Most of our projects are built from scraps we have laying around. You can reuse just about anything it seems! The incubator below is our first attempt and we learned quite a bit from it to make the 2.0 version that much better. Below are some simple steps to help you get the idea we used. The measurements are just what we went with but you can use the same concept for different sizes. This incubator is 3.5 cubic feet(16"x20"x19"), enough for two sets of quail rails (120 eggs each).
All the building materials we used were scraps. The 1x2 for the frame were last years tomato cages. We did decide to purchase a thermostat and heater kit from www.incubatorwarehouse.com as well as their quail rails. Once the rails get installed we will update the pictures. The hinges were cheap for a box of 20 on amazon..$10 Total cost $160 for 240 egg incubator.
We welcome any and all feedback as this is our first DIY post. Hope it helps!