I made mine similar to the Automatic Chicken Coop Door model (the one with the long video). Used a Add-a-Motor drapery motor model A 20 to power it. This cost around $100. The frame and track was made from left over 2x4's and a guillotine style door from an old road sign. Made it to screw between two studs and added it later in the building process. It was mounted fairly high to keep it out of the deep litter shavings. I made to door longer than the opening to allow sand and shavings and poo to fall down and not interfer with the door operation. This also makes it almost impossible to open from the outside without a pry bar, keeps the preditors out. I love the auotmatic door feature of my coop. I still check them morning and night but on my schedule because I want to rather than because I HAVE TO . Also can sleep in without guilt or take LB (lovely bride) out later than 9 and not worry about Bob and the girls.
