NX Assembly Mass Properties: Reference Set Usage, Settings, and Overrides [NX 1953]

This video does a couple of things... It explains the basics of the two distinct ways that NX uses Reference Sets (for display control and for identifying the set of bodies to use for assembly mass properties rollups) and then goes into the settings and the way to override these settings in special cases.
There's a lot of overlap with one of my other videos here, but the tail end of this one (the override bits) is new, in response to a customer question this week. :-)
I hope this is useful for you!

[@lechatvenere]

I just have a question regarding assertion for mass. I had old assemblies made on NX7 to NX12 (and older) and some had assertion for their weight for some reasons. But since we are in NX1929, in assemblies, all those asserted mass can't be updated and can't get them back to "from design", I have 0.000 kg and always the green hand on top of the window, even if I erase the value of the assertion.
Do you know how to unlock or unset this old assertion ?
Many thanks for your answer ;)

[@taylorandersonnxvideos]

Sounds like you may still have "Asserted" selected as the "Source" in the Mass Panel. Can you check that?

[@lechatvenere]

@@taylorandersonnxvideos Hi :)
I actually delete some values in the "MassPropCenterOfMass" developped menu X, Y, Z. Somebody in my company said to me how to proceed.
I didn't seen them because the menu is always packed and nothing shown of by itself. I just click on the little arrow besides and the values just appear.
It's quite weird that these values were automatically added by NX old version and can't be deleted automatically when you delete them in the MassPropMass.
Maybe if Siemens can manage that in the next version, it would be really nice !
Thanks for answering ;)

[@PuratchiEppothumVellum]

Do we have any option in NX similar to "flexible assembly in creo"

[@taylorandersonnxvideos]

Certainly! These are called "Deformable Components" in NX. 🙂

[@PuratchiEppothumVellum]

@@taylorandersonnxvideos I was searching for the option in NX12.. is it available only in latest version?

[@taylorandersonnxvideos]

Deformable Components have actually been around for 20 years or so. Just use the Command Finder in the upper right to find them in NX 12. :-)

[@guillaumepeigne9174]

I believe there is one major point that your video doesn't show, and that is the content of the MODEL reference set of the assembly itself.
If the assembly weight of the assembly is based on MODEL, but some of the components are removed from this ref set, they will still be counted in the weight, which is to my view wrong. It seems that how weight is counted goes down to the definition of each single part having bodies under the part navigator. Starting from the 1st assembly level and upward, nothing you can do about which ref set is to be used as weight reference for each assembly level will change the result, unless you suppress parts.
We can't use this function at work because we often wave link parts from a sub assembly in order to modify them. Reference set allows us to remove the sub assy from MODEL, but this new weight calculation just adds up the waved bodies, giving us double the weight...

[@taylorandersonnxvideos]

@Guillaume --
Thanks for your comment! So... For modifications after linking upward, I would highly recommend using Promotions, which automatically take care of the mass properties bookkeeping for you. (That's the main reason that Promotions exist, really.) There are many ways that people use WAVE links, and we cannot predict or guess which one *you* are intending, so if you use WAVE you'll need to manage/remove the duplicate body mass yourself. Thanks again!

[@guillaumepeigne9174]

@@taylorandersonnxvideos Thanks for your reply. I would say that the main issue with promote is that you cannot suppress it effectively if you want to see how the body was originally. Moving the "current feature marker" before will not make reappear the original body if you want to check how it was looking like. Original bodies are just hidden or sent to some parallel dimension until a hard "delete" of the promote feature. The same happens with assembly cut, as it is most certainly based on promote as well. Not a popular feature here :).
Anyway, regarding the wave, I actually don't see the issue. The weight calculation is supposed to be based on the reference set, which is actually not exactly true, as it takes all components, regardless of if they actually are in the reference set. This is to me and my colleagues, very misleading. A simple fix would be to make the weight calculation based exactly on the reference set. No need to worry about what users do with wave or not.
Moreover, if you were to place an existing component (released, and with weight and so on) just for illustration, that you don't want to be part of your delivery (or weight), it will still be added to your weight. While removing it from the MODEL ref set would give you the correct weight, if it were to work the way we see it.
Regards!