topic Assemblies that subtract from Other Assemblies in Inventor Forum

Assemblies that subtract from Other Assemblies

Anonymous — Wed, 30 Aug 2017 02:35:45 GMT

I am struggling with (plastic) parts having an unmanageable number of features. One of my parts is up to 200-400 features. Too many to flat-list under one level of part hierarchy. Inventor doesn't provide folders to organize features at the part level, so I'm looking at making my part into an assembly of assemblies.

My main problem is that the logical assembly organization would include sub-assemblies that carry their subtractive parts with their additive parts. So that a mounting feature may have additive posts, but also holes that extend through other sub-assemblies. I can't figure out a method of having sub-groups (perhaps exploded out from a multi-body part), that contain additive and subtractive geometries, that will subtract from each other, without causing further effort of secondary operations.

Any ideas?

Re: Assemblies that subtract from Other Assemblies

johnsonshiue — Wed, 30 Aug 2017 02:56:17 GMT

Hi! This is an interesting question. If the part has multiple solid bodies, you can easily turn it into an assembly by using Make Components command (Manage -> Make Components). It will push each solid as a separate part in an assembly. Would it work for you?

Many thanks!

Re: Assemblies that subtract from Other Assemblies

Anonymous — Wed, 30 Aug 2017 04:50:32 GMT

That approach works so long as the subtraction operations don't cross parts. As far as I can tell you can't make components and preserve subtractive geometries cross-part

Re: Assemblies that subtract from Other Assemblies

mcgyvr — Wed, 30 Aug 2017 12:33:21 GMT

Why don't you just stay with a single part file and logically rename the features for easier identification?

And then use the "Select Features" selection filter to easily identify the feature in the model browser upon selection..

Re: Assemblies that subtract from Other Assemblies

johnsonshiue — Wed, 30 Aug 2017 17:00:21 GMT

Hi Troy,

You could but it is probably not as straight forward as Make Components. You can use Thicken/Offset command to create a zero offset surface on the Subtracted faces. Then use Make Part command (like Derive) to push the surface body to a different part in the same assembly. Would it work for you?

Many thanks!

Re: Assemblies that subtract from Other Assemblies

JDMather — Wed, 30 Aug 2017 17:46:54 GMT

Another option might be to work up to a certain stage...

start a new part file....

Derive Component previous file into the new file and continue on...

Cascading repeat as needed.

Re: Assemblies that subtract from Other Assemblies

kelly.young — Wed, 30 Aug 2017 18:51:25 GMT

@Anonymous I see that you are visiting as a new member to the Inventor Forum.
Welcome to the Autodesk Community!

I was about to reply but @JDMather's idea beat me to it!

Can you supply a bit more information about your modeling needs, what kind of 200 features are you using, how your hole creation is needed to be separated? Maybe a post quick sample piece showing your desired workflow and someone might find you a shortcut.

Are you trying to make the part parametric where it will scale or involving iLogic to turn features on and off? I am just wondering how you want your grouping needs to be managed and what the desired effect is.

Please select the Accept as Solution button if a post solves your issue or answers your question.

Re: Assemblies that subtract from Other Assemblies

Anonymous — Thu, 31 Aug 2017 02:47:30 GMT

Derive Component previous file into the new file and continue on... Cascading repeat as needed.

Interesting method. Still built in a linear way, with the same relationship fragility, but generating sub components along the way.

Anyway to derive in place? Everytime I derive, the derive part is floating and I have to fix its spacial coordinates again (unlike say, project geometry or copy object)

Re: Assemblies that subtract from Other Assemblies

Anonymous — Thu, 31 Aug 2017 03:01:12 GMT

The part is a plastic box, with rails, guides, embossing, screw bosses, posts, cutouts for connectors, knockouts, and the like. Once you fillet, thicken, add holes and modify... each major feature becomes 8-15 minor features.

You might have 8 screw mounting posts. And each screw post, for example may be an assembly of 6 features, but also include a cutout of the enclosing plastic box... which is a separate part.

Inventor feels like programming with giant functions, that are hard to maintain. Hierarchy is important for organization and maintenance.

Re: Assemblies that subtract from Other Assemblies

SBix26 — Thu, 31 Aug 2017 11:26:33 GMT

@Anonymous wrote:

Anyway to derive in place? Everytime I derive, the derive part is floating and I have to fix its spacial coordinates again (unlike say, project geometry or copy object)

Can you explain in more detail? When I use the derive tool, the derived body is fixed at the same location (relative to the Origin) as it is in its own file. I've never experienced a floating derived part. So either you or I (or both!) are missing something here.

Sam B

Inventor Professional 2018.1.1
Vault Workgroup 2018.0
Windows 7 Enterprise 64-bit, SP1

Re: Assemblies that subtract from Other Assemblies

JDMather — Thu, 31 Aug 2017 14:37:30 GMT

@Anonymous wrote:

... Still built in a linear way, with the same relationship fragility,

Nope!

Rock solid - robust modeling technique.

If you attach your file here I will make wager (before seeing it) that I can very significantly reduce complexity of technique used to model the geometry.

If you can't post the file because of confidentiality - can you at least post image of the browser feature tree?

Re: Assemblies that subtract from Other Assemblies

Curtis_W — Thu, 31 Aug 2017 14:43:52 GMT

@Anonymous wrote:

... I can very significantly reduce complexity of technique used to model the geometry.

Unless it's less about creating the one model but more about creating a reusable "library" of features from which to make other types and variations of the same type part file. In which case simplifying the model geometry might not be all that helpful.

troyJNA3R,

In any case please share more information about the design if you can, and someone will be able to suggest something. It does sound like the current process you're employing is overly complex. There might be other tools such as iFeatures, etc that you could use for this.

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com