By remzak Follow
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Building RC planes is tons of fun, but figuring out where to start is tough. The goal of this Instructible is to get you started in the hobby and turn you into a successful hobbyist. When selecting electronics for your new scratch-built rc plane there are many factors to consider. You need to consider the size of the plane, speed you wish to achieve, necessary thrust, and desired flight time. For parts I recommend looking on Hobbyking as they sell high quality parts at much lower prices than their competitors. Customer service is poor, and shipping takes a long time but with proper research it is a great resource. I have sourced all my parts from them and in 1000+ dollars worth of parts I am yet to be disappointed. In the first step I will go over selecting electronics, in the second I will go over connecting your electronics, and in the third I will discuss putting the electronics in your plane, and in step four I will go over some designs for homemade rc planes that I like.
Your entire plane is built around your motor and this is what you must choose first. When considering rc brushless motors there are several pieces of information you must take into account. The first is your brushless motor kv. The kv of your motor is the number of revolutions per minute it will spin per volt. The lower the kv, the stronger the motor and as a result, you will want a larger propeller for maximum thrust. Often slower motors will also result in slower flying planes, a big plus for your first hobby grade rc plane. If you select a motor with a higher kv and a smaller propeller the speed of the thrust will be higher, and as a result your plane will fly faster. For your first plane I recommend a motor kv between 850kv and 1500kv.
The next factor to considering a motor is size. Many beginners will end up significantly over-powering their planes and doing so adds momentum in crashes. Lighter, slower planes do not break as often as fast, heavy planes. My first motor was a 56 gram Turnigy 2200kv motor and every plane I built with it was a rocket and crashed like rockets crash. Hard. For trainers with under 36 inch wingspans a 24 gram motor will provide plenty of thrust for someone new to the hobby. I recommend the Turnigy 1300kv 24 gram motor which provides great thrust and high efficiency for it's light weight. It is also fairly inexpensive, costing around 10$ from Hobbyking. This motor is not a good motor for larger planes however and there are many options for planes with 36-60 inch wingspans. Generally for these planes a motor between 30 and 70 grams will have more than enough thrust. The Turnigy Aerodrive series is a good place to start but they are fairly expensive. If you are looking for a cheaper option look for similarly sized Turnigy motors that are not Aerodrive branded. Finding the right motor always requires a lot of research so be sure to read reviews, comments, and questions before purchasing a motor. Avoid electric ducted fans (EDF) for now; once you are more experienced they can be used to make fast aerobatic jets.
After selecting a motor the next logical step is to select a brushless electronic speed controller (ESC) that matches your motor. The motor will have an Amp (A) rating in the description section on Hobbyking. It is good general practice to select an ESC rated for 30 percent or 10A more than the max current draw of your motor. For the 24 gram Turnigy 1300kv motor a 10A ESC will work fine and will be very light. If you are uncomfortable with not having a large buffer I recommend an 18A ESC.
The 10A ESC I use is the Turnigy Plush 10A ESC, which is around 10$ from Hobbyking. If you want an 18A Esc I recommend the Turnigy Plush 18A ESC. For larger motors I recommend between 25A and 40A ESC's depending of the current draw of your motor.
The next part of your plane is your battery. Modern rc planes use lipo batteries, which have a good power to weight ratio and can discharge a large amount of current very quickly. The motor that the I recommend uses a low amount of current and I recommend fairly small batteries. Another fault in my first order of parts from Hobbyking was battery size and cell count. Large batteries weigh a lot and decrease not only your thrust to weight ratio and also increase the minimum speed of your plane. Also important to your choice of battery is the number of cells (S). Each lipo battery cell is around 3.7 volts. Remember that kv is the number of rotations per volt, which means that the more cells your battery has the faster your motor will spin. There are however limits as to the number of cells on both you motor and ESC. This information will be listed clearly in the descriptions of your motor and ESC.
If you are using the recommended electronics I recommend a 3S (11.1volt) lipo battery between 500mah and 1000mah. It is better to have a light plane with less battery life than a overloaded plane with better battery life. I cannot say it enough, WHEN you crash it is much better to have a light plane than a heavy one. A 3S 500mah Turnigy battery from Hobbyking will be just over 5 dollars so you should buy spares. For a larger plane with a larger motor a battery with between 1000mah and 2200mah should be good. 2S batteries will still have plenty of power for most planes and are lighter, cheaper, and smaller for the same mah battery, so if you want to use them it is fine, just be aware that you will have 1/3 less power than you would with a 3S lipo battery. Whatever battery you buy, read reviews and buy at least two to extend your flying time.
While on the topic of batteries it is important to purchase a charger. If you are on a budget a simple 2-3S lipo balance charger from Hobbyking should be fine, but if you know that this is the right hobby for you pick up a Turnigy Accucell 6, which will let you charge batteries faster and more accurately. It will also let you charge 1, 2, 3, 4, 5, and 6 cell batteries instead of just 2 and 3 cell batteries. The first option will cost 10-15 dollars. My Turnigy Accucell 6 cost me 30 dollars. The Turnigy Accucell 6 can charge 12 times faster however, so it is a good thing to get if you have spare cash.
The central component of any rc system is the remote control. Almost all modern remote control elements are 2.4Ghz. It is a frequency with good range and a nearly infinite number of people can use the frequency at any given time. I recommend a simple Hobby King 2.4Ghz 4ch Tx & Rx V2 as it is cheap and has good range. For your first few planes 4 channels will be plenty anyways. If you plan to be in the rc hobby for a long time I would recommend an OrangeRx computer radio. It will give you many more options and more channels. The Hobbyking radio is only 25$ and the OrangeRx is 60$. If you live in North America you should get a mode 2 radio which means that the throttle is on the left. A mode 1 radio has the throttle on the right side. A radio is the fundamental part of your rc plane and it is important to get a reliable one because if it fails you lose control of your plane.
To control the elevator, rudder, and ailerons you will need small motors, called servos. These servos can be precision control and have variable movement. You need one servo for every control surface. These servos will move control rods which are connected to the control horns on your control surfaces. I recommend the HXT900 servos from Hobbyking. They last a long time and are high quality for only 3$ apiece. If you are feeling rich you can purchase metal-geared HXT900's which are more durable. Whichever you pick I recommend purchasing 4-6 servos depending on whether or not you wish to add ailerons. Having 2 spare servos will save you the time it takes to ship new servos in case you ever have a catastrophic crash. Usually a servo will break once every 10 crashes or so. To be honest you cannot have too many servos so feel free to purchase to yours hearts content.
Additional materials other than electronics vary greatly for the rc hobby. In general however there are several elements that stand out. You need a propeller that matches you motor, recommended propellers can be found in the motors description. Buy lots of pare propellers because they are cheap and they will break fairly often, In addition you will want 18 gauge steel wire to make pushrods rof your servos. You can buy control horns or make them out of Popsicle sticks. Connectors for the batteries you buy are a must, I recommend XT-60 connectors (Hobbyking) or you can simply buy crimp on connectors from Amazon or RadioShack. You will need connectors for the brushless motor to brushless ESC connection as well. If you want ailerons on your planes you should buy a servo y splitter cable and it is always a good idea to buy servo extensions. Aside from those specific parts you will want Popsicle sticks, barbecue skewers, drinking straws, Adams foam board, heat-shrink, a hot glue gun, hot glue, and lots of packing tape. A sharp utility knife and or hobby knife will do a good job cutting Adams foam board. Adams foam board is 3/16" thick foam with a layer of paper on either side. It is widely regarded as the best material for building rc planes. It can be purchased online of at Dollar Tree, and so I am told Dollar General now. In total rc is a hobby that will cost around 100 dollars to get a good foothold in, and trust me, if you stick with it it will be worth every penny.
BE CAREFUL CONNECTING YOUR ELECTRONICS. IF YOU CONNECT THEM INCORRECTLY YOU CAN RUIN THEM OR SET THEM ON FIRE.
The first thing you connect is your motor and speed controller. Three wires are attached to your brushless motor, attach a male quick connect crimp-on connector to each one. The ESC also has three wires and attach a corresponding female connector to each wire. If you have crimp-on connectors use your wire strippers to attach a connector to each wire. You may also want to heat-shrink your wires too add strength and ensure that there will be no short circuits. Next, connect each motor wire to an ESC wire, it does not matter which wire is connected to each. If you want to create a permanent connection you can twist the three wires together and test the direction. Later you can solder and heat-shrink the wires.
You should now attach a corresponding battery connector to the red and black wires coming out of the other side of your ESC. Before soldering test connect the connectors and make sure you solder the wires so that the red wire lines up to the red wire and the black wire lines up to the black wire. Before you solder, also put the heat-shrink on the ESC power wires, after you solder you will not be able to. After you solder on the connector heat-shrink the connection.
You now are ready to bind your receiver to your transmitter. Put the bind plug in the bind port and plug the ESC wire into port one on the receiver with the black wire up. Plug in your battery to the ESC. Power on your transmitter while holding down the bind button. The receiver led should stop blinking. Unplug the battery and turn off the transmitter. To test the connection power on the transmitter then plug in the battery. After the motor beeps a few times you should have throttle control. Always power up you transmitter before plugging in your battery and turn it off after unplugging the battery unless you are binding the transmitter to the receiver. This ensures that your rc plane will never fly away without your control. If you are having trouble there are many YouTube videos demonstrating the process.
After connecting the ESC to the receiver attach a piece of tape to the motor shaft and ensure that when the motor is running it spins counter clockwise. If it is spinning in the wrong direction you can simply reverse two of the motor/ESC wires. NEVER swap the ESC power leads. Once the motor is spinning counter clockwise you can remove the tape and move on to the next step. This would be the time to solder the connections between the ESC and motor if you are creating a permanent connection.
You are now ready to connect the servos to your receiver. With the black/brown wire up connect a servo to channel 2 and one to channel 3. To test these servos power on your transmitter, then plug in the battery and move the control sticks. The servos should move.
You now have a functional set of electronics for a simple plane with throttle, elevator, and rudder. With the included hardware attach the half servo horns and tighten on a screw. You are ready to add a propeller and add these to a plane. In the next section I will discuss various planes that are popular and have good instructions.
Now that your electronics are working I have several recommendations for first planes. Be warned, building these planes will take time to do a good job. The build times will range from 1-10 hours for high quality builds. That said if I had to recommend one place to start with I would recommend FLITE TEST. They have high quality plans and the finished products fly great.
The Nutball: A fun and outrageously simple plane. It takes very little time to repair or rebuild and is easy to fly. Not one of my personal favorites but so simple and effective it has to make the list. It also has detailed build videos on YouTube. It can be found in detail at flitetest.com. BUILD DIFFICULTY: 1 FLIGHT DIFFICULTY: 2
The FT Flyer: Designed by FLITE TEST this plane is very stable and can fly very slowly. About as easy as it gets to fly. It is a great plane to learn on and it is capable of basic aerobatics. It is probably my favorite simple plane. Also easy to repair but it is so sturdy that unless it is a very bad crash it probably won't break. Once again flitetest.com has the plane and more details. BUILD DIFFICULTY: 2 FLIGHT DIFFICULTY: 1
The FT Simple Storch: A great traditional trainer with a true airfoil this plane is the first I list with ailerons. It will be slightly harder to fly but looks nicer and it more capable of acrobatics. A stable flyer I would recommend a 1000mah 3S lipo. It is probably the most durable plane I have recommended yet. Plans and details can be found on flitetest.com. BUILD DIFFICULTY: 5 FLIGHT DIFFICULTY: 4
FT Delta: This plane has elevon control and is a fast and responsive acrobat. Probably the hardest plane to fly I have recommended yet. When you are ready however this plane will be a lot of fun and can really wow with tricks. Plans and details can be found on flitetest.com. BUILD DIFFICULTY: 3 FLIGHT DIFFICULTY: 5
I am not liable for any damage you cause to property, people or anything else. Don't be stupid. Be safe.
