Here is a Drawing for a Home Built Bator from the book, "Raising Poultry The Modern Way" by Mercia 1975 It's perfect if you want to hatch a small clutch, I wouldn't try to put 50 eggs in it, but it works.
Here it is in action.. With a few modifications including the fan, and some protection around the light. It was also built with a Plexiglass top and front.
Here it is in action.. With a few modifications including the fan, and some protection around the light. It was also built with a Plexiglass top and front.