Separate object, after 'intersect faces with model'?


I’m trying to create the head of a star knob screw. To select ‘interface with model’, the groups must be exploded.

After performing intersect with model, is there a quicker way to remove the undesired ‘perimeter’; than using the eraser tool?

Skp file: 021_progress.skp (2.4 MB)


Just draw one point (with overlaps), of the star knob with roughly the process you are using. Delete unwanted edges and surfaces. Group geometry, then copy 4x by 72 degrees. Explode geometry, delete unwanted lines and pull up to desired height.
Use the extension, Round Corner by Fredo6 to round or bevel edges.


Here’s one way to make a a five pointed round knob.


Once you have a simple path, as shown by Box, use a section and Follow me for 3D shape. You’ll have to clean up the shape, but … I think it’s going to be simpler that way.


You can simplify the cleanup by not making the profile so big.


@Box , the top is a curved surface
I think it’ll be easy to clean up if it’s made by pieces.


It all depends what is wanted, I’d probably just cut a dome from the top.


But it will lose its top rounded edges


Well, for me I would actually make it using SUbD, but that’s a whole different topic.
We are simply both offering ideas for possible solutions. Nothing is ever totally wrong or completely right in SU.


Thank you so much for the demonstrations .Unfortunately doing it this way, turns outs very differently for me, as seen in the video.

I made sure all 4 sides of line were treated as one; i.e 4 total. Same result with rounded off edges at top and bottom of outer perimeter.

Edit: I partially found the cause. As you use the offset tool to move closer, to the center of the ‘pentagon’, The ending offset shape ends up in a more ‘star-like’ shape. I’ve uploaded 2 more videos to demonstrate this.

2nd edit: I followed mihai’s suggestion in post # 6, and was able to achieve the following: