How can I transform the external geometry of an assembly into a part?

I have an assembly with some parts in there. I want to transform it into a single part and shell it.
The problem is: when I transform it into a part file, it comes with various imported features (which imported feature was a part in the assembly). When I tried to apply the shell feature, I realized that the internal geometry was kept.
I tried to save as STEP, and had the same problem.

I wanted, if possible, to keep only the external geometry of the entire assembly as a single part.

Is this possible? If positive, how can I do it?

1 Answer

It is difficult to give the best answer without seeing the context, but you have three options I can think of:
- Save the assembly as a part file. When doing this, there is a "Geometry to save" option. You can try your luck with these and see the results. I most often use All Components.
After your new part is saved, it may have multiple bodies as you discovered. Try merging these all together - Insert - Features - Combine - Add

- In an assembly, you can insert a new component. You'll need to pick a sketch plane, then exit out of sketch mode. Once done, you are editing a new empty part, within the assembly. It is scary, but not too bad.
Now, go to Insert - Features - Join. Pick all the parts you want to "merge" in the new part, maybe try playing with the Force Surface Contact if something goes wrong.
Then you can save that new part off as the STEP file you desire.

- Last up is "Defeature" I've never actually used the tool, but it is meant to strip out internal and other "extra" features which you don't wish to export to someone. Brose the help file and see if it would be helpful in this case based on the examples.