Do you have pictures of your incubator?
Promise not to laugh?...its a work in progress... I did a failed test hatch lst month and resolved the majority of problems. I thought I had them all licked, but the temp gradient cropped up. I closed my vent holes on the right and the temp is up by about a degree on the right side, so I think I am on track.
The incubator from the outside: I taped plastic sheeting on the top of the lid to drape over the opening so I don't lose much heat when I open the lid to rotate the eggs. The port is on the right with a temp probe that goes to my computer with data recorded every 10 minutes. The probe is nestled in a 2 oz taped gel pack to simulate the interior of an egg, sort of a home-made water wiggler:
This is the domed lid--I put all the working parts up there and out of the way. Fan on the left, Hot water thermostat center and porch light with foil deflector on the right. You can see vent holes drilled in the center and right if you look closely:
And the aerial view of the eggs. Rock heat sinks below with water pan. Pre-placed tubing from the outside to administer water on the right and left, the right goes to the water pan, the left goes to a sham-wow for lock-down. A cookie rack over that with the eggs perched at a 25 degree angle on foam-board props surrounded by more jars/bottles of water heat-sinks. The thermometers are on the front glass, back center, digital remote in the blue gel pack and a dial that normally sits across the top of the eggs but i placed over the gel pack to see if the temp was reading true in the remote:
There ya go.