topic Re: Derived part from a Derived part... How many levels can I go? in Inventor Forum

Derived part from a Derived part... How many levels can I go?

Anonymous — Tue, 23 May 2017 21:56:47 GMT

Is there a practical limit to the number of "nested" layers with which I can derive a part from another?

I currently have a project where many parts can be defined (using derive) from one "master" part. Once I started using that, my workflow really sped up, and I have it working well, where changes to the master will propagate to the children. Let's call this derive, Level 1.

Since then, I found it very convenient to also derive adjacent parts with relation to each other, making them fit together better. These parts still have geometry also derived from the master I mentioned above. Derive Level 2.

Next I want to insert each of these parts into sub-assemblies, and those subassy's go into another larger assembly. All of these parts are fitting together very well - they all reference the same original geometry, after all. Derive Level 3.

Trouble happens when I try to do the insertions of IPT parts into the IAM assemblies in "level 3". This can take a very long time (10 minutes per operation). As an experiment, I have exported some of the derived parts into STEP files, then inserted them into the subject assemblies, and that works quickly and normally. The assemblies and parts have no broken constraints or features, the parts are all less than 2MB each; the assemblies about 1MB.

Have I run into some limit to the number derived parts and assemblies that can be nested together?

Am I using Derive in the intended manner?

Re: Derived part from a Derived part... How many levels can I go?

johnsonshiue — Tue, 23 May 2017 22:13:33 GMT

Hi Steven,

In theory, there is no limit in terms of how many levels you can derive. But, it does come with a price though. For every level you derive, Inventor will have to check the file status and propagate the notification. When the derive child part is loaded, all its parents will need to be loaded too. When there are too many levels, the dependency may become too complicated or fragile for you to manage. You may end up doing a lot of rework. I have seen customers dataset with 4 derive levels and it works fine. I have never seen a dataset with 10 levels.

Many thanks!

Re: Derived part from a Derived part... How many levels can I go?

Anonymous — Tue, 23 May 2017 23:03:59 GMT

I hope I don't layer it on 10 levels deep!

Thanks Johnson

Re: Derived part from a Derived part... How many levels can I go?

PaulMunford — Wed, 24 May 2017 20:27:29 GMT

I once created a 6000 part assembly all based on a single layout part, with derives up to four levels deep... the assembly behaved ok, but creating drawings was a pig...

Notice that every derived part is the same size as the part, plus the master? There can be a lot of repeated data loaded into memory!

Judicious use of 'Suppress Link' can help. If you're interested I can dig out an iLogic routine that suppresses all derived links in an assembly?

Re: Derived part from a Derived part... How many levels can I go?

Anonymous — Wed, 24 May 2017 21:22:06 GMT

Yes, I'd be very happy to see that!

Suppressing links manually sounds reasonable when passing through once, but later if you ever have to change the master, going back up the chain to find and refresh all the affected models sounds like a nightmare! Any automation would be greatly appreciated.