I needed a larger incubator this year so I built this over the weekend. It's 24"w x 48"h x 18"d, can fit 12 egg boxes and is made of solid birch.
I built in a Herpstat thermostat, then I also built in a closed system, self exhausting computer power supply that powers a 3 channel, blue backlit speed controller that powers and controls a pair of 6,000v cold cathode lights, a pair of 50mm fans that blow down against the back wall, and a third 50mm fan than blows from the back toward the front of the unit. The Herpstat powers two - 3' sections of 11" flexwatt. I used weather strip along the inside front and a set of magnetic cabinet latches so the door snaps shut and has a tight seal.
without flash to show lights off
lights on (turned up to full brightness)