www.automaticchickencoopdoor.com

If you want peace of mind with your pet chickens, get their product.  It is a well-made wooden pop door that has a timer and mechanical lift.  All you need is electrical power to your coop.  It was fairly easy to install, the hardest part is cutting out the door hole on the coop and adjusting the fit if your studs are not standard width.  Their videos are very helpful.  The reason for my glowing recommendation is the personal service behind their product.  I made a few errors in setting up the door initially.   This led to a premature wearing of gears on the automated mechanism.  So I had a work around, but it was getting worse, so I contacted the seller.  He got me in touch directly with the manufacturer of the part they used.  The manufacturer responded immediately with a P.O. for returning my product to them.  They convinced me that if I send it I will be happy with the results.  I thought I could replace the gear myself, but was persuaded to send the part in for repair, $12 shipping.  Becuase it was under 1 year warranty, I was able to get the product back in less than a week, working better than it had since I first installed it.
So thanks again to automaticchickencoopdoor for standing by their product and the makers of the door lift for speedy repair. If you follow their installation info precisely, there should be no problems like mine.  The door comes stained/varnished already, so you really don't need to paint the door or rails at all.  Beacuse of the humidity when I installed it after I thought the paint was completely dry, it stuck a little and was the source of my inital problem, I think.