Setting eggs tomorrow,, I have it fine tuned to hold %47 humidity, and the PID controller works great at maintaining perfect temp, the nice thing about the PID is that you can set the differential degrees to as low as. Here is the final configuration, using halogen bulbs ( 72 watt) can't wait till I set a batch in my new bator. I used a STC-1000 PID controller for a thermostat, very accurate. I really like the re-purposed mini fridge, the inside is clean white plastic one piece shell, that will be easy to disinfect, the outside shell is thin powder coated steel, with all the fridge parts out it is very light, and super insulated with high density foam, pic one is the original orientation, I will use the back of the fridge as the bottom. Rate has been 99% it holds 12 eggs I had 2 quiters, all other viable eggs hatched to healthy chicks. I have hatched 5 batches in the bator to this point.
I also changed the bulb to a 60 watt halogen. I have changed the stat to a Bi-Metal thermostat, It works really great I tried different size light bulbs, the 40 watt, is what worked for this cooler. I did drill a few 1/2" holes around the side, and a couple in the plexi glass.(all can be covered with duct tape to fine tune humidity). The fan is mounted in an end of an old cigar box, and bolted through the drain hole in the bottom of the cooler, (very stable) The fan runs all the time and is wired directly to the cell phone charger, both 12vdc, just try to match amperage as close as you can, all requirements are labeled on each devise. The wire mesh I cut and bent to make a safe shelf for the eggs and chicks as they are hatched, away from the fan and bulb, and up off the floor to allow air flow under the eggs. I ended up using, an old space heater stat I had in the barn, not used for 5 years, its highest settings works perfect for maintaning 99.5
This stat did not work the lowest setting would not shut off the light bulb untill 105 degrees. Picture 2 shows the bator done with the hot water stat wired and mounted. ($12)(more on this later)ġ lamp assembly from a lamp I made in shop class 35 years ago (12vdc)ġ new from store hot water element stat. 1 old tower cooling fan from a discarded computer. It maintains a perfect 99.5 degrees, at 55 percent humidity.