Friday, June 8, 2018

How to Get Started Flying RC Airplanes

For thousands of years man has dreamed of flight. Nothing has amazed people as much as flying machines have in the past century and there is still more to come. What is even more amazing though, is the progress in personal flight toys. You can fly everything from a miniature helicopter, to a one 20th scale Cessna, which you can build at home yourself.

The more amazing thing about today's RC airplanes is the fact that anyone can fly them, and some airplanes are very easy to fly. For example, I bought a $50 Hobby Zone airplane and the controller had two controls, one that could steer the plane left or right and then the second was throttle (speed) control. How can you get any simpler then that!

As easy as it can be, it still can be difficult for beginners to get started in this hobby. Since I now have the knowledge that every beginner should know, since I was a beginner once, I wanted to share it with other people so everyone can enjoy the RC airplane hobby.


Wednesday, May 23, 2018

Servos - The Beginners' RC Planes Guide

Servos are the end units in a radio control chain. They are used to move the aircraft's control surfaces, the motor throttle and to actuate other devices such as retractable landing gears. A servo consists basically in a motor, gearbox, feedback potentiometer and an electronic board inside a plastic case. Outside are the servo arm and the servo cable and plug.

The servo arm is often a plastic piece with holes on it for attaching push rods or other mechanical linkages.

There are linear and rotary servos, but the most widespread today are the rotary servos whose arm rotates about 45 degrees left and right from its centre point.

The picture on right shows some servo hardware, such as mounting screws, rubber pads, and different sorts of servo arms.


Wednesday, April 4, 2018

Batteries - The Beginners' RC Planes Guide

Batteries are available in different sizes, weights, voltages and capacities C, which refer to their stored energy expressed either in amps-hour Ah or milliamps-hour mAh. For example, a battery with a capacity of 500mAh should deliver 500mA during one hour before it gets totaly discharged (flat).

Radio control sytems are usually powered by rechargeable batteries. Rechargeable battery types available on the market today are: Nickel-Cadmium (NiCads) Nickel-Metal hydride (NiMH) and Lithium-Polymer (Lipo) batteries. Even Lead-Acid batteries are also used as ground power source.

Normally the NiCads stand more "abuse" which means that they may be charged at higher rate (normally 2 - 4C) and have the ability to deliver higher current, i.e. discharge rates up to 2C continuous or 8 to 10C during 4 - 5 minutes and even up to 100C during very short time. They have some designations such as the Sanyo AE for high capacity and AR or SCR for quick charge/discharge.

A NiCad cell consists basically in a positive plate foil of nickel metal with nickel oxide/hydroxide, a negative plate foil of cadmium metal with cadmium hydroxide and an isolating porous separator film moistened with an electrolyte of potassium hydroxide (caustic potash). The two plates are sandwiched between the isolating porous separator films, rolled up and enclosed in a nickel-plated steel can. A spring-loaded vent is fitted at the positive terminal end in order to release the electrolyte and/or gasses, in case overpressure occurs due to overcharge. See picture below.