Last weekend I’ve added FPV camera and transmitter to my quadcopter. I’ve used FatShark 600TVL camera, ImmersionRC transmitter, minimosd OSD module (flashed for cc3d), FatShark power regulator and a cheap FPV camera mount I got from ebay:
The camera mount requires two servos, which can be used to provide stabilization and view “forward” even when the copter is in deep tilt. CC3D flight controller can use those two servos – see “Gimbal” tab in OpenPilot GCS (ground station).
The build itself was a huge challenge:
* the camera does not fit the mount – I needed to cut the holder and drill a hole for a signal cable.
* the camera mount is designed to point forward. I hoped to hide the camera inside the frame so it won’t get hurt during a crash, but that was not possible – I ended up mounting the camera sticking out a lot.
* there are no mounting holes or slots for transmitter or power regulator, so I tied them with cable ties. They stay in place, but are not rock solid.
* all cables are too long, but I did not have spare plugs, so I could not cut and redo them. All the cables and wires look messy
The result can be seen here:
And here is a video showing the first fligh attempts:
And a longer, uncut version showing a lot of mistakes. It’s not easy to judge altitude with such wide angle lens, so I had few close calls with a ground.
And so I crashed today. I flew too far, lost orientation and decided for a firm landing instead of flying away into unknown. I’m glad I haven’t put cameras on this time.
Just last week I have installed the Diatone 5025 Propeller Guards. They looked nice and the green/red colours LEDs helped with orientation during hoovering, but not in flight. I’ve installed them to match DJI Phantom – red in front and green on the back, but I found them more confusing than helpful. Anyway – they lasted exactly one crash. The propellers indeed didn’t break, but one of them got bent. So the guards haven’t delivered on their promise. I paid £15 for them for which I could 8 full sets of propellers. Don’t buy them.
Most people are drawn towards drones for the ability to take amazing photos and videos. The stuff that can be done using flying machines is incredible yet not all is as easy as it seems.
There are tens of cheap flying models with cameras on board, but unless you invest serious money you WILL be disappointed with the result.
Below is a shot comparison of video recording taken from three platforms:
* Hubsan X4 H107C HD – amazing toy to learn flying, but as you can see the video is useless. £35
* DJI Phantom FC40 – entry level DJI quadcopter (discontinued) – quite capable machine that carries a stock 720p camera. You’ll get similar quality image with similarly priced machines. It’s fun to play with, but the results are shaky. £350.
* The same as above but upgraded with Walkera G-2D gimbal with GoPro Hero3+ Black attached. The image quality is more than reasonable. You can see propeller guards and quadcopter arms in the picture – this can be solved by repositioning of the gimbal. As you can see the gimbal makes the camera rock solid in two axes, but the image is still shaky when copter yaws (rotates). Fixing that would require a 3D gimbal. Total price for this set up £350 Phantom + £70 gimbal + £250 camera =£670.
The video contains 4 parts – three streams combined and then each of the videos is shown in full.
Click fullscreen for best results.
Let’s start with something exciting – the final result! Say hallo to Bandit the Quad!
Building the Bandit was a lot of fun, but also a bit of frustration when I kept discovering I needed more things. Below you will find my final checklist.
Bill of materials
Frame. I used Emax 250 Nighthawk Pro Frame made from carbon fibre. 250 is a size class. It is supposed to mean that the distance between opposite motors is 250mm, but in reality the size is 280mm. Close enough I suppose. This size is comfortable to build and not scary to flight.
Motors. I used MT2204 2300KV outrunners. Two of them with clockwise nuts and two with counter-clockwise, which should keep the propellers steady.
Flight controller (FC). I used CC3D – small, open source based controller. It is inexpensive and has a very decent software helping to set it up.
Electronic Speed Controller (ESC). I used Emax 12A. The brushless motors require alternating inputs on three wires to spin. ESC is a component that translates PWM impulses from the flight controller to inputs for a motor. Those are smarter than they look – they are microcontroller based and their software can be updated. Mine use SimonK firmware, which seems to be a standard in this class of quads. Mine ESC have BEC (Battery Elimination Circuit), which provides power to the Flight Controller.
Propellers. I used 6×3 carbon fiber props. I do not like them – they look cheap and have scratched edges straight out of the box. Also the carbon fibre is very tough, so in case of unavoidable crash the motor may be hurt more that with a plastic prop which would just snap. On the other hand some say the carbon fiber props give less vibrations. I’ll probably will be changing them.
Radio transmitter (TX). I used Spektrum DX5e because I happened to have one. I like it – it feels good in hand and Spektrum is recognized as a good quality brand of RC.
Radio receiver (RX). This is a crucial component – it needs to work well with your transmitter and with the flight controller. I opted for Spektrum AR610 – one of the simplest and cheapest in line. It uses PWM communication with the controller, which is fine for now.
Power Distribution Board (PDB). In Quadcopters there are two almost separate set of electric systems: low current signals (RC-FC-ESC) and high current power to motors via ESC. PDB helps with the latter. You may use PDB or you can make the harness using wires (14AWG should be enough). PDB leaves exposed contacts which may lead to short-circuits, but it is easier to assemble than the harness. You choose.
Battery plug. I own few batteries with XT60 plugs, so I used the same in my quad. I bought one already soldered to a piece of 14AWG wire.
14AWG wires to connect the battery plug with PDB.
Battery. I used 2100MAh 3S LiPo from DJI Phantom. Most people recommend smaller and lighter ones around 1300MAh 3S.
LiPo Battery charger. Self explanatory
Mini USB cable. The flight controller needs to be set up from a computer. CC3D uses mini usb, not micro as phones do.
Battery straps. You need to fix the battery to the quad somehow. I used two velcro straps.
Heat Shrink. There’s quite a lot of things to solder and isolate. Heat shrink is much safer and looks better than isolation tape.
Cable ties. There are a lot of wires in the finished quadcopter and the frame offers no help in hiding them. My receiver does not offer any mounting holes, so I used the cable tie to fix it as well. I used few of 100x2mm and some of 150x3mm cable ties.
LiPo Charging bag. Rarely the LiPo batteries can cause violent fires. LiPo charging bags contains the most of the flames. Grab a bag, they are worth it.
Crocodile clips (see tips and tricks)
Soldering iron and solder. You will need to solder the motors, ESC, PDB/harness and a battery plug. I used 30W iron and I felt it was to small for the power cables.
Helping hand/3rd hand tool – you want the wires as short as possible, which means the soldering is harder than usual. Without the helping hand tool from Maplin I would be sitting here until next Christmas.
Heat gun. I didn’t feel using a cigarette lighter would be good for the machine. Heat gun is the cleanest way to shrink the shrink wrap. Go PRO and buy one!
Small spanners for the frame and propeller nuts. I used pliers instead.
Computer with internet access.
Multimeter – to check for the soldering work before connecting a real battery.
Tips and Tricks
ECS and motors have three wires with no information how to connect them. I soldered the middle wires together and then connected the remaining ones using crocodile clips in a random order. This allowed me to check the rotation direction of the motors before committing the proper joint. I happened to choose wrong order on 3 motors! You will check the rotation direction while setting up the machine in Open Pilot software.
It is extremely easy to scratch the carbon fibre with any sharp tools. I have made circles around few bolts where I used pliers instead of a correct spanner.
You can get a pack of 75 cable ties in three sizes for a £1 in Poundland. You want to have different sizes, so you would spend £5 in B&Q and £9 in Maplin to get them. And you will end up with many unused ties.
If you haven’t soldered the 14awg wires before practice it on a side before starting the real thing. I found this to be the hardest part.
Remember you put the shrink wrap before soldering ;)
The build took me two evenings after I have gathered all parts.
My Hubsan X4 (H107) had developed a problem synchronizing with transmitter (tx to rx). Since I had to disassemble it completely and solder broken battery cable I wasn’t optimistic that I could fix it. But I knew the quadcopter was flying after my repairs, so I kept thinking that the problem may lay somewhere else.
I suspected the transmitter. Symptoms below were appearing in random order:
* Hubsan X4 established link to transmitter (LEDs on), but does not react to throttle
* Link is established, but drops immediately – LEDs flashing on quad-copter or LED flashing on transmitter
* Red LED flashing quickly on the transmitter
I tried all the usual IT magic: turn it off and on again, shake, press all buttons in random order and combinations etc. with no result. I tried to do the factory reset and recalibration – the transmitter did not respond to that. I needed to think outside of the box. And then it hit me!
The solution was (drumroll…) to change the batteries in transmitter.
The Hubsan X4 transmitter has a battery status build in, but it seems to be broken – it was showing more the batteries still have 3/5 of the juice while the batteries were clearly dead.