topic Re: Need help with subtracting an assembly from a model in Inventor Forum

Need help with subtracting an assembly from a model

davidharper — Mon, 28 Nov 2022 23:38:24 GMT

Bear with me if this has been answered already, but I haven't seen a solution yet.

I need help subtracting a complicated assembly from a solid. I'm attaching example files to help describe what I'm trying to do. "EA1" is the assembly I'm trying to subtract and has been placed into "EA2"; EA1 references the solids "ES1" and "ES2" while EA2 only references ES2. In the assembly EA2, what ways could I subtract the assembly EA1 from the solid ES2?

For a simple example like this it's easy to just create a sketch based on projected edges then extrude-cut, but the actual assembly I'm working on has many more surfaces and bends to cut out so I can't easily and thoroughly do this.

Ideally, you could you the assembly itself to extrude-cut, but I haven't found a way to do that yet. I also read a couple threads where the sculpt tool was mentioned, but even after reading through the "To Trim, Extend, or Sculpt Surfaces" topic, I wasn't able to figure out how to use it: I was unable to select any surfaces on the solid nor on the assembly.

Re: Need help with subtracting an assembly from a model

davidharper — Mon, 28 Nov 2022 23:40:03 GMT

EA2

Re: Need help with subtracting an assembly from a model

WHolzwarth — Tue, 29 Nov 2022 08:00:14 GMT

Problem is, that the main IPT needs another name than an initially same part in the EA1. Without that, a cyclical constraint shows up.

See attachment (2023 files). I expect, that the more complicated task needs another workflow.

Re: Need help with subtracting an assembly from a model

davidharper — Tue, 29 Nov 2022 14:26:53 GMT

Okay, I've adjusted the files so EA1 only contains ES1, and EA2 contains both EA1 and ES2.

Re: Need help with subtracting an assembly from a model

davidharper — Tue, 29 Nov 2022 14:27:22 GMT

Adjusted .ipt files

Re: Need help with subtracting an assembly from a model

WHolzwarth — Tue, 29 Nov 2022 17:47:28 GMT

Try that:

- Edit E2.ipt

- Copy Object -> Select all members of EA1.iam. Result is Base1 (blue color)

- Combine Cut with the initial solid of E2.ipt and Base1 as toolbody

It's a static result, not following any changes in EA1.iam

Re: Need help with subtracting an assembly from a model

davidharper — Tue, 29 Nov 2022 18:19:09 GMT

Thank you for your help, I wasn't able to get this to work but decided to go in a different direction:

I've created a new assembly file, imported the assembly I'm referencing, and extruded based on a sketch of the imported assembly.

Re: Need help with subtracting an assembly from a model

johnsonshiue — Tue, 29 Nov 2022 23:13:12 GMT

Hi David,

As Walter illustrated, this can be done in Inventor. But, it is a bit tricky. It is because Inventor is a distributed design tool. The geometry resides in individual parts. The parts are reusable. They are not aware of where they are used. In your case, you need to edit EA1 and make a copy of ES1 and delete ES1:2. In this way the change to ES1 will not propagate to ES1:2. The try the Copy Object workflow using Surface output (associative).

If you like altering geometry in an assembly without limitation like this, you may consider using Fusion 360. It offers more flexible modeling environments and geometry can be altered regardless of the component structure.

Many thanks!