Receiver batteries

We will look at the procedure for installing the radio system of an rc helicopter.


Before proceeding to install your radio system, you will need to do some tests to ensure that it will function properly in the rc heli. The range test should be performed according to your radio manufacturers instructions, but here is a general procedure.

Walk away from the receiver, while moving the transmitter sticks.


Continue walking until the servo movements become erratic.


Walk back towards the receiver, and stop when control returns to normal.


Compare this distance with the specified minimum range check distance in your owners manual.

If the distance you found is less than the specified distance in your manual, then the radio is not safe to use in your model and will have to be sent back to the manufacturer for repair.


Before mounting the servos in your rc helicopter, ensure that the throws are at 100%, and that the servo arms are set perpendicular to the servo body. Also, center all the trims and make sure that the batteries in both the receiver and transmitter are fully charged. This is important because all adjustments you will be making require the radio to be on. When you are about to attach the servos to the fuselage, disconnect the battery and servos from the receiver. It is important that only the rubber grommets supplied with your servos touch the rc helicopter body, and that the mounting screws are tight enough to compress the grommets. Do not tighten the screws too much, or the grommets can become too compressed to much to be effective shock absorbers. Once the servos are installed in the fuselage, reconnect the battery and receiver. After double checking that the all the trims are set to neutral and that the servo arms are mounted properly, you can proceed with installing the ball links onto the inner holes of all the servos.


The rc helicopter should come with pre-cut pushrods. Install these on the servo arms by either screwing on the ball links, or using snap on clevises. If you are using the snap on clevises, be sure to secure them by sliding on a piece of fuel tubing. This will prevent them from coming loose in flight. Once the aileron linkage is connected, move it with your hands to see if the swashplate moves freely, without friction. Install the other linkages in the same way, but be careful to match the throw of the throttle servo to the carburetors range of travel. If this is not done properly, it can cause overheating and damage the engine. Also, be sure that an idle position on the transmitter does not turn off the engine completely. There still needs to be a way to turn off the engine, but this can be accomplished with the throttle trim tabs on the transmitter.


The gyroscope should be installed as shown in the owners manual. Make sure to place it where it is unlikely to be damaged. Most rc helicopters will have a specified location for the gyro. Use servo mounting tape to attach the servo, this will insulate it against vibration and attach it firmly to the fuselage.


Mount the on/off switch on the side of the rc helicopter opposite the exhaust. Also, mount the switch in a place where it will be easy to access. Orient it in a logical way, so that you will not turn it off accidentally.


The receiver and battery are now ready to be mounted. Before proceeding, cover both with plastic wrap to protect against fuel, dirt, and other contaminates. Pack them with rubber foam, and secure them with rubber bands. Depending on the type of antenna your radio system has (wire or whip), the antenna will have to be either routed outside the helicopter, or left inside the canopy. Be sure to follow the instructions in your owners manual, and don't wrap the antenna around itself. This will reduce it's range and could lead to a crash.