Hi Ked! I was researching incubators and some of the explanations I found made me squint at my screen trying to find how the words and the image lined up. I'm pretty sure now that I understand how an egg turner works in a little round incubator (just roll it in a circle - the outer ones rotate more than the inner ones, that's okay right?) but I don't know how it works in a little one that's not circular, or in a big one.
You've got a big rack incubator, right? How does the egg turning work?
The ones in the round incubators, like a nurture right 360 or similar tabletop, don't go around in a circle, as that would twist the chalazae wrong. Instead, the turners very slowly rotate one direction to turn the eggs 180 degrees, and then go back to starting position, so the eggs get rolled gently back and forth rather than spinning. Depending on the model, they generally do one complete back and forth every couple of hours (1-4), and are constantly in motion. Most people leave these in for hatch, and just switch the turner power off to stop it from moving during lockdown.
In some tabletop incubators, there are racks for turnings, and the racks are usually an additional insert with its own motor. Typically these racks are removed at lockdown to give the chicks space to hatch. Instead of rotating the eggs, they tip them to one side and then the other. Again, these are in constant motion, and complete one tip back and forth every few hours, depending on the model.
HOWEVER, some turners that look like this, like the one for the maticoopx, turn on an interval instead of constantly. IMO, that's better than constant trembling of the motor, even if the turning motion itself is slow. Again, you'd most likely (and should) remove these for hatch.
In cabinet incubators, they can either have a built in turners, or they can be static incubators (and require hand-turning). I'll be real honest... most people do not get them without a turner, because the volume of eggs you're putting into a cabinet would mean spending SO MUCH time turning them daily that it would be prohibitive. That SAID, some people are incubating, y'know, ostrich or emu eggs or something, and they need the large incubator but it's only going to have a few eggs. But generally speaking, most "incubators" that are cabinets and don't turn, are actually Hatchers people are using as incubators.
And the turners in those are just a big shelf. You put your eggs onto an egg tray of the correct size for the eggs you have (the hole size varies, so you can get ones with holes for quail eggs, or partridge, or chicken, or duck etc, and they'll mostly kinda look like this:
and sometimes rather than plastic trays, you screw in inserts into a whole-shelf tray, if the eggs are large (like peafowl eggs or goose eggs)
And then tray goes onto the shelf. without the trays, the inside of the cabinet looks like this (you can see the stack of trays to the right side there):
The trays are of the correct size to fit onto the shelves fairly snugly, and each level holds 2 normal trays or one large egg tray. For quail eggs, since they're so tiny, you can actually stack trays and fit 4 per shelf, 2 in front and 2 in back.
Then once it's loaded, the trays tip back and forth every 4 hours or so. Here's what that looks like with and without the trays
The black box in the bottom is a hatching bin. When the eggs hit lockdown, they move into the hatching bin to lay still, while the rest of the eggs keep tipping normally.
The point isn't really that the eggs need to be "turned" specifically. They just need to be moved in a way that prevents the forming embryo from adhering to the inner membrane. So, rotating them a little, tipping them a little, it's all doing the same thing. Going back and forth allows the chalazae a chance to rest and makes it easier for them to hold the yolk suspended where it belongs.
