An end effector for transferring a tray is described. The end effector includes an end effector base attached to a vertical drive column of a tray engine. The end effector further includes a slide having multiple arms that are attached to the end effector base to support the tray, when present. The arms of the slide enable the tray to slide along a length of the end effector base. The arms face each other and extend along the length of the end effector base.