Multicopter Safety!

I thought that it might be worthwhile writing a little article about safety as many people are starting with multicopters without having any previous RC experience and many not be fully aware of the risks involved and the measures that we can take to reduce them. I'll break this down into 2 parts, with the first part being about initial copter setup and then looking at pre-flight checks that you should do before every flight.

Setting up your copter for the first flight

• Think safety! Get into good habits from the start and don't get sloppy or be tempted to cut corners
• Take your time. It can be tempting to just throw everything together to try and get your copter flying in as short a time as possible, but take the time to do it properly as it will save problems later.
• Know the risks. A multicopter is basically a flying lawnmower and can do serious damage to yourself and others. Not only that, but the Lipos we use to power our copters are potential bombs, so ensure that you follow proper charging procedures and store them safely and check them regularly for damage. Many multicopters are made using carbon fibre and care must be taken when working with it as carbon fibre dust is extremely dangerous if ingested.
• Remove Propellers. Probably the single biggest cause of accidents with multicopters is motors suddenly spooling up when working on the copter with power on. Always ensure that you remove the propellers when making any adjustments with power on.
• Suitable Location. Don't be tempted to test fly your copter in your front room or basement, find a large open field away from other people and property. A multicopter can fly surprisingly fast and can gain altitude quickly.
• Connecting the Battery. Don't connect the battery until you are ready to fly and once the battery is connected assume that the throttle is armed and don't be tempted to fiddle with the copter at this point. Before connecting your battery make sure that the transmitter is turned on and that the throttle is set to zero and if you have throttle lock on your transmitter enable this function.
• Situational awareness. Be aware of your surroundings and any potential hazards such as overhead power lines, other RC aircraft and most importantly other people and animals. Also take note of the prevailing wind direction and beware that the copter may suddenly catch the wind if you climb above tree level.
• Know your limits! Until you are confident in your flying ability, avoid high speed or high altitude flying. Keep the copter close to you to avoid losing orientation and if you do lose orientation it is better to lower the throttle and try to land than rather than risking flying further away or even the possibility of a fly away.
• During flight. For your first flights try to keep low (2-3m) and slow (walking pace). When your battery is getting low, avoid flying high. Stay in one spot and don't walk around as you might trip as it's difficult to concentrate on walking and flying at the same time, particularly walking backwards.
• After flight. When you have landed the danger isn't over until the battery has been disconnected. Leave the transmitter on and set the throttle to zero and set throttle lock. Only after you have disconnected the battery is it safe to turn off the transmitter. 

So you've taken that first step and had your first few flights and hopefully survived it without any injuries/damage to property and without crashing too many times. This is the time that you're most likely to have an accident as your confidence is growing and you get complacent in your abilities and start becoming careless in your actions. This is the time to go back to my first point above, about thinking safety, now is the time to write yourself a pre-flight check list.

I can't write your pre-flight check for you, but I can give some advice to the sort of things that should be in it. Once you have written your list, you should print it out, laminate it and stick it to something that you always take to the field with you. I have mine written on the back of my transmitter. There's no point in doing this if you're not going to use it, so get in the habit and use it every flight. Real pilots with thousands of flight hours still use a check list for every take-off and landing and so should you.

What should be in it? - Here's what's in mine.

Pre-Start

1. Inspection (physical and visual inspection of the copter for damage)
2. Area Clear (Check that it is safe to fly)
3. Tx Antenna Up (Pretty obvious, but mainly for old school radios)
4. Tx On
5. Check Correct Model Memory (Quite important this one!!)
6. Sticks, Switches, Batt (Check battery voltage and set sticks and switches)
7. Throttle Down+Locked
8. Connect Flight Batt

Start

1. Area Clear (make sure it's still safe to fly)
2. Throttle Hold Off
3. Arm Motors 
4. Start Timer (I time my flights to have an idea of when to land)

Shut-down

1. Disarm Motors
2. Throttle Down+Locked
3. Disconnect Flight Batt
4. Tx Off
5. Tx Antenna Down

After Flight

1. Inspection - Full inspection of the copter to check for damage. The vibration from flying can cause screws and nuts to become loose, so have a good check for these. Check for any damage to the frame and cracks and chips in propellers and make sure that they are still attached securely. Check the Lipo and cables for any damage. I always have a quick feel of the motor and ESC temperatures because an excessively warm motor or ESC could be symptom of a component that is soon going to fail.

Let me know if you think I've missed something. What do you have in your pre-flight check?

Flying high in the French Alps

At 1400m and with snow-capped peak of Mont Blanc looming large in the background, Plaine Joux is the perfect setting to host a meeting for large scale helicopter enthusiasts. This weekend 13&14 October 2012, the Club des Gypaetes de Passy Mont-Blanc hosted its annual helicopter meeting. With fantastic organisation, great displays of piloting skills, the magnificent setting and a bit of luck with the weather it really turned out to be a great event.

I'm no roving reporter, so I didn't go around getting names of pilots or details about their models, so I'll just have to let the pictures do the talking. The quantity of models on display was truly amazing and the amount of scale detail in some of the builds really had to be seen to be believed. The livery of many of the models has clearly been influenced by the mountains and there were numerous helicopters in the colours of both the French and Swiss mountain rescue service.

Of course no meeting would be complete without someone there to film it and my friend Guillaume was on hand with his trusty Vortex-8 Octocopter to capture all the action. At over 1m motor to motor this is one really big model and it certainly drew a lot of attention from the crowds of people that came to enjoy the meeting. Today I spotted that he's recently purchased 2 large Pelican cases to transport all of his equipment and it certainly makes life easier for transporting all the required equipment safely to a shoot. The case with all the Lipos needs 2 people to lift it though!!!

Notice the silicone anti-vibration mounts under the camera mount plate. These are expensive to buy, but are really effective at reducing vibration to an absolute minimum. The Sony cx740 produces outstanding high definition images and today was the first try of the new wide angle lens, so I'm looking forward to seeing the results. To help line up the images there's an ImmersionRC transmitter and Duo5800 receiver with 2 patch antennas and a 9" screen. Slightly obsessed with carbon fibre, even the sun shield is made of 1mm carbon fibre plate. Did you spot the 2 large Pelicases under the table?

 Here's a little video that I made (note to self: must get better at filming and editing) of the event and a few more pictures from this fabulous weekend in the mountains. Thanks to the Club D'aéromodélisme Les Gypaetes for once again hosting such a great event.

Turnigy nano-tech v Zippy compact

My friend did a little test for me today to see which battery gave him the best flight times. This wasn't a 100% fair test, as one was a 5000mAh and the other 5800mAh, but interesting results none the less. The frame used for the test was the dji F450 with the Wookong flight controller, RCTimer motors and Graupner 10x5.5 e-props.

Capacity: 5800mAh
Voltage: 4S1P / 4 Cell / 14.8V
Discharge: 25C Constant / 35C Burst
Weight: 569g (including wire, plug & case)
Dimensions: 162x46x34mm
Balance Plug: JST-XH
Discharge Plug: 5.5mm Bullet

V   

Capacity: 5000mAh

Voltage: 4S1P / 4S Cell / 14.8V

Discharge: 35C Constant / 70C Burst

Weight: 531g (including wire, plug & case)

Dimensions: 154x50x33mm

Balance Plug: JST-XH

Discharge Plug: 4mm Bullet-connector

At 569g, the Zippy Compact only weighs a mere 38g more than the nano-tech and is only a few mm longer, yet manages to pack in and extra 800mAh of capacity. More importantly, the Zippy is nearly $10 cheaper than the nano-tech, so presents a significant saving and seemingly excellent value for money, but does it live up to its specs?

Let's have a look!!!

So there you have it, the Zippy compact wins. Ok, I know this wasn't a 100% fair test, but given the lower price, very similar weight and size and the 30% more flight time the Zippy is a clear winner!

AQ50D Flight Controller

I thought I'd write a little article about this flight controller as I don't think it grabs many headlines, but anyone who has flown with one will attest to how stable this controller is right out of the box. At over $150 it is perhaps a little overpriced given the seemingly limited features that it has, but what you get with this board is out of the box stability and an absolute minimum of setup time to get your copter in the air.

The AQ50D supports 8 different copter configurations, quad+, quadX, hex+, hexX, Y4, Y6, OctoX and X4. It has a 6DOF IMU, but only flies in ATTI mode, with no option to switch to manual mode, so you won't be doing any aerobatics with this one. It also supports 2 axis camera gimbal stabilisation and the closed source firmware can be upgraded using an additional cable.

So you've read the specifications and I can feel you thinking what's so special about this board? Well, what makes this board so special is that you don't actually need a computer to set it up. It has 4 dip switches which are used to select the copter configuration, quad+, Y6 etc, one calibration button and a gain potentiometer. Once you have done the throttle calibration on all of your ESCs, you connect them to the board, connect up the receiver with the supplied cable, power it up and push and hold the calibration button until the LED flashes, set the gain to about 50% and go an fly.

Now that's what makes this board special! That and the fact that this board seems to be quite immune to frames that produce a lot of vibration and can keep your copter flying really stable in strong winds that would keep other controllers grounded. I've tried a lot of different flight controllers and none of them have come anywhere near as close to this in terms of stability.

You can of course connect this board up to a computer to adjust settings and you will need to do that in order to adjust the gain and servo speed if you're going to use a camera gimbal. In the GUI you can adjust settings for the flight control, but I'd really just suggest sticking with the default settings. The GUI is nice and intuitive to use and has a good layout making it easy to figure out what you're adjusting.

The board does support future updates and add-on sensors, but the developers really seem to be taking their time to come out with firmware updates and hardware upgrades. In the last few weeks we've finally seen the altitude sensor add-on, which will allow altitude hold function and early tests of it are looking promising. Apparently there is a GPS board on its way, but the prototype was first seen over a year ago and no news since then.

Pros: Ease of use, great flight stability, intuitive GUI

Cons: Price, lack of features, slow to release upgrades

Here is a little video showing you just how good this controller is straight out of the box.

For those of you that don't understand French, he basically explains that he has a brand new board that he's never tried before and he then goes through all the steps of calibrating it, once by pushing the calibration button and then the stick calibration which involves holding throttle up and rudder left for a couple of seconds.

Ignore the video title, it's a bit confusing about the name of the board. There are basically 3 versions of this board, AQ50, AQ50-Pro and AQ50D. The latest, AQ50D is the only one worth buying (the one shown in the video) as the other 2 have thermal drift problems which are quite annoying. The AQ50-Pro can be upgraded with an add-on sensor, but avoid this option as its still not as good as the AQ50D.

LANC-Ctrl for Sony CX cameras

This is just a quick post to show you the Lanc-Ctrl working on a Sony cx740. This is a great little device if you have a sony cx series camera with the LANC control port. It allows you to start and stop recording, take still photos and control the zoom functions. It has an ultra-bright LED status light so you can see exactly what it's doing from the ground.

If you're thinking of moving to a 2 man aerial filming operation, then this device simply adds more control for the camera operator to allow them to capture those special shots. The cost is just shy of €75 and is available here: http://mikrokopter.altigator.com/sony-lancctrl-camera-remote-control-p-40797.html

Here is a video of my friend G testing it out on his trusty Vortex-8 Octocopter, which I will hopefully be doing an article on soon. As you can see, the Sony cx740 is a really great camera for aerial video and has a superb 'balanced optical steadyshot' stabilisation system that really helps to get rid of vibration. Coupled with the LANC-Ctrl this is a great combination for filming with a multicopter.

Adding Lights to a Multicopter

So, you're thinking about taking up night flying, want something to aid with orientation or just looking to sex up your flying machine, then adding some lighting to your copter is the way to go. Personally I like to keep things simple, using just a couple of LED strips in 2 different colours to help me out with orientation when I'm up high and just enough to be able to do the odd night flight.

If you want to add some simple strips like on my copter above, then you don't even need to get your soldering iron out any more because Hobbyking now sell 200mm strips with JST connectors attached. Combine 4 of these with one of the JST-XH to JST power distribution lead and you can add LED lighting strips to your copter in a matter of minutes. One good tip if you want to light the whole arm up is to use some   almost clear heatshrink tubing over the arms, which helps transmit the light all the way around the arm and has the added advantage of protecting the LEDs a bit and stops them getting knocked off.

The downside with this setup is that they only operate on 2s - 3s Lipo's and the power distribution cable is designed specifically for a 3s Lipo. If you do fly with a 4s or 5s Lipo you can always change the JST-XH connector to one that fits your Lipo and then just tap off 2 or 3 cells. The current draw of these LED strips shouldn't be enough to unbalance your pack that much, so I wouldn't worry about that when only tapping off a couple of cells from a 4/5 cell pack.

9 mode Multi Colour/Function LED strip with controller

If you want a more bespoke lighting setup than just a couple of strips of LEDs then you can also purchase much longer strips of LEDs by the roll, so you can wrap it all around your copter. The LED strips can be cut to the required length or soldered together to make even longer strips. Also available is fibre optic light strips that are really nice if you just want to highlight a particular part of the frame with more complex bend radii.

For the full UFO effect then you want some flashing, pulsating, colour changing lighting for your multicopter. Again, you can purchase a receiver controlled colour changing LED strip from HobbyKing which uses RGB LEDs to provide a changing colour spektrum which you can select using a spare channel on your transmitter. Flytron make some really good Strobon - combined navigation and strobe lights which are really bright and would look excellent on a multicopter.

 The video below shows the Strobon light attached to a hunter v-tail frame from Dialfonzo.

On my builds, I like to use a receiver controlled switch to control my lights, so that I don't have to have them on all the time and it's fun to fly at night only switching them on and off every now and  then. This adds a little bit of complexity to the installation, but is well worth the effort if you have a spare channel. It also always gets a smile from spectators when you take your copter up high and then start turning the lights on and off.

Here's a little video I made to show just how easy it is to add some lights to a multicopter. Apologies for not being the best film maker and my croaky voice, as I was suffering from a cold when I filmed this.

Blow the Budget Copter

So you've decided to blow your kids college fund, take out a second mortgage on your house or maybe just having a mid-life crisis and you're looking to put together a top of the range copter, so what are you going to get for your money? Well, depending on just how much you're willing to spend, the sort of features that you're going to get with a premium copter are: GPS waypoint navigation, custom ground station software and  enough lifting power to carry a small family pet.

Of course if you've got the money then you can get someone to do the hard work of putting the system together for you, but this does not guarantee success and flying experience isn't something that can be purchased. If you're brand new to multicopters and looking to do aerial work with it, then I highly recommend purchasing a cheap multicopter to learn to fly before jumping in at the deep end.

Let's start by looking at some RTF options.

Draganfly X6-ES
From the makers of one of the first commercially available multicopters, the draganflyer, comes the Draganfly X-series of multicopters. These are designed for the emergency services for carrying out aerial reconnaissance, so prices are difficult to come by, but I expect that the price will be $30k+

The custom ground control is super cool looking and features real-time telemetry, spoken verbal alarms, camera control, live digital vieo downlink and mapping.




Microdrones md4-1000

The md4-100 boasts an impressive flight time of 88 minutes (although it's not mentioned if this is whilst carrying a payload), making it ideal aerial inspections and surveys. This is one big machine and is once again primarily designed for emergency services and other government bodies, making prices difficult to come by, but don't expect change from $50k.

$10K RTF

Coming back to a slightly more realistic budget, there are a number of RTF packages available for around $10k. For a long time, MikroKopter pretty much had this corner of the market to themselves, offering features that no other platform had. There are a number of stores offering RTF packages featuring the MikroKopter control board at its centre and one of my favourite is the Cinestar 8. The frame is specifically designed with vibration dampening features to allow smooth aerial video to be shot. The basic version retails for just under $10k, but with all the optional extras including camera gimbal then the price could be as high as $20k.

Sub-$10K RTF

If you have a slightly lower budget and don't mind being restricted to using only one model of camera then perhaps you might like the DJI S800 complete with Zenmuse camera gimbal and WKM flight controller. There were a few reported problems with the initial release of the S800 with some of the ESCs overheating and causing crashes, but I think that those problems have mainly been solved now. The special thing about this combo is the Zenmuse gimbal which uses direct drive brushless motors to provide just about the best camera stabilisation available for multicopters. The only downside is that the Zenmuse is designed specifically for the Sony NEX-5.

Do-It-Yourself Option

There's something quite satisfying about getting a bunch of parts and taking the time to put them together piece by piece until finally you have a complete machine ready for its maiden flight. Building it yourself also means that you have a much greater understanding of the copter, so that if something does go wrong, you'll know how to fix it and like I said earlier, experience can't be purchased.

Frames

When it comes to top of the range multicopter chassis, there are so many options to choose from but there are 4 that I think really stand out from the crowd. The Cinestar range of frames that I mentioned in the $10K RTF copter are available as frame only, allowing you to choose the rest of the components yourself.

The second manufacturer whose frames have to be considered is Droidworx. They are a New Zealand based company that produce high quality heavy lift copters. They now offer a retractable landing gear, which is great for 360 degree pans without the landing gear spoiling the photo/video.

The next copter that I think is worth having a look at is the Flexacopter. The special feature of the Flexacopter, apart from the stunning good looks, is the stainless steel wire dampeners which allow you to mount your camera gimbal on a platform that is extremely well isolated from vibration. From the videos that I've seen produced using the Flexacopter, it really does appear to be a great frame for aerial video.

The last frame that I want to talk about is the ECILOP Easy. This was developed Aleksey Zaitsevsky and utilises a radically different form of camera stabilisation.  This is a frame and camera stabiliser all in one, therefore saving you a small fortune on the need for a seperate camera gimbal. The stabilisation method is much like a steadicam and uses the weight of the battery  to balance the camera and produces astoundingly stable footage. The downside to this design is that it complicates the installation of all the electronics, is only available as a quadcopter (at present) and is limited in the choice of camera that you can use. At only $495 this represents really good value for money and I'm sure that we will see a number of frames incorporating this  stabilisation method in the future.

Control Cards

As I said earlier, this is an area that for quite some time had been dominated by MikroKopter, which is still the industry standard by which all others are judged. More recently, dji have released the Wookong-M which boasts many similar features to Mikrokopter but is more aesthetically  packaged and has an easier to use interface. The latest newcomer to the market is the YS-X6 from Zero UAV offering a few more features than the dji, but in a very similar package. The MikroKopter has limited range waypoint flying unless you purchase quite an expensive licence, whereas both the Wookong-M and the YS-X6 offer limited waypoints without an expensive license. In order to use many of the additional features you need to purchase a radio data link, which attaches to a computer so that you can do point and click waypoint flying.

Motors, Props & ESC 

It's not possible to recommend any one brand for these, but if you stick with the frame manufacturers suggested setup then you can't go wrong.

Batteries

As far as I'm aware they haven't yet developed a miniature nuclear powered battery and hydrogen fuel cell technology is still not advanced enough for our use, so you're going to be needing some really high capacity Lipo's. My friend, who has recently sold his house to fund one of these copters, tells me that the Turnigy nano-tech 5s 8000mAh Lipo is just the job for this application.

Camera Gimbals

A good camera gimbal can cost more than all of the rest of the components combined and is an absolute necessity if you want to produce high quality video. Unless of course you purchase a frame using the steadicam style system like the one used in the ECILOP, the name of the game nowadays is Direct Drive. This trend was started with the release of the Zenmuse Z15 from dji and looks set to continue with the soon to be released Hero range from PhotoHigher. The AV200 also from Photohigher has been, and to a certain extent still is, the industry standard but it's days look to be numbered.

Licence & Insurance

So you've blown your kids inheritance on building the world's best multicopter, but what can you do with it? Well, if you want to go into business making films or taking aerial photographs then you're going to need a licence and insurance. Depending on where you live in the world makes a big difference as to how complicated and expensive this process is. Make sure that you check the regulations where you live before you invest a small fortune in a business that you can't get off the ground.

In my forthcoming article I am going to be writing about the different regulations around the world and how different aviation authorities regulate the use of multicopter 'drones' for both professional and hobby use, so stay tuned...