NAMBA Propwash October 2017.pub

A toggle switch with a waterproof cover is a better solution. The battery plug is also a problem area. Tape should be used to hold all plugs together. Moisture remains as the most serious danger to modern electronics. I believe that the 2.4 MHz radios are even more sensitive to water than the older systems. If it’s raining or even misting, you need to keep the transmitter dry. A plastic bag over your hands and the transmitter works well for this. The receiver in the boat is the hardest to keep dry. Radio boxes have been the long time solution. These days they have taped lids. Either 3M electrical tape or hockey tape is used. Electric racers use the hockey tape because they go through a lot and it’s much less expensive. The 3M tape works better under adverse conditions. Safety Corner – RC Systems By Lohring Miller NAMBA Safety Chairman Radio controls have come a long way. My first RC unit was a single channel 27 MHz unit with vacuum tubes and expensive dry cell batteries. The planes it “controlled” were still mostly free flight. Today we have ultra reliable 2.4 MHz frequency shifting radios that are almost interference proof. Ultra accurate digital servos provide mechanical output. Though the electronics have improved, many of the mechanical issues haven’t changed. Since safe control depends on the entire system, let’s look at these issues. All radio systems still need power. This is provided by batteries. Again batteries have come a long way. Today’s alkaline batteries are low cost and have a long shelf life. Some racers put new ones in their radios on every race day. Most of us use rechargeable batteries. The LiFe 6.6 volt receiver batteries are tiny and easily last all day. Servos like at least 6 volts for their best torque. That means 5 cell nickel cadmium or lithium metal hydride packs. Some of the newer servos are designed for 7.4 volt batteries. Most boats only run one servo that draws significant current. Because of this there’s no need for an independent servo supply. Lithium metal hydride or nickel cadmium rechargeable 9.6 volt transmitter batteries are still good, especially for the older transmitters. Newer transmitters are designed for the 6.6 volt LiFe cells. All batteries need to be fully charged with a suitable charger before race day. The better radios display the transmitter voltage but receivers aren’t often monitored. This isn’t usually needed since one transmitter is often used for several boats. That way the transmitter battery gets a lot more use than the receiver batteries in the boats. The weakest link between the battery and the receiver is the switch. Electric boats with a battery elimination circuit in their speed control don’t have this problem. If there’s power to run the motor, there’s power for the receiver and servos. The common slide switch on a Dubro mount can suffer from leakage and corrosion. PROPWASH 6 October 2017 Receiver battery packs Toggle Switches with Covers Dubro Switch Mount Taped Plugs