topic Re: Mass Properties and Substitute Model States in Inventor Forum

Mass Properties and Substitute Model States

CPEng16 — Fri, 02 Dec 2022 20:38:19 GMT

Hey all,

Still new to inventor but I ran into a problem with using substitute model states and getting mass properties.

Basically if you activate the substitute model state the mass properties never save and have to be calculated manually, see the video.

This causes problems when using the substitute model in a bigger assembly if you want the mass properties to automatically be pulled into the drawing. I thought that was the whole reason for using substitute model states is to use them in a big assembly so I don't understand why the properties are always N/A. Is this a known limitation of using substitute model states or is there something I can do different to fix it?

Thanks

CPEng16

Re: Mass Properties and Substitute Model States

johnsonshiue — Sat, 03 Dec 2022 04:49:03 GMT

Hi! The iProperties dialog may show N/A. It means the values are not yet computed and stored. To persist the mass prop, you need to make sure the assembly and the substitute part are both saved. You may reference the mass prop in the drawing to see if it does persist.

I did try your files. After the mass prop is updated and the files are saved, N/A no longer appears. You may want to consider turning the following option on.

1) Tools -> App Options -> General -> Update physical properties on save -> Part and Assembly.

2) Tools -> App Options -> Save -> Mass Prop Change -> Yes to Save -> Prompt to Save.

Many thanks!

Re: Mass Properties and Substitute Model States

CPEng16 — Mon, 05 Dec 2022 18:26:43 GMT

I'm not able to get it to work. I did enable those options but I cannot get the mass properties to transfer to the drawing. I made a quick assembly of the .iam to better represent what I'm trying to do, I used the substitute versions and I cannot bring the mass into the drawing. Look at "double substitute.idw" and "double substitute.iam"

Best Regards

Re: Mass Properties and Substitute Model States

CPEng16 — Tue, 06 Dec 2022 16:30:40 GMT

Hi @johnsonshiue,

Would you mind checking if you can make an assembly of a substitute assembly and see if you can get mass to populate the drawing? I've updated my files in the post above to include that.

Best Regards,

CPEng

Re: Mass Properties and Substitute Model States

johnsonshiue — Wed, 07 Dec 2022 00:39:35 GMT

Hi! The behavior does not make sense to me. It seems to have something to do with the subassembly in substitute Model State. I will need to work with the project team to understand it better.

Many thanks!

Re: Mass Properties and Substitute Model States

CPEng16 — Wed, 07 Dec 2022 18:46:11 GMT

Thank you @johnsonshiue for looking into it!

Re: Mass Properties and Substitute Model States

johnsonshiue — Fri, 09 Dec 2022 13:28:49 GMT

Hi! I have contacted the project team and got some information to share. The behavior is currently considered a limitation. The mass prop still needs to come from the source Model State, not the Substitute. This has been reported as a user story, INVGEN-66280 for future implementation.

Many thanks!

Re: Mass Properties and Substitute Model States

CPEng16 — Tue, 13 Dec 2022 00:53:58 GMT

Thank you @johnsonshiue for following up. I don't fully understand why there is a problem but I recognize that there must be some complexity behind the scenes. I probably will refrain from using substitute model states until this is fixed though. I could make a substitute model manually and override the mass properties as a workaround for now.

Best Regards,

Sam

Re: Mass Properties and Substitute Model States

felix_hofbauerJECSJ — Fri, 07 Mar 2025 11:00:44 GMT

Hi!

I have a similar problem.
For packaging planning we have to "cut" the assembly into pieces. It is an old plant which is being dismantled.
So I use sketches in an assembly and extrude these sketches on different levels and "cut" away pieces, each cut-step represented in a model state.
There also occurs the problem that sketches can't be reused.

So in the assembly when I open the iProp i see the correct value of mass after updating the iProperties. So if I change the model state I have to update again.

It would be great if Inventor can represent the different masses in a drawing of the corresponding model state and not just the mass of the "primary" state.

Re: Mass Properties and Substitute Model States

johnsonshiue — Fri, 07 Mar 2025 20:31:56 GMT

Hi Felix,

Based on your description, it sounds like a bug to me. I just want to make sure you are aware that iLogic rules should only run when Edit Scope is set to Factory Scope (all pencils). If there is an iLogic rule trying to alter any configurable item (features, parameters, properties, or BOM structure), such change will be captured on the table.

Please share the files that exhibit the behavior with me. I would like to understand the behavior better.

Many thanks!

Re: Mass Properties and Substitute Model States

felix_hofbauerJECSJ — Mon, 10 Mar 2025 08:49:55 GMT

Unfortunately I can't share these files because of business reasons but maybe i can reproduce the issue with a dummy project.