What is trimming? I mentioned this in an earlier article about Control stick configuration on transmitter for indoor RC helicopter. Trimming means adjustment. You want to adjust that the helicopter stays as stable as possible while hovering.
Basic RC helicopter for beginners have no special trimming on the model. Simply by using sliders or buttons on the transmitter you can adjust single channels. In more complex models there you have a whole series of trim possibilities.
Rotor blade tracking:
That means, that both rotor blades are in same level when they are spinning. In standstill you can’t see it. They have to spinn. To differentiate which blade you have to trim simply put a stripe of tape with different colours on each blade end. If the rotor spinns and you look from the side, you can see, which blade is upper or lower to the other. Goal is that both turns in the exact same level and height of the rotor head. To change, you have to change the work angle (pitch) of one of the blades. To do so, you have to change the length of a lever by turning it’s head once or twice in or out. How much and in which direction you have to try out.
The gyro is used for stabilizing the helicopter in its rotor axis. In some models other movements (like rolling) are also controlled by gyro. That meas, when for example a blast turns the helicopter the gyro is registering the motion and changes the pitch of tail rotor to counteract against.
How intense reaction is can be adjusted by a potentiometer or by menu. Some advanced gyro can be adjusted from transmitter. Is a gyro adjusted to severe it will make a pendular movement.
The swash plate:
It is use to transfer the motion made by servos to the turning rotor head. In neutral position swash plate should be adjusted that it is totally horizontal. If it is not, you should turn ball-link at the end of the linkage rod until swash plate is horizontal.
Same here. In neutral position (stick and trim slider at transmitter in middle position) servo lever should be in a position that it can move maximum in both directions. On special adjustments, please take a look into your manual because every helicopter is different.
Last but not least. The balance:
A ready to fly RC helicopter for beginners is in balance right out of the box (at least should be… ). To find out whether a helicopter is in balance or not, lift it by holding it at the rotor head. It should pending horizontally and not tending to one side. This would mean that it would yaw to that side while hovering and you would have to compensate it with control stick movement.
A dis-balance could come from e.g. a newly installed heavier battery pack. To compensate that you have to attach counterweights.
Control stick configuration on transmitter for indoor RC helicopter