Hi Klokl, hi folks.
The perimeter of each end cap is smoothed (or softened) and thus, its surface is "joined" with the cylindrical part.
To change that, try this procedure:
1 - Show hidden geometry. You can now copy the end cap but its edge will keep their smoothed characteristic. To change that, continue at step 2.
2 - Double click one end face to select it and its perimeter.
3 - Right click on one of the selected edges of the perimeter.
4 - Choose "Unsmooth" or, if some edges are smoothed and other not, "Soften" to bring the Smooth/Soften" window.
5 - Slide the softening cursor all the way to the left to unsmooth all selected edges.
6 - Now the end cap can be selected and copied away.
Just ideas.
