Assume you’re a contract manufacturer and you receive a new part to quote. After unfolding, you see it’s going to be complex and expensive, but it would be simpler and cheaper as an assembly of several parts. You could start from scratch and redesign the parts, but by using multibodies, you could break the existing part into several parts, all in the same file, and save the existing work.
The following is a very simple example. You want to make the middle and right flanges as separate parts:
Make the sketch shown and use Insert > Features > Split to cut the part.
Add a jog and tab to make a fastening feature.
Next, make the middle flange into a separate part. The small square sketch will be used to cut away the bend in another Split command, but here you need to understand the extruded split does not work exactly the same as an extruded cut. The split extends infinitely in both directions and will cut anything it encounters. It has no ‘Blind” or “Up to Next” options. Instead, you’re given a preview of all the possible separate bodies that could result from the command. In the following picture, check “Consume cut bodies” and check Body 5 to delete. Do not check Body 1 or the split will extend all the way through the part.
Here’s the result of this split feature:
Next, add an Edge Flange to attach this to the main part:
Finally, punch holes through all bodies for assembly hardware:
Another benefit of multi bodies is that a Flat Pattern is created for each body. You can create configurations of the part with each flat pattern unsuppressed to make fabrication drawings with bend lines and notes. Here’s the flat pattern for the large tab:
Here’s the flat pattern for the small tab. Notice it’s in a different orientation, and that is taken into account when making the drawing view.
Multibodies can streamline major design changes without deleting lots of existing features. Experiment with them, get comfortable with them and add them to your bag of tricks.