DIY Low cost chicken egg incubator (useful!)

Now then. Don’t ever say there’s nothing useful on this site.

As part of our traveling, we spent a week staying with Firdouse and Shihama in their home / English Tuition Cente in Mi-Ella, near Wallesmulla in Southern Sri Lanka.

In return for their hospitality, we helped out with a couple of projects. Linds was clearly going to be better at teaching than me – she’s a teacher – so being the selfless philanthropist I am, I agreed to get busy on google and throw together some wires and assorted oddments to create a Heath Robinson contraption for a fraction of the price of the real thing. OK, so that’s pretty much my hobby anyway, but this time it was for a good cause. So here, for the benefit mainly of Firdouse and the guys in Mi-Ella,  but also for anyone else interested, is how to build an incubator for as little as I could work out how to. Do not, of course, follow these instructions unless you are a fully qualified electrician, and have independent knowledge of how to safely wire up mains electricity. No joke. You can kill people (and chicks) with this.

First of all, read up on it. Useful info is to be found on:

After reading up on hatching eggs on the above sites, I came up with the following as a method for building a really cheap, functional ‘forced air’ (If you’re going to do this and that still means nothing to you, go and read those sites!) incubator:


  1. Polystyrene coolbox
  2. Three pole adjustable thermostat from a water heater
  3. 40W household lightbulb (NOT energy saving – we’re using it as  heater!) and holder
  4. Some wire mesh
  5. Piece of glass, smaller than the lid of the polystyrene box
  6. Two identical smallish ice cream tubs
  7. PC motherboard cooling fan
  8. Old mobile phone charger
  9. Some wires suitable for 240V,100W
  10. A plug
  11. Some tape
  12. An egg tray
  13. Some tye-wire, or a couple of wire coat hangers will do
  14. Some aluminium foil or thin sheet
  15. digital thermometer with external probe, and preferably a humidity sensor (though I couldn’t find one with a humidity sensor)
  16. Some Chuck Yeager test pilot eggs


  1. Cut a hole in the side of the polystyrene box so that the ice cream tub sits half way in.

  2. See how much room you need for your bulb and fan, and place the mesh in the box to create a space for the eggs away from them. You don’t want chicks touching hot bulbs or moving fans… The mesh should also hold everything an inch off the bottom of the box, to allow for good air circlation. If you cut it right, it should hold itself in place by the loose ends sticking in to the polystyrene.

  3. Place a water tray in the box on the floor. This is for some water to keep the air humid, not for the chicks to drink.

  4. Sort out your wiring. It should be something like this:

    This is the thermostat and the bulb wired up in series – read up on those sites if you don’t understand this! And don’t whatever you do mess around with mains electric unless you’re 100% confident that you know what you’re doing. Your Mother would be horrified.

  5. Cut the rim off the second ice cream box lid so that it fits inside the first (the one that fits in the side of the polystyrene box. Fit the thermostat into this cut down lid, and run the wires out of the bottom so that there is no way for moisture to run into the ice cream box.

    This allows you to seal the dial away with the second lid, preventing accidental adjustments. Very pleased with this incredible innovation.

  6. Wire up the fan to the mobile phone charger. Wither a 5V or 12V fan is fine running off a mobile phone charger, which invariably will output 5V.

  7. Fit it all in the box. Keep wires exiting downwards, so that any water that collects on them (if things get too humid inside) doesn’t run down into the electrics. No bare wires should be visible anywhere.

  8. Cut four holes in the sides of the box. They should be about 1/2 inch square, about 2 inches above mesh level, and you should keep the bits you cut out to plug them with if need be.

  9. Use the aluminium foil / sheet to shield the eggs from the direct light of the bulb, without blocking the fan. This ensures that the eggs receive a warming breeze, instead of a grilling.

  10. I ran a wire across the middle of the box so that the egg try was supported at a 45 degree angle depending on which send of it was heavier. This provides a very simple mechanism for tilting (“turning”) all the eggs at once –  just tilt the tray the other way!

  11. Cut a hole the shape of your glass but about 1″ smaller in the top of the box. Then cut a bit out of the top so that the glass sits flush. Tape it in good and safe. Come to think of it, perspex or similar is a safer bet.

  12. Seal a sandwich bag or similar with about an egg’s worth of water in it. Wrap this around the sensor for your thermomter. This is now a fake egg, so your thermometer measures roughly what is happening to hte inner temperature of the eggs, instead of just the air temperature. Leave the thermostat sensor unwrapped, but near the eggs.

  13. Fill the dish in the bottom of the box with water to keep things moist. I popped a spare lump of polystyrene in to act as a level gauge! Use the Mississippi guide (link above) to gauge correct moisture level.

  14. Turn it all on and make sure it stabilises at the 39.2 degrees C you no-doubt set it at. Leave it a couple of days, and ensure that the temperature doesn’t fluctuate too much, Make small adjustments to the thermostat if it does.

  15. You’re ready for eggs! Get hold of some fertilised ones (not Morrisons free range), handle them gently, pop em in the holder and turn them regularly. Do all the stuff you;re meant to – candling, throwing out dead ones etc. I can’t really help much here, because we left as soon s the eggs went in the incubator!

  16. Here, for your viewing pleasure, is the finished article. I’m still waiting to hear how successful the first hatch will be, but apparently things are looking good with only a few days to go!

    One more thing. Seriously, don’t mess around with mains electric unless you 100% know what you’re doing. Just go to Nando’s instead.