The helicopter’s tail rotor performance is directly related to the gyro’s performance. Improper mounting and vibration reduce the gyro’s ability to provide tail rotor corrections resulting in a tail that is less responsive and decreased yaw corrections. A gyro that has come loose will make the model uncontrollable, invariably resulting in a crash. Even though electric helis have little vibration, it is important to use double-sided foam tape to mount the gyro (usually included). The actual location of the mounting area is often determined by the heli’s design, but it should be perpendicular to the main shaft. For hard 3D flying, a Velcro strap provides added security.
To ensure long life and smooth flying characteristics, there are certain key areas that require lubrication. I prefer Tri-Flow lubricant available at most bicycle shops. In general, use only enough to lubricate the part and avoid excessive amounts which could attract dust and dirt. The areas usually requiring lubrication are the mainshaft, tail rotor shaft and tail rotor pushrod (in support areas). These areas should be lubricated during the initial build and periodically thereafter (every dozen flights or so). Also, it is a good idea to lubricate the heli before long term storage.
Always be sure to check the ball links for excessive tightness. Tight links will prevent your servos from centering properly and make it more difficult to fly. To loosen, use a pair of needle-nose pliers and carefully squeeze the link while it is attached to the ball and recheck it. Be careful not to break it. Also, a link that is slightly too loose can be tightened by squeezing it while it is detached from the ball.