Large Assembly drawing - LOD catch 22

[torbjorn]

I am working with a drawing of a relatively large assembly, I there are about 25000 components, about 4500 unique. 

I am creating simplified LOD's for the main components to get a lightweight top assembly. With the configurations I need to be able to show, this top assembly is about 500 components, about 190 unique. I can easily place views on my drawing, a base views, projections, details, sections are generated in maybe 10 sec. Perfectly fine, works smooth!

Then I place the first balloon  

This will take about 20 minutes to complete, waiting. Of the component count, I see that Inventor loads the full model, and probably does some verification. This single balloon changes my drawing from a lighweight easy to open / easy to close drawing to a monster that needs 20 minutes to open and 20 minutes to close.

And even worse; as long as the drawing is open I cannot change anything in my assembly, because of the old "LOD cannot be saved because a different Level of Detail representation is being edited..." error message. Due to the balloon/part list on the drawing Inventor is loading the master LOD - and I am trapped.

I.e, when I find something I need to change in the assembly (it happens - I am not perfect), the drawing has to be closed...  i.e 20+20 minutes before I can continue on the drawing...

Anyone have a good workaround for this? 

(I know I can create fake balloons and a manual part list, but that feels a bit nonproductive work, when all the info already are in the system.)

Torbjørn

IV 2017.4

[johnsonshiue]

Hi Torbjørn,

The large assembly performance on Inventor 2017 or earlier is not as good as 2018 and 2019. Would you be able to upgrade to 2019? We have made significant improvement in performance when dealing large assembly workflows.

Many thanks!

[swalton]

I don't mix LODs and drawings because of this issue.  

As I understand it, Inventor needs to load a separate memory image of an assembly for each LOD in a drawing.  Once you place a Parts List, Inventor needs to load the Master LOD so it knows what parts are present in the assembly.

Instead, I use LODs to perform my design work in the assembly environment.  Once I am ready to start documenting the large assembly, I create Design View Reps that hide the small or hidden components.  Sometimes I copy a LOD in the assembly to a Design View Rep.  When I create views in the drawing environment, I use these Design View Reps to help Inventor minimize the edges, surfaces, and lines it has to display/calculate.  

I find drawing performance is better without hidden lines or shaded views.

[torbjorn]

Upgrading would help, I know. I was i Munich last week, and got a quite good overview of what to expect of newer releases. But I cannot upgrade until the company is ready.

Newer releases can handle larger model drawings, but I don't think there are any better support for simplified LOD workflows. I mean, the principle is great. Autodesk have created this great tool for working with the largest assemblies a long time ago. For each main component (that is one BOM line at the top assembly), I can easily create a locked view rep with the components I want to be included in the simplified LOD. Using this to control the shrinkwrap, I get a very lightweight multibody part with all small holes removed. 

In the top assembly I then have to create one LOD calling the simplifed LOD's of the main components. I have in princple got the perfect model. It has full control of the complete BOM, I can get important properties such as weight and COG based on the complete model, and I have that easily generate all the drawing views I want. So far it is great, it works, and it is actually quite fast! And this works just as fine even when the assembly is 10 times larger than this specific one.

But Autodesk forgot the last step of using this workflow, creating a drawing with partlist and balloons. The info needed for the drawing is only the first level of the BOM, but the system loads the master model. This makes me sad. Almost there, but stopped development one foot before the finish line.

I understand that the focus has been working with full assemblies, and it is great that it becomes quicker and more effective. Does it mean that a workflow based on simplified shrinkwraps will be discontinued in the future?

Torbjørn

[torbjorn]

Thanks for sharing experience and thoughts.

I will give this a try, base the drawing on view reps. (Already have the view reps, as they are used to control the simplified shrinkwrap LOD's)

But I suspect the time consumption could be similar or even more, because here I need to load the master LOD before even placing the first view. Also the model is a bit mode complex as no details is washed away (no shrinkwrap process). But we will see 

Thanks,

Torbjørn