fly them at 24 hour feeding' thats feed, at lets say' 8 to night and fly to mor at 8, see how that goes,and if there flying of like you say'' well theres to much food in them, remember its through the belly you train rollers, Their on a 24hr cycle at the moment mate but at about 5 pm. As for feed their on a spoonful and there's no way they would fly an hour on that amount which is what I've read young birds should be doing but once the buggers decide their landing there's no stopping them? Would a splash of high protein feed give them a boost or make em fly off?