How to Start
Step by Step Guide
In this chapter, we will assume that you just started in this hobby, and that you know about zero, on anything, and still want to do it alone. We will therefore go step by step, trying to understand on the way what does what, to only some limited extent, for now.
Let's first review what is what and how things will be connected. First as an overview, and then we will spend some more time on each item.
Overview of a complete package:
Some frequency ranges
Radio Systems, from HobbyPeople
Aircraft radio systems consist of a transmitter (or controller), a receiver, one or more servos, and batteries. Servos are the part of the airborne radio system that convey mechanical movement. Each moving part will need a servo to make that part move. Radio systems are available with a wide variety of features. However, they all share similar quality and basic functions.
When you first look at a radio system, you'll see how many channels it has and then what channel it's on. The word channel is used two different ways: firstly, an airplane radio is very often a 4-channel radio. This means that it controls four functions on the plane (ailerons, elevator, rudder, throttle); secondly, it refers to the actual radio frequency the radio transmits. There are several frequencies legal to use for R/C airplanes and each one has been assigned a channel number.
When deciding on a radio, it is important to decide on how many channel functions you want. Most airplanes use four channels. However, some aerobatic, scale, and sport planes use five or six channels (adding flaps and retractable landing gear). So, you may want to think about the future and what plane you want next, and buy a radio that will control all anticipated functions.
The FCC has set aside 50 frequencies in the 72 MHz band (channels 11-60) dedicated to aircraft use only. No license is needed to operate these radios. However, if you have an amateur (ham) radio operator's license you may be able to use a radio in the 50 MHz band. Also, there are six frequencies set aside in the 27 MHz band that are legal for any kind of model use (surface or air). Just remember, whatever channel your radio is on, check the field where you fly for any other radios on the same channel and do not use your radio when theirs are on!
Many fields have a frequency control system. Before you use your radio, be sure you understand the system and are using it correctly.
AM vs FM / PCM vs PPM
This refers to the signal type (or modulation). A radio wave of any frequency can have different signal types.
The following features can be found on many economically priced 4 and 6 channel units:
Computer Radios vs. Standard Radios
A computer radio allows more adjustments and channels to be mixed in a more precise way. Computer radios also have more trims and setup adjustments making the radio installation and flight-trimming process of the plane easier and more precise. Also, the settings can all be saved to memory and settings for more than one plane can be saved. In more advanced computer radios, the mixing is programmable, actually allowing custom combinations of channels and movements (and even control inputs). Competition pilots find this kind of adjustability a must. Many beginners simply find computer radios too complicated.
Standard radios have basic mixing but it is not as precise nor as adjustable as a computer radio. Also, the setting cannot be saved for more than one plane. However, these radios are simpler to use and are less expensive.
Make sure to not mix the term "radio Channel" which relates to a specific sub-frequency, with the channels used to control servos.
Batteries: Set of batteries, usually between 6 to 30 batteries. When you start, 1st time flyers are usually with 7 to 10 batteries. The rule is that the more batteries you add, the more speed the motor will deliver. Then, the more speed the motor will deliver, the more Amp the battery will need to give and therefore, flight time will be reduced. As for the plug to a battery, always use a FEMALE plug. This is the standard and this is mainly due as you want to avoid as much as possible the risks for short cuts, when the batteries are in a bag. Also, when installed in the plane, make sure it can't move almost at all, as if not, it will impact your CG while flying and eventually you may loose control of the plane. Also, try to think who the battery will go, if you will crash the plane (usually on the front), and try to install the battery in the way that it won't destroy your receiver, or ESC or any other part, as much as possible, if a crash happens.
To better understand number of cells (Total Voltage) and Ampere, effects, we can use the common dam analogy. The number of cells will tell you how high and large is the dam. and the Total amp, how much water is waiting behind.
So if 1 cell is equivalent to 10 meters high, 2 cells 20 meters, etc... and let's imagine that you suddenly remove all the wall of the dam. The higher it was, the stronger the water will fall. For how much time the water will fall is a matter of how much water you had initially (Ampere). And also, if the water goes stronger, meaning faster, for the same quantity behind, it will be passing the dam faster too. So if you want to keep the same time, for the water to pass the dam, and you make the wall higher (more cells), you will need to add more water behind (more Amp). Multiple combinations can be deducted from the above picture.
Now, to make things a little more fun (some would say more complicated), our cells don't all have the same constitution and this impact the "fluidity" in our water example. In other words, some cells won't allow the water to drop as physics would normally think, and in fact, it prevents the water to go too fast, and the more you will try to force it, the more the battery will heat instead of delivering any more strength to a point that the battery may be damaged. This means that you'll need to select the battery type, according to how much Amp/minute your motor will need. Example will follow....
You can either buy batteries, per the unit, which means that you will actually need to build packs. It is easy, but needs some little practice. The good side is that you then can repair packs yourself, or build them in any shape you like.
Or decide to build ready packs. A little more expensive, but well done and easy to get.
Each pack has his own advantages and inconvenient. Let's see some weights/size differences for common packs
For 8 Cells
weight in Grams
ESC: This device is made of 1 plug to hook into the receiver, 2 wires to connect to the plane battery, and on the other side, 2 or 3 wires to connect to your motor. It takes the energy from the battery and split it between the motors and the receivers (and therefore servos). Some ESC have cut the motor when the battery is too low, in order to save some electricity for the servos, and receiver, for landing without the motor. Others cut the motor, is the motor asks for more energy than the ESC is supposed to handle. This can happen is you put some propeller that requires too much work from the motor, to be used. A classic symptom will be that when you push the motor stick, the motor works and then stops as a certain point. This is the point where the motor ask the ESC to deliver more than he can handle. If the ESC doesn't have this feature, and this happens, your ESC may be destroyed if this configuration happens. Also, most ESC don't have polarity protection, if you'll inverse the plugs of the battery. They will just burn some circuits on the spot. Don't put it too close to the receiver box, as it may have some weird reactions if they are too close one to the other.
As for the connections plugs on an ESC, they are also standards. The battery side of the ESC is ALWAYS Male, as the battery is always FEMALE The motor side can be either directly solder to the motor, or plugedm if the motor was plugged as well. The positive is solder directly is less loss of electricity as plugs are decreasing a little the overall connectivity. The down side of it is that you won't, easily, be able to use this ESC, for different planes.
In some cases, you may need to not have the BEC function. 2 choices are then available.
Plugs: simple... always plug the (+) wire on the (+) of each connector. make sure that no wire is left not protected as shortcut are not good.
Servos: It is a device that will help to move the some parts, to make your plane turn or move up or down:Servos are chosen according to the type of plane flew. In electric flying, we select always the lightest possible ones, still keeping in mind how much torque (strength) needed and how good quality they are. The balance is not always a clear cut, so common sense is the rule here. For most low speed Park flyers, the 9gr will do fine. You have different types of servos. Some with stronger torque, some with faster reaction to the commands, some with metal Gears, or with plastic ones. All have plus and minuses. Common sense is again the rule here. As for installing the Servos, make sure that their body part won't be able to move at all, once installed as if not, they might move during a flight to a point where you may loose control of the plane.
Receiver: This is a device, with an antenna, that will receive orders from your radio, and communicate them to your servos and Speed controller.
Never forget to fully extend the antenna from the receiver, and to also check that during flight, the extended antenna won't be able to touch the propellers). Fix it with some scotch tape.
Glues: When you start in this hobby, it is not easy also to decide which glue to use for what. In general, follow the below rules:
Motor: There are 2 types of motors, brushless and brushed. The first type is expensive, but does not require maintenance and will also not die, after X uses. X is usually 100s of flights, for brushed motors, if used within their capabilities. Brushless are also much more expensive, and deliver more power. So, if you don't need a lot of power, brushed motors would be more suitable, and cheaper. If you have to replace one, every 2 years, or so, still worth it. To start, it is recommended to use a 400 type of motor, or less. It delivers good power and is pretty cheap.
If your motor is brushed, to make it pull, you need to put the RED wire (+) on the (+) of the motor. To make the same motor push, you need to inverse, and have the BLACK wire (-) soldered to the (-) of the motor.
For brushless motors, for pullers, match the colors, and for a pusher, just switch 2 of the cables.
You can now go to the "How to build your plane" Section