Incubator help please.

I tried to build an incubator.Problem is it's useless.Looks pretty good in my opinion,but looks don't hatch eggs.It holds a steady 99-100 degree temp,humidity about 40-55%.Eggs are fertile,hatching 12 or 12 under hens.Hatched 6 out of 250 in this piece of junk.And they didn't live long.Pics below.

It looks good, temp and humidity is correct. Have you been turning the eggs regularly and how much ventilation is going on in there?

It has 4 5/16th size holes in the front below the door.And 2 5/16th and 2 5/8th inch holes in the top on the back side.I've added a tube to put water in without opening the door.I've also added a cable pulley system to rotate the eggs from the outside.It has 2 fans in it.1 in the top blowing on the heater,1 in the bottom blowing on the water pans.
Had 3 chicks hatch yesterday,poor excuse for percentages,but,at least they are all stags.
For now the temp is running 98.6 bottom tray-100.2 top tray,49-52% humidity.Is the humidity level close to what it's suppose to be?

It's not working this year either.HELP.

I aim for 30% days 1 - 18, and 65% days 19 - 21. Have you opened any eggs after a failed hatch to try to figure out what went wrong?

lazy gardener said:

I aim for 30% days 1 - 18, and 65% days 19 - 21. Have you opened any eggs after a failed hatch to try to figure out what went wrong?

Click to expand...

x2 35% then 60% but that raises when they are hatching.

Trying to help keep your thread bumped....


IMPORTANT: I HAVE NEVER BUILT AN INCUBATOR! But.....I'm about to try it. I have been doing hours and hours of research (probably 100+ hours over the last month or so!). I have since collected a small mini-fridge, digital thermostat, large speed-controllable PC fans, and am thinking about using the heat coil out of my Hovabotor...still trying to collect as much Info as possible before I start my build.

Hopefully, more experienced people will help chime in.

A couple of things I have questions about:
1) from what I've been reading, do you need a little larger (or more of the size you already have) air holes? You do have a larger cabinet, seems like it would need more air flow?
2) what if you put your fan at the top, blowing across your heat source, instead of at the bottom blowing upward?


Anyone else with more experience (or ANY experience) who can chime in and help Alan out?

This was double posted. There are other good responses in the other thread: https://www.backyardchickens.com/t/960221/my-diy-incubator/20#post_14975808

But without knowing WHY the hatches failed, or at what stage, it's hard to give advice that may help solve the problem.

walnuthill,sorry about double posting.I'd forrgot about this one.
Here are pics of 2 eggs I checked.Set them Monday of last week[10 days in]


Any ideas? Does it matter how much air the fans push? Top or bottom water? Heat from top or bottom? Why does it hatch preset eggs and not fresh eggs?

Those are two pics of the same break out.

Consistent low temps or consistent high temps, setting chilled eggs in a warm incubator, and too much fresh air in the first four days are among the potential causes. If your turner has a violent action that jolts the eggs, that could also cause issues. Same with ensuring that the air cell is up rather than down.

As more developed eggs are successful, I'd look first at temperatures. Can you find something that will simulate the mass of an egg but that can be penetrated and that won't spill or leak when you tilt your racks? I used pourable silicone to cast an egg sized and shaped mold and make a hole in it to insert the tip of a digital medical thermometer. I leave this fake egg in the turner tray and press the button once a day to obtain a reading. Rather than displaying air temperature at the moment, this fake egg reflects the couple-hour average incubation temperature. This temp is critical for development over the full incubation period and should be 99.5-100F.

Next is to check for temperature dips or spikes. Dips below 98.5 that last more than an hour, or spikes above 103 that last for more than an hour, can cause lasting effects to the embryo by interrupting critical development stages. You will need a thermometer with memory to record this. Compare the temperatures with your medical thermometer and adjust your readings accordingly, if your medical thermometer reads 99.6 and your weather thermometer reads 98.7, be sure to adjust your recorded high/low temps by adding 0.9.

During the first four full days of incubation, leave the vents closed.

Candle at 10 days, disturbing the eggs as little as possible including gentle handling and putting them back in the incubator as quickly as possible.

After 12 days, the embryos are better developed and more tolerant of changes that would be fatal to a younger embryo. The closer they get to hatch, the more robust they are. So your issues are those that affect early development of the embryo.