Trimming/splitting polysurfaces

I am currently working on a stair. I have the steps profiles designed as polysurfaces made up of 2 surfaces and a swept surface on which they sit. I am trying to split or trim the steps part that goes beyond the surface, but it doesn’t work, What shall I do?
Thank you.

I’ve also had difficult trimming or spitting at times. What I found that works - is to first set the cplane to the object you want to split, and then perform your split or trim, Have you tried that?

The first step in a failed trim or split is to intersect the object you are trying to trim and the cutting object. The resulting curve needs to completely span the object you are trying to trim, you can usually see pretty quickly where your problem is. If not, you can post your file so we can take a look.


Thank you for both replies. I tried setting the cplane, but did not work. But then I looked closely at the intersection and the cutting object(the surface) wasn’t spanning all the length of the stair. After I extended it, I could trim the steps with no problem.

I have a hack-trick I use to trouble-shoot problems like this : create an intersecting curve between the two surfaces and see if there are any gaps or other obvious problems.

The exact command name is Curve --> Curve From Objects --> Intersection

Thank you. I’ll bear it in mind.