Frankenbator
I'm sure there are many a DIY Styrofoam incubator how to's on the Internet, but this one is a bit different. By using Flex Watt heat tape I get a more even distribution of heat and the incubator comes back up to regulated heat quicker after candling (about 4 minutes). Using the Flex Watt also allows me to put heat directly over a cup(s) or jar(s) of water to increase humidity during incubation and lockdown. By doing this I avoid using sponges and I don't have the mess, the chance of dripping on eggs, and I don't have to open the incubator as often if at all.
I recently incubated 14 eggs shipped 1,300 miles from sea level up to 5,000 ft elevation (where I live) and we hatched out 11 of them. Pretty darn good for a DIY incubator.
Cost to me: $44.50
The Styrofoam:
I started out with a used insulated shipping container. This is where the "Frankenbator" comes from. I did not have the lid and it was old and very used. I'm not sure of the exact size (I will measure it), but it's about 26in x 26in on the inside (think egg turner). The walls of the Styrofoam are at least 2in thick. It was tall, too tall to heat the whole area so I cut the walls off and built them into the lid that I was missing with Styrofoam glue ($3 hobby lobby) and sealed with aluminum tape. The Styrofoam box was free. Styrofoam cooler can be bought for about $15 or ask around at restaurants. I needed one that would fit an egg turner. Cost to me so far $3.
The Heating Element (Flex Watt):
I love flex watt. It's inexpensive, easy to use, and gives very even heat compared to a light bulb or even the heating element used in a hovabator. It's safe to use with Styrofoam as far as melting goes. It comes in a lot of sizes and you can cut the length to whatever you need. It's very efficient and I can run with the vents open for oxygen and keep my temps steady. I used aluminum foil tape to attach the flex watt to the top of the lid. You can also make a brooder cave out of it. I had a bunch laying around so cost for flex watt is $0 for me. Normal cost would be two 12in lengths for $12 (amazon) and flex watt cord for $9 (amazon). I just tap the heat tape at the end and use grounding screws to attach a cheap lamp wire I get for $4 from home dept. I will try to add a pic later.
Aluminum foil tape ($9 home depot) is used throughout the project to seal the patched together lid, cover holes, attach wires, and heating element.
The Thermostat:
I'm using a ZooMed 1000 watt Thermostat. I'm not sure this is a great or even good thermostat, I just had it on hand so I used it. The air temp varies about 4 degrees between heat up and cool down cycles. You can get these for $29 (amazon), but I think there are better thermostats out there.
Automatic egg turner:
I found an old (as you can see) automatic egg turner on craigslist for $25. It works great. I think it's an old Little Gian egg turner. It holds 48 or 47 eggs. I think you can buy a new one for $45 at feed stores. Cost to me $25
Lid sealing:
I sealed the lid with a staggered application of weather stripping you use for doors. $5 (home depot).
Window:
I used two thin plastic sheets of plastic that I got from Hobby Lobby for about $1.25 each. By using one on the inside and one on the outside it has a great insulating effect. Cost $2.50
Air flow. Living at 5k feet leaves me with a bigger challenge when it comes to shipped eggs. Eggs from sea level are more dense and need a lot of oxygen exchange. Because the flex watt is so efficient I run my whole incubation with the vent holes open and bring in continuous oxygen.
That's about it.