What Graupner to use?

[38super]

Hi All
I just finished my F550 build and is working great. I am using Turnigy 4s 35c-70c 5000mAh which gives me about 8 min safe flight time leaving me with 3. 75 volts per cell at end of flight. I just ordered same battery with 60c/130c which should help a little. I am using stock dji 8" props. I want to get as much flight time as I can. I what to move up to Graupner.
My question is what prop size will give me the most flight time and is there and modification to the Graupner I have to make in order for it to fit the stock DJI motors
Thanks..... William

 

[haha49]

9.5 you have to ream the hole out it's not all drilled through. The 10 inch ones have an 8mm hole in the shaft so they fit right on no mods needed. I've flown both (they're the same) I use a lion power 4s lipo which is 10400 mah and I get 15 minutes in 16 km/h winds. I was happy with it I was also flying into the wind with the wind ect to test it under load. I should get a 20 minute hover or more. My end voltage is 3.83 which I still had more to go it wasn't to much weight the motors didn't get warm I was very happy with the result. With plastic DJI 10 inch props it does really well but the motors heat up with that kind of weight because the prop can flex allot more.

You don't need that high of a C rating for the hexacopter. Changing the props should add about 2-3 minutes of flight time. It all comes down to type of flight the plastic 10 inch dji ones I found are the best out of the plastic ones. I had cheap carbon fiber ones they were horrible (badly made prop)

10 inch ones are the

Graupner 25-12.5 cm/ 10-5" Eprop

9 inch ones are the

Graupner 23-12.5 cm/ 9-5" Eprop