My DIY incubator set-up, hatched 12/14.

[Kiraeh]

Only from the extra thermometer in there, the plastic isn't that thick. I started this latest hatch with 27 eggs and it was just a tad crowded but manageable, and there's been a bunch of infertiles(my lesson not to buy hatching eggs at the end of a three week heat wave haha) as well as an early quitter from an egg that had several days development on it before I stored it in my basement before setting(awkward, but I had extras of those eggs so nbd). I don't think I could incubate more than 30 in any case.

I have already melted two holes in the Styrofoam from the light getting dislodged briefly. The upside to this DIY system is I can take all my bits and put them into a different box and I think I'll do just that before I run another hatch. Build something big enough to put turners in, and a bit sturdier.

 

[Tonyroo]

If your gonna do several hatches through out the year, consider making a wooden box incubator, It will last a longtime and your less likely to catch it on fire. If your handy with power tools you can make it to your exact measurement. Or you can find a used wooden dresser drawer at a thrift store that can be modified into a incubator also.

 

[Kiraeh]

Yeah, that's my exact thought(well, I hadn't thought to convert furniture, that's an extremely good suggestion). I have all the tools, and having the experience with the cooler I know what features I want to have. It's the cheapest part of the build too, a loss of $12 to ditch it. I won't be hatching again this year, so it'll make a nice winter project.

 

[Phunktacular]

I might have the same incubator as you: little giant, holds up to 42 eggs? I bought mine at TSC, but went for the $49 still-air version (model 9300 I think). I hatched last month, eggs from my flock, and out of 26 fertile eggs we got 22 chicks. This month, I have more in (at Day 13 now), and have had 1 quitter. I do not have the egg turner, so I turn by hand and the eggs lay on their side. I have an additional thermometer in the middle of the tray. The eggs get set around this. I open the incubator To remove the ones immediately around the thermometer. I move the ones at the outer edge to the inner circle around the thermometer, and turn them. I turn and move all others and the ones I first removed get placed last at the outer edge of the eggs. I think you are right that the turner is keeping some eggs consistently cooler. The only other thing I’ve done is put the whole incubator into a larger cardboard box that is approx 1-2” taller so any drafts are minimized. It sits on top of a bedside table in a room that is not used.

good luck!

Especially, in the still air foam incubators, it is important to place your thermometer/temp sensor over the top of the eggs. Even with a turner in there. You want the ambient temperature just above the eggs to average around 100 deg F. That way, the eggs should be above 99 but, below 100 deg F.

I had very inconsistent temperatures in a Foam incubator and I decided to build my own incubator out of a broken beverage cooler. I get great results and have hatched hundreds of quail and chickens, now.

Link to my incubator build thread.
https://www.backyardchickens.com/threads/home-built-incubator.1337443/#post-22338344