You will need:
- A chilli bin/polystyrenebox with lid/wooden box with lid if you can't find the other two. I used a polystyrene box from a catering company delivery.
- A thermostat. I found one at Musgroves for $5. It's an old hot water cylinder thermostat and works just fine.
- A thermometer and maybe even a hygrometer (measures humidity).
- A light bulb and socket.
- An old computer fan. I used a CPU fan for mine. (Optional)
- An unused phone charger which will power the computer fan.
- A piece of glass so you can look through and see the temperature and the eggs as they hatch.
Cut a hole in the lid of your polystyrene box for the piece of glass to sit in. I found a craft knife did the trick for cutting through polystyrene, but if you have proper polystyrene cutting wire use that. Cut the hole a couple of centimeters smaller than the piece of glass so you can make a ledge for the glass to sit on. This is better than having the glass stick out the top of the lid.
STEP 2:
Place the glass in the groove you cut for it and duct tape it securely in place. Duct tape will help to keep the heat in, as the glass will probably be the area of greatest heat loss in your whole incubator.
STEP 3:
Now we have our incubator ready, we need to add the two most important parts - the lightbulb and the thermostat. The lightbulb is going to generate the heat that the embryos need to grow, and the thermostat is going to regulate the heat. You'll read that a hot water cylinder thermostat is not accurate enough for this task, but this was not my experience. Once the system settles you will find that you are seldom adjusting the thermostat and the temperature is staying either constant or near constant. We went for quite long periods without any adjustment. Even the bought incubators recommend checking the temperature four times a day, so this seems comparable to that. You can allow your incubator to settle by turning it on and monitoring it for three or four days before you begin incubation.
Attach your thermostat switch to your light socket. If you turn the thermostat to the lowest temperature you will be able to test whether it is working. Heat it with direct light from the lightbulb and see if it turns itself off and on. Once you have wired this correctly, Make some holes in the side of you incubator box to plug both the lightbulb and the thermostat through. Ideally you would want the thermostat closer to where the eggs are going to be and the lightbulb further from the eggs. This is because you want the thermostat to respond to the ambient temperature rather than the heat radiated from the lightbulb. It is not crucial, as you will see from my picture where I did not follow this advice but was still able to successfully hatch eggs. I would have followed this advice if my length of wire permitted it.
STEP 4:
Skip this step if you are going to make a still air incubator rather than a forced air incubator. If you have a computer fan available I recommend using it. I would have more confidence in an incubator with a fan circulating the air, especially if I was putting a lot of eggs in it. A fan will provide a more consistent temperature throughout the incubator.
Make a small hole in the side of the incubator near the lightbulb. Heat rises so the fan should be closer to the top of the incubator to push the hot air downwards. Push the wires through this hole so the fan is suspended on the inside of the incubator. Cut the phone charger plug off the end of the wire and attach the red and black wires from the computer fan to the two wires you find in the phone charger. They only work one way, but it shouldn't take too long to work out which as there are only two possible ways to connect them! The reason for the separate power supply for the lightbulb and the computer fan is that computer fans run at 5 volts and lightbulbs run at 240 volts. So the mains would blow the fan out of the water.
STEP 5:
The next step is to place the area where you will put your eggs into the incubator. Place your thermometer (temperature) and hygrometer (humidity) in the incubator in the opposite end to the lightbulb. These should be lower than the eggs to stay out of their way when they are hatching, but close enough so that they are reading the actual temperature of the eggs. Also place a small container beside these so you can regulate humidity. On top of the hygrometer place a cut to size piece of chicken wire. This must completely cover the whole incubator so that the chicks can't hurt themselves by touching the lightbulb or any sharp edges. It will also assist you in cleaning if you don't allow your chicks to touch any of the other objects in your incubator.
STEP 6:
Stand back and admire your handiwork! That is a complete home made incubator which you will be able to introduce some lucky chicks to the world through.
I hope you have as much success with the incubator that you have just built as I had with mine. If you have any questions about attaching the thermostat or computer fan feel free to leave a comment. I'll get back to you as soon as I can.