he has missed one important thing - when the end cap is taken off the cassette as well as the white spacer there is a black fitting which needs to go back on after the cutting - if not careful it will drop down inside the cassette and be lost - take it out before you cut andput aside with the end cap and spacer - it is effectively the locking device which seems to stop rotation after re-assembly
Well, we saw a spirit level NOT ONCE - these free running meshes (ie mesh not retained in the tracks) are just as important to be plumb, level and square.
