You need a transmitter (Tx)2 channels (most use a 4 channel Tx), a receiver (Rx), a servo for the rudder, a winch for the sails and a battery pack to feed all the above with energy.

Rudder Servo

You may be surprised at how much pressure the rudder is under in some conditions.

So you need a rudder servo that is light, with metal gears, High torque and ideally waterproof.

A wide range of them do exist and one of the most popular, if you're using Futaba Tx, is the (here comes the techy bit)  P-S9202 with a torque of 7.1Kg/cm, water and dust resistant, dual ballraced, 0.21sec at 60 deg with a cordless motor. Pretty good starting servo for our IOM boats. Just plug it into your receiver and steer away !!!

Brushless technology has recently emerged and improved servos by increasing the life of the servo and for smooth operation.

 

Checkout my dedicated page on my servo rudder shortlist

The winch

Now you have the radio to steer your boat but nothing to adjust the sails to get it moving so the winch is absolutely vital as it will adjust the angle of your sails.

Now you know as stated above that the rudder is under high pressure but the winch requires to hold the sails regardless of the wind and so it needs to cope with even higher pressure.

Most common winch are built by RMG (AUS) , and KBits (UK), but also by Futaba, Hitec and Graupner.   Most RC Sailors use one of the first 2 winches. The RMG which uses a drum to sheet in and out whereas Kbits one uses an arm connected to a very powerful Hitec servo.

Great choice of product here again... they are all good but the choice is yours. Just plug it into your receiver and sheet away !!!

The battery

So now you can transmit and receive signals, steer your boat and control the sails or can you ??? Well the wind will power your boat to move forward but you need another power source to power all that equipment. To do that you need reliable, powerful batteries.

 

Varying from 6.0v 700mah to 7.2v 2700mah battery packs are key to power all your electronics so do take care in selecting the right batteries for you and do take care of them.

 

The voltage will ensure that enough “oumf” is going to all the various electronic equipments while the capacity (mah) will in a nutshell dictate how long you can sail (the higher the capacity the longer you can sail without changing batteries). The voltage will vary depending on the type of winch you use but for the capacity you'll have plenty with 700 to 1100mah to last you for around 2 hours of great sailing, depending on the conditions and use.

 

Ok so far but how do I know what is good for my boat and my usage ?

 

First of all, look in your boat and find out how the battery pack should be positioned as it will dictate the shape of battery pack you need (in line or 3/2  : 2 cells on top of 3 or 3/3 3 cells on top of 3).

 

What you need to find out next is the power you need to power all your equipment - this is mainly driven by the type of winch you use. Most common winch is the RMG 280D or now the new E series but either model will work fine with either a 6v or 7.2v battery pack. Servos only need 6v max to work but amount of voltage sent to the servos will be regulated by the receiver which will only send the right amount so even if you use a higher voltage battery pack you won’t burn out your servos. If you use a different winch refer to the manual to know what voltage it will take. A 6v battery pack will require 5 cells whereas a 7.2v will require 6 cells (each rechargeable battery is 1.2v).

 

Now you know the battery pack shape the voltage and the number of cell you need. What you still need to find out is the type of batteries, their capacity and the connector you want to use.

 

Let’s  look at is the technologies available. Although Lipo batteries are making an appearance I will focus here on reliable Nicad and NiMH (Metal Hydride). In a nutshell Nicad battery can be quickly charged but it is vital to keep them cycled as they have a “memory effect” and in time they will loose power if not properly cycled. Metal Hydride do not have this memory effect, they are "Greener" for the environment but do loose their power quicker (3-4% daily vs approx 1% for nicad) so they need to be charged just prior to be used in order to get full power when you need it. Their other advantage is they are typically available in bigger capacities over nicads. Without twisting your arm most of us use NiMH batteries for the reasons listed above. We typically use NiMH batteries from 1650 to 2700 mah of capacity which allow us to sail for several hours without the need to replace the battery. Though we do recommend having a spare battery fully charged as backup.

 

Now the last but not least element to complete your battery pack the connector.

 

Most common connectors are futaba, tamiya but the best and gaining in popularity are the Dean Ultra connectors. Further to tests these later one have proven to be the best as they provide the best connection and the least amount of energy loss. But to start with go with whatever connectors you have already fitted in your boat (fyi futaba are small rectangular black connector, the tamiya is bigger, bulkier and with one square and one semi circular one and they’re typically semi-transparent in colour). Resist the temptation of changing the connectors now but rather plan it and do it as a project when you have time.

 

So where can I find them ?

 

You can buy ready made battery packs from the useful RC shops, which you are now familiar with. Check out Kbits, Sailsetc, Housemartinsails, etc... (Key Suppliers)

Or you can buy each battery cell at your local hardware store and build your own battery pack. The choice is yours.

Transmitter & Receiver

Your choice is simple as most RC sailors use transmitters from either Futaba, Hitec or Graupner.

In Ireland most RC sailors use is 40 MHz FM frequency which provides a good range of frequency so that we don't end up controlling some one else’s boat.

 

Again, keep it simple as there is no need to buy expensive programmable models with a zillion channels. A standard 4 channel like the Futaba Skysport 4 is sufficient. You will need to decide on the type of battery you will use as they come with a choice of AA size battery or with a battery pack. Make sure you get the model with the throttle on the left (it will be the channel you will use for controlling the winch and your sails). With more advanced model such as the 6 EXA you can actually change the mode of the transmitter so to have the throttle on the left, but this feature is not on all transmitter so watch out before buying.

 

Transmitters will normally come with their own receiver which you will need but most are sold with 3 servos and various bits. To cut down the cost some suppliers may sell the transmitter (Tx), the receiver (Rx) and a servo separately.

 

A new constructor is emerging and becoming more and more popular with its new technology. Spektrum build transmitters and receivers with a 2.4 Ghz technology. This technology removes the need to have numerous crystals as they will operate on their own unique frequency removing any chance of having frequency conflicts. Also it removes the occasional glitches you may experience with FM systems. More expensive but they seem to become the most popular one as more skippers migrate over to them.