I recently got a PX4FMU plus PX4IO board kit and I am installing it on my little DJI Flamewheel F330 that I had been using previously with my APM 2.

The F330 is a perfect candidate for this because it is an excellent and sturdy test bed.

It flew very well with my APM 2.

Previously I was using An Oring suspension mount on the 4 standoffs you can see in the photo above.

This time I decided to try mounting the PX4 stack on a thin fiberglass plate plate which is mounted on some 1/2" pads of Kyosho Zeal anti vibration gel. 

The PX4 stack is already pretty high so I thought I'd try this before using both the Zeal and the O-ring mount I had planned.

The Zeal Gel which comes with double sided tape on both sides is almost a quarter inch thick and it seems appropriately flexible and vibration absorbent in this application with the four 1/2" square pads.

The Accel readings will tell the tale.

Note that the inter board connector on the left is about 2mm  shy of closing. 

3DR supplies 8mm M3 standoffs and I think that 6 mm ones would work better, although their would be a slight interference fit at the other end of the board.

Notice all the stuff still hanging off of it.

The GPS, the arming switch, the buzzer and the battery power leads for the PX4's built in power supply.

Still have to figure out where to stick all this stuff on my little Flamewheel.

I have already installed the firmware and bench tested this PX4FMU plus PX4IO stack. 

The PX4 stack is upside down from normal spec, but it makes the connectors easier to get at and it is easy to do with the new Mission Planner adjustable Board Orientation parameter.

I will also be attempting to use one of the little 3DR Receiver servo to PPM-Sum out converters, so this promises to be an interesting adventure.

I will keep everybody posted and new pics as this build - test continues.

Please feel free to post comments and questions.

Upload Stable, Beta or Developer Firmware to your APM or PX4 for ArduCopter, ArduPlane and ArduRover.The ArduPilot Developers have put together a Great new site from which you can upload any version of Firmware Drivers to your APM or PX4 board(s).

The site is Here!: http://firmware.diydrones.com/

From this site you have access to Stable, Beta and Developer firmware builds.

Every type of ArduCopter, ArduPlane and ArduRover configuration is supported.

And the APM, the PX4FMU and the PX4FMU + PX4IO are all included.

The PX4 is here and soon it will have a fully supported version of ArduCopter:

From what I have been able to glean, Chris and Company are now in the process of revising this controller for better use by our group including an enclosure.

I Do not know for sure if they are planning on modifying the board itself but indications are that they are.

Now this is completely unsolicited by DIYDrones and may even be an annoyance to them, but there are some things I would like to see in there and I'll bet some of you would as well, so now is your chance to sound off before it becomes a fete acompli. 

Whether it will do any good or not I haven't got a clue.

An enclosure is good, but a internally vibration damped enclosure that was truly effective for reducing Accel vibrations to a fully tolerable level would be great.

Also, the existing PX4 pretty much requires that you use a PPM-Sum receiver with it.

PPM-Sum receivers are great, but only a few are available (Futaba and FR-Sky) not counting Graupner for obvious $$$$ reasons.

Personally I would like to use my plain old vanilla Hitec Aurora 9 and I think a lot of people would be a bit put off by having to upgrade their whole radio system because they didn't want to include a few extra RC inputs.

That's the 2 biggies I can think of, this is the place to put in your thoughts and we can see if anyone is listening.

This feedback is certainly unsolicited, I hope it is not also unwelcome.

I Have inserted the starting pass at a much needed section on Vibration Control in the ArduCopter Wiki and would very much like feedback for corrections or additions from you all.

This is  the close coupled mount that I use on my little F330 Flamewheel.

To achieve this plus and minus one tenth G vibration dampening.

In any case, please review the Vibration Control Wiki section under Assembly and give me some (constructive) feedback.

Thank You,

Gary McCray

Here is a picture of my little JVC Adixxion, replacement for my malfunctioning GoPro Black.

As you may know I published a BLOG of my experiences and trials and tribulations with the much vaunted GoPro Hero 3 Black.

Finally after much wasted time dealing with the GoPro Company sent it back for a refund I started searching for an alternative camera. I considered both the Sony Sport Cam and this little JVC Adixxion.

The Adixxion seemed much the better camera but was $350.00.

After Christmas I found an incredibly short lived deal for $99.00 and immediately purchased the Adixxion.

The overall experience with this camera for me has been the complete opposite of the experience I had dealing with the GoPro Camera and the GoPro Company.

Namely I am very happy with it. 

Likes:

Size and form factor are better than the GoPro and even more so when the GoPro has its case on it.

Has standard mount base screw socket on side and bottom (and picture can be inverted so camera can be used upside down).

Has 1080P 30 fps and 720P 30 and 60 FPS and generally a better picture in daylight than GoPro.

Built in image stabilization definitely decreases multicopter vibration problems. Not in GoPro.

5x digital Zoom works without image degradation on 1080P due to large camera chip. Not in GoPro.

WiFi live preview actually works on IPad and with computer and with negligible delay (less than 1/2 second).

Much easier and more intuitive 6 button menu and navigation than 2 button GoPro.

Built in color LCD viewfinder.

Single battery life is better than the GoPro with the additional add on battery.

Nothing malfunctioning at all.

(You do need to do a firmware update from the JVC web site for the WiFi to work properly.

Dislikes (none major to me):

Night time video not as bright as GoPro.

Doesn't have all the fancy super high resolution video modes the Black had (of almost no interest to me anyway).

Although the IPad and PC based WiFi worked much much better than the GoPro, the Adixxion does not currently support direct connection to an Android so my Nexus 7 is not of use to me for WiFi at this time.

Basically a lot more to like than to complain about, really glad I got it.

Haven't tried the WiFi live preview while flying yet, but will report back on the results of that, live preview actually does work well enough to use it for FPV so long as the camera WiFi and the RC signals do not interfere with each other.

GoPro should take a lot of cues from this camera for their future efforts.

If they get the bugs out of the Black it will be a cool camera, but right now, this is a more useful camera to our RC community in almost every way.

Even if you have to pay full price, you won't be unhappy with this camera, but if you can find any kind of deal at all (Amazon currently $250.00) you'll make the GoPro owners envious.

I previously posted a BLOG about setting up the FJI F450 Flamewheel with the APM2 and the copter was a great success so I thought I'd put together a smaller and lighter version - The F330 Flamewheel.

My F500 weighs 2 pound 11 ounces ready to fly and I am shooting for 1 pound 11 ounces with the F330 and still quite a substantial battery as you can see.

This copter should fly very well outdoors, is much better suited to flying indoors than the F450 and uses the same excellent DJI motors (and in this instance ESCs) as the F450 so will have a very high performance potential.

There are a few things that it is worthwhile to know when using the excellent and robust Flamewheel and I did things a little differently as well.

I am mostly just going to point up the things you will need to know regarding the Flamewheel.

For general quadcopter construction you can refer to the Arducopter Wiki and to my downloadable PDF file Downloadable instructions I have provided there.

Rather than order the Flamewheel F330 ARF kit, I elected to order the F450 ARF kit and a separate F330 Frame kit.

This cost me an extra $40.00, but it comes with 30 amp ESCs instead of 18 amp ones and I can also use the extra frame as spare parts for my F450.

The F450 ARF kit also comes with 2 sets of props (8" and 10" and the F330 kit comes with only one set of 8" props.

You may not elect to do this, the 18 amp ESCs are probably a little smaller and the frame is lightly loaded, so going over current should be very unlikely and 10" props WILL NOT fit on the F330.

In any case, currently the ARF F330 kit is available for $180.00 and the F450 for $190.00 and the F330 frame by itself is $30.00.

The above Picture shows the prop clearance on the F330 with 8" props on it.

9" props will fit but 10" ones will not.

I will be switching to 9" Carbon reinforced GemFan props which I very much like for both their considerable strength and their higher than normal efficiency.

A 9" prop is definitely better suited to this frame and motor with  a standard 3 cell LiPo setup although 8" would be fine for a 4 cell setup.

General assembly notes.

1. Go to the DJI web site Flamewheel support section to get a copy of their "manual" none is included with the Copter kits. It is more of an assembly diagram than a manual, but the pictures are definitely useful.
2. I put the ESCs in after assembly because it allows me to fit things more closely but then does require a bit of creativity when soldering the ESC leads to the bottom plate / power distribution board. Your choice.
3. Use Blue or purple removable Locktite very sparingly on the threads of the Allen screws when you assemble the frame. Try to keep excess off of the plastic. Not actually achievable, but do the best you can.
4. The motor and frame screws have a shoulder on them and you need to tighten them all sufficiently so that the shoulder fully seats. I recommend installing all screws (with Locktite) loosely then tightening all the screws on each frame arm one at a time. Do this in one sitting.
5. When installing the motors, pre-bend the motor leads upward a bit where the exit the motor bottom so that the motor can sit flat. Have the leads exit towards the center of the copter (motor bottom screws are off set and it can only be installed 2 ways), toward the center is correct. The motor screws are short and it is tricky to start the first screw on the motor bottom, ensuring that the motor lead is not pushing the motor up helps. Use blue Locktite on each screw and install all 4 screws for a motor loosely and then tighten them.

1. I Thread the motor leads down through the first 2 large frame member holes, but you can also run them around the frame member if you wish.
2. Install the ESCs with tie wraps. I do them from front to back through the frame member of the copter and between the motor bullet connector sockets for a slightly neater and more secure installation.
3. I install the ESC power leads through the slot in the bottom of the frame member and then trim and solder them to the power distribution board. This is a little harder than the normal method of going around the outside of the frame members but it is neater and provides a little additional battery clearance.
4. When you solder the ESC and Battery power leads to the power distribution board you will need to flux and preheat both the pads and the wire in order to get a wet and properly tinned solder joint, the board can soak up quite a bit of heat so set your soldering iron hotter than you normally use.
5. You will need an external BEC because the OPTO ESC's do not contain a BEC and Castle Creations makes an excellent and very reliable 10 amp one for about $20.00. You should also be able to use the one that is supplied with the APM 2.5 board and it is smaller. Use a switching BEC in any case, they are more reliable and a lot more efficient than linear ones.
6. You do not need to and in fact can't balance the DJI ESCs as shown on the Arducopter Wiki, they are digital, optically isolated and are completely pre-balanced at the factory. Basically they work great out of the box.
7. I am probably going to use a APM 2.5 on this Quadcopter and I will either use two rows of double sided Velcro or suspended O ring mounting of the enclosed APM.
8. You can use the stock 8" DJI props and they will work OK, but I will be switching to GemFan 9" multirotor "Carbon" props which are only $2.00 each and in my opinion much superior to the stock 8" props. They are almost impossible to break and the 9" ones will be considerably more efficient with these motors and a 3 cell LiPo than the stock 8" props. The 9" GemFans are not made for the DJI hub, but you can bore them out to about .31" with an ordinary drill and they work fine (I use 11" GemFans bored out this way on my Flamewheel F450. (The bigger the diameter of the prop you can fit the more efficient it is all other things being equal and not exceeding motor or ESC maximums.)
9. The ESCs automatically disarm after 10 seconds without the motor turning, but now, the APM also disarms after 10 seconds so, there is not conflict, anytime you have sat still for over 10 seconds you need to rearm. This is a great safety feature.
10. When you are setting up the APM with only the USB connected, the ESCs may beep continuously, ignore them or throw a pillow over the top of the whole thing (our dog hates them).
11. After you have loaded and adjusted the firmware when you turn your transmitter on and plug in the battery , the ESC's should emit a short series of musical notes and then be quiet. You are then ready to arm and fly.

I have only covered the substantial differences for the DJI F330 FlameWheel from the Normal Quadcopter setup. For general quadcopter construction you should refer to the Arducopter Wiki and to my Downloadable PDF file instructions I have provided there.

If my F450 is any comparison, this F330 should be even more fun and a lot easier to use indoors - (safely).

My starting PIDs will be what  normally use on my F450: Angular Rate P = .145, Angular Rate I = .030 and Stabilize P = 4.0

I will post additions to this Blog when I finish this project and as I gain experience with the F330. Please feel free to comment or ask questions, I will monitor this BLOG and respond as best I can.

The Picture above is of my FlameWheel 450 with one added propeller motor Unit. It is for testing the feasibility and potential value of providing 4 opposed motor propeller units for providing position control instead of copter pitch and tilt. For testing purposes the horizontal motor / ESC is controlled manually from a separate receiver channel controlled by an analog "dial" on the transmitter.

Oliver Seeler and I are both pursuing the possibility of providing a more stable multicopter platform by separating the stability control of the copter from tilt and pitch based position control. Oliver is using a Hex Flamewheel with a setup  very similar to the above at the moment.

This Blog is an outgrowth of a Forum item started by Oliver under "Aircraft platforms" entitled "The Witch Gets a Broom".

First test flights are complete on both of these copters and some significant data has been learned.

On Oliver's Hex considerable thrust was required to move the copter horizontally even at a slow pace. On my copter a very small horizontal thrust (< 1/3 throttle) moved the copter smoothly at a slow walking pace and my Quad's motor thrust is tiny in comparison with Oliver's Hex.

Oliver's Hexacopter's center of gravity is considerably lower than mine due to tall landing gear, a camera mount and GoPro camera but his horizontal motor and prop unit are mounted in the same location as mine. This means that the horizontal props center of thrust is considerably further above Olvier's Hexacopters CG than is true for my Quad.

From this result we have concluded that it is very important to have the horizontal thrust line aligned closely to the copters center of gravity. Failure to do so induces tilt which the stability mode of the APM counters by applying opposing vertical thrust, doing a surprisingly good job of cancelling out the horizontal thrust. My copter as seen above does not have this problem and requires very little power to smoothly produce horizontal flight.

Also, Oliver's Hex has the prop mounted in a pusher mode and on my Quad it is mounted in tractor (puller) mode. It appears either mode can be made to work satisfactorily. I was concerned that mine in tractor mode would have the horizontal prop wash interfering with the copters downward prop wash and might induce instability. At the power levels tried so far, no negative effect is observable and transition to and from horizontal flight is very smooth and without tilt.

My conclusion from the results achieved so far is that using a horizontal propeller for position control actually does make more stable flight possible with little or no pitch or roll of the airframe. I will continue to test in this configuration at higher power settings to insure stability is not significantly degraded.

But I am also beginning work on a setup that will place prop motor units between each of a Quads 4 vertical thrust rotors.

The intention of this configuration 4 x 4 is that the 4 horizontal motors will completely take over horizontal position control.

The existing APM programming and the Vertical thrust motors will be responsible for stabilization, altitude control and the yaw or horizontal orientation of the air frame. This way only balanced symmetrical vertical thrust on the air frame is required to adjust altitude and yaw and the only asymmetrical thrust is in direct response to outside forces trying to pitch or tilt the air frame. Basically it's entire vertical thrust resources are used keeping it level and there is no purposely induced tilt or pitch as is conventionally necessary for position control.

Control for the 4 x 4 unit will necessarily be more involved as it will be desirable at a minimum to produce differential control of all 4 props using a stick. This means that zero thrust of all 4 motors would be at "stick center" position and pushing in any direction would produce differential activation on one or 2 motors in that direction producing a horizontal displacement similar to what is done now with a quad copter using the APM.

This is not achievable from a transmitter directly and requires at least translation of stick center to = zero throttle on all four motors.

My initial solution to this will to be to either use an auxiliary (in addition to the APM) Arduino processor to take normal stick input servo data and translate it to the controls for the 4 motors or I may attempt to simply incorporate the control into the APM if my programming capabilities and available resources prove adequate to the task.

The hardware part is easy, the programming part, less so.

Oliver and I very much welcome and would like to solicit your comments, thoughts and contributions on this project, and if somebody with more APM programming experience than I would like to jump in there, please feel free.

Keep in mind, the silly thing in the picture actually works and there is no perceptible air frame tilt or pitch when you use the horizontal motor to move it.

This is a new kind of aircraft which so far appears to be feasible and also that it might have some really significant advantages and capabilities.

Current Design Above.

The GoPro Hero 3 is the newest series of the popular GoPro hero Camera which has already gained wide popularity for use in RC planes, helicopters and multicopters.

It is an amazing little camera with incredible video and photo capabilities and the WiFi up and down link and remote provide an excellent complement for our our RC / APM planes and copters.

It is the intention of this Blog to provide an ongoing forum for users of this camera to report their experiences and methods and for potential users to investigate the usefulness of this camera for their purposes.

Your responses can and should include what you like and don't like about this camera, specific information regarding mounting and stabilizing it and if possible pictures of your planes, copters, installations and mounts and even examples of pictures and videos acquired with this camera where practical.

Although I am going to start by reporting my early experiences with the GoPro Hero 3 Black I received on December 10th 2012.

I will add significant information from your posts to this main post as  can manage.

The GoPro Hero 3 is somewhat smaller than previous GoPro's and now incorporates the WiFi capability built in.

It is available in 3 versions, White, Silver and Black.

The Hero 3 Black is the top of the line version with better lens, faster video, lower light capability and most importantly a really wide range of video options up to and including 4K at 15fps pro quality cinema and 2.7K at 30fps which is fast enough to be useful.

In 1080P HD (up to 60 fps) mode it features wide, medium and narrow fields equating to a 3 tier zoom capability with no loss in resolution And 720P HD can be used at up to 120 fps.

The Hero 3 Black is fully capable of being useful in a professional film making role.

All the Hero 3 cameras are supplied with a ruggedized, waterproof case and the combination of case and camera are designed to be used continuously in conditions that would immediately destroy the vast majority of other cameras including many other "Sports" cameras.

The Hero 3 Black also comes standard with a separate WiFi remote that can also program the cameras various modes.

All Hero 3 cameras can also be connected to an Apple or Android tablet or phone and in addition to controlling the camera, they can provide a (limited) live preview.

At the moment the standard definition "Live Preview" option suffers two significant problems.

There is an approximately three second lag between what the camera is "seeing" and what the phone / tablet is displaying, so definitely not for FPV use.

Worse, as of the current release of their Android App they turn off the "Live Preview" screen while actually recording video (at least on my Black).

This was not the case for the Hero 2 with WiFi and is a devastating loss for the Hero 3.

I do very seriously hope a future App release will fix this.

While it is actually on the "Live Preview" does provide sufficient resolution and clarity to be useful even with the delay.

Even though the camera uses a typical 2 button menu set up on a tiny LCD display for a huge variety of options I found it fairly straight forward to set up as desired and the supplied remote mimicked the cameras setup methods exactly.

Because the GoPro is very small, many after market plane and copter mounts are available that will even accept it's ruggedized case and in the simplest use you can even mount one of it's supplied base plates to your plane or copter, right side up or upside down.

Pan and tilt mounts are available as are ones that incorporate yaw as well.

An inexpensive "FlameGear" mount is available for multicopters but at this time the $20.00 more expensive XP version is recommended over the one actually made for the GoPro as it has a wider landing gear and more rugged camera mounting system. A friend got the GoPro one for his DJI Flamewheel F550 Hex and thought it inadequate.

I will probably get the XP version for my DJI Flamewheel F450 Quad and will report back on it when I have had experience with it.

The APM, ArduPilot and Arducopter do provide for automatic stabilization and even automatic camera pointing with servo controlled mounts.

All this having been said, my GoPro Hero 3 Black arrived with a very serious malfunction and I am undoubtedly going to have to send it back.

Every third or fourth time I shut my camera off, the LED on the back of the camera comes on at about half brightness and the battery heats up quickly.

It will not turn back on when this happens and the only way you can get it to work again is by removing the battery and reinserting it.

Clearly something very bad is happening and the mostly shorted out Lithium battery is a very serious fire hazard aside from being really bad for the battery.

As this is from the very first real production batch of these "Blacks" I am sure this is a teething problem, but be forewarned.

You might want to wait a bit, they don't call it the "bleeding edge" for nothing.

Assuming they get it fixed and eventually get live preview to work during video recording, this little camera is a great place to start in setting yourself up for photography or videography.

Hi, I previously set up a KKX525 with the APM2, but when one of my ESC's started fading, I thought I'd try something a little more upscale.

I have now put together a DJI 450F Flamewheel ARF including DJI motors, Opto ESCs and props from "RC-Drones" at a reasonable $180.00 and am quite happy with it at this point in it's evolution.

If you try this there are a few things you need to know, but no real problems.

Generally follow the downloadable instructions I have provided on the Arducopter Wiki for assembling and setting up and testing a quad copter and in addition see below.

1. If you get the ARF kit, it will come without instructions, but the manual can be downloaded from the DJI website under their FlameWheel support section. It is some help.

2. When you assemble the copter assemble the top board so that the narrow slots are in the front and the back and the wide slots are on each side.

3. Use blue or purple thread lock sparingly on all screws and try to keep it off the plastic. 

4. One of the nifty features of this quad is that the bottom board is also the power distribution board, heat the connection pads adequately to get a good wet bond with the ESC and Battery Wires.

5. You can cover the solder joints with liquid electrical tape or "Glyptol" if you can find it.

6. I tie wrapped each ESC under each arm with 2 tie-wraps front to back through the arm webbing.

7. You will need to add an external switching BEC, the DJI 30 amp Opto ESCs are great optically isolated ESC's but they do not include a built in BEC. I used a Castle 10 amp switcher for about $20.00 you can get cheaper ones from HobbyKing but you should use a switcher, they are much much more efficient. You do not need to cut or remove the ESCs power wire, it doesn't do anything.

8. You do not need to balance or tune the ESCs as shown on the Wiki (in fact you can't they are not programmable).

9. I recommend O-ring suspension mounting of the APM board between 4 standoffs secured at the ends of the long thin slots at the front and back of the top DJI board (assuming you put it in as I described in (2.) above.) Put a machine screw in the top of each standoff and suspend the APM board between them by putting a thin O-ring through each APM corner hole and passing the 2 loops over the top of the screw in each standoff. Size the O-rings so there is little or no APM board movement, they will still provide good vibration isolation. Too much free movement and they will cause handling lag. If you prefer you can mount a fiberglass or plastic board to the standoffs instead and Velcro or double side foam tape the APM board to it. I like the suspension method best though.

10. DJI supplies 2 sets of props, I recommend that for a 3 cell battery you use the longer 10" ones, Only DJI props will fit the self locking oval shaft of the motor unless you do what I did below. The shorter 8" props are for 4 cell use.

11. I didn't like the DJI props although they worked OK. They are light, flexible, noisy and would break easily. So I bored out some very nice GemFan 11" x 4.5 props that I was previously using on my KK to fit the outer diameter of the oval part of the motor shaft (about .31") and because of a thinner hub section I also had to add a washer under each prop. This is a very highly recommended modification, they are quieter, more efficient and will not break at the first unpleasant encounter. These are not the expensive carbon fiber Gemfans but the $2.50 carbon filled ones and they are still great, however looking at Innov8tive's web site I see they now have a 10" x 4.5 version of this prop already hubbed correctly for the DJI motors, buy these, they are a no brainer. My guess is if you use the stock ones you'll need new props soon anyway.

12. When starting the Flamewheel, it arms as per normal (throttle down and to the right) but if you do not spin the props within 10 seconds or so, the DJI Opto ESCs will shut down and you need to disarm (down and to the left) and then rearm again. Anytime you are on the ground longer than 10 seconds without turning the props you will need to rearm. This is not a big deal. You will quickly get used to it and given the capability of these things to shred flesh you will probably come to appreciate it as a worthwhile safety measure.

13. When you are setting up your board with only the USB connected, the ESCs beep continuously, ignore them.

14. When you turn your transmitter on and plug in the FlameWheel's battery, the ESCs should emit a short musical series and be quiet. You are then ready to arm and fly.

I have only covered substantial differences to the normal quadcopter setup procedure, but I highly recommend the Flamewheel 450, it flies quite well with standard PIDs but I will publish PID info later as I tweak it. (See Below).

Although the current stock PID's fly quite adequately, I have found the following changes decreased "twitchiness" and increased stability:

As of 12 / 8 / 2012

Reduce the Angular Rate PIDs P value from .175 stock to .145

Increase the Angular Rate PIDs I value from .010 stock to .030

Reduce the Stabilize PIDs P value from 4.5 stock to 4.0

The above will be revised as I continue to tweak.

Loiter will probably want some tweaking too and I will publish that after I have more extensive experience.

Roll and Pitch inputs are very sensitive so you need a light finger on the control sticks, but once you learn control with them I think you will be happy with them, If not you can probably detune them with the same PID's I am changing above.

I have a friend who has also successfully set up the Flamewheel F550 Hexacopter with larger motors and Graupner props following these procedures with such adaptations as are necessary with a Hex and he is using stock Hex PIDs.

Hope this helps, please feel free to ask questions I will respond as best I can.

I know that it is taken as common knowledge that a hexacopter with a single motor failure cannot be flown beyond a controlled crash landing, but this is just plain wrong with our ArduPilot Mega hardware and if we can't do it, it is because of inadequate software.

I have a KK X525 quadcopter which I have flown very successfully for some time with the APM2.

One ESC on it is now progressively failing, continuously reducing power to it's motor after about 2 minutes flight, but all you notice immediately is the need to feed in a little more throttle and eventually it starts descending even at high throttle.

Once it touches the ground you need to switch out of any auto mode to prevent it flipping over (usually too late).

But the moral is that even with one motor failing it tries to maintain level and flight is still controllable.

On a hex if one motor fails all you should have to do is shut off the opposite motor and it should still be completely controllable as long as you have sufficient thrust in the remaining 4 engines to hover the copter.

Auto shutdown of an opposite motor could be handled entirely in software on the APM and control should be fully maintained. as you still have 2 motors turning each way and the lefit points are still symmetrical.

No spinning, no loss of control, no nothing.

If the Arducopter doesn't do this it should and I would definitely like to know what you think.

This could be a tremendous safety and long term cost advantage for a hex and not require an Octo as previously thought.