I think you need to clarify what you mean by short. Is is the curve or profile you are using? this file you attached doesn't show any history.

Something to note, a curve or line should always be longer or at least the length of the cross-section of the solid you want chop up. Otherwise, use the offset command to extend the solid if the solid is too short relative to the curve or plane.

Well, the Pipe-Tool and the trim tool are two different tools. I still can't figure out what the issue is with trim tool to fail and what you are doing to fix it.

It seems you saved the file for review. When you do that, it takes out the history of what you did and so I can'f follow what you did.

My understanding is that you are trimming the bottom of the vertical tubes in that file with this red line. See pic. If so, that red line is in the wrong location. It should be away from the entire solid for you to trim across it.

I see what you did. First of all, you meant to say solids versus surfaces for trimming. That incline is a solid. The tool was not designed for using with solids but I suppose the program looks for intersecting surfaces of the solid, which is something not discussed in the manual.

2nd, the tool was designed for lines and actual surfaces extruded from lines.

3rd, your logic is wrong. Anyone can figure that only the portion in blue intersecting with the tube will be trimmed out of the tube. You can't trim more than the solid can intersect. You'll need to extend the end of the tube further into the incline.

4th, the way you are using the solid incline with the trim tool is the same as subtracting the incline from the tube. think about it.

I just don't see a flaw with the trim tool but the way you are using it with a solid and the incline being in the wrong location.

In this sample, it is best you just match the end face of the tube to the end face of the incline and avoid the trim or subtract tool at all.

There a feature called face offset that works as an extend tool. See attachment.

I offset it 20mm.

If you need to remove the trim feature, just right click on the concept explorer and delete that trim feature from the tree. The offset feature does not work well with organic shapes as far as I know. The algorithm doesn't know how best to extend, but for simple geometry it works wonders.