RC Sailboat Controls are rather different then your typical Radio Control.
We will first look at what channels on the radio control transmitter, control which part of the RC Sailboat and then we will look at the specific setup concerning the radio gear on an RC Sailboat.
Transmitter Channels and Controls – RC Sailboat Controls
The most common type of transmitter for RC Sailboats are the stick type transmitters. The stick type transmitter allows the ease of use over the sail control. On a stick type transmitter referring to the image below, the left
side channel, typically throttle on an airplane controls the Sails. Moving the left side stick up or down would draw the sail in or let the sail out. Motion on the stick is vertically.
The stick on the right hand side controls the rudder on the RC Sailboat. The rudder channel operates as like any other rudder channel. Motion on the stick is horizontally.
These two channels are the required minimum for RC Sailboat Controls. You can see all the extra switches and controls on the radio to the right. These may be used for controlling those fancy features on your RC Sailboat. In some cases these extra features include alternate lighting, winches, or anything else to make the sailboat appear and operate more scale like.
Radio System Controls – RC Sailboat Controls
Now that we have talked about the transmitter we will look at the rest of the components that are required in order to run an RC Sailboat. The component that is responsible for talking to the transmitter is the receiver. The receiver is what talks to the transmitter and then converts the radio signal to an electrical signal that can be used to control the rudder and sails of a sailboat. The reciver can be purchased with the transmitter if you choose to take that route. Purchasing a transmitter/receiver combination is more common when building your own boats.
Receiver Battery – RC Sailboat Controls
To power the radio equipment a standard receiver battery is required. This is a battery that operates on 4.8-6.0v. Although a 4 cell disposable AA case can be used, it is highly recommended for an RC sailboat to use a rechargeable battery. The main reason is to ensure the battery pack can supply a sufficient amount of current to the servos. For larger RC sailboats a rechargeable battery is a requirement. The average user would use a 4.8-6.0v NiMh pack however LiFE, Li-ion, LiPo packs are available but be certain to include a Voltage Regulator in your system to limit the voltage.
Sail Servo – RC Sailboat Controls
The most important servo for an RC Sailboat is of course the Sail Servo. The sail servo comes in two different styles that are most common. Each style has its own specific set of advantages and disadvantages. The first style of sail servo that we will talk about is the sail winch servo.
The sail winch servo as pictured on the right hand side uses a drum like wheel to house the sail line. When the drum rotates the line is either let out or brought in. The Sail winch servo typically allows for 3 rotations of the drum with
torque specs around the 150 oz-in / 11 kg-cm. The biggest difference is that these torque specs are at a relatively short distance from the center point of the drum. This small distance increases the amount of torque relative to the next sail servo type that we will be looking at.
Sail Winch Servo Advantages:
- Amount of force generated to pull in the sails
- Amount of total line length (travel) that can be brought in – approximately 3 revolutions of the drum
- Relatively Small Space Requirement, even with larger servo sizes
Sail Winch Servo Disadvantages:
- Slow Reaction time relative to transmitter input as winch must rotate up to 3 times
- If the Sail Line is not tight at all times, any play/slack in the lines can allow the line to fall off the drum. A line that falls of the drum does not operate correctly
The other Sail Servo style is the arm type. The arm type sail servo uses quite a long arm in order to get an acceptable amount of line draw. As you may expect this operates nearly the same as a standard servo where the only difference is the servo arm itself. For a typical one meter Sailboat, you would require a servo of this style that has at least 150 oz-in / 11 kg-cm of torque as a minimum. This style servo requires more torque then a winch servo as the amount of force produced at the end of the arm is reduces due to the length of the arm.
Sail Arm Servo Advantages:
- Very quick response time vs the Sail winch Servo
- More servo options as any standard servo can be used with a long sail arm. Options for very high torque servos are available
- Line has less chance of getting tangles or wrapped upon itself as compared to the winch style servo
Sail Arm Servo Disadvantages:
- Require a lot of space due to the radius of the outer point of the sail servo arm
- Lower amount of Line Draw force due to length of Arm requiring higher torque at the servo for equal performance that of a winch style servo
- Generally has a smaller total line length(travel) that can be brought in resulting in lower amount of sail movement (travel)
Steering Servo – RC Sailboat Controls
The steering servo is responsible for operating the rudder on an RC sailboat to provide directional control. In most cases a Futaba S3003 Standard Servo would be more then suitable. In general for a one meter RC Sailboat or slightly larger, you are looking for a servo that can manage a torque specification around 45 in-oz / 3.2 kg-cm. Smaller Sailboats require less torque.