About a year ago I set on my journey towards becoming a quadcopter pilot. Back then, I had no idea what I was doing and I was treading into new territory as I had never built anything as substantial as this before. I spent 5 months researching; visiting countless websites, watching tons of videos and posting a lots of noob questions on RC forums until I found myself ready to build my first quadcopter.
So, I got out the soldering iron, put on my safety goggles and began soldering.
I ended up destroying an ESC (Electronic Speed Controller) within 5 minutes, but luckily I had bought a spare. Eventually, I managed to complete it without destroying everything and connected the battery for the first time. This is the moment where my heart was racing because it could only go two ways, it could have either worked, or it could have ended up in a small cloud of black smoke. But in the end, my quadruple checking of all the connections paid off, and no smoke came out. I was thrilled.
I put this instructable together as a collection of all the information I learned across the hundreds of websites, videos and tutorials I encountered since the beginning so that you don’t have to spend 5 months and can instead get started with your quadcopter within a day.
This is a very informative and rather extensive guide, covering everything from how to choose the perfect combination of components, how to put it all together, what tools and equipment you’ll need to the health and safety considerations to ensure that you won’t be reading this from the hospital bed. To get you started right away, there are some recommendations of different setups including a setup that will give the most performance and a setup that will give similar results but won't be as costly. At the end is a separate section where you’ll learn how to fly your newly built quadcopter. There are also some nifty tips and tricks scattered throughout that will help you on your journey towards becoming a quadcopter pilot. Once you finish reading it, you will know everything you need to know about building, flying and repairing quadcopters.
You can apply these techniques to build a quadcopter of any size. This guide will focus on mini quadcopters which range from 180mm to 300mm (measured diagonally, motor to motor). In this instance, I chose 250mm.
There is a good amount of detail included, so brace yourselves.
Step 2: The Parts List
Step 3: How It Works
Step 4: Choosing Your Components
Step 5: Setup Recommendations
Step 6 to 18: Putting It All Together:
- Soldering The XT60 Connector
- Preparing The Flight Controller
- Prepping The Motors
- Measuring And Cutting The Motor Wires
- Testing Motor Direction
- Desoldering The Motor Wires from the ESCs
- Soldering The Motors To The ESCs
- Soldering The ESCs To The PDB
- Soldering The XT60 Connector To The PDB
- Adding Accessories - Buzzers & LEDs
- Connecting The Wires
- Connecting the Battery
Step 19: Maintenance And Repairs
Step 20: Health & Safety And The Law
Step 21: Learning To Fly
Step 22: The End
Below are all the components, items, tools and equipment that we will need to build a quadcopter.
- Flight Controller
- ESCs (Electronic Speed Controllers)
- UBEC (Universal Battery Eliminator Circuit)/voltage regulator (if needed)
If you want to add FPV you’ll need:
- FPV camera
- Action camera
- Video transmitter
- Goggles or a small screen
- Voltage regulator
- OSD (On Screen Display) (very useful) (optional)
- Battery charger
- Power supply for battery charger (if needed)
- Low voltage battery alarm (very useful)
- Pin headers
- Servo leads
- XT60 connectors
- Heat shrink tubing
- Zip ties
- Wires of various gauges (14 AWG, 22 AWG etc.)
- Battery straps
- Servo tester (optional)
- AA battery holder with servo lead (optional)
- Screws (M3)
- Nyloc nuts (M3 & M5)
- LiPo fire safe bag
Tools and equipment
- Soldering station/soldering iron
- Safety goggles
- Fume extractor
- Helping hands (optional)
- Hemostat (useful for gripping wires for soldering) (optional)
- Wire strippers
- Wire cutters
- Hair dryer or heat gun
- Screw drivers (hex, Philips, flat etc.)
- Magic Smoke Stopper (very useful) (optional)
- Multimeter (also useful) (optional)
This guide does not include instructions on adding FPV but I included the FPV parts list anyway.
Here is a tutorial from ‘DroneFlyers’ on how to add FPV to your quadcopter, should you choose to do so.
Before you start choosing your components, it’s a good idea to learn about how they work.
Let's begin with the frame. The frame provides the structure and rigidity and it's where all the components will be mounted onto. The flight controller manipulates the RPM of the individual motors in response to the users input. If you tell it to go forward, the flight controller will adjust the RPM of the rear motors so that it goes forward. The ESCs take the signals from the flight controller and adjust the speed of the motors. The motors and propellers provide the thrust and the lift for the aircraft. The battery provides the power to all the components. The radio (transmitter and receiver) are what allow you to control the movements of the quadcopter.
A Useful Philosophy of Mine
‘Learning how to fish’ rather than ‘being given a fish’ before you choose your parts will make the process so much easier. This philosophy stems from the proverb by Lao Tzu:
“Give a man a fish and you feed him for a day, teach a man how to fish and you feed him for a lifetime”.
If you learn how to fish, you won’t have to depend on anyone to give you a fish and you’ll be able to get a fish whenever you please. The same applies to quadcopters. If you learn about how the components work and interact with each other, you won’t have to depend on others as much for answers. Things will make more sense and you will be able to better answer most of your own questions.
Learn about how each component works. Learn about how each components interacts with the next and how they all work together. Once you do, you'll know exactly why things are the way they are, why each component is connected the way it is and why it behaves in the way that it does. When something doesn't go as expected, diagnosing the problem becomes that much easier because you know how it should work and why it should work.
To get you started, here is an excellent video by 'Painless360' which explains how the ESCs control the motors.
A great resource for information is the blog created by Oscar Liang. His blogs often answered the exact question that was stuck in my mind on numerous occasions. Visit his blog and explore the wealth of information he has to offer.
The beautiful thing about this philosophy is that you can apply it to literally anything. Let's take driving for example, if you learn about how all the different mechanisms and parts in a car work such as the clutch or engine, you'll know why the car behaves in the way that it does and why letting go of the clutch makes the car go forward and why letting go of it too quickly makes the car stall, for example.
There are 9 basic components to consider when choosing your parts. Below are explanations of what to look for, for each component. At the end of this section there are some recommended setups depending on what you’re looking for:
- Highest performance, and
- Similar performance but lower price.
Here are a few useful tips and places of great information that you should definitely check out:
The biggest factor to consider when choosing your component is the take-off weight which you want to be around 600g for a 5" setup. Anything above 650g is approaching the heavy side (relative to your thrust to weight ratio). Meaning if your setup weighs 670g but has a thrust to weight ratio of 9 then the high thrust to weight ratio makes up for the weight but regardless of thrust to weight ratio, a heavier quad will fly slightly differently to a lighter one.
To achieve the lightest setup possible, you need to be smarter when choosing your components. For example, instead of using a separate OSD, power filter and current sensor, you could buy an All-in-One flight controller which combines all of these onto a single board. This not only saves weight but also makes your build cleaner.
There is a great tool which helped me tremendously in determining whether my component combination would work well and that is ‘eCalc’. Once you have chosen your components, punch their values into eCalc and it will tell you your flight characteristics such as max amp draw, flight time, top speed, climb rate and much more. You can then use this data to determine whether the components will work well together.
Visit RC Forums
If you ever find yourself confused or encounter a problem that you don't know how to solve, the first thing you should do is visit RC forums such as RCGroups. There is a thread on virtually every topic and chances are someone will have already encountered the same problem so search around for answers and if you can't find any, post a question in the relevant thread. The awesome community will be more than willing to help you :)
Try to Buy from National Sellers
You can save money if you buy from national sellers as shipping costs and customs charges can add up. If you're buying from an international seller, make sure to consider shipping costs and customs charges. I made the mistake of not taking this into consideration and ended up paying over £100 in customs charges alone. Each country has their own customs charge rates so be sure to check this before buying.
Good places to buy from:
Watch out for Clones
There are many out there, some are easy to differentiate, others are much harder. Stay away from eBay for the main components such as the motors ESCs and batteries. You want a high quality and reliable product for the main components. Most of the sellers on eBay, sell clones. Generally, clones are unreliable and are of low quality but not all of them. There are some higher quality clones out there and if you're on a budget, clones can be an option for you.
Use Zip Ties to Fasten
Zip ties are handy for securing components to your frame and to keep wires in one place. If you need to secure something, think zip ties.
The Magic Smoke Stopper
The Magic Smoke Stopper is a useful tool which costs only a few pounds to make. It's a current limiting device and allows you to diagnose any faults before they do major damage to your components. You can potentially save the life of an ESC or motor. This article and video explain it in more detail.
Use a Low Voltage Battery Alarm
This little guy is very useful for telling you quite loudly when it's time to land. It's very difficult to guess this because usually you're having too much fun to take notice of the battery voltage and you end up with a dead battery.
You can use a multimeter to check the current/voltage of a terminal/pad before you solder the component onto it to check whether you are receiving the correct current/voltage. You can also use it to check the power requirements of components such as LEDs (if you don't know it already). For example, Let's say that you want to know how much current/voltage your LED is pulling when it is being powered off the flight controller, you can use the multimeter to check it and determine whether the separate voltage regulator you wish to power it off, will supply enough or too much current/voltage to the LED to prevent it burning out. You can also check the exact current/voltage draw of the system as a whole or individual components and gather technical data about your aircraft.
Now onto the components.
Two types of frame styles are common: acro and FPV. Acro frames are what's known as 'true X' frames because the arms form a perfect X shape. FPV frames are different in shape and come in multiple styles such as 'X' and 'H'. Here is a comparison of the two. They're also referred to as 'bus' style frames because of the bus shape in the centre. This shape allows for better placing and spreading of the components which are suitable for FPV.
How to Choose the Frame
To start, you want to determine the size of your frame. 180mm to 300mm are very popular sizes for FPV and acrobatics. Anything bigger is delving into the ‘aerial photography’ range. Larger size quadcopters offer more smoothness and the movement isn’t as twitchy, allowing for smoother footage. So first determine the purpose of your quadcopter and then depending on that purpose, you will know what size bracket you're in.
Once you’ve chosen the size of your frame you want to determine the motor size and Kv rating.
Types of Motors
There are two types of motors: inrunners and outrunners. Inrunners are where the rotor (the part that moves) is inside the motor whereas outrunners are when the inside remains stationary and the outside can of the motor rotates. Inrunners can spin faster but outrunners produce more torque to be able to drive the propellers which is why outrunners are very common with multirotors.
Motor Numbers Explained
When looking for a motor, you will see 2 sets of numbers. The first set is the size of the motor/rotor (the first two represent the diameter and the second 2 represent the height) and the second set is the Kv rating. Kv doesn’t stand for kilovolts like you would think it would, it instead stands for RPM per Volt applied. So if you have a 2000Kv motor and a max supply voltage of 12.6, the motor will have a max RPM of 25,200.
A couple of examples of the numbers you would find written on a motor:
You may find a letter or two before the first number. This is usually the series of the motor from the manufacturer. For example, SunnySky has the 'X' series, Cobra motors have the 'CM' series and T-motor has the 'MN' series among other series of motors.
The Inverse Law
Follow the 'inverse law': where higher Kv rated motors spin at higher RPMs but swing smaller propellers. Lower Kv motors spin at lower RPMs but swing larger propellers. Lower Kv motors tend to be larger in size, therefore the first set of numbers would also be larger. Higher Kv motors tend to be smaller in size, therefore the first set of numbers would be smaller. You can use this information to determine what motor you need. Larger quadcopters tend to use larger propellers which mean lower Kv motors are used. Smaller quadcopters tend to use smaller props which mean higher Kv motors are used.
How to Choose the Right Motor
The first step is to calculate the amount of thrust you need from the motors. Thrust is measured in grams, so your motors must produce enough thrust to actually be able to lift the aircraft off the ground, but in order to hover, the motors must produce at least twice as much thrust. This ensures that the motors have no trouble lifting and maneuvering the aircraft. The absolute minimum thrust-to-weight ratio is 2.
To do this, take the take-off weight of the quadcopter and multiply it by 2 then divide by 4 (because we have 4 motors) to get the amount of thrust that each individual motor must produce. If you want a higher thrust to weight ratio, replace the first number (the minimum thrust-to-weight ratio) with the ratio in mind. So if you want a ratio of 4:1, you multiply it by 4 then divide by 4.
But you may be wondering, "how do I know the take-off weight when I haven’t even chosen my components?" Well, we use a rough estimate weight which is calculated by adding the weight of the individual components. The average weight of a mini quad is around 600g so this will be the weight we’ll be using.
Higher ratios are better suited for racing and acro ranging from 3:1 to 6:1. I’d recommend starting with 4:1 as 6:1 will be too much to handle and you will struggle to fly for months because it will be so sensitive.
Edit: Actually, build your quad with the end goal in mind which in this case is speed. Start with the highest thrust to weight ratio possible. This will save you money from having to upgrade in a few months time once you've gotten used to it. Choose your components as if you can already handle the speed even if you can't. It really doesn't take long until you get bored of the 4:1 thrust to weight ratio so build a quad with a thrust to weight above 7:1.
To dampen the speed, use a 3S battery, use a low camera angle and decrease your rates (which we'll talk about later in this tutorial). I regret not going all out on my first build and settling for a tamer setup instead. I've just upgraded my motors where I can get a thrust to weight ratio of 11.3:1 while the take-off weight is lower than with the old motors. (These motors are the T-Motor F60 2207 2450Kv in case you're wondering.)
A great resource for motors is MiniQuadTestBench. QuadMcFly from RCGroups started the site as a home for his results from his motor tests. He tests the latest motors and produces elaborate data sheets providing you with the performance data of the motor (thrust, amp draw, efficiency, etc.) as well as a commentary about the overall performance of the motor, how it compares to similar motors and whether it is worth your money or not. A highly recommended source.
Propellers are measured by the diameter and the pitch and are measured in inches. The diameter is essentially the length of the propeller and the pitch is how far the propeller would move in space in one revolution. So if you have a propeller that has a pitch of 4.5 inches, in one revolution, the propeller will have moved 4.5 inches (in a perfect world). The motor manufacturers provide a datasheet that can be found on their website and tells you which propeller size they recommend. It's best to follow their recommendations otherwise you could end up either under powering the motors resulting in poorer performance or overpowering the motors, causing them to draw too much current and possibly blow the ESC, resulting in a lovely cloud of smoke and a shameful visit to Hobbyking.
How Different Propellers Affect your Aircraft
By increasing the propeller size on your setup, you can drastically increase the thrust produced by the motors but, this is not without its downside. Larger propellers draw more current and the responsiveness of the quadcopter is decreased because they're not spinning as fast as smaller propellers. 230-270 size quads typically run 4", 5" and 6" propellers. 4" propellers offer greater response but don't provide as much thrust as a 5". 6" propellers offer greater thrust but at a cost of lower responsiveness. 5" propellers sit comfortably in the Goldilocks zone and provide a good balance between thrust and response.
'Bullnose' propellers allow the propeller to be smaller while offering the same thrust of the larger propeller. This is because the surface area of the blades is increased. The same can also be achieved by increasing the number of blades. A bullnose propeller is essentially a regular propeller with the tip chopped off, making it flat instead of curved at the tip.
A 5" bullnose propeller will produce similar thrust to a regular 6" propeller. But again, this is not without its downside. Bullnose propellers tend to be slightly less efficient resulting in slightly lower flight times. This decrease in efficiency is due to the shape of the propeller. The flat tip increases wingtip vortices which mean that more turbulent air is produced, decreasing the amount of clean air for the aircraft to move through making the motors work harder and draw more current.
The propellers shown in the pictures above are all examples of bullnose propellers.
More information on this topic here.
The most popular propeller used to be a 5x4.5. But recently, tri-blades have taken over and almost completely replaced the dual blade prop. The tri blades offer a much greater 'bite' and grip the air much better making it more responsive at turns. We are also now beginning to see more quad blade props and even hex blade props being used/tested. The best bet (as your daily driver) would be the tri blades as they offer a good balance of thrust and responsiveness.
ESCs are measured in amps which indicates the amount of current it can continuously provide to the motor. To determine the ESCs, you want to find the max currentdraw of the motors which can be found in the motor datasheet. It is recommended to leave a little headroom and buy an ESC that has a value of at least 5A above the maximum current draw of the motors.
RC vehicles almost exclusively use LiPo batteries. This is due to their high discharge rates. But they are also quite delicate in their construction and are very sensitive to overcharging and over discharging. They can easily puff, making them unusable or even burst into flames. It is not uncommon for houses to catch on fire due to improper handling and care of LiPos but as long as you treat it with the respect it deserves, you can fly for years without having any trouble.
How to Take Care of LiPo Batteries
Your best bet is to use a LiPo fire-safe bag when charging which can contain the flames in the event of it bursting. Never charge indoors or near any flammable materials such as on top of your desk. Never discharge the battery past 20% capacity and never overcharge past its maximum capacity. If you do, the battery life can be decreased dramatically and it may swell or puff, rendering it useless.
What do the Numbers mean?
When looking for a LiPo battery, you will find 3 numbers; the C rating, the capacity and the voltage/number of cells. The capacity is how big the battery is and the C rating is how quickly it can deliver the current. The number of cells is written as ‘S’ so 3S would be 3 cells and 4S would be 4 cells and so on. Each cell has a nominal voltage of 3.7V and a max voltage of 4.2V. Usually, the combined nominal voltage of all the cells would be written along with the cell count. They essentially mean the same thing. If you see 14.8V written, divide the 14.8 by 3.7 and you get 4, therefore the battery has 4 cells so it is a 4S battery. In motor datasheets, the voltage written is the total nominal voltage of the battery.
These numbers are displayed on the pack. For mini quads, 3S and 4S are the most common. 5S batteries may be too heavy and can offer more disadvantages than advantages. Increasing battery size to maximize flight times only works to a certain point where if you go any higher, you end up achieving the opposite because of the increase in weight. 3S and 4S strike the perfect balance between weight and flight time. Although people are getting more power hungry so 5S and even 6S mini quad setups are beginning to pop up which can achieve absolutely ridiculous speeds of 120mph.
How to Choose the Right One
To determine what battery you need, you need to add up the maximum current draw of the entire quadcopter. So let’s say each motor draws 15A. 15 x 4 = 60A. Add a few amps for headroom and you have your maximum current draw. If you multiply the C rating by the capacity, you get the amount of discharge current of the battery. If you have a battery with an 1800mAh (1.8A) capacity with a 65CC rating. 1.8 x 65 = 117A, which is plenty.
I highly recommend you read this article from The Drone Girl: 15 Things Every LiPo Battery User Should Know. It's an excellent source of information on LiPo batteries.
A transmitter is a long term investment. You want to make sure your transmitter is reliable and that you can trust it because if your transmitter fails on you while you’re flying, your aircraft can drop out of the sky and potentially injure or even kill someone or damage property.
The biggest thing you need to consider is the number of channels, as long as you have enough channels, you’re good to go. The minimum number of channels is 4, one for throttle, one for pitch, one for roll and one for yaw. More channels are needed for extra functions such as arming with a switch, turning LEDs on and off etc. I recommend getting at least 6 channels so that you’re not so restricted.
The best beginner radio is the Turnigy 9X/FlySky FS-TH9X. It costs around £60, has 9 channels and offers features that you would expect to find in a transmitter 3 times the price. The Turnigy 9X and FlySky FS-TH9X are exact clones except for a few minor differences. The biggest difference is that the antenna isn’t hardwired into the module on the FlySky. This makes it easier to swap modules than in the Turnigy because you don’t have to desolder anything like you would if you had the Turnigy. The FlySky turns out to be the better option since it has a smarter layout. As far as the internal electronics go, they're exactly the same.
For an excellent transmitter which you can’t beat for the price, I recommend the FrSky Taranis X9D Plus. It costs £169 with an included aluminium carry case and is by far the most popular transmitter on the market. It is highly reliable, offers great features and allows you to customize any and all of the switches, something you can’t do with the FlySky/Turnigy without an upgrade. By the time you add all the needed upgrades to the FlySky, you will have ended paying the same price as the Taranis and you still wouldn't have all the features that the Taranis offers.
Some transmitters come with the receiver but some don’t. To choose the receiver, you need to consider the number of channels it supports and what type of channel it is such as PPM, PWM, SBUS, SUMD, DSM2 and DSMX. The differences between them are mainly how the signal travels between the receiver and the flight controller. Out of the list, SBUS seems to be one of the best options as it is digital and you can use one wire to carry up to 16 channels and maybe even more, depending on the receiver. It also has faster response times because it is digital. Whereas with PWM, you need one wire for each channel and if you have 6 or 7 channels, your build can become quite messy.
For the Taranis, I recommend the FrSky X4R-SB. It was designed to run SBUS and you can even switch between PWM and SBUS. There is also a 6 channel version (X6R) and a 8 channel version (X8R). Another thing to consider is whether the transmitter module and receiver are compatible. If not, you may need to buy an additional module for the transmitter in order to make it work.
The battery charger needs to be designed to charge LiPo batteries. LiPo batteries have to be charged differently to NiMH or NiCd due to its construction. If you charge a LiPo with a NiMH charger, bad things will happen.
Chargers have a maximum output current and maximum output power rating. This will determine how quickly a battery will charge but with LiPos, you don’t want to charge them too quickly. You want to charge LiPos at 1C, maybe even 2C but the quicker you charge it, the more likely the battery life will decrease. '1C' simply means 1 multiplied by the capacity. If you have an 1800mAh battery, you would charge it at a rate of 1.8A for 1C (1.8 x 1) or 3.6A for 2C (1.8 x 2).
Depending on the charger itself, you may need an external power supply. Some chargers have a power supply built in and some don’t. Just make sure that the power rating of the power supply is greater than the output power of the charger to ensure healthy operation.
I recommend the Turnigy Reaktor 250W 10A or the 300W 20A version paired with the HobbyKing 350W 25A power supply. This is an excellent charger that is reliable and has a broad range of functions such as regenerative discharging and can charge almost any kind of battery, not just LiPos. The 250W version goes for around £30 and the 300W version goes for around £50.
Most of the time, the electronics (flight controller, receiver, camera etc.) only need a 5V power supply but the voltage from the LiPo battery is greater than that and would fry the electronics if you were to power it directly off of the LiPo. Therefore a voltage regulator/UBEC is needed.The Pololu 5V step down regulator is a popular choice. It's small, extremely light and reliable.
BEC stands for Battery Eliminator Circuit and all it does is eliminate the need for a separate battery to power the electronics. Instead, you can use the same LiPo battery to power the electronics because a BEC reduces the voltage of the LiPo to the voltage required. Most ESCs have a BEC built in but is of the 'Linear' BEC variety which is highly inefficient and produces a lot of heat. An external BEC or UBEC (Universal Battery Eliminator Circuit) of the 'Switching' kind is preferred since it's much more efficient and more reliable.
'OPTO' ESCs don't have any BEC in them and require you to use a voltage regulator/UBEC to power the electronics. OPTO ESCs are lighter and smaller which makes a big difference with mini quadcopters where weight makes all the difference.
I highly recommend the Hakko FX-888D. It's quite expensive but if you're going to be doing much soldering, it is worth every penny. Otherwise, look for a soldering iron that is preferably temperature controlled and is over 40W.
If you want to get started right away, below are some setup recommendations.
How the Battery Size Influences the Speed
The battery and motors have the biggest influence on flight characteristics such as top speed, vertical acceleration and flight time. Simply changing the battery from 3S to 4S can increase top speed by as much as 20mph or more and increase vertical acceleration by as much as 20ft/s or more. But, increasing the battery size may cause the motors to draw excess current and increase the operating temperatures above safe working level. This is where eCalc comes in handy because you can check beforehand whether increasing the battery size on your setup would work or not.
You can use this information to make adjustments on the setups recommended below by changing the battery size to either increase the speed or even decrease the speed if it's too powerful for you. If you're starting out, it's better to start slow and work your way up. Feel free to switch around any other components to suit you.
The Best Performance (Advanced) (this setup has a top speed of 80mph and a vertical acceleration of 90ft/s)
Alien 5" Frame - £105.27 - 130g
KISS Flight Controller - £27.01 - 5g
4 xKISS 24A Racing Edition ESCs - £70.92 - 4g each (16g total)
4 xT-motor F60 2207 2450Kv Motors - £72.24 - 35g each (140g total)
4 xHQ 5x4x3 Propellers -£2.32
SMC 37A 4S 1300mAh True Spec LiPo Battery - £17.05 - 150g
FrSky Taranis X9D Plus Transmitter - £153.50
FrSky X4R-SBreceiver - £20.40
ImmersionRC Tramp HV/TBS Unify Pro VTx
ImmersionRC Spironet/TBS Triumph
Fatshark Dominator HD V2
Total = £1000+
Similar Performance But Cheaper
ZMR 250 V2 Carbon Fiber frame - £17.28
Naze32 Flight Controller – £17.24
4 xSunnySky X2206S 2100Kv Motors - £35.40
4 xLittlebee 30AESCs - £44.84
4 xHQ 5045 propellers – £3.10
Turnigy Nanotech 3S 1800mAh LiPo Battery - £15.04
FlySky FS-TH9X - £60
Total = £192.90
Now that we have chosen our components, we can start building.
Step 1 – assembling the frame and mounting the flight controller.
The first thing we need to do is assemble the frame. Most manufacturers provide an instruction manual, usually on their website. Follow the instructions of the manual and assemble the frame, ensuring the flight controller mounting screws are in place. Once assembled, you can mount the flight controller. You can either do the soldering for the flight controller while it is mounted or you can do it before you mount it. I chose to solder while it is mounted as it keeps it firmly in place as I’m soldering.
Connect Voltage Regulator (if needed)
You can also connect the voltage regulator at this point. A voltage regulator is only needed when you are using ESCs that don’t have a BEC in them. I’m using ESCs that don’t have a BEC so I will need to use an external BEC or voltage regulator. My frame comes with an integrated Power Distribution Board (PDB) which has holes where you can solder the voltage regulator to. Yours may not. If it doesn’t, you can simply connect the VIN and GND to one of the spare positive/negative pads on your power distribution board. I’ll show you how I connected mine to the PDB.
The Pololu 5V step down or buck regulator is pretty common and is very straight forward. The Pololu comes with a pin header that has 4 pins. We only need three pins so break one off so that you have 3 pins. Solder the pin header into the VOUT, GND and VIN. Once soldered you need to bridge the SHDN pin to the VIN pin. This makes the output current 600mA. If it wasn’t bridged then the output current will only be 20mA which isn’t enough to power the electronics. I did it by soldering a pin taken from a pin header to bridge the two. A simpler method is to bridge them with just solder. Once bridged, connect the VIN and GND to any spare +/- pads on the PDB. The VOUT and GND connect to any power pins on the flight controller. Once it is connected to the flight controller, you can then power your other electronics off of it such as the LEDs and the receiver.
Creating the XT60 connector is very simple. All you do is solder a red wire of the correct gauge to the positive terminal and a black wire of the same gauge to the negative terminal and then place heatshrink over each wire at the solder joint.
Before you solder onto the flight controller, test that it works by plugging it into the computer using a micro USB cable. If all the correct LEDs light up and it has connected successfully, you can then disconnect it and move onto the soldering.
It's a good idea to flash your board beforehand. To do this, jump the boot pads on the board and then connect it to the computer and launch CleanFlight. Go to 'Firmware Flasher' tab on the left, enable 'No reboot sequence' and choose the correct firmware from the drop down menu. Once it has loaded, click on 'Flash Firmware'. Once the board is successfully flashed, disconnect it from the computer and remove the solder from the boot pads. Watch this video to learn more.
The Naze32 comes with a set of pins. Solder the pins to their corresponding holes. You can solder them in any way you like. I chose to go for a low profile build and I soldered the breakout cable pins beneath the board.
Make sure you solder the pins right the first time. Dry test the pin placement/configuration first and once you've found a placement/configuration which you like, proceed to the soldering. Trying to desolder the pins is exceptionally irritating. Once you've removed the set of pins, it's virtually impossible to get them back in even after you've removed the solder from the holes because the pins fit perfectly and there's no wiggle room. Albeit I was using a solder vacuum pump to remove the solder. You'll probably find better results if you use a desoldering station to completely remove all solder from the holes.
Mount the Motors
In order to know how long we want the motor wires, we need to first mount a motor to the boom. This can be done by using the screws provided with the frame or the screws provided with the motors themselves. What we’re going to do is use one motor and one ESC to get the right length and then use that length to cut the wires of the other three motors, this way, we can save some time since we don’t have to repeat the process for all 4 motors.
There are 4 mounting holes for the motors. For this stage, you don’t need to put in all 4 screws so you can use 2 and make sure that they are opposite each other so that it fits correctly. When you're done, you can add the other two screws or even stick with two. Some pilots such as FinalGlideAus have reported that they've had no trouble using only two screws. The key is to make sure that they are all the correct tightness.
The wires that come out of the motor can be quite long so we need to measure them and cut them. Start by zip tieing the ESC to one of the booms. At this stage, it doesn’t matter which boom, any will do. Now you can adjust the position of the ESC along the boom to see how you want it to fit.
Once you have it where you like, cut the motor wires ensuring that there is enough length to reach the solder pads.
Now you can remove the motor from the frame and measure its length.
Once you have your length, cut the wires of the other 3 motors to the same size.
Once you have stripped the motor wires back you can then test the motor direction.
Use crocodile clips to connect together the motor wires from the ESC and motor. Use some more crocodile clips to connect the battery to the ESC using the XT60 lead soldered earlier. Connect the signal lead from the ESC to the 'OUT' pins of the servo tester. Connect the power supply to the servo tester through the 'IN' pins with a 3 or 4AA battery holder. Plug in the LiPo battery and then slowly turn the potentiometer until it spins. Observe the direction that it spins in and take a note of it. Repeat for all motors and ESCs making sure you know which motor is spinning in which direction. To reverse the motor direction, you can do so by simply switching any two of the motor wires.
There are a total of 7 wires soldered to the ESC. The three on the right connect to the motors and on the left, the red and black are for the power. The twisted black and white wires are for the signal. In order to have a cleaner build, you want to remove the 3 motor wires on the right and solder the wires from the motor itself directly to the ESC. This saves weight and makes it look nice and neat. You want to repeat this step on all ESCs. Remove the heat shrink before soldering to expose the solder joints.
Now that the three motor wires have been desoldered, the ESCs are now ready to be soldered on to.
First, strip the ends of the wires. Then tin the ends of the wires by applying a small amount of solder onto them. Tinning just means to apply solder onto the joint beforehand so when you want to solder them together, the solder is already on there and you won’t have to grow a third hand just to hold the solder. Tin the ESC pads also, if not already.
Once the wires and pads are both tinned, you are ready to solder the wires to the pads. Place the wires on top of the pads and apply heat using the soldering iron until the wire melts into the pad. Repeat for each wire until all motors and ESCs are connected.
Once all motors have been soldered to the ESCs, proceed to mount the motors to the frame using the screws provided. Make sure that the screws you're using aren't too long. Long screws can poke into the windings of the motor, resulting in damage. Check the length by peeping through the gap at the bottom of the motor and see if you can see any screws poking into the windings.
Be wary of the placement of the motors. You have two spinning clockwise and two spinning counter-clockwise. Below are where each motor should be placed and the direction it should be spinning:
Top left = Clockwise
Top right = Counter-Clockwise
Bottom right = Clockwise
Bottom left = Counter-Clockwise
A way to remember this is that all motors spin inwards towards the centre. If you look at the picture above, you can see that the arrows point to the centre along the y-axis.
When mounting the motors, make sure that the quadcopter frame is facing forward and double check that the motors are in the correct places before moving onto the next step.
The reason for this is to do with torque. Each motor produces torque in the opposite direction that the propeller spins in. If we had all motors spinning in the same direction, the quadcopter would spin as fast as the motors would be (in theory) making the yaw axis uncontrollable. To counteract this, we have two spinning clockwise and two spinning counter-clockwise. This cancels out the torque of the other motors, allowing for stable flight. It's the equivalent of what a tail rotor does in a helicopter.
Before you solder the ESCs to the PDB, put the heat shrink tubing over the ESC but don’t apply the heat yet. You may need to swap some of the wires later and you won’t be able to with the heat shrink in the way. Some ESCs allow you to reverse the direction without having to resolder any wires. The KISS ESCs have jumper pads where if you bridge them, the motor spins in the other direction. On the Littlebee ESCs, you can change the motor direction through BLHeli which is a software used to program it.
First, tin the wires and the pads and apply heat to both of them until the wire melts into the solder on the pad. Make sure that positive (red wire) goes to positive and negative (black wire) goes to negative. Do this for all 4 ESCs.
You can use double sided sticky tape beneath the ESC to dampen any vibrations.
Once you have shrunk the heat shrink, secure the ESCs to the frame using zip ties or even insulation tape, although zip ties look neater.
Take the XT60 connector you made earlier and connect it to the PDB. The red wire goes to positive and the black wire goes to negative. Double, triple check that you have the correct polarity otherwise things can go south very quickly.
You can add LEDs strips and buzzers to your quad to make it even more awesome. The LEDs help with orientation and the buzzers are useful for when you crash and can’t find your quad. You can flip a switch and the buzzer will beep, making it easier for you to find.
Adding the buzzer:
Some flight controllers have holes specifically for the buzzer. To add the buzzer, simply solder the positive wire to the positive hole on the flight controller and the negative wire to the negative hole. Double check that the polarity is correct so positive is going to positive and negative is going to negative.
To add the LEDs, solder a servo lead onto the LED solder pads. DI is the signal or data in connection, VIN is positive and GND is negative. DO is the data out connection. This is only needed if you are daisy chaining multiple LEDs. To daisy chain multiple LEDs, connect DO of the first LED to DI of the second LED and repeat for any additional LEDs, connecting the DI of the previous to the DO of the next. Once soldered, connect the positive and negative servo lead to the spare ESC pins (5 or 6) and connect the data lead to pin 5 (LED/5) on the Naze.
Once all the soldering is complete, the wires need to be connected. The following are all the wires that need to be connected:
4 signal/ground wires that come from all 4 ESCs,
1 power wires (Red+Black) from the voltage regulator,
3 wires (Red+Black+White) from the receiver and
3 wires (Red+Black+White) from the LED.
Connect the 4 signal/ground wires from the ESCs to the ESC pins on the Naze32. Make sure that it is the right way round and that pin set 1 is connected to motor 1. Each flight controller has different orders of the motors. Check the photos above for the order for the Naze32. The second picture is the order from the KISS flight controller for comparison. On the bottom of the board, you can see which set of pins are for motor one and so on.
The last two sets of pins (5&6) are the spare ESC pins which we can use to connect the accessories. Connect the voltage regulator wires to one of the spare pins. Make sure that it is the right way round. For the LED, the red and black wire go to the second set of spare pins and the data wire (white) connects to the ‘LED/5’ pin. Make sure that it is the right way round.
Now all the soldering and building is complete. Next, you need to set everything up by performing calibrations and configuring the settings. This will be included in Part 2 of this guide which will focus on the software side and expands on learning how to fly. It will include: how to calibrate the ESCs, how to setup the flight controller and transmitter while covering topics such as failsafe, what to do if you lose your quadcopter and more.
Part 2 coming soon.
Centre of Gravity
Your Centre of Gravity (CG) should always be in the middle. If you're adding FPV, you will have extra weight at the front so you're usually going to have to compensate by moving the battery backwards a little. If you don't have FPV, place it dead centre.
Connecting the Battery for the First Time
Use the XT60 connector that you soldered to the PDB to connect it to the XT60 connector attached to the battery. The XT60 is keyed so it can only go in one way. But before you connect it, use the smoke stopper mentioned earlier to diagnose any faults before blowing any components. This article and video explains it in more detail.
Once you connect it you should hear 5 beeps coming from the motors/ESCs. This depends on the ESC itself but most ESC's I've heard have 5 beeps. The first three beeps confirm that the ESC has turned on and the last two beeps confirm that there is a successful connection to the flight controller. If you only hear three beeps when you should be hearing five, double check the connections between the ESC and flight controller. Check that they're the right way round.
It is wise to buy at least one spare of each component. If you can't buy at least one spare of each, then just get a spare ESC and motor. The other components are less likely to fail/break but it's useful to have a spare lying around.
The most important ones are the ESCs and the motors. The ESCs are the most likely to be the first ones to go. Although the electronics are fairly sensitive and can easily be fried is not careful. Make sure you don't overheat them with the soldering iron and ensure that the polarity is correct. Once, I fried my flight controller because I plugged it in the wrong way and didn't bother double checking. I didn't have a spare lying around so I couldn't fly until I bought a new one. Being more observant of these kinds of things will save you a lot of time and money. Also, buy extra props. Lots of them. (Tip: use polycarbonate props instead of glass nylon. What you lose slightly in performance you gain in convenience. The trade-off is worth it. I recommend the HQ V1S PC version).
Buying spares is useful because it saves time and money as you don’t have to wait for the components to arrive and don’t have to go through the pain of shipping and customs charges all over again. This way, when you have a bad crash and your motor shaft bends, for example, you can get back to flying within the day or even the hour.
Buy Multiple Batteries
You'll find that you need quite a few more than just one battery. Flight times for race quads are typically around 4-8mins which isn't a very long time. Waiting one hour for your battery to charge, flying for 5 minutes and then waiting another hour for it to charge is just inefficient and not to mention annoying. The problem is, batteries can be expensive, especially if you're buying multiple. If you have at least 2 or three, it'll give you a little more time to fly before having to recharge. Some people even carry more than 30 batteries! Which allows them to fly for the whole day without having to even worry about charging.
If you have a bad crash or one of your components spontaneously commits suicide, you can easily fix the problem with a soldering iron. Simply repeat the steps you took to install that particular component and replace it with a new one. For example, one of your ESCs gets burnt out. You would desolder it and solder in a new one. You would then flash it, calibrate it and test it to see if it's working properly. Done.
There are certain things you must consider when pursuing this hobby. Remember, these are not toys and they must be treated with respect. We live in a time where the general public fear drones and the government has made flying them quite strict. Careless UAV (Unmanned Aerial Vehicle) owners unknowingly make silly mistakes and end up injuring someone or damaging property or flying it too high and interfering with airliners, forcing the government to enforce stricter laws which makes it harder for the responsible people who love this hobby to fly their aircraft.
It’s important to know the laws in your country regarding the flying of quadcopters. In many countries, you cannot fly above 400 feet, or fly in the near proximity of airports and airfields. If the aircraft is fitted with a camera, it must not be flown within 50m of any buildings, people, or large gatherings of people such as a stadium. It’s best to fly in the morning in a large open field where there will be hardly any people around and where there is no risk of injury/damage occurring to people or property. Here is a CAA article on the laws regarding UAVs in the United Kingdom.
Health & Safety
Buy a Fume Extractor
During soldering, ensure that you have some form of fume extraction. Even a gentle fan blowing the harmful fumes away from your face can make a big difference. It is best to buy a desktop fume extractor(£15.99) or build one. It’s nice and small and is cheap to buy/build.
Always Wear Safety Goggles
Always wear safety goggles when soldering. Solder can spit and may one day spit into your eye, causing permanent eye damage. This can be prevented by simply wearing safety goggles.
Charge Batteries Outside and In a Firesafe Bag
When charging your batteries, always charge them in a fire-safe bag. If it bursts into flames, the bag will contain the flames and reduce the chances of fire spread. But this is not a bulletproof method. It reduces flames, it doesn't eliminate them so don't rely on this method. Charge outdoors, away from any combustible materials. Here is a video from FliteTest about a useful battery bunker you can make to safely charge your batteries outside.
Just like a full-size aircraft, one must first learn how to fly. It may seem easy, but you’ll be surprised.
Practice on Something Smaller First
It’s not a matter of if you crash, it’s a matter of when. So to prevent damage to your expensive quadcopter, it is highly recommended that you build or buy a cheap ‘sacrificial’ quadcopter. This way, when you crash, you won’t have to worry about replacing expensive components and you can fly without the fear of breaking anything. It’s best to start with the small and fairly harmless micro quads such as the Hubsan X4. These micro quads are very cheap and are surprisingly durable. Once you have mastered the basic flying techniques on the micro quad you can move onto your larger, more powerful quadcopter.
Learn from YouTube
To learn the basic flying techniques, I recommend watching this excellent video series created by Jack FPV . He goes into good detail and provides drills and exercises that you can use to practice such as fixed position hovering and flying in patterns. FliteTest also has a great video which really helped me understand how to fly quadcopters when I was learning.
Flight simulators are an excellent way to learn how to fly without the risk of damaging anything. You can fully let go and fly without fear of crashing. FPV Freerider and Liftoff are great platforms for learning and are inexpensive. Buy your transmitter first so that while you're looking for the other components, you can connect it to your computer, learn how to fly and master it before you've even built your aircraft.
The video above is me flying on the FPV Freerider flight simulator. I connected my Taranis to the computer and used that to control the quadcopter. If it's raining outside or if the weather isn't permitting, flight simulators is a good way to fulfil your needs.
I hope you enjoyed this guide and I wish you good luck on your build.
Part 2 is coming out soon and will include the software; how to configure and set everything up to get you up in the air. Until then, I bid you farewell.
Be sure to share your thoughts in the comments below :) and Happy Flying!