Andy
I have made a 3D model which is 2.5 Kgs (5.5 lbs) and using OS 50 SX. But it is not able to pull the model out of hover. Even hovering is very difficult!! Using 5% nitro fuel and have tried 13 x 4 and 12 x 6 props. No tunedpipe.

Any suggestions??

Thanks
Vikas