sub-assemblies

[needsmuchHelp]

I am using nx5.02 and I wanted to know if there is a way to create a sub-assembly of multiple components with-in a current assembly? I want to keep the assocativity of the main assy. For example if I have 10 components in an assembly called assy1.prt and I want to to create a sub-assy using 5 of those components and want to name it assy2.prt. Is this possible? Any suggestions?

 

[JohnRBaker]

First set the Work Part (it's best that you do NOT select one of the components that you wish to move) to the level in the Assembly where you wish to insert the new sub-assembly. Once there, go into Assemblies -> Components -> Create New... and select the components that you wish to be included in the new sub-assembly.

Now as for 'associativity', note that Constraints/Mating Conditions cannot be moved from the level of the assembly as which they were created as they are stored in the context of the active work part when they were created. That means that moving a fully constrained component will NOT cause the referenced constrained to also be moved. The constraints will be left in the original part file, just that they will be considered invalid or 'broken'. Under most situtations, the only thing that you can do is delete these now invlaid constraints, make the new sub-assembly the work part and recreate your constraints/mating conditions.


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

http://www.siemens.com/plm

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

 

[hudson888]

And if you understood John's post then you'll know that while you can create an assembly by selecting components with which to populate it, the downside is that in doing so you will effectively lose your mating conditions.

If your mating conditions are really important then consider copying the original assembly, (using "Save As" would be okay), and then removing all except the parts that you wish to place into the sub assembly. You would then re-open your original file, remove the same components and add the sub assembly in their place.

If your mating conditions reference some parts destined to live in the top assembly and others being shifted to lower levels then you're basically out of luck and you'll have to do something unfortunate no matter what method you use to re-structure the assemblies. In that case pick the option that creates the least work.

Now if you have a static assembly with mating conditions that can be fully satisfied within one assembly or the other then you'll be Okay! But if you have some kind of mechanism that works while all the components live in a single assembly then you will find that mating conditions spread across two or more assemblies will not express freedom of movement in the sub assemblies and as such your mated assembly may not be all that it could be.

If this has changed in NX-5, which I haven't tested for this yet, then I apologize in advance and applaud the improvement. Up until NX-4 it appears to have always been thus so I would advise caution.

Best Regards

Hudson

 

[JohnRBaker]

You can resolve the issue of partially constrained mating conditions (freedom of movement) between components at different levels of an assembly using, in pre-NX 5, Variable Component Positioning, which you access from Assemblies -> Components -> Repositions Components... and after selecting the component in the structure that you wish to change the positioning, you select the Options tab.

In NX 5, you go to to the Assembly Navigator and select the component of interest and with MB3 select 'Overise Position'.


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

http://www.siemens.com/plm

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