We've seen the claims before, 10x, 5x, 3x the energy density for some new wondrous cells.

Panasonic 18650GA cells have a gravimetric density of 224 Wh/kg allowing some fixed wing drones to achieve 2+ hours of flight, these new SES cells claim 400-500 Wh/kg and are apparently available for sale now.

Could we see a 1 hour multirotor flight as normal soon?

http://www.solidenergysystems.com/technology/

https://www.greentechmedia.com/articles/read/a-new-lithium-metal-battery-takes-flight-in-drones

RC Electric Calculator App for Android - version 3.0 is coming out shortly with many improvements and some calculations specifically for multirotors/copters! (Free update of course if you have already bought v2.x)

It's basically an 8-in-1 calculator for electric powered model airplanes, helicopters, multicopters, cars, trucks and buggy's, if fact anything that uses rechargeable* batteries. (*As long as the voltage is known then any rechargeable battery including LiPo, LiFe, NiCd and NiMh batteries can be used for some calculations). US imperial units and metric units are also catered for!

One of the units used for the calculations in the app is the mAh (mill-amp-hours). All batteries have a mAh or Ah rating, this is the capacity of the battery or how much energy is stored. After you've recharged the battery your digital charger will show you how many mAh has been put back into the pack i.e. how much was used. This number is used to calculate a number of things in the app, like expected flight time using 80% of the pack or the average current used during the flight or run.

A use for this app is to calculate the average current draw of a multicopter in a hover and then from this calculate the expected flight time. (I flew with ArduPlane for 29 minutes from 2300mAh and the app calculated the average current draw as 4.6 Amps, or 1.6C and 77% of the 3000mAh pack!)

Link:

RC E-calc Pro - only $1.99

As from v2.0 all the calculations are made "on-the-fly" so no buttons need to be tapped, just input your values and the calculations will be made when enough data is available.

The images should be self explanatory as to how it all works but feel free to ask any questions.

Use RC E-Calc Pro to calculate the following:
- Average Current Used by the aircraft during a flight/run.
- Average Discharge Rate (C-rate) of the LiPo battery during a flight.
- Expected Flight Time using 100% capacity of a battery.
- Expected Flight Time using 80% capacity of a battery.
- Realistic Flight Time using 80% capacity of a battery and 70% average throttle.
- Power in Watts from Volts & Amps.
- Volts from Power & Amps.
- Current in Amps from Power & Volts.
- Static thrust of a propeller in pounds or kilograms.
- Power to Weight Ratio in Watts-per-pound or Watts-per-100gram.

Examples:

a) Fly (or drive) for 11 minutes and 20 seconds, then recharge your 2200mAh LiPo, when finished your charger states that 1720mAh was returned to the battery. This app will then calculate that the average current draw for the flight was 9.11 amps, the discharge rate was 4.1C and you used 78% of the rated capacity of the battery. (Img #1)

b) How long can you fly your plane safely? It is recommended to fly using only 80% of the capacity of LiPo batteries to maximize their longevity so using the 9.11A average from the example above, the full throttle current draw (you will need to measure this) is 16A, input 2200mAh and 16A into the app and it'll calculate that you should be able to fly (at FULL throttle) for 6 minutes 36 seconds until the battery is 80% depleted or for 8 minutes 15 seconds (also at FULL throttle) until it is 100% depleted. (Img #2)

A "Realistic" flight time for a plane is also calculated which works out to be 11 minutes and 47 seconds using 80% capacity and 70% average throttle, very close to the actual flight time in the first example.

For helicopters and multicopters the flight time is very dependant on what style of flight, but you can use this calulator's section to calculate the expected flight time in a hover.

Future plans: Add wing loading, cubic wing loading calculator, (suggestions?)

Disclaimer: The formulas used in these calculations come from various internet sources, with some variations added from my own experience. Your results may vary! While a lot of effort was put into ensuring accuracy, this app is not intended to be professionally accurate.

Comments & suggestions very welcome.

thanks,
Graham

P.S. Sorry it's not on iOS.

I wanted to do a few real world hover tests with different prop sizes to satisfy my curiosity.
I tested 3 sizes of some commonly used props, the RCTimer Carbon 10x4.7, 11x4.7 and 12x3.8, all carefully balanced. There are other very similar props branded differently.

The 'copter is a carbon Tricopter, battery used is a new Turnigy 3300mAh 30C 3 cell. The motors are the very good Sunnysky x2212 980kv. Weight is 1046 grams (37oz) and the altitude above sea level here in Johannesburg, South Africa is 1500m or 5500ft.

The method was to take a fully charged battery, connect a BNB Products "Digital Power Recorder 50" inline, takeoff to 2m (7ft) altitude, hit alt_hold and let it hover in the same place for 90 seconds, then land. I then trimmed the log in the software to show only the first 60 seconds starting once the aircraft was stable. Not terribly scientific but enough to get some interesting data.

A summary of the tests:

First observation is that there is not very much in it, the 10x4.7's are about 3.1% less on the watts compared to the 11x4.7's and about 5% less compared to the 12x3.8's but there is noticeably less power with the 10x4.7's.

In fact, at the altitude I'm flying at I would not use the 10x4.7's as there really is not much power in reserve if you're coming down from a fast descent, it takes a second or two and 2m lost altitude to arrest a descent. It would be really bad with a payload.

I also expected the 12x3.8's to be lower watts than what they are, but this may be due to the larger surface area compared to the others and there must be more drag.

Here are the graphs:

10x4.711x4.7

12x3.8

Further to our first attempts at fully automated formation flying (see http://diydrones.com/profiles/blogs/ardupilot-formation-flying-attempt), Phil (http://diydrones.com/profile/PhilRudram) with his rebuilt Valdez (v2) and I headed out to try again.

Most of the flights were really good with the two planes following the route (and each other) very well. The turns especially were almost mirror images of each other and watching the two planes from the ground flying in almost perfect formation was amazing.

The first afternoon was really calm and this benefited both planes a lot. Each flight lasted around 25 minutes.

On the first day we tried a triangular course with waypoints around 700m (2300ft) apart but on the second day the course was set rectangular with the long legs around 1200m (3930ft) apart. The wind however had picked up a bit and was a bit lumpy with thermals starting to build.

We took about 2 hours of onboard video with a Mobius camera and a bit of ground video, but due to the wide-ish angle of the Mobius' lens the lead plane was often quite small although they looked really close at times both from the ground and from the FPV video setup on my plane.

All went very well until... not unexpectedly - a midair collision!

See the video for details.

Went for our long distance flight attempt today, flew a test flight with a 6S 2600mAh LiPo and then put in the 18650 batteries in, the log unfortunately shows both flights as I forgot to reconnect so I have calculated the time and total distance from the launch of the second flight to the landing. 

Basically we did a 300m diameter Loiter for most of the flight, biggest problem was the phugoid motion of the plane losing height on every downwind leg and having to regain the lost height on the upwind leg using precious amps to do so. I tried just about every parameter to tune the plane better throughout the first hour but could never get it to behave.

Special thanks to the devs (especially Tridge and Paul Riseborough), to Steve B. for assisting and UAVDS for making it possible

Plane: Super Sky Surfer

AUW: 3078g

Motor: Maytech MTO3548 790Kv

Prop: APC-E 9x6

Batteries: 6S4P NCR18650b 25.2V, 13600mAh

Battery weight: 1172g

AutoPilot: APM2.5, APM:Plane v2.78.

Weather: Calm (0-4km/h), clear blue sky, 26°C. Altitude: 1668m ASL

Time flown: 126m 53s

Total Distance flown: 116.475km

Calculated consumption on nominal capacity: 115mAh per km (will update after recharge).

Estimated current draw: 5.2A average

Lowest voltage on pack 18.0V

Average speed: 55km/h

Droneshare: http://www.droneshare.com/view/bfgodhs

Tlog: https://db.tt/UfVPiyBE  (12MB)

KMZ: https://db.tt/1Tmzim1W  (3MB)

Looks like a good fpv/camera ship for long distance flights with ArduPlane.

$189 - airframe kit only

http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=101&products_id=2482

http://youtu.be/9stpfujoUcA

Specifications:

• Wingspan: 2520mm / 99.2inch
• Kits Airplane weight: 2.4kg (5.3lb) including all reinforcement parts
• Extra Payload: 3.0kg-4.0kg (6.6lb-8.8lb)/ flight weight>6.0kg
• Customized Brushless Power system:
• Customized Motor for Airtitan:  M60K/ Power 1500W
• Testing static thrust: 5.5-6.0kg (6S, 15" Prop)
• Propeller recommend: 15*6 / 15*7
• ESC: Advanced 80A OPTO (without Built-in BEC) 
• External UBEC: 5V/6A,5.5V/6A or 6V/6A (Switchable)
• Material of fuselage and Wing: EPO

We tried some formation flying with 2 different APM equipped planes.

Both were loaded with AP v2.76 and the same exact mission except for the chase plane flying 20m higher than the target plane. Both planes had cameras in, a Mobius HD Cam and 1.3GHz video link in the chase plane.

In the video I first flew in FBW-A mode then in full AUTO.

We found that the distance between waypoints was too close at 600m as there was not enough time to catch up before the next turn when a plane fell behind or pulled ahead. Due to the variability of the airframes, getting the airspeed synchronized was troublesome as was their turnrate.

We did manage to get some air to air video but our fun was cut short by Phil's plane stalling on the downwind turn with Ardupilot ramping up the throttle too slowly and not being able to recover from the resultant spin, the crash is in the video.

Will try again soon.

Been testing a brushless gimbal on my quad, it's an own-design laser-cut Liteply gimbal which uses a Foxtech AIO (Martinez) controller ($50) and Foxtech 2208-70kv motors ($21). Information is a little hard to find on the controller and tuning of these things a little tricky but so far the results have been very encouraging.

The gimbal was laser cut from 2.5mm Liteply but needed some reinforcement to prevent flex so this is now version 3.1 :)

3mm or 4mm might be a little better in the stiffness dept. but this is not bad at all. It's also really light at less than 35g for the ply parts!

Camera is one of the new 1080p Mobius Camera's which is pretty amazing for the price of $70. just the colours are a bit saturated but that will be sorted out with later firmwares.

A very short video flying above my Johannesburg suburb showing the fantastic stabilization (Note: this is only 720p and I tried to keep the upload size small with a low bitrate, Youtube also takes some of the quality away):

Are model planes dangerous? Are multicopters dangerous?

Below is a link to a thread showing what happens to people who thought they weren't.

WARNING: Most of the images in the thread are VERY graphic, including severed fingers and large open wounds!

Don't have a meal before viewing...

Please everyone, take an extra bit of care with your propeller driven craft! Safety of the people, safety of the vehicle.

http://chrismeme11.over-blog.com/article-36258812.html

Eventually I got around to part 2, part one is here recorded with a laptop from a TV card.

Part 2 was recorded on-board the quad with a 808 #16 v2 keychain cam, the flying was done FPV with video glasses and a 1.2 GHz BOB Fox 700mW video Tx & Rx. Quad is my own design EPP folding H-frame quad. Editing the vid down to size wasn't not easy as I took about 120mins of video but any way here is the result (but watch out for part 3).

Please excuse the bit of Jello on the video at times but this #16 cam is very sensitive to any vibs.

Following on my Carbon H-Quad, I have now built a foam one!! (Ok, it has a bit of carbon too)

The problem with the full carbon one was weight. Yes, it was super stiff but it was around 300g heavier than my X525 frame and thus my flight times were 3+ minutes shorter, thinner carbon plate would've helped but it's fairly expensive, difficult to come by (here) and difficult to work with.

My main priority was portability, it has to fold as small as possible and I also really do prefer flying the H-frames, orientation being the major advantage but also no props in onboard video.

I had a few blocks of a hard black EPP foam and I picked one up the other day and it was really firm (no twist) AND light (100g for the whole block), suddenly... bing!... I had spare arms for the X525 so why not.

A quick drawing in CAD to check the angles and sizes and some problem-solving with mountings and construction and here it is... took about 2 hrs to make and another 2-3 to assemble. I used the carbon pivot plates cut off from the old frame and they're just cyanoed to the foam with 2 bolts right through and 2 through just the arms and plates. Flies really well with very little twist (not enough to cause the yaw problems associated with twist)!

Weight is 925g ex-battery so 78g lighter than the X525 with the same components (The carbon frame was ~1300g).

Before attaching the motors, closed	Open, no components
3	4
5	In the old box!

Thanks to the Dev team for getting ACv2.9 to us, especially as it fixes a lot of features that have been broken for a while. This one in particular is one that I had been trying to get to work - http://diydrones.com/forum/topics/automated-parachute-drop.

The mission was to takeoff to 2m altitude, fly to WP2 @ 25m alt, drop the chute, fly to WP4 to a) stay out of the chutes way and b) not yaw towards home hopefully to capture the chute while it fell with the 808 #16v2 keychain camera attached to one 'copter foot, then descend to WP5 @ 5m and land.

Some of the flight was a little wobbly as I had adjusted a few PID settings yesterday while experimenting with something else. Below is how the mission looked. The setup was followed as per the camera control wiki page > shutter configuration - http://code.google.com/p/arducopter/wiki/AC2_Camera. A simple 5 gram servo released a rubber band holding the chute underneath the 'copter.

I had to change the nav speed to 2m/s because the waypoint was very close to the takeoff point and that was still too fast as the 'copter had reached the waypoint before the 25m altitude had been reached.

Waypoint radius was set to 1m and I had turned AUTO_VELZ_MAX to 150cm/s from 125cm/s but that also made the takeoff very/too rapid.

The OSD (On Screen Display) is an instrument that provides the pilot with navigation information helping him to conduct a safe and conscious FPV (First Person View) flight. The information are imposed on an image from on-board camera, giving more control over the RC model and facilitating safe return to base.

OSD displays all key information about  model:

• GPS position and time,
• altitude and speed over ground in metric or imperial units,
• course (CMG) and number of visible satellites,
• distance and direction to base,
• current, voltage and consumed energy for electric planes,
• way-points near to plane.

OSD with autopilot it can display additional information about:

• artificial horizon,
• barometric altitude,
• variometer (also provide acoustic vario signal),
• magnetic heading (compass).

With OSD FPV flights are safer. Pilot knows where he is and know way to home even in unknown terrain. The OSD with artificial horizon allow to continue flight in conditions of reduced visibility, for example in the cloud or at night. It also works as user interface for configuring autopilot. It displays menu and allow to choose between many options using included keyboard (locally) or RC channel (remotely).

OSD supports PAL and NTSC standards. The system automatically detects transmission standard from on-board camera and adjusts the information system. In case of loss of the signal from the camera, OSD continues to generate in the video standard in which the camera worked, allowing you  to complete the IFR flight according to the instruments

The UAV Autopilot is the safety part of FPV system. It offer IMU based stabilization of the plane in hard conditions, flight through the waypoints and automatic return to base in case of RC link lost. UAV Autopilot offer 3 flying modes activated with free RC channel:

• Transparent mode (OFF), where signals from RC are redirected to servos
• Stabilization mode (STAB), where flight is automatically stabilized. User using his RC set desired angles of pitch and roll ordering to the autopilot to keep them
• Autonomous mode (AUTO), where autopilot continue flight to the next waypoint without user input.

Autopilot offer many mixers to allow wide choice of flying platform. Actually it support settings:

• Classic T
• Ailerons on 1 or 2 channels
• Flying wing
• V-tail or reversed V-tail
• Reverse on aileron, elevator and rudder

RC Autopilot can be configured using OSD. It displays menus with option to choose. Configuration can be done also in flight. http://www.rcgroups.com/forums/showthread.php?t=1811191

A friend has one but we haven't flown with it yet, looks good though.

(More construction photos in link below)

I was flying with an APM2 equipped X525 quad frame but there were a couple of thing I didn't like, namely:

if using a GoPro or other wide angle camera the props would show in the far corners of the video.

Also, orientation at a distance was difficult even with two bright neon-orange legs.

Thirdly, it didn't fold as compactly as I would like for transportation.

Lastly, it looked like all the other X525 framed quads.

So after seeing an H-frame quad on the 'net somewhere I set out to build my own. The first frame was from 3mm ply and balsa using the aluminium arms and feet from the X525 but stiffness was a major issue with motors 1 & 2 sitting higher and at a slight angle while in flight. This caused some strange yaw problems... well, there wasn't any at times, the motor angles cancelling out their yaw effect. I tried covering the ply with very light carbon tissue and epoxy and even some carbon tow braces but could never get rid of the twist between the front and rear arms. A fumbled toggle switch at the wrong moment caused a crash and showed another reason why ply is a bad idea, it breaks very easily!

So...

Next was to find something really stiff and strong, either fiberglass sheeting or carbon, prices were a bit unreal both locally and online, while some suppliers showed no interest at all in selling me any (I'm still waiting for some replies).

I eventually found some 1.5mm woven carbon sheet at Hobbyking but it was only 300mm x 100mm.
The 100mm was fine but I needed 600mm (23") long. This is when an engineering friend came to the rescue (HUGE thanks again, Wladek!), he said I could join 2 sheets mechanically with fiberglass sheet and rivets! So 4 carbon sheets were ordered and some plans drawn up in CAD.

Wladek has some nice machines at his work so we were able to do some very accurate drilling, milling and cutting. 12mm aluminium square tube was sourced locally and milled into a C-channel, saving 1/4 of the weight. Two 0.5mm plastic strips were used to make up the extra 1mm thickness (the X525 arms are 13mm). The carbon is riveted with 3208 rivets to the c-channel.

At first we used the carbon in it's original rectangular shape but we have since cut down the sheet to its present form saving 1/3rd of the weight. If I had to do it again I'd use 1.0mm sheet rather than the 1.5mm saving another 1/3rd. Also initially the ESC's were inside the frame but after many unexplained "ins" and other problems in which I started to suspect an overheating ESC, I have now moved them out into the airflow under the props and all seems well.

Anyway, it flies really well, looks great in the air and fulfils all my requirements, especially no props in the video! (See here). Final weight is 1279g (45oz) dry, with a 3 cell 5000mAh LiPo adding 353g (12oz) totalling 1632g (57oz), about 250g (8oz) heavier than the X525 with the same hardware. Flight time is about 13 minutes. Motors are 20-22L's, ESC's are Super Simple 20A, batts are Zippy Compacts (3S 5000mAh), props are 11x4.7 APC SF.

More construction photos here: Picasa Album

Cheers

link to CAD file>H-Frame2.dwg

This looks rather nice, the Dianmu system only has RTL (return to launch) whereas the Standard system has that plus waypoint ability. (http://www.skylarkfpv.com/en/), RCGroups thread here. Video on the thread or one sample below.

A friend is in the market for a Stabilization/OSD/RTL system and while so far I've been advocating ArduPlane & APM2, he's not very computer savvy, wants as few bugs as possible and wants something as close to plug-n-play as possible and so I am considering recommending this:I like the way all the setup is through the OSD displayed on the screen.

Dianmu is US$198, (more here) Standard is US$298. (more here)

Features below:

One video sample: https://www.youtube.com/watch?v=EdMJbYRcQVs

Had a little fun flying in a local park here in Johannesburg, South Africa. Used a GoPro Hero on my own design anti-vibration mount and my quad running the newly released v2.5 firmware. Click on the photo to go to the youtube video.

Quad specs:

APM2

KDA20-22L motors from Hobbyking, 11x4.7 APC SF props

2 x Super Simple 25-30A ESC's from Hobbyking, two more on the way

2 x Hexfet 25A ESC's from Hobbyking (2 of 4 were DOA)

3S 3000mAh Turnigy 25C

X525 frame

Superimposed volt/current graphs - 9x5 3-blade in red and 11x4.7 2-blade in blue

Further to my informal testing of 3S and 4S batteries with the same prop I did a test with 9x5 3-blade props (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5248) and 11x4.7 2-blade props (APC SF 11x4.7).

Test procedure: using freshly charged batteries I took off and hovered at ~2m for 60 secs and then landed.

Quad specs:

APM2

KDA20-22L motors from Hobbyking

2 x Super Simple 25-30A ESC's from Hobbyking

2 x Hexfet 25A ESC's from Hobbyking (2 of 4 were DOA)

3S 3000mAh Turnigy 25C

X525 frame

Average values:

11x4.7 uses ~11W less power and ~1.1A less current on average for the 60 second flight than the 9x5

Full graphs below: 9x5 first.

11x4.7

I have an old BNB Digital Power recorder so I wanted to have a look at the hovering power requirements of my quad. The weight of the quad with either battery is very similar.

Quad specs:

APM2

KDA20-22L motors from Hobbyking

2 x Super Simple 25-30A ESC's from Hobbyking

2 x Hexfet 25A ESC's from Hobbyking (2 of 4 were DOA)

10 x 4.5 props from Goodluckbuy.com

Batteries: 4S 2200mAh Nanotech 25C

3S 3000mAh Turnigy 25C

X525 frame

(Click the picture for the Youtube video)

Some onboard video taken from my quadcopter in the Kalahari desert, South Africa, bordering the Kgalagadi Transfrontier Park. Sorry not GoPro quality and there's no sound.

Separate Mediatek GPS's on both ArduPilot Mega and the Remzibi OSD. A Hobbyking 420 TVL camera provides the video sent back to the ground via a BOB Fox 700 1.2GHz transmitter. Radio is a Hitec Aurora 9.

Some FPV videos to follow when I get to edit them.

Software is v2.3, with PID's fairly high.

And yes, that is a "kalahari-ferrari" in the beginning

A couple flights this morning using my trusty old ArduPilot Legacy & ArduIMU. Separate Mediatek GPS's on both AP and the Remzibi OSD. A Hobbyking 420 TVL camera provides the video sent back to the ground via a BOB Fox 700 1.2GHz transmitter. FPV is done with video goggles. Radio is a Hitec Aurora 9.

After switching to RTL (return to launch) the plane turns very well and returns towards home banking about 70m before 'home' and then goes into a stable loiter pattern at a height of around 70m and loiter radius of 70m.