Using trim surface disappears

Hi everybody

I have the problem that when I try to trim a certain portion from my surface the surface just disappears. I used the trim command earlier in a much smaller region and it worked perfectly. Does somebody know, what could be by problem?

Ps: In the picture I posted I want to cut out the area inside the pink polyline.

dear @isabel.schumacher123
did you check the size of details you are working on - compared to the unit / document tolerance ?
there is some small detail, that already looks trimmed.
_untrimall to remove all trimming from the surface.
does your curve self intersect ?
does your curve really define a proper and tight region ?

if you need more help, please post the file

kind regards -tom

without a file, people can only take a lot of guesses. if you need help pls upload the model.

Hi Tom and encephalon

sorry I am new here a didn’t know that you would reply so fast. I am really impressed! Thanks for helping me out. Here is the file Vp_moved_mesh.3dm (15.8 MB)

i suspect you wanted it to look like this?

it seems to work in Rhino 7.52 but looking at the stray curves i would not doubt that your issue is being caused by some self intersection or a mess of some sort. when you create trim curves be sure that each curve does not cross over it self as Tom suggested and use one single continuos curve.

Yes! Thank you. I found the problem. I had some small curves which were not connected to the large one and generated the trouble. Thanks again for helping me out :slight_smile: