One final point for you and all others new to the program:
I grouped those two planes used to intersect the ends. Therefore, when they were deleted, they disappeared completely with a single click. If I had left them as raw geometry, I would have needed to delete all 4 edges on each square. Obviously, the face would have disappeared as soon as I started this action...however that part of the face that formed the end of the curved cover would have remained, instead of having to fill it in later. The face on the far side would have been the wrong way round, however, (blue face outwards) unless I'd flipped the face on the square before intersection.
It's useful to consider such things beforehand...whether to group the intersector, the intersectee, or not. For instance, you can produce a line of 3D text, or extrude a 2D logo and intersect it with a curved surface, leaving the outline of the text/logo branded onto the surface...ready to receive a separate colour, or whatever. It's much easier to clean this up after intersection if the 'branding iron' is grouped beforehand, so it can be deleted by a single action...otherwise you may need to clean up the remains of hundreds of separate faces on both sides of the curved surface.
The Pro version of SU has a new assortment of Solid Tools which can perform all manner of such Boolean intersections...both subtractive and additive.
