A beginners' guide to RC sailboats

Radio Control Boat Modeler, Jun 2000 by Houle, Tom

Before you buy your radio, check with your local club about open channels. This will ensure that you don't buy a radio with a frequency that another skipper is already using.

* The controls. The left stick moves the rudder in the direction the stick is pushed. For the left stick, pulling it back toward you (while holding the transmitter in your hands at belly level) pulls your sails in over the deck. Moving the left stick forward and away eases the sails and runs them out until they hit the shrouds. I wouldn't reverse the left stick operation. I once had the misfortune of sailing a boat with the sail-control stick reversed; the owner is still trying to understand why his boat sails funny.

* Servos. The sail-control servo is like a rudder servo on steroids. It has a ball-bearing output shaft and a more-powerful, high-currentdraw motor than its smaller cousin. Like the rudder servo, the sail servo draws its power from the 4-cell, 4.8V receiver battery pack. Futaba makes two excellent sail servos. The S-125 has been around for years and will work nicely with sail areas up to 600 square inches; the S-180 is a larger, more-powerful version of the S-125. Even though the S-180 weighs more, I use it exclusively now on my 600square-inch boats (Wisconsin winds can be unpredictable).

* Pulley blocks. I recommend that you install small, nylon or brass pulley blocks at each end of the sail-winch arm. These blocks reduce the friction of the sheets as they pass through the arm and allow the sails to be winched in quickly in strong winds. Without these friction-reducing blocks, you can stall the sail servo and risk draining your receiver battery.

As an alternative to pulley blocks, some skippers use a 5-cell battery pack. This works very well in a stiff breeze; the S-cell pack increases torque and speeds up sall-am travel, but it doesn't-as some skippers believe-increase battery life. These benefits also come at a price. By adding a fifth cell, which increases battery voltage from 4.8 to 6 volts for AA batteries, you add weight and increase the current drain by a factor of 1/6. You could ensure longer battery life by going to larger-capacity batteries, but is this really necessary? In my opinion, no. Use friction-free Pop-Up Mfg.* no-snag blocks, and your Futaba servo will never know it's running on a 4-cell pack. Even on a windy day, you should be able to squeak out a couple of hours of sailing time with a fully charged, 4-cell pack, and you can always carry backup cells.

* Installation. When installing radio components into your boat, make sure that everything-receiver, battery pack and both servos-- is accessible. You never know what unscheduled maintenance-like battery replacement-will be needed. I like to install a charging jack on the radio board, which allows me to easily plug in my charger without having to access the battery pack. As a side note, the battery gurus now say you can plug in a charger with a C-10 charging rate (a rate of charge that's 1/10 of the battery pack's rating, i.e., 50mAh for a 500mAh) and leave it plugged in for weeks. Good to know.