Awesome, how old are they? Mine are now 17 weeks & wondering when they might start laying. I have a Gold Lace Wyandotte, Buff Orpington's, Black Sexlinks & Black Australorps.
I had an Easter Egger and an Orpington start about the week before Easter, at 22 weeks, then an Australorp started shortly after and quit for a few days. The rest all started laying sometime after that, they slowly started laying for a few weeks after until everybody was laying.
The sex links should start laying anytime now as they're bred for production and tend to start laying sooner and the others should lay anywhere between now and up to around 24 weeks, a couple of mine took a little longer. Could be 26 weeks and beyond. But you ahould have at least one start laying really soon and the others shohld lay before that. Have any of them started squatting yet or looking red in the face? Do youhave oyster shell out yet? If not, you should start offering it about now and if they do any of the other stuff, they're close to laying.
I have 1 Barred Rock, 2 Black Australorps, 3 Buff Orpingtons, and 2 Easter Eggers.
Good luck!