When I’m not home I need a non-flexible door (11” wide by 15” high) to cover my pet door from sundown to sunup. I live where both my pets and small wild creatures reside, i.e. Skunks, Raccoons, and Possums co-exists. When I’m going to be late getting home or go away for a weekend I only have two choices…lock my pet in the house or lock my pet outside. My pet could have freedom during the day if there was a way I could lock/unlock the pet opening with a timer. No I can not use the collars that work with magnets, lasers, or chips because I have to many pets. I found an automatic shade that might be adapted but the cost was $300.00. Could any of you woodworkers advise me how to go about building this on my own. Maybe runners on both sides of the pet door for the solid door to slide up and down, stops at the top & bottom. Would I need two motors, one for up and one for down? What kind of motors? timers? pulley?