1st time poster long time lurker here. i have been flying a while and know my electronics(broadcast engineer) .. ok the problem is just before liftoff the servos make the heli cump up and down very slightly after liftodd hovering etc is stable ... but every 5 secs or so the cyclic servos jump slighly which vibrate the bird slightly like a glitch then stablises again...then a few seconds later same thing ... i have done all the usual grounding silicon leads etc ... adjusted varios gains (wich sometimes reduces) .. v450d rx 2703 tx evo10 ... the head etc is dfc align the bird is highly modded and flies extremely well ... the only thing i can think of that the servos have a bit of slop and the gyro is trying to compensate