Hi,

Does anybody have any experience of using large (14"+) propellers for a hexacopter in order to extend flight time during heavy lift?

I know the motors will need uprating a lot to cope with the maximum instantaneous load / sudden change in propeller speed, so am considering 6 of these: http://www.hobbyking.com/hobbyking/store/__14734__Turnigy_L3020B_60...

Ultimately all I'm trying to achieve is 25 minute flight time whilst carrying 800g of camcorder, and another 200g of toys (FPV TX and sensors eventually). Hexacopters sound like less weight whilst being tolerant of a motor failure, but I could be tempted with going up to a octocopter if someone had a real life example of lifting that weight for a good long time.

Horribly, I'm expecting to be putting a kilo of li-po's in to get a long flight time, plus 900g for those motors, so I anticipate a 3.5Kg build, is there a better way? 

Looking at the lead time on the ArduPilotMega 2.0 (which I already have on order) I need to start ordering motors and props soon because hopefully I'll be ready to start building in a few weeks... so any help will be appreciated!

Thanks in advance.

Tim