ORIGINAL: alienteabagger
Sounds like you had a DYNAMIC BALANCE issue. Main rotor blades can be STATICALLY BALANCED but once they get moving if the c.g. of one is way off from the other then once you hit a certain headspeed (rotor rpm) that imbalance can and will cause that shaking.
p.s. Crashed my T-Rex today
What's the story on the Trex and what's the damage report $$ ?