These pics show the cantilevered (I think that is the correct word!) kick-back sector plate arrangements used at each end of the layout. They are obviously of foam-core construction too and are fully removeable for transport purposes. The are fixed and pivoted by a brass screw into a captive top-hat style threaded bearing glued into the baseboard. A removeable brass drive pin locates into the actuating arm underneath through the visible quadrant slot.
Power is transmitted via jack plug leads direct from the main DCC bus. The ends stops are 13mm ali angle with brass screw & nut adjusters. To provide a softer and quieter 'stop' at the end of travel I have used soft silicone rubber cupboard door buffer pads. These are obtainable from DIY stores in self-adhesive sheets.
These sector plates are long enough for two coaches and a 4-6-0 tender loco, the longest train the layout will see. The direct drive from the Tortoise works okay but is probably at the limit of its strength. If I were to do it again I would probably use a mechanism that gives more mechanical advantage to the Tortoise output, and reduce the friction of the sector plate to baseboard interface. The foam-core board has a smooth shiny surface and takes spray dry silcone lubricant okay, so I have got away with it (just)! Balance is also an issue with the design - any longer and some support for the other end of the plate would be required.