I have a Trex 450 Sport V2, no issues with the build, upgrades include spartan quark,datapod,scorpion 2221-10 v2, scorpion 45A esc v3, savox cyclic & tail, metal tail upgrades, boca ceramic in main bearing blocks. Everything else is pretty much stock, however no matter what i've tried, at times I get a violent vibration seen clearly in hover throughout main rotor down to skids. Here is what i've tried - replaced dampers, thrust bearings, blades, main block bearings, main shaft, main gears, new servos, all new tail components. I'm sure i've left some things out but I feel as if I've tried everything and am exhausted. Balance/tracking good, dampers didnt change vibration, (nothing bent) new thrust bearings, blades not to tight or loose,3 different main shafts, new tail shaft & components, all new servos, boca bearings in blocks(seated properly), up/down with throttle curves, you name it I've probably tried it and still get an occastional violent shake. An occasional jitter from the tail otherwise rock solid and mechanical very smooth. The trex is new only 3mos old and I keep replacing with new and am at the end of my rope haha. Please any advice!