ONE fixed component and you have no control over which one it is (it's always the first component placed) and it can't be edited. Also Mating Conditions are hierarchical meaning that the order in which they are created is critical whereas Assembly Constraints are not and therefore it's easier to make changes later on. It's like a sketch where you can add and remove dimensions and constraints anytime you wish without needing to reorder, unlike features where order is critical. This also means that with Assembly Constraints it's much harder to get into situations where you get circular references, something which is quite common with much more common and frustrating with Mating Conditions (and for that matter with modeling features).

It also allowed us to improve and make it easier to apply things like variable positioning as well as gave us the opportunity to implement some new concepts which would complicated Mating Conditions even more.

This is just an example of where advances in mathematics and software architecture has allowed us to make a significant enhancement to our product, but not without avoiding the need to give up something, in this case Mating Conditions, in order to get the maximum benefit out of something new.

Note that we've spread this transition over 3 full releases, NX 5.0, NX 6.0 and NX 7.0, so we think we've taken the correct approach and that our customers should not have any long term concerns once they commit to the move, which of course will not be optional once you move to NX 7.5.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[mander66]

Thanks for the replies everyone, I guess I will bite the bullet and get used to the new Assembly Constraints. This forum rocks! Thanks again people!