Hello, Thanks for suggesting the video I made. You cannot slide a 5mm hex shaft all the way through and end cap bearing, but you can with a through bore bearing. Through bore bearings are much commoner in my experience with Rev (On the Team USA 2018 robot, there were multiple through bore bearings but only 1 or 2 end cap bearings). End cap bearings can be used instead of shaft collars in some scenarios, as they constrain the shaft laterally along its axis. Shaft collars do the same thing.