Saturday 15 December 2012

What's happening with my blog?

I thought that I should probably let people know what's been going on and why the articles have stopped coming. Well, basically it's all down to work getting in the way of life and doing 80+ hours/week isn't conducive to maintaining a blog on the side. I've been working away from home and haven't managed to do any flying/building for the past month or so and it's been killing me.

I'm heading home at the end of next week and will hopefully have the time again to work on my blog. With Christmas coming, I might just have to treat myself to a few new bits and pieces, so will have more products to write about.

In the meantime, thanks for all the continued support and once again, many apologies for the lack of recent posts from myself.


Sunday 21 October 2012

FPV - What to buy?

For this article, I'm going to just look at the basic items needed to get started in FPV and make a few recommendations on items to purchase and a list of retailers that I've dealt with that have provided good service. Hopefully you will have already read my previous article FPV Basics and will already know which frequency you are going to use. The recommendations in this article are for putting together a quality system on a budget and in my next article I will talk about some upgrades that you could make in the future.

Camera

If you already own a camera such as a GoPro then you can use this as your FPV camera and save a bit of expense. If not or you want to go for a dedicated FPV camera, then there is one really great camera that I can highly recommend. Not only that, but the vendor provides excellent customer service! The camera is the PZ0420, which is a 600 TV line super HAD CCD camera with WDR from Securitycamera2000.com. It comes with a controller so that you can set it up just how you want using the built in on screen display (OSD) and is available with a choice of lenses in 2.8mm, 3.6mm or 6mm.


Transmitter and Receiver

I think that it's best to buy these as a pair, so at least you know that they will be compatible with each other. As there are 4 different frequencies, I will make recommendations for each frequency, but make sure that you check that the channels are legal to use in your country before purchasing as on some transmitters only 1 or 2 channels may be legal in your country.

900MHz


Sticking with my mantra that anything over 500mW is too much for FPV, I'm going to recommend the 500mW transmitter and the 900MHz receiver with Comtech tuner from DPCAV. If you're lucky enough to live somewhere where this frequency is legal to use and isn't saturated by mobile telecoms, then it will give you great range even with the stock antennas. Transmitter & Receiver 



1.3GHz

Choosing a transmitter for this frequency band can be tricky as many of them transmit on illegal frequencies. Civilian aircraft DME (Distance Measuring Equipment) uses frequencies between 962MHz and 1213MHz, so make sure that you don't transmit on these frequencies!!! One of the most popular transmitters for this frequency is the Fox 800 and there are many threads about this on various FPV forums, but again I'm going to recommend something below 500mW. For USA customers then I highly recommend readymaderc.com as not only will you get great service, but he has transmitters that have the 2 legal frequencies available in the U.S. For all other international buyers, then this 400mW transmitter from BEVRC.com is a great set. Don't forget the low pass filter if you want to use it with a 2.4GHz radio system!

2.4GHz

When it comes to 2.4GHz and 5.8GHz, there are 2 options, you can either go with airwave based systems such as those from ImmersionRC or with SkyRF based systems, which are more popular due to their price. If in the future you think that you might purchase other ImmersionRC products such as the very popular EZ-OSD or you want to use the built-in receiver in Fatshark goggles, then it makes sense to go for an airwave based system. The 500mW transmitter from ImmersionRC has been designed from the ground up by dedicated FPV flyers and is designed to be plug and play with other ImmersionRC products. Combined with  the DUO2400 receiver this is a great package, however it is a little bit expensive. ImmersionRC also do lower power transmitters for those wanting to stay within the legal power limits.



The other, much cheaper option, is this 500mW system which is available from many different retailers and is what I personally use. It's very easy to set up and on totally stock antennas I've gone over 2Km with a crystal clear picture. See my Lazy EZ* FPV article for the very simple installation that works great.




5.8GHz

As I mentioned for the 2.4GHz, it comes down to a choice on your future plans as to whether or not to go for an airwave or skyRF system. This is the one time that I will break my rule, by recommending a transmitter over 500mW, the ImmersionRC 600mW transmitter along with the ImmersionRC DUO5800 diversity receiver. As with the 2.4GHz system from ImmersionRC, it's not cheap, but is really good quality equipment.

I believe that the distance record @5.8GHz was done using a 200mW SkyRF system, together with a circular polarised antenna system. The SkyRF receiver has a little bit more sensitivity than the ImmersionRC receiver, which is why it can achieve good range even at the lower power output of the transmitter. This combinations is available from most FPV retailers and is great value for money. This is sometimes sold with a couple of different receivers, make sure you get the RC305 receiver that looks like the one in the picture below and not the RC805 with the digital display as it has some design flaws.



Don't forget that you really need to use circular polarised antennas with 5.8GHz!!!

Video Display

You're either going to be someone who prefers goggles or someone who prefers a screen and this will affect your choice for this crucial part of the FPV system. My personal preference is for video goggles as I feel that it gives a more immersive flying experience and certainly from the reaction of people that try the goggles when I'm flying, it's always difficult to wrestle them back off them, whereas people tend to get bored after a couple of minutes watching the screen.

Fatshark make a range of goggles specifically designed for FPV and no matter which ones you choose, you almost certainly won't be disappointed. For the most immersive experience choose the Base model as it has the largest Field of View (FOV) and for the clearest, sharpest picture try the Predator goggles that have a built in 5.8GHz receiver and even a built in head tracker that will allow you to control a pan & tilt mechanism for the camera.


Choosing a good screen is very difficult as you need to find a good balance between size, luminosity, portability and price and importantly no blue/black screen! In my opinion, anything under 7" is too small to use for FPV and 10"+ is way better. If you're in the USA then you might be able to pick up a 10" Haier screen for as little as $40. For international pilots then The Foxtech M800 is a very nice monitor with good resolution and great brightness for use outdoors and comes with a sun hood for outdoor use.

What Else?
All of the items that I discussed are good quality equipment that you shouldn't need to upgrade as you progress with FPV and add more equipment to your setup. From here you can add things such as Antenna trackers, On Screen Displays (OSD), Long Range Radio Systems (LRS) and autopilot systems. In my next article I will look at what is on the market to take your FPV experience to the next level and in the next article after that I will look at a Blow the Budget system using some of the very best FPV equipment that money can buy.

Thursday 18 October 2012

FPV Basics

For anyone wanting to get into FPV, my advice is always to start simple and then build from there. Too many people expect too much from their first system and it almost always ends badly when newcomers set out with the goal of achieving too much with their first system. If it's your first time trying FPV then it's all about the KISS principle and simple is definitely better.


Safety!
Before we get to the nitty-gritty of putting together a basic FPV system I just want to mention the 'S' word. As with all aspects of this hobby, it is important to always think about safety and with the addition of the FPV equipment the are additional safety considerations to take into account. Certain things like range checking become a lot more crucial, there are a lot more batteries to check before flight and you also have to plan your flight carefully before setting off. Think before you fly!

Regulations
The rules for FPV vary from country to country, so check what they are in your country so that you stay on the right side of the law. Some countries require that you fly using a buddy cable, some countries require you to have a spotter and almost all countries don't allow beyond visual line of sight flying.

Which Frequency?
Not all frequencies are legal in every country, so it is important to check that whatever frequency you decide to go for is legal to use in your country. There are 4 frequency bands that are currently used for FPV and depending on where you live in the world and what frequency you already use for flying, will decide which frequency will work best for you.

900MHz
In a lot of countries 900MHz is used for mobile telecoms, so is not available, but it is quite a nice option if it is available where you live. The pros of 900MHz is that because of the laws of physics, it will in theory provide the best range for the lowest power output and is much better at penetrating objects such as trees and buildings. The downside of 900MHz is that the antennas are huge, the receivers aren't very sensitive and the picture quality is the worst because it has the lowest video bandwidth.

1.3GHZ
In many countries there is a legal frequency at 1280MHz that can be used for FPV. The good thing with 1.3GHz is that like 900MHz, it has good range at low power and relatively good penetration of objects. The antennas are a bit smaller, but still relatively large and the receivers are reasonably sensitive and the picture quality is ok. The cons with 1.3GHz is that the band can be a bit congested and the second harmonic is at 2.4GHz, so it can interfere with 2.4GHz radio systems and requires a low pass filter in order to work with a 2.4GHz radio system. Also, the third harmonic of UHF long range systems sits right on the band and can drastically reduce video range. Be careful when purchasing systems advertised as 1.2GHz as many transmit on frequencies that are used for civilian aircraft DME (distance measuring equipment) equipment and you can get into big trouble for using these!

2.4GHz
2.4GHz is perhaps the frequency best suited for FPV use as it is legal just about all over the world and thanks mainly to wifi, the receivers are very sensitive and the antenna designs well advanced. The video bandwidth is pretty good, so should allow a good quality of picture. The negatives are that you can't use a 2.4GHz video transmitter with a 2.4GHz radio control system, which are currently the most popular systems for flying RC aircraft. In urban areas 2.4GHz is very congested due to wifi networks and 2.4GHz doesn't have the same penetration as 1.3GHz or 900MHz.

5.8GHz
Apart from one quite important thing, 5.8GHz is a great frequency for FPV. The antennas are nice and small, so easy to fit on the smallest of models, it's legal in most countries, has great video bandwidth for the best picture quality and has sensitive receivers and it works perfectly with 2.4GHz radio systems. The one very big downside however is that it really suffers from video drop-outs if you don't have line of sight all the time and also suffers quite badly from multipath fading effect, so circularly polarized antennas are a must. It will also give the shortest range of all the frequencies.

Here is a link to a great video from Alex AKA IBCrazy, who invented a few of the most popular antennas that people currently use for FPV, where he explains pretty much all of what I've just said above.


How to be successful in FPV - Frequency selection from C. Alex Greve on Vimeo.

How much power?
So you've decided which frequency to go for, now you need to decide what sort of power transmitter you are going to buy. Again, there are different rules in different countries and the legal maximum power limits are usually very low. You can use high gain directional antennas and still achieve reasonable range whilst keeping within the legal power limits. If you do decide to go for higher power transmitters then in my opinion, regardless of frequency, with modern antenna design anything over 500mW is overkill for FPV. It is far better to use the lowest power possible for what you want to achieve.

Gain and polarisation
These are 2 words that you will come across a lot in FPV and it's important to have a basic understanding of what they mean and how they affect video range. When we talk about gain, which is typically expressed as dBi, describes how well the antenna converts input power into radio waves headed in a specified direction. As a receiving antenna, the figure describes how well the antenna converts radio waves into electrical power.  The higher the gain, the more efficient the antenna is, but with higher gain also comes more directionality, which can be a problem when used for FPV.

I like to think of it like a torch with an adjustable beam. A high gain antenna is like the spot light which produces a very tight beam but only lights up a very specific spot on the wall, but can shine a long way. A lower gain antenna is the opposite and is more like a flood light which lights up the whole room, but doesn't light up something a long distance away. If this was the beam of the antenna then you can imagine how hard it would be to try to stay flying in this narrow beam and you wouldn't be able to fly behind it, but if you could then you can fly a long way.

Polarisation is the direction in which the radio waves travel with respect to the Earth's surface. There's no need to know in depth radio theory, although it can make interesting bedtime reading, but knowing a little about this is really useful for FPV. There are 2 types of antennas that we use for FPV, linear polarized and circular polarized.

The type of antenna that usually comes with your FPV transmitter (rubber ducky) is a linear polarized antenna. With these types of antenna it's really important that you keep the orientation of the transmitter and receiver antenna the same otherwise there is a significant loss of signal.

The circular polarized antenna is a more advanced design of antenna and works in all orientations, which is great for FPV use as the signal will not drop when you bank and turn or fly upside down. There are 2 types of circular polarisation, left hand and right hand and the most commonly used is right hand polarisation, so make sure you purchase one of these. The other advantage with circular polarisation is that it overcomes the issue of multipath fading effect.

Here is a nice video that explains gain and polarisation really well.



Antennas 101 - Polarization, Diversity & Gain Patterns from Joop Media on Vimeo.

Now that we know a bit more about the various frequencies, antenna gain and polarisation, lets take a look at what we need to put together a basic FPV system. The components we need are: some sort of camera, a video transmitter, a video receiver, a pair of antennas and a video display device. For these basic components I would advise purchasing good quality equipment right from the start, because even as you add more complexity to your FPV system you will be able to stick with these. In my next article I will recommend specific components, but in this article I just want to give a basic overview of what to look out for.

FPV Camera
Most people use a CCTV camera for FPV, mostly because they are lightweight, inexpensive and have good light handling abilities and because they output an analogue signal there is no video lag. You can of course use other cameras such as the GoPro as the main FPV camera, but the wide angle lens makes it very difficult for proximity flying and there is a slight lag in the video output. On the subject of lenses, it's good to pick a lens that gives you a natural field of view and somewhere around 3-6mm seems to be the most popular with many pilots and most FPV cameras come with a 3.6mm lens. Not all cameras are created equal, so a few key features to look out for are WDR (Wide Dynamic Range) and Pixim cameras offer really great performance. With the analogue video transmitters that we use for FPV, the maximum resolution that they can transmit is 480 TV lines, so even if a camera is described as being 700 TV lines high definition, what we receive will still only be standard definition.

FPV Transmitter & Receiver (often written as Vtx & Vrx)
A few years ago the only solution was using adapted CCTV surveillance devices for FPV use, but nowadays there are dedicated FPV retailers that stock FPV equipment that has been tried and tested for our use, so it is no longer as much of a guessing game when it comes to finding a good package. Don't be tempted to try and get  a cheap set from one of the many wholesale sites like dealextreme as it can be really hit and miss as to whether you get a good set or not. Transmitters that come with a built in voltage regulator are great, because they allow you to connect them directly to the main flight battery without the need of a power filter. For the receiver, look for the advertised sensitivity as this can make a massive difference to your range. As dBm is a logarithmic scale, a change of 3dBm equates to a doubling in range, so a receiver with a sensitivity of -85dBm will have half the range of a receiver with a sensitivity of one with -88dBm.

Note: Never power the transmitter without the antenna attached as you will burn it out and keep an eye on the temperature of the transmitter when doing any ground tests as they can get quite hot without the cooling air that it would get in the air.

Video Goggles, Screen or Laptop
Personally, I feel that to get a truly immersive experience then video goggles are the only option. For your initial FPV setup, this will probably be the single biggest investment so it's important to get a good set as this really makes a big difference to the enjoyment of the whole FPV experience. Most FPV goggles at the moment come with a resolution of 640x480 and I wouldn't recommend going for the lower resolution goggles that are available. Some have built in video receivers, which are great if you just want to go for a quick flight, but I've found that the built-in receivers aren't as sensitive and you have to check that they are compatible with your video transmitter (more on this later). Nice features to have are adjustable IPD (inter pupil distance) the ability to wear glasses with them and good light blocking to make it possible to fly on a sunny day.

A cheaper option is to use a video screen that accepts a composite input or even a PC monitor using a composite to VGA adapter. The important feature for screens, apart from running off 12 volts is that they don't do the 'blue/black screen of death'. This feature is common on many screens and instead of displaying static when the video sync signal is lost, they go to a blue or black standby screen which can take several seconds to recover from. Again, try to find a screen that has a resolution of at least 640x480 to make it a more enjoyable experience.

The third option is to try and use your Laptop as an FPV monitor. This has the added benefit of also being to act as a ground recorder to record your flights. There are however 2 big issues that I have with using a Laptop, the first being that you have to find a suitable converter such as easycap and secondly you have to rely on your computer not suddenly crashing. If you can manage to get easycap to work on your computer (lots of problems with driver compatibility) then a good program that allows recording and full screen live video is virtualDUB. You need a pretty powerful computer for this though. Don't forget to turn off any screensaver or auto shut-down and turn your wi-fi off or it could affect your video if flying on 2.4GHz.

Antennas
This is an area that can be a total minefield for newbies and if you don't pick a good combination for the transmitter and receiver then your range is going to be very limited. First you have to make sure that you choose an antenna that is designed for your chosen frequency and you can't use a 5.8GHz antenna on a 1.2GHz system or vice-versa. One thing that absolutely doesn't work is high gain omni antennas, so avoid these like the plague. The current trend is to use circular polarised antennas and these have proven to be a bit of a revelation, especially at 5.8GHz. A 3 lobe Skew Planar Wheel (SPW) antenna on the transmitter coupled with either a 4 lobe Clover Leaf (CL) or a higher gain Helical antenna on the receiver works amazingly well.

Compatibility
I mentioned earlier on about compatibility issues between different brands of equipment and just want to expand on this a bit more. Some brands of FPV equipment use airwave modules and others use skyRF modules, which although work on the same frequency band actually use different frequencies within the band. If you don't purchase the receiver and transmitter as a package, make sure that the frequencies match, even if they're the same brand. The other thing that may cause problems is the antenna connectors and you need to make sure you get the correct connector for your Vtx/Vrx as it is sometimes possible to mate the wrong types and the centre pin won't actually be mating.

In my next article I'm going to be doing a 'What to buy' article where I will look at the pros and cons of various components, make recommendations of what to purchase and provide a list of quality FPV retailers.






Wednesday 17 October 2012

News! GoPro 3 announced.



Exciting news today as GoPro announce the Hero 3 camera. It will be available in 3 different options, White, Silver and Black priced at $199, $299 and $399 respectively. The Black edition looks to be the most promising, with improved low light performance, 12MP 30fps burst and 2.7kp@30fps! It also features built in wi-fi and comes with a wi-fi remote control and claims to be 25% lighter and 30% smaller than previous models. Let's just hope that they kept the live video out!!!


The sample video looks amazing!

Monday 15 October 2012

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?


Sunday 14 October 2012

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.












Friday 12 October 2012

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.

Wednesday 10 October 2012

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.


Tuesday 9 October 2012

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.

Friday 5 October 2012

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...