Over the Labor Day weekend I built a tractor from a set of Catawba Brougham ConvertiCoop plans. http://catawbacoops.com/. It comes in a .pdf and a 3D walkthrough. The only problem I had was on the sides it calls for trimming one of the 1x4 to about 3" I got around this by making a jig I could run a skil saw along trimming the extra material but I don't know why the guy didn't just make the frame legs 3/4" taller or trim the top board. Still its a nice set of plans and looks good. Weight is a bit on the heavy side but the side aren't permanetly attached so they can be removed to make moving it easier just make sure the chickens are on the bottom with the ramp up and don't lift it high enough for them to run out. Otherwise two men can move it without problem. Still need to finish it but it houses my mille fleur d'uccle hens. The ramp uses some paracord and eye hooks to raise/lower it. Theres two nest boxes, one at either side and a roost inbetween.