I built an incubator with a 6 egg shifter. The shifter is a ½ doz egg carton on a platform that goes from 40° off horizontal on one side to the same angle on the other. It's timed to shift at 2½ hours and, for later in the hatch, 5 hour intervals. I rotate the eggs 90° by hand daily always leaving them pointed side down. Roo's hatched seem to have more points to their comb.
I wonder if I should increase or decrease the shift rate for normal combs.