Jesus***** Ok il tell this for the last time, leave your heli alone if you dont a: are a skilled engineer og experienced modellbuilder b: dont want to spend the next month with trial and error pulling your hair out along the way c: potentially blow away lots of money and never get into the air. If your helis doesnt fly almost for sure its you doing something wrong, helis are sensitive delicat machines, micros even more so than the bigger. So unless you qualify for any of the above leave the bloddy thing alone, you wont be able to make it any better before you gain a good load of experience, the heli is perfectly flyable as is. Forget the engines, drilling stupid holes and all this crapp its written by morons in a feeble neverending pursuit of improvement, most of them dont even know how the heli is supposed to behave or potentially can behave. Biggest tip of the year,,,,,Leave it the **** alone and get on with the practice,, this is hard and there is no way around to make this a videogame experience. Sure there is alot of upgrades that can be done but they need to be done in a correct maner and sequence, changing a single component can upset the unity of your heli and make it unflyable until you upgrade other components to fit the first one. Eyh! take your fingers of that dremel cutter,, i see you in the back there!!!