This is my current design running for 10 days right now. It's been holding temp in C by .2 degrees. And automatically brings humidity to 50%. Design is simple but fully automatic. The container is sealable Tupperware with closed foam insulation on 4 sides and bottom. The tupperware lid is reinforced with plywood for east accessory mounting. It's powered by a old dell computer Power supply. Has auto turner, fogger, and 12v ceramic heating elements. I bought a digital thermostat off eBay for $9 which automatically controls power supply to heat and humidity individually. So far the only issue has been the lack of resivor for water for the fogger, I'm planning a external resivor and will move the fogger out side the incubator and pump in for for next trial. Forgot to mention it has 2 PC fans to circulate the air and fog. I'm running the test next to my Chinese incubator, mine holds temp better as far a I can tell.