After building your rc helicopter, you will need to make several adjustments before flying. This is a critical step, small errors here could lead to a crashed rc helicopter later on. Be sure to carefully follow the instructions that came with your model while making these changes. We will explain one or two things that probably differ from your instructions, but follow these general tips, and you will have an rc helicopter suited to learning to hover.

We talked about the set-up of the throttle in the article titled “Choosing a Radio For Your RC Helicopter“. You will need to ensure that every control moves freely. Do this by disconnecting the linkage from the servo, and move it back and forth. If it moves with little resistance, and moves the control surface as much as it needed, then it’s fine. Match the throttle servo arm to the throttle by adjusting the throw of the servo, or the length of the servo arm. Make sure that the throttle is neither completely closed on idle, or over driven when open. Make these adjustments with the throttle servo disconnected, so as not to overdrive it accidentally. The throttle arm should be 90 degrees to the body of the servo when at idle, to improve the effectiveness of the trim. When the throttle stick and the trim at at idle positions, the carburetor should be closed. This will turn off the engine, and it is important that you be able to do so in an emergency. When the throttle trim is increased fully, it should move 1/8 of an inch. This movement should allow the idle of the rc helicopter to be adjusted, and the engine to turn off.

The tail rotor will need to be adjusted so that the blades have a small positive angle of attack when the rudder servo is neutral.

The gyroscope will need to be adjusted so that it controls one quarter of an inch of the rudder movement.

Collective pitch can be adjusted until the movement is from 0 to 5 degrees. This aids in making the rc helicopter more controllable when learning how to hover. Having negative pitch available can allow the rc helicopter to descend very rapidly, and large positive pitch can make it climb higher than is desired while learning how to hover.

The collective pitch can be set using the pitch gauge using the following method:

1. Turn the radio system on.
2. Level the swashplate using the elevator trim tab on the transmitter.
3. Attach the pitch gauge to a rotor blade, making sure to keep the tail boom, flybar, and swashplate level.
4. Using the transmitter, move the collective pitch to it’s upper and lower maximums, and note the pitch on each.
5. The pitch range is the difference between the upper and lower pitch limits, we want a window of 5 degrees.
6. The window can be adjusted by changing where the push rod attaches to the servo. Moving it in will cause the window to decrease, and moving the push rod farther away will decrease the window.
7. The maximum pitch needs to be 5 degrees, do this by altering the length of the rod from the head to the swashplate
8. Repeat steps 3 to 7 for the other rotor blade.

By following these simple procedures, you can prepare the rc helicopter for it’s first flight, and reduce the chances of a crash.