Upgrading The Radio Equipment of your RC car

Upgrading the radio equipment of your RC car

An RC car is controlled with a transmitter that transmits the driver’s commands to the car’s receiver, from where the information goes to the steering and other components. The radio technology of RC cars these days uses the 2.4 GHz frequency, which makes it possible to drive dozens of cars simultaneously without having to manually change the frequencies. After the transmitter and the car’s receiver are bound, their functioning won’t be interfered by other radio equipment. Transmitters are only compatible with receivers of the same manufacturer. Some manufacturers have slower (for hobbyists) and faster (for racing) transmitters and receivers to meet different demands.

When it is time to upgrade your radio equipment, it’s generally a good idea to go for equipment from a bigger manufacturer instead of cheaper ones from smaller brands. This way your equipment is guaranteed to work interference-free. There are a few manufacturers we’d recommend, e.g. Sanwa, Futaba, Spektrum, Hitec. Out of these, Sanwa and Futuba have the largest product range for different needs. Normally an RC car requires two channels, one for steering (ch1) and one for throttle (ch2). However, in most cases, controllers have 3 or 4 channels. The extra channels can be used to control additional parts such as the winch or the lights in Crawling cars, or in racing cars they can function as a power source to the timer’s transponder.

The range of a radio these days is very good, and it can be up to hundreds of meters in open spaces. It’s important to bear in mind, however, that while indoors, interference can be caused by other devices using the 2.4 GHz frequency such as WLAN access points. This is when you’ll notice the importance of using high quality and interference-free equipment. The higher the quality the less there is any interference when the signal is traveling from the transmitter to the receiver. If you are planning on upgrading your radio equipment and you’re going to race with your car or if you use the car somewhere with many other drivers, we recommend you pick your radio equipment from a reliable brand.

When choosing new radio equipment, there are a few things to consider:

“Stick” radio or a wheel-and trigger system?

The number of radios with a wheel-and-trigger system in the markets is considerably higher and brands have a large selection to choose from. The “stick” radios are a bit less common, but for example Sanwa and Futaba has some high-quality stick radios.

How many channels do you need?

As we already mentioned above, the radios tend to have three channels. If you have controllable parts in your car (e.g. in a Crawler), you’ll need extra channels to control them.

Need for telemetry?

More experienced drivers who need accurate information on the car in real-time can make use of telemetry. By using telemetry, it’s possible to get information on temperatures, the RPM of the motor or the battery voltage. Note that telemetry components are sold separately

Model memory

If you have several cars, it’s important to have a model specific settings saved in the memory. If you want to switch between cars by selecting another car from the model memory, you need a separate receiver for every car. This way you can use the same controller to drive your Touring car and your 2WD Buggy. The controller saves the settings and makes the appropriate adjustments to suit the current car. When switching cars, just select the right model from the controller.

Installing radio equipment

When you are installing your new radio equipment, it’s good to note that the receiver requires a power supply (typically the power components function with a 5‒6.0 voltage – check the manual to be sure). In most electric cars the receiver gets power from the integrated BEC-circuit in the speed controller the wire coming from the speed controller powers the receiver. In cars with combustion engines the receiver requires a separate power supply (a separate battery) that is connected to the receiver’s power connection (BAT). In cars with combustion engines, the power to the steering servo and the throttle servo come through the receiver.

Note 1!

It’s important to bear in mind that the electric systems have only one power supply for the receiver. So, when you’re using the ESC in which the BEC-circuit gives power to the receiver, an external BEC-circuit cannot be used without modifying  the car's wiring.

Note 2!

If you want to use the newer HV (High Voltage) servos, make sure that the receiver can handle the 7.4 volts.

Binding the transmitter and the receiver

The receiver must always be bound with the transmitter before use. You only need to do it once. You’ll find more detailed instructions for the binding in the manual of your controller.

In practice, the receiver is set in binding mode by pressing a button or installing a separate Bind-connector (depending on the brand). After this, select the binding mode on the controller so the receiver and the controller can bind their frequencies. When the binding is done, the receiver is ready to use. Turn the power off and remove the bind connector.

It’s good to note that in some cases you may need to redo the binding because of interferences or if there is some sort of an error in power management. Normally re-binding is necessary only when you move the receiver to a different car or a different memory slot in the controller.

Note!

After replacing the radio equipment or any of its components, you need to recalibrate the ESC and check and adjust (if necessary) the EPA, Travel, and Trimm.