Trouble with trimming/wire cutting a solid/polysurface | Rhino 5 Mac

Hi - as seen in the photo I attached I would like to remove the solid part below the horizontal line (applied throughout the c plane) from the object. I tried wire cutting, I tried trimming but the end result always removed the extrusion above the horizontal line. I also tried boolean difference by creating an intersecting box but that failed. I would greatly appreciate some help. Many thanks.

Hello - please always post a file for this kind of thing, it’s hard to help without it.

-Pascal

SweepExtrude.3dm (2.8 MB)

Hi, here’s the file. Thank you

Hello - try Split, from the Front view, and then Cap the result (if you want a closed object.) Trim works too - just make sure you click on the part to delete ( from Front again).

-Pascal

Thanks for the suggestion. Following your instruction, after splitting/trimming it, the extrusion created from the sweeped surface was deleted. I assume capping the result will only cover up the exposed faces in a single plane. I would like to ask if its possible for the end result to be completely solid internally because I will be 3d printing this object.

Hello - if an object is closed - with no naked edges (use ShowEdges) then it is considered ‘solid’ as far as printing goes.

-Pascal

I see, thank you for all your help :slight_smile: