I've been a long time DIY Droner right back to the APM 1, mainly on fixed wing platforms but more recently quad-copters.

There is surprisingly little info and discussion on DIY Drones about the 3dr Solo, despite the fact that it is ripe for hacking and modding.

The Solo launched with quite a few issues and the actual release was less than stellar so many of the initial reviews out there are somewhat patchy. Most of the reviews are also from people with no experience of DIY droning so there is very little evaluation of its modding potential.

I wanted to take the time for myself to evaluate the Solo trying to look at it from a consumer point of view but also keeping an eye on how good it will be for modding and hacking.

I plan on doing a series of further videos to explore how far you can go with the Solo to spec it up and improve it from stock with as little money as possible.

Last week I was privileged enough to be invited to fly over Stonehenge Aotearoa, a modern day full scale adaptation of the original Stonehenge.

This was a great opportunity to test out the new Spline waypoint functionality that is coming in the next release.

The footage was captured on a 3DR X8 + GoPro.

It is a combination of manual flying for the close up shots and spline waypoints for the further out footage.

Stonehenge Aotearoa is a fully functional Astronomical Structure including a gigantic clock and calendar.  In addition to demonstrating the changing altitude of the midday sun over the year, it also identifies the current date, the times of the solstices and equinoxes and the precise time of local noon. It also reveals things that we cannot see - the ever changing length of a day (due to the eccentricity of the Earth’s orbit) and, where the sun would be seen if you could view it from space - the constellation it would appear to be moving through.  It also identifies the time of solar conjunctions with bright stars.

Unlike the original, visitors are able to take guided tours through the structure and see it working.

With the recent addition of ADSB support in Mission Planner and the discussion about feeding data from a drone into a 'national feed' there has been much excitement about the possibilities in the future.

This video is a great explanation about the challenges we face with sense and avoid using existing technology and then also goes into some exciting research that the author Bruce Simpson is working on involving passive radar technology.

Bruce has been in the UAV game for a long time and while I am not affiliated with him in any way, his material and youtube reviews are very interesting.

There has been a lot of discussion recently over the FAA's approach to airspace integration.

A lot of people see the FAA as the enemy rather than as a partner.

I thought I would take the opportunity to share how the same problem that the USA is facing is being dealt with in New Zealand with far less angst, far more co-operation between parties and a better outcome for everyone.

New Zealand has exactly the same problem as the USA or really any country with air traffic. We have thousands of private and commercial aircraft flying around and a rapidly growing list of RPAS (here we call them Remotely Piloted Aircraft Systems, not drones) wanting to get up in the air.

In New Zealand, the Government has seen RPAS as a huge opportunity to develop and grow an export market and create a new high tech industry. The opportunities that RPAS offer our large agricultural and horticultural industries are significant. Not to mention Search and Rescue which costs the country dearly every year both in lost lives and financial expense.

Rather than squash the opportunity with regulation, the New Zealand Government wants to foster and grow it.

The Government has created an entity called Callaghan Innovation and its sole purpose is to foster and support innovation in technology based New Zealand companies. In partnership with researchers at our Universities, this organisation helps turn ideas into reality by cutting legislative red tape and connecting the people with the ideas to capital, resources and the rule makers.

In New Zealand we have two organisations that manage our air space. The CAA (Civil Aviation Authority) is the equivalent of the FAA and creates the regulations.

Airways Corporation is a Government owned, for profit 'company' that manages all air traffic (our ATC network) for the whole country.

We also have a relatively new organisation called UAVNZ. This group consists of UAV manufacturers, commercial UAV operators, military representatives and private citizens interested in flying UAV’s for recreation. Importantly, Callaghan Innovation is one of the driving forces of UAVNZ. It is free for anyone to join UAVNZ but they plan on offering additional paid services in the future.

All these parties have come together to create www.airshare.co.nz. The purpose is to develop industry guidelines in conjunction with the CAA and to organise trade shows and symposiums where all the parties can develop an integration plan together.

One of the most exciting developments is that UAVNZ is working on an interface into Airways Corporation via its website that will allow any member  (for a small fee) to be able to register their UAV flight plan with Airways Corporation. This will cause that airspace to be shut down for the duration of the RPAS flight, notifying all commercial and private aircraft to avoid the area. This will allow an operator (whether commercial, recreational or for research) to fly above the 400ft cap that is currently in place and potentially beyond line of site without having to jump through too many hoops.

In New Zealand, the CAA allows commercial operation of RPAS. There are not too many specific rules at present, however an operator should demonstrate they have a suitable level of processes and procedures in place to ensure safe operation and flights. In the future the CAA aims to better define what is required to achieve the right to operate commercially and this is being worked on in partnership with airshare.

You can currently fly a UAV in NZ without too many restrictions, so long as it is kept line of site, below 400ft and weighs less than 25kg. One off exemptions are given to fly above this altitude and beyond line of site, either by special application or by activating one of the designated UAV Danger Zones. The aim is to reduce the red tape and simplify the process of these sorts of operations.

In the future, it seems highly likely that an approved operator will be able to fly almost anywhere by registering their flight plan with Airways Corporation.
At the same time, researchers are working on what would be required (think transponders) to fully integrate RPAS into the NZ airspace.

I was at a meeting the other week for something unrelated to RPAS and it was really refreshing to hear someone from CAA talk about the huge opportunity for RPAS and how they are keen to foster growth in the industry by making the integration process simple and safe.

The FAA could learn a lot from this approach and likewise those in the USA faced with crippling rules and legislation could also learn from a partnership based approach.

We live in exciting times and with the right regulatory framework the possibilities for RPAS are limitless.

A lot of people have bought the RTF 3DR Iris as there is a plethora of info out there on both performance and modifications.

The X8 is the heavy lifting RTF option and is a little less common.

I've been an Arduplane fan for about 3 years now, starting with the APM 1 in a Skyfun and working my way up to an APM 2.6 in a Skywalker X8 complete with Cellular Telemetry over 3G.

I've never been into copters as much but I thought it was about time I checked out what all the buzz was about and share my experience here.

I bought a cheap quad online for $100 with the intention of learning to fly quads and wrecking a cheap one before letting loose on something a little more expensive.
After getting to the point where I could just about turn the thing inside out, I thought it was about time to upgrade.

I did a lot of research on the DJI vs 3DR and then looked at the Iris.
My thinking was that the Iris is a nice toy but its not really worked up for doing anything too serious, that left the Y6 or the X8 and I eventually decided to go all out and order myself an X8.

I also needed new radio gear as my old Hitec radio was showing its age so I added in a D7 radio, full telemetry kit, spares and a Gimbal all from 3DR to support the cause.

It went on back order with around 2 weeks after ordering before it shipped which was acceptable.

Then the fun began with shipping. For some reason the shipment got held up in Memphis. I left it for a few days then made a call to fedex who weren't much help.

Next I dropped a line to 3DR to see if there was anything they could do and after about a day to respond they managed to work some magic and the package began moving again.

When the package finally arrived it had an "Opened by New Zealand Customs" sticker on it. This always makes me nervous as you half expect it won't get packed back in as well or that something would be damaged during the premature unboxing at customs.

Opening the box, I was a little surprised at the internal packaging, it wasn't exactly a stellar packing job given the journey that box had taken, however there is no way of knowing whether this was the way it was packed by 3DR or whether the re-pack at customs was less than stellar.

However the good news was that nothing was obviously broken and the copter itself was placed in such a way to minimize the chance of any breakages.

 The X8 itself had foam protecting the motors, plastic wrap over all aluminium parts to avoid scratches and one leg was folded in to maximize the space available in the packaging.

The first thing that strikes you about the copter is its size and weight. This is not a toy and everything is constructed with heavy duty components while minimizing weight.

The second thing that strikes you is the fact that if this thing goes down, due to its weight its going to be a write off.

Extreme care will be the order of the day when flying it. Its certainly no acrobatic machine and you can see how its size and weight lend itself perfectly as a camera ship.

There are also some nice touches that make it a true RTF option for someone who doesn't have the build capability to put together their own ship. The LiPo Guard pouch for charging the batteries is a great idea and the included charger while towards the bottom of the quality range is more than adequate for most needs.

One thing that becomes apparent once you have everything laid out is the lack of things to actually put together. 3DR advertise this as a RTF kit which I was skeptical about and was expecting to spend at least a day building it, however it really is ready to fly with only minor assembly.

Nevertheless I took the time to check over the entire unit, tightening screws, applying loctite and double checking everything.

Connecting it to the mission planner was straight forward, and all the settings were dialed in and ready to go for the airframe. A firmware update was needed to bring it up to the latest version and because I am new to Pixhawk I had some head scratching before I discovered you need to press the safety button when loading firmware.

I decided to fly it without the Gimbal initially in case there were any mishaps.

So how did it fly...

Well pretty much perfectly.

Stabilize was as solid as a rock. I fully expected to spend the entire first flight battling to keep control of it while modifying PIDs, but it gently lifted off the ground and sat in the air perfectly stable.

Flicking it into Alt Hold mode yielded similarly successful results. I took it for a wee spin to test its responsiveness and was impressed by how rock solid this ship is.

I was feeling so confident about its performance so far I did a quick double check that it had GPS lock and then dropped it into Loiter and there it sat.

Since then I have dumped about 6 batteries through it and I continue to be impressed.

Next step was to add the gimble and take it for a spin with a GoPro.

This has been the hardest part of the whole process, tuning up the Tarot Gimbal can be quite a challenge and a novice would certainly struggle with it. It took me about 2 hours to get a nice smooth config. The settings I needed turned out to be completely different from some of the configs posted on the internet, however once its setup it really is a nice Gimbal.
I will post some shots from the GoPro once I take the X8 for a flight with the Gimbal attached.

In summary, the 3DR X8 2014 edition is a rock solid camera platform suitable for professional use.

It really is RTF but I would not recommend it to someone who has no experience either flying or with the APM. There are simply too many things one could get wrong that could dump this air-frame into the dirt.

This is the perfect system for someone that:

• Already has experience flying an APM or Pixhawk based plane or copter
• Doesn't have the time required to put together a large X8 copter or doesn't have experience building models.
• Wants a heavy duty camera platform

Hats off to everyone at 3DR, you continue to improve with leaps and bounds and credit where credit is due, the X8 is a formidable piece of machinery.

I like devices that have multiple purposes. My theory is that if I am going to load up my UAS with electronics that it may as well be electronics capable of performing multiple tasks.

For those that have seen my posts on Telemetry over 3G, you would know I am a fan of the Fatbox 3G router for Telemetry over cellular networks.
Its a small, compact device with two Ethernet ports which means I can easily add in Video over 3G later for a super long range UAS. For the same weight or less than a custom hack, I get a device capable of delivering two completely different tasks. Best of all, it works out of the box with no tinkering or software development required.

In the same regard, the problem of how to locate a lost model has been something I have long looked for a 'multi-tool' solution for. Especially if I'm looking at a really long range platform.

After looking at the options, I determined that a smartphone with a prepaid SIM actually makes a great 'lost model' location device. Simply activate the "Find my iPhone" mode and you can find it in no time.

As a byproduct, you are putting a fairly capable device in the air, so I set about looking at what else could be done with an iPhone on a UAS. Aside from the obvious task of taking video, it turns out that the iPhone geotags any photos it takes. You can then use the geotags to create 3D models.

They aren't the greatest quality or accuracy compared to doing it properly with expensive gear, but its a fun / cheap way of dipping your toes into 3D models without breaking the bank.

You will need to mount your iPhone on your aerial platform on a slight angle for the best results, then download one of the many cheap or free apps that allow you to take a snapshot every X seconds.

I used the free Hyper3d service to process my images, but there are quite a few options on that front now.

Obviously, an iPhone is an expensive bit of gear to have hurling around in a UAS and you wouldn't want it to get broken in a big crash. This is why I bought a 'pre-broken' iPhone off Ebay for $20.

The reality is that you are not going to be using this thing to make calls or surf the web, so the condition of the screen is almost irrelevant. iPhones work perfectly fine with a smashed screen and if you do have a big crash then there is nothing more to break on it. All you need to be able to do is turn it on and make it start taking photos.

In terms of the quality, with a bit of practice you can get fairly good results.
Certainly good enough to make your Grandmother go... Thats pretty cool.

Now, if I could only figure out how to use the iPhone to deliver 3G telemetry, then I could get rid of another device.

Way back in December last year, I put up this post which showed me ground testing 3g Telemetry.

Since then I've been very busy with other projects and only got back around to looking at 3g Telemetry last month.
I bought the new Skywalker X8 platform as the Hugin in the above post just was not strong enough to cope with AP duties.
The X8 is the perfect APM platform, I really can't rate it highly enough. It has mountains of space, can easily carry a 2kg payload and I'm getting flight durations of in excess of 1 hour and 20 minutes with 10Ah of lipo's on board.

I'm a fan of keeping things simple so only having 2 servo's on board increases reliability. About the only down side (which is actually an upside for me) is that it has an insane glide ratio, this makes landings slightly challenging, however it does help achieve the long flight times. Some X8 users have already added parachutes, however I tend to enjoy the challenge of bringing her down incident free.

I've flown around 20 flights now on 3g Telemetry and it works really well, I've had less trouble with it than the usual point to point radios and the range is well.... practically limitless. Not to mention the simplicity of my ground station setup, no antennas and nothing else to cart around other than my laptop and phone.

A lot of people commented in the previous post that I would not get great altitude, my testing has revealed I can go very high (thousands of feet) and still have plenty of signal. My longest flight has been 45km, which tested hand-off between cell towers which is also seamless.

The great thing about the fatbox is that its plug and play, it has built in dynamic DNS so you don't need to know the IP address you are allocated.

Data usage averages around 7mb for a 1 hour flight.

If you are keen on doing this yourself, make sure you join the group "Telemetry over cellular IP" some users are making some great progress on code that allows cheap 3g modules to be plugged directly into the APM.

Also take the time to read my previous post here which covers off the important topic of cellular APN's and how to make sure you get your SIM cards configured correctly to allow a direct non-fire walled connection to the internet.

Its now been a whole year since I got addicted to the crazy hobby of Autopilots.

What a wild ride!!!

There has been some fantastic moments and some of total frustration, but it has been an exciting and rewarding journey.
There are a lot of people who ask about getting into the hobby and have somewhat ambitious ideas about building a drone to do X and Y before they have even completed their first flight.
This is a short video compiled from some of my mishaps over the last year that hopefully helps show those considering getting into the hobby why it is an extremely good idea to start small and cheap and gradually work your way up to more ambitious goals.

When I started, I was a relatively competent RC pilot. All of the crashes and incidents in this footage have arisen from me making stupid mistakes on the Autopilot side.

By setting the wrong waypoints and RTL'ing straight into a tree, by setting my altitude wrong, by trying to do PID tuning while in the Air, by putting too much weight on a plane and it not getting off the ground and hitting a tree etc etc.

All in all, the crashes when compared to the number of great flights have been relatively few, looking back at the log I've kept, I've flown 165 individual flights in the last year, with a combined total of 95 hours in the air.

These have primarily been logged on one of the 3 SkyFuns I have built and destroyed in that time.

The first one only lasted 5 flights, the next one I got 36 flights out of and the last one is still going strong.

I've now progressed onto a composite FPV168 and also a Hugin (which you can see being destroyed in the last clip with too much weight to get off the ground).

Over the next year, I'm planning to get the new Skywalker X8 and perfect Telemetry and video over a cellular link which I have been experimenting with more recently.

Best of luck to you all, and hopefully this video serves as a lesson in what to avoid doing and saves you the time / expense yourself.

I think its time for a new DIY Drones contest which I would like to propose.
The T3 is fun, but it doesn't have any real point other than the winner gets some bragging rights.
At the end of the day, speed is not the goal for most of us so a competition that measuers speed yields no useful information that helps us move forward as a group.

The contest I would like to proprose is an ongoing endurance contest, instead of running over a timeframe, it is continuous and reviewed weekly so that the leaderboard shows who currently has the greatest endurance on each given platform. (Lets stick to commercially available models not custom built ones).

As part of the contest you would submit information such as prop size, battery capacity, cell count, model, weight and payload details etc.
The benefit of this is that we would be able to tabulate the results and publish a document showing the endurance relationship to weight and battery capacity for every type of model that is commonly flown.

That would save us all a LOT of messing around and would be a golden resource for newcomers, even the FPV community could benefit from the data we can extract from an Autopilot.
For each model eg Skywalker, Bixler, Skyfun etc we would be able to publish recommended motors, prop and battery for maximum endurance.

This would also be an excellent resource for people who are trying to choose the right platform.
For example, if you know you need to lift 500 grams of payload then you can find out which model is going to be able to do that with the longest endurance. It would even give you the battery, motor and prop choice in order to achieve your goal.

This information is basic stuff that almost all of us struggle with and can end up costing a lot of money through trial and error trying to figure out. My thinking is that the hardware and software are open source, yet our own individual knowlege is not collated very well, you have to read through thousands of conflicting forum posts to try and put it together yourself. If we all worked together and shared the information we learn daily, then it will make it easier for all of us and we would have some scientific measures behind a lot of the 'opinions' that go into current recommendations. Just as important as the sucessful combinations are the failed ones as these can act as "don't do this" examples for newcomers. These aren't captured anywhere at the moment.

You can also use the data to benchmark changes you make to your own platform, if we have a standardised way of measuring endurance, then instead of just saying "I got 35 minutes" in a post, you can actually measure your real relative performance to other setups, then measure the increase or decrease in performance when a change is made to one of the variables.

The other benefit of this is that it will also push manufacturers to consider efficiency more as they try and get their products into the leaderboard, especially on the airframe front.

I am happy to co-ordinate it and get it off the ground if there is support from the leaders here at DIY Drones.
I can build something to collate and deseminate the data and perhaps later on down the track we could webify it so it is fairly automated.

The key thing where I might need some help is measuring the endurance from a log file in a way that is fair and ideally automated.

I forsee the goal would be something like...

- Launch
- Fly at the slowest speed possible without stalling in Auto mode
- Loiter over a target with 100m radius until your battery cuts out
- Land

Details to be accurately recorded in order to have a valid entry:

So what do you all think? 

You may have seen my earlier post "Releasing the Shackles - How far do you want to go"about doing long range APM telemetry over cellular links. For the last 4 weeks I have been testing and have finally cracked the nut. Read on for details..

Amplified Engineering in Australia produce 3 potentially useful products

• Fatbox GPRSV2 - Serial Router with  GPRS (850/900/1800/1900) - 85kbps (Dual SIM)
• Fatbox 3G HSDPA - Serial Router with HSDPA (850/1900/2100) WCDMA and UMTS - 3.6Mbps down 384kbps up
• Fatbox HSUPA - Serial Router with HSUPA (850/900/1900/2100) WCDMA and UMTS - 7.2Mbps down 5.6Mbps up

The Fatbox is a heavy beast at 400+ grams. Removing it from its rugged steel case is straightforward and reduces the weight to ~120 grams. I ended up halving the case and using the bottom half as the mounting bracket in my plane.

Getting the Fatbox working on a network is fairly easy. You plug it into your LAN and configure it via its built in web server. There are all the standard settings you need to connect to any compatible cell network.

The most important thing is choosing the APN, by default most cellphones are setup to use an APN that is behind a firewall. A firewall prevents anyone from connecting to the device from the internet which is what you want for your cellphone, but not what you want for telemetry.

Here in NZ the default APN on most phones is internet.telecom.co.nz however if you call the Telco and ask for the details of a non-firewalled APN, they will tell you to use direct.telecom.co.nz. The same thing works on the vodafone network, you just use direct.vodafone.net.nz instead of internet.vodafone.net.nz. It might take a few calls and escalations before you can talk to someone who knows what they are talking about and what you want to do. You might also need to have the APN added to your SIM card depending on the provider.

If you use the right APN, you will get a public IP address that is fully routable on all ports. Perfect for Telemetry. It is my understanding that every carrier in the world has non firewalled APN's you just need to ask nicely to find out the details or do a quick google search. This costs nothing extra and although it doesn't give you a fixed IP address the address you get is fully routable and not firewalled so you can connect to it from any other computer on the internet with no restrictions. The fatbox has a built in Dynamic DNS client, so as soon as it is connected, it can update a DNS alias to point to its current dynamic IP address. This means you can register a DynDNS name such as myplane.dyndns.organd then connect to it without needing to know the IP address. If your fatbox drops its connection, as soon as it comes back up, it will get a new IP address and register it with DynDNS to allow you to continue operating (other dynamic DNS providers are supported).

This works in practice as well as it does in theory. After a power cycle, I was able to connect to my fatbox over the internet after around 12 seconds.

The next challenge was getting the serial port to talk to the APM. This turned out to be a little trickier than I expected.
I ordered a Sparkfun TTL level shifter but because of the way these work (voltage stealing), it didn't work at all. There were lots of dropped packets and CRC errors. I ended up ordering a Solarbotics DTE which I did get working reliably.

I connected the Fatbox up to the APM via the DTE converter, configured the Fatbox serial port to 57k and exposed the serial port as a server on TCP port 5760. Then I loaded up APM planner and changed the drop down list from the serial port to TCP. The host name is your DNS name (or the IP address if you know it) ie myplane.dyndns.org. The port stays the same at 5760.

It connected and I was able to do everything in the Mission Planner that you can normally do. Set waypoints, configure the APM etc.... I had to double check there were no cables in the line as I couldn't believe how well it worked - Woohooo.

On to even greater things...

The Fatbox also has two ethernet ports which can be routed at the same time as the serial port. I was interested in using one of the Ethernet ports for a Pan/Tilt/Zoom IP camera to give me unlimited range video (now you can see why I ordered the HSUPA version of the fatbox).

I configured the second ethernet port as a DMZ and then opened pinholes in the Fatboxes firewall so that all the IP camera ports were exposed to the Fatboxes internet facing interface. I tried it with a Vivotek PZ6122 which is a great little camera (that is no longer made), it weighs 300 grams, has Pan, Tilt and 10 x Optical Zoom. Its hard to find a high quality PTZ IP camera in a lightweight package but this fits the bill nicely and I picked it up for a steal on ebay. This camera also works in low light and automatically changes to black and white in low light conditions. I reduced the framerate down to 15fps and set it to a fairly low bandwidth setting and it worked very smoothly over the cell link.

Now I have it all working on the ground, the next step is to get it airborne and see what sort of altitude I can get before I lose cell link. I'm fairly confident it will go to 400ft which is as high as I can legally go anyway, but more importantly, I'm hoping to get some very good range out of it. With the combination of high mountains we have here in NZ (which forces Telco's to be able to operate at altitude) dual antennas on the plane (with short cables) and the high bandwidth of the fatbox, it should be able to go significantly higher than 400ft. NZ has outstanding cell coverage so this should allow me to fly long range missions just about anywhere in the country. The Hugin airframe can lift a lot of weight so I should be able to load it up with 15,000mAh of 4S batteries for a 90 to 120 minute endurance depending on speed.

I am talking to the manufacturer of the Fatbox about maybe putting in an order for a few of these and customizing them for DIY drones use. The customized version would come without a case and have direct TTY level outputs to save messing around with a serial converter. Let me know how many people might be interested in this to see if it is worth the time.

My next post will be to report the success of the first cellular flight.

I'm also really keen to find a trustworthy person to try controling the plane from overseas once I have everything working properly, a pilot could operate it via the APM planner and see what is happening over the internet using the onboard camera. It seems like something that just has to be done!!

Since I got into building my own drones I have been fascinated with the prospect of extremely long range drones that are not restricted by the limits of point to point wireless technology.

The public cell network seems like the perfect solution for long range drones as it covers most countries and now supports extremely high bandwith.
I've done some experimenting with the dronecell and various other options but they have all missed the mark somewhat in some way.

I stumbled across this solution the other day and it seems like the perfect solution for larger very long range drones.
The FATBOX GPRS2 is a wireless DTU with a few extra bits of trickery that lend it as the perfect long range solution for our needs.

• Serial port - The serial port can be interfaced to the APM mavlink port (the same one used by the XBee) with the simple addition of a TTL level converter.
• Dynamic DNS - it has a built in Dynamic DNS client, this means when you turn it on, it automatically connects to the internet via the builtin GPRS modem and registers its IP address with a DDNS provider. This means you can simply type in the DNS name into the mission planner to connect to the APM without needing to know the IP address.
• Transparent - unlike most GPRS modems, the Fatbox can be setup to be a transparent serial router. When you turn it on, it exposes the serial port over UDP on its IP interface. As the APM mission planner supports UDP, it should be plug and play.
• Dual SIM - if coverage is an issue, you can insert two SIMs from different providers, if it loses its connection, it will automatically connect with the other SIM and register its new address with DDNS. You will get a brief dropout on your APM planner but can then just reconnect.
• Ethernet interface - this is the kicker for me, it has a built in ethernet interface that can be used at the same time as the serial port. This opens the door for video or any other ethernet based device you might want to add to your drone. You could also add a wifi link for redundancy and access the serial port via wifi and fall back to GPRS if you go out of range.

The only downside is that out of the box it weights 420 grams.

It comes in a steel case and the board itself only weigh 120 grams so I am going to look at other case options or perhaps just fly it naked.

Mine should be here soon so watch this space for the results of my testing.

* note: In some countries, by default your SIM card is on a firewalled APN which means you can't contact the IP address over the internet. This is usually just a case of ringing your provider and asking for the name of a non firewalled APN.

I like to spend my time in the field actually flying and not spending hours plugging things in.

Here is the latest upgrade to my Ground Station which provides a single wire from my antenna to my laptop.

All I need to take to fly is the antenna, laptop, plane and an XBox controller.

A single USB cable goes from the laptop into the case on the back of my XBee Patch antenna.

This cable goes into a USB hub.

Plugged into the Hub is:

• Xbee for Telemetry
• XBox 360 PC interface which turns an XBox controller into a wireless joystick.
• WinTV usb capture dongle

Also in the case are my 5.8 Ghz Video RX. I have put the antenna connector on the outside of the case so I can either use a small rubber duck antenna or connect it to my 5.8Ghz patch antenna which also fits on the stand with a short extension cable.

The Video RX outputs to the USB capture card which sends live images over the same USB cable as Telemetry to my APM planner where I overlay the picture.

There is a 2200mAh LiPo which provides power to the video RX. So I don't have to keep opening the case, there is a charger inside the case with a power input on the outside so I simply plug in a power pack to charge it up, or connect it to a power cable I have in my car.

The second photo shows it with the antenna on and you can see the power switch for the Video RX.

The stand it is mounted on is an aluminium commercial speaker stand so it is light, extremely durable and folds up very compactly to sit on the back seat of my car.

On the other side, you can see the long USB cable that enters the side of the case and runs to my Laptop. The Video RX charging connector is underneath.

The tray holds my notebook so that I can use the mouse while holding my plane.

The 900Mhz patch antenna is 14dBi so you don't have to point it directly at the plane unless you are on a long distance mission. The whole center piece swivals and the patch antenna also tilts up and down for more precise alignment.

This setup is for my new Ritewing Zephyr which has almost finished construction. Once its done I'll post pics of it and hopefully I'll get around to making a video of the whole system in operation.

Below you can see the GS being used in the field prior to the latest upgrade (shows the laptop stand in action).

Thanks to Michael for adding Elevon mixing to the Joystick control in the APM planner. That was the final piece of the puzzle to getting this up and running.

I have recently been pushing the limits of the XBee Pro to see how far it can go.
Unfortunately my current plane (SkyFun) only has a 38 minute duration and a maximum travel distance of 20km, this means the furtherst I have been able to go is 10Km (a 20Km return trip).
I have a 14dB patch antenna which has still shown signal of 85%+ out at this distance.

I wanted to find out how far the XBee could really go.
This meant planning a one way mission.

I spent about a week looking for the perfect start and destination, plotting the course and arranging access to the landing location with a local farmer.

The start point was my normal local park and the landing location was a farm paddock 16Km away.
The flight was over sparsely populated farm land and at a constant incline meaning I could increase altitude during the flight in order to get greater range.

My plan was to launch and monitor the flight from the launch location until I lost contact with the plane via Telemetry. After this I would drive to the landing location where the plane would be circling and manually land.

I calculated that even if I maintained contact with my plane during the flight and it made it all the way that I would still have time to make the 12 minute drive without running out of battery power.
With a tail wind, the plane would average 60Km/h at 45% throttle.

With everything planned and 45 test flights already in the bag with this airframe I was ready.

I launched and the plane took off to the waypoint as planned.
I was hoping for at least 12Km as this was ideal conditions.
The point on the map above shows the point I lost contact which is 10.6Km from the launch location.
The XBee maintained a very strong signal up until the last Km and then it began to drop off very rapidly.
It begins to be unusable below about 40%.

I packed up the ground station and drove to the destination which took just 11 minutes.
The plane was circling perfectly as expected and I put it in FBWA and landed without incident (apart from the slightly startled flock of sheep).

It turns out that the 10Km I had been flying to is around the maximum range of an XBee.

I am working on a much bigger aircraft that will have a 1 hour plus duration at a higher speed so I am going to have to look into more long range options for telemetry. GPRS / cell is preferable as we have excellent coverage here and fully routable and cheap internet plans. However, for experimentation I have been surprised at the distances that can be achieved with an XBee with a cheap patch antenna added on.

Here are a couple of tips for people wanting to achieve maximum range..

 - Minimize antenna cable length. My XBee is mounted on the back of my patch antenna and I run a long USB to my laptop. This maximizes gain and reduces lost signal.
 - I use either the ground or my car to enhance the ground plane effect. Putting the antenna in front of my car door or right beside my car makes a big difference to the distance. Also keeping it as close to the ground as possible.
 - Altitude is king, the higher you can fly the greater the achievable distance. Due to the fact my destination was on an incline, my end waypoint was 400m high relative to my starting point.
- Fly long straight missions so you can line up your antenna properly, I am building an antenna tracker that removes the need for this but Ardustation2 is currently broken since the last Mavlink updates.

The stock skyfun platform is pretty good, but as a lot of people have pointed out, the power system is barely enough for our needs by the time you add a few goodies on.
There is lots of info on the web about motor upgrades for the Skyfun but most of the motor upgrades published on the net are all about speed. I wanted my Skyfun to have enough power to lift all the extra weight, but then to be able to settle down to a slow and efficient cruise speed to maximise the amount of time in the air. That means means going for a slow turning large prop. Finding info on this sort of upgrade is next to impossible. 

Lets start with the airframe:

I took a stock RTF Skyfun, removed all those hideous decals and then set about applying Gaffa tape to all of the vulnerable surfaces. This has already proven its worth during my initial testing as I had a high speed collision with a power poll with practically no damage. Gaffa is quite heavy, but it is incredibly strong and prevents the foam from tearing. Applying it to any part of the airframe where torn foam is possible reduces damage considerably. The tape can then be removed and easily replaced after an 'incident'..

After multiple failed canopy gluing attemps, I have also applied a thin strip of Gaffa tape around the edge of the canopy to keep the plastic on, which has proven effective. The canopy now feels very sturdy.

I'm using the stock servos, they seem fine for the task as it is not going to be a high speed machine.
RC equipment was upgraded to a 9ch JR PCM system.

Mounted just behind the receiver is a keyring video camera, I set it into a hole in the fuse at a 45 degree angle. This gives a great view and has the advantage of being closer to the CG for maximum stability and does not result in any part of the aircraft obscuring the picture.
I chose to mount the camera upside down so that the USB cable can be inserted into the camera (from the bottom) without needing to dismount the camera, it also allows easy access to the camera controls. The downside is that the image is upside down, but this can easily be flipped on a PC later.

I spent a lot of time on motor research and determined I needed the biggest prop I could spin at the slowest speed possible in order to gain maximum thrust and low speed efficiency. I settled on a Rimfire 400. Specs are below..

Model: RimFire 400 (GPMG4560)
Diameter: 28mm (1.1in)
Length: 30mm (1.2in)
kV 950
Constant Watts: 160w
Burst Watts: 220w
Weight: 54g (1.9oz)
Shaft: 3mm (0.12in)
Voltage: 2-3S LiPo
Airframe: Up to 1kg
ESC: 25 Amp
Prop: 8x6 to 10x4.5(slow fly)

I decided to run with a 10x4.5 slow fly prop, however a prop this big is wider than the distance between the two vertical stabilizers. This requires reversing the motor, pushing the shaft through to the opposite end and drilling some holes in the motor mount in order to attach the motor to the back of the mount. Doing so clears the back of the stabilisers by 8mm.

Next came the battery, I wanted to be able to cruise for at least 30 minutes and my rough calculations indicated this would require at least a 3000mAh battery. I settled on a DN 3300 30C pack. In my first few flights with this I have achieved 35 minutes and 37 minutes respectively without much consideration for efficiency. I think this can be extended further by reducing airspeed.

A battery pack this large would normally have to be seated well towards the back of the cockpit, this would have meant mounting the APM in front of the battery, something I really wasn't too keen to do. A battery this big in a crash would completely destroy anything in front of it (APM). My camera, receiver and APM were already consuming most of the back of the cockpit and putting a battery this large at the front of the plane shifted the CG too far forward.

I opted for belly mounting the battery, bomb style. This proved to be very useful as it allowed the CG to be easily shifted by quite large amounts without running into any obstacles. It also keeps the CG very low which has improved stability noticeably. It now flies more like a high wing trainer.

At the moment it is being held by industrial Velcro, however my next upgrade is to install a Velcro strap through the fuse for additional safety.

The only downside is that it exposes the battery, particularly on hard landings. I couldn't see an easy way around this that would maintain CG flexibility and didn't add a lot more weight, so I opted for sponge foam with gaffa tape over it along the bottom of the battery. I will review this after a few more flights to see how it goes but so far if I'm careful with landings its fine. If it looks like the battery is wearing too hard, then I will add some more rigid protection. Long term I will probably build some form of capsule underneath for at least the front of the battery to slot into. Most of my landings are in long grass so isn't an issue. 

Total weight including the battery is now 900 grams which is under my target of 1kg. I have yet to measure the thrust from the motor, but at full throttle it achieves a slow vertical climb so it must be slightly higher than 900 grams.

The next step is establishing the slowest speed I can possibly fly so I can figure out how long I can stay in the air for. I would be very happy if I could get it closer to a 45 minute flight.

I've been spending a lot of time over the last few weeks trying to figure out the optimum battery, motor and prop configurations in my skyfun to provide the maximum range and endurance options. Operating on a limited budget, I've been trying to avoid trial and error and make the right choices based on specs.

This is not easy but I've settled on a lower kv motor than many have chosen, running a larger prop with a 3300Mah 3s battery at only 20C (lower C batteries weigh less). The motor I've chosen is a Scorpion II SII-2208, 1100kv, 130W, 45grams, 12Amps, 10 x 4.5 prop.
I'm still mulling over ESC choice.
The final choice was also based somewhat on easy availability in New Zealand (Turnigy is not widely stocked).

There are a lot of suggestions on this and other forums about motor and prop choice which is helpful but what is missing is a semi technical discussion about endurance, range and speed and how to maximize these on any given platform. In the commercial UAS and military worlds, range, endurance and speed can mean the difference between a useful platform and something that is useless. In general, many of the systems people are building here do not seem to be optimized and are achieving quite poor endurance and range.

In commercial aviation, the optimum cruise speed is not based on endurance or range but rather to minimise time. Airliners need to get to their destination in the minimum time while using the least amount of fuel possible so the optimum cruise speed is the speed that flies the fastest possible speed using the least possible fuel per hour.

UAS's are totally different, in general our missions are to fly to a destination, loiter over a target for as long as possible and then return. In this scenario, we need to maximise range for the first part of the journey and get there as efficiently as possible (minimum watts per mile). Once at the target we need to switch to an endurance mode and fly at the minimum speed possible to maximise the amount of time over the target. We then need to return home at a speed that maximises range again (this might alter if a payload is dropped).
Alternatively we might need three modes, in an emergency you might need to get to a target quickly (optimal cruise speed as per airliner), loiter for as long as possible (maximum endurance) and then return as efficiently as possible (maximum range).

I'm not much of a maths guru but using logic I figure the first and easiest step is determining the maximum endurance of an airframe which would be done by finding the minimum amount of thrust required to maintain level flight. At this point, power consumption is minimized and the endurance is maximised (while speed and range are sacrificed), this would have to assume that motor and ESC efficiency are linear (from what I have read brushless motors are more efficient in the medium power bands anyway).

At the other end of the spectrum is the maximum range which I'm a little less sure on how we calculate on a model. For this I figure we need to know about the drag characteristics of each airframe across the full range of speeds.
I also figure that to calculate the optimal cruise speed (max speed with minimal power as per airliner) we would also need to know about drag at different speeds.
Is there anyway the APM logs could be used to figure out useful drag measurements to calculate these speeds for our airframes?

Or, are these speeds the APM could actually calculate itself by performing an 'in flight calibration'?
You could define in the flight planner which portions of the journey should be for calibration and which for maximimum range, endurance or efficient speed.
The APM could then slowly adjust the crafts speed downward in the calibration phase to determine the minimum amount of power required to maintain altitude and store this as the loiter speed. It could then slowly increase the power and measure which power setting delivers the maximum range for input power and then the maximum speed that uses the least fuel per hour.

I realise that there is also windspeed which could affect these numbers, which might mean that the APM might always need to be in 'calibration mode' and once put into one of these modes, constantly optimize the power so as to deliver maximum range, endurance or minimum time depending on what you want.

Once my new motor arrives (my stock motor now barely maintains flight) I will do some testing and add to this post, but would be interested in others thoughts on this topic as there seems to be a severe lack of discussion on such a relevant topic to UAS.