FrSky 2016 EU LBT Firmware

If you haven't already, you will soon notice that FrSky has new logo and a new look. There are more than just cosmetic changes in the latest hardware landing with EU distributors though...

Yet another fundamental change has been released for the EU market - the EU LBT ('Listen Before Talk') firmware. Affected products include the X-Series receivers and Taranis X9D transmitters. Post-2015 EU firmwares and the newer 2016 EU LBT firmwares are not cross compatible; you will need to upgrade the firmware on your Taranis in order to bind to receivers with the newer EU LBT firmware.

So what do we need to know? Here is a quick run down of the pros and cons as a result of the changes:



- Both CPPM and SBUS output come as default with new X4R-SB receivers (selectable with jumper (now provided) during bind process)
- L12 support has returned meaning users will regain the ability to use the L9R receiver as a long range option (no need to upgrade your L9R's firmware)
- Stability and range have been improved over earlier EU firmwares released in 2015 (untested by HobbyRC although several community reports seem to support this)
- If you are running OpenTX, D8 support may be available to you (meaning compatiblity with the D4R-II receiver)


- Ensuring both your receivers and transmitter are running compatible firmware is another headache
- V-Series receivers are still not compatible with newer transmitter firmware

FrSky X4R-SB EU LBT Firmware

FrSky X4R-SB with the latest EU LBT firmware and updated branding


Identifying your transmitter's firmware

Understandably, you may be unsure which firmware your Taranis currently has installed. Simply head over to the model setup screen and scroll down to the internal RF mode setting - each firmware has different compatible protocols:

- D8, D16, LR12 - You have pre-2015/non-EU firmware compatible with D-Series, V-Series, X-Series and L-Series receivers. This firmware was the standard prior to 2015 and is still in use outside the EU.

- D16 - You have post-2015/EU firmware compatible with X-Series receivers. This firmware was released at the beginning of 2015 and was the first to conform to new EU regulations concerning RF transmission. You may also notice a small sticker on the reverse of your transmitter labelled 'EU 2015'.

- D16, LR12 - You have post-2016/EU LBT firmware compatible with X-Series and L-Series receivers. This is the latest firmware which is a progression of the post-2015/EU firmware but is not cross-compatible.

If you are still unsure which firmware you have, we are happy to help you find out.


FrSky Taranis EU LBT Firmware

FrSky Taranis X9D with the latest EU LBT firmware and information sticker on reverse


Affected Products:

Of HobbyRC's FrSky product range, affected products include:

- X4R-SB Receivers
- X6R Receivers
- X8R Receivers
- Taranis X9D Transmitters


Optional Firmware Flashing Options:

If you don't fancy flashing your own receiver, HobbyRC offer a firmware flashing service at the point of sale. Available firmwares for the X4R-SB are: 

- SBUS, CPPM + 2xPWM (EU 2015)

Note that all the newer firmware available for the X4R-SB enable CPPM output (when pins 2+3 are jumpered at bind) 


The new firmware can be downloaded from the FrSky website here:

Building The Lumenier Danaus

Last week we built an FPV ready quad for a customer based on the new Lumenier 'Danaus' frame (previously 'Monarch') - here's how we got on and a few of our observations from the build process.

It’s hard to say anything about the Danaus without first mentioning the QAV250, many people (ourselves included) have been very impressed with Lumenier’s outstanding frame – in particular the carbon fibre version which has arguably set the benchmark for 250 class racing frames. The solid 3mm 3K carbon fibre unibody frame plate is beautifully machined and exudes quality. It has quickly proven itself as a favourite among seasoned FPV pilots and novices alike. The Danaus shares many of this frame’s features from the landing gear to the power distribution board but if you’re expecting it to follow in the QAV250’s footsteps, you’ll likely be disappointed.


In the words of the designer of the Danaus - Andy Shen,

“It's not as quick as a QAV250 of course, but it's faster and more agile than you'd expect. It emboldened me to try new things and really improved my skills”.

I think that sums up this product nicely.


The obvious feature which sets the Danaus apart from most other frames is the integration of prop guards into the frame design. If you’re new to the hobby, crashes are going to happen – it’s inevitable. Propellers get smashed, motors burn out and ESCs get fried. Shielding those props from impacts can help to not only mitigate these damages but in some circumstances, avoid potential crashes all together. Similarly, you gain the confidence of being able to install more expensive props and motors onto your build knowing that the odds of them being damaged are significantly reduced.

I’m trying not to hark on about the QAV250 too much but if you’ve ever owned one, you might be a little surprised when first you open up the Danaus. At 1.6mm the glossy frame plates are much thinner than you will be used to. They are made from a glass fibre / carbon fibre-laminate (basically glass fibre sandwiched between two layers of carbon fibre) and are somewhat flexible. If you have ever tried to bend the 3K CF QAV250 main plate you’ll already know that you can’t. You can see the obvious difference in the image below:


Building The Lumenier Danaus


The design of the Danaus however is inherently different from the QAV250 – it has two full sized plates rather than one. Once these two plates are connected by the aluminium standoffs, the strength of the frame shows itself quite clearly. If Lumenier had produced this frame in the same design but with two 3mm thick plates it would weigh far too much for 250 class components, not to mention the fact that cutting out two pieces this large from 3mm 3K carbon fibre would cost a small fortune. Put the material choice out of your mind, once you get over this initial difference you’ll start to appreciate that, while clearly bearing many resemblances to the QAV250, the Danaus is a completely different beast.


Building The Lumenier Danaus

Building The Lumenier Danaus


As usual with Lumenier products, the production line is pretty solid. The frame plates are faultlessly tooled, the power distribution board is reassuringly well made and everything goes together without a hitch. At the time of writing, the manufacturers have not yet published a build manual. That being said, it’s pretty hard to go wrong – there are only four main components and if you can’t work it out from the images available online, you’ve probably stumbled into the wrong hobby.

Our client wanted a build as close to the Lumenier specification as we could manage. We recommended to him the following:

-          4x Lumenier 2206-11 2350kv motors

-          4x Lumenier 5x3 Carbon Fibre props

-          4x Lumenier 12A N-FET SimonK ESCs

-          1x Full Naze32 flight controller


In addition to the basic guts we added FPV and GPS gear:

-          CC1333-B Sony Super HAD CCD 600tvl board camera

-          TS5823 5.8GHz 32CH 200mW video transmitter

-          Lumenier Anti-Vibration Mount

-          Mobius ActionCam V3

-          Ublox 7 56 Channel GPS receiver module


The first job is to solder the ESCs, XT60 pigtail and any other 12V breakouts you might need to the PDB (power distribution board). Make sure you plan ahead and solder anything you might need before you start screwing the PDB to the frame, it’s not a massive job to remove it but it’s a pain nevertheless. In addition to the XT60 pigtail and the ESCs we soldered a 5V BEC and a feed for the video transmitter. Note that the PDB is labelled ‘QAV250 PDB v1.0’ – it’s hard not to continue drawing similarities between these two frames!


Building The Lumenier Danaus 

Building The Lumenier Danaus


Take care when going off piste with your ESCs, the PDB is a neat way to manage your gear but it can get a little cosy under there. We found that ESCs with capacitors which are orientated along the length of the ESC are a difficult/impossible fit. Specifically, Emax 12A Simon Series ESCs were a problem so try to avoid this type of ESC if you can. Those which have the capacitor positioned across the length of the ESC are a much more suitable candidate. Such ESCs include:


-          Lumenier ESCs

-          AfroESC 12A Ultra Light ESCs

-          HobbyRC 12A Multirotor ESCs


The same obviously applies for QAV250 builds.

With all the soldering out of the way we moved onto the motors. We’ve always been more than happy to recommend Emax motors to our customers. Their build quality is great and other than only being rated up to 3s, they are cracking little motors for the vast majority of people. The Lumenier motors are a real touch of class though – manufactured by T-Motor, they ooze quality as soon as you pick them up. If you’re happy to swap the Lumenier sticker on the side for an OEM T-Motor sticker then you can find motors which have probably rolled off the same production line at a much more palatable price - just search for the ‘MN2206’.


Building The Lumenier Danaus


As for actually mounting the motors, it’s pretty straightforward. That being said, we did manage to foul the motor wires inside one of the motors with the provided screws. One of the mounting holes on the base of the motor sits directly beneath the three wires which run to the ESC. Obviously you should always be careful never to touch any wires or the windings when mounting your motors but we just didn’t expect it using all Lumenier components. I’m sure this was just a one-off but either way, you have been warned! 

Here we come to one of the benefits of the Danaus - the freedom to splash out on expensive props without fear of damaging them so easily. The flat t-style Lumenier 5x3 Carbon Fibre props are a lovely addition to this frame and the ability to screw them directly to the motors lets you throw those hefty prop adapters back into the box. The significance of the weight that this actually saves you is debatable but the motors and props certainly look a lot smarter at the very least. These props come nicely balanced and they should reduce vibrations overall. It would be nice to have some 5x4 carbon fibre props from Lumenier perhaps with a greater surface area - we found that the flight times with these props are a little lower than with cheaper 5x3 ABS props. If you really want CF props then they’re beautiful but there’s a strong argument to go for a set of Gemfan 5030 CFs (which incidentally are a fraction of the price).


Building The Lumenier Danaus


The flight controller mounting holes are spaced at 30.5mm as expected for frames of this size. You can stick your FC on a self-adhesive foam pad to reduce vibrations being transferred to the accelerometer or mount it on nylon standoffs like we did. This didn’t cause us any issues and made for a more finished look overall.


Building The Lumenier Danaus 

Building The Lumenier Danaus


Once cut down, the CC1333-B mounts nicely on the camera mount plate at the front of the frame. With earlier batches of the QAV250, we found that Lumenier neglected to include suitable screws/nuts for this. They seem to have fixed this problem now and the camera installation was quick and easy. You’ll find that, although not quite as well as the QAV250, the Danaus does shield the board camera reasonably well - it would take a direct head on impact with a small tree/post to hit the camera.


Building The Lumenier Danaus

 Building The Lumenier Danaus


Along with the Mobius, we mounted the receiver, video transmitter and UBEC right at the front of the quad. The TS5823 transmitter sits right under the anti-vibration mount without wasting any space or hindering the Mobius. The Ublox 7 GPS module was placed directly above the Naze32 flight controller to keep it a safe distance from the nasty 2.4GHz and 5.8GHz gear.


Building The Lumenier Danaus 

Building The Lumenier Danaus


We wanted to keep the battery inside the frame if at all possible and fortunately managed to balance the quad with a 1500mAh LiPo (Turnigy nano-tech). You would probably manage this with a 1300/1400mAh pack further back but anything much bigger like a 2200mAh pack would probably see you having to mount it on top.


Building The Lumenier Danaus


Still struggling to shake the notion that this was a QAV250 v2, once we got the Danaus in the air it seemed notably slower. It doesn’t feel as powerful as the QAV250 and yet it flies with more grace. I’m sure this is in part due to the frame’s weight – Lumenier compare the Danaus’ 205g to the G10 QAV250 with props guards which tips the scales at 230g. Perhaps a more relevant comparison would be to the Carbon Fibre QAV250 with prop guards which only weighs in at 175g – 30g less than the Danaus.

Once again though, it really is futile to continue pitting these two frames against each other - the Danaus isn’t a racer and it was never meant to be. That doesn’t stop it from being a really fun frame for FPV though. You certainly can’t get proximity, exploratory style flight with the QAV250 as comfortably as you can with this frame. Videos are already popping up of the Danaus bouncing around gardens and playgrounds without a care in the world. You start to realise how aptly named the frame is when you see it float around, freely bumping into bushes and legs – it really does look like a butterfly. Conversely, it’s unfair to say that this frame is only good for bouncing around your garden – it’s still a decent 250 class frame and it still has punch. When you give it full stick, there’s nothing about the frame which stops the motors delivering a serious kick. You might find it a little less responsive than some other frames but it’s certainly no slouch.

The Danaus has captured a lot of people’s imagination – I’ve already had at least two separate people divulge their plans to Frankenstein two frames into an X8 configuration. I’ve had people who might not otherwise dive into the multirotor world take a chance on building a quad due to this frame’s forgiving nature. To put it as succinctly as I feel capable of, I think Andy Shen and Lumenier have delivered a fun, well-polished and refreshing frame which hopefully we will start to see a lot more of. Here are a few shots of the final product:


Building The Lumenier Danaus

Building The Lumenier Danaus

Building The Lumenier Danaus

Building The Tarot TL250A Mini FPV Frame

An unfortunate incident with my 250 quad and a goalpost gave me a good reason to get building with this frame. Here are a few of the highlights of my afternoon and how I found the frame to work with.

Like many other people, I wasn't interested in buying any of the proprietary components from Tarot (camera, VTX, OSD-GPS, etc.) as I've already got parts which I want to reuse. I pretty much transferred everything from my old quad straight onto this frame:

Naze32 flight controller (full)
12A Ultra Light AfroESCs
Emax 1806 2280kv motors
- OrangeRX R615X receiver (case removed)
- TS351 video transmitter + clover leaf antenna
Mobius ActionCam
Turnigy nano-tech 45C 1500mAh LiPo

In addition to the parts I already had, I also swapped out my FatShark 600TVL CMOS camera for a HS1177 board camera and upgraded to some tasty Emax (probably re-branded Gemfan) 6030 carbon fibre props - the option to use 6" props on this frame was one of the reasons I bought it. 

I'm certain plenty of people will want to mount a Mobius to this frame and I wanted to as well. Tarot definitely didn't design the frame with this in mind which is absolutely their prerogative, it's designed to be a light FPV racer with bags of power. Don't worry though, it's definitely possible 

The obvious first step was to swap the XT60 connector for the correct gender. It's not much trouble but I found myself rolling my eyes from the outset, wondering whether Tarot had opened up the production line for high school Work Experience week. Anyway, I took the old connector off and mounted the new on the underside of the PDB since I wanted to under-sling the battery rather than top-mount it:

Tarot TL250A Mini FPV Frame


As many other people have found, the frame's fits together like a low tolerance Tetris flavoured sandwich. Holes are off, mounting points are virtually non-existent for non-proprietary components and solder pads are tiny/irregular. It all fits but only just and it's certainly not as enjoyable an experience as I've had with the larger Tarot frames. That being said, despite its diminutive proportions, once it's assembled the whole whole things feels solid and I have no worries about it falling apart (which is good because I don't fancy putting it together again in a hurry).

I ended up using the PDB for ESC and motor connections only, everything else I ignored - if you don't want to use the rest of it you don't have to. Once I'd managed to wrap my head around the correlation between the Tarot motor numbering convention and the Naze32's (hint: there isn't one), I soldered the two supplied servo wires onto the ESC connection points. Signal wires connected to all four ESCs, power and ground connected to just one as Tarot (quite rightly) recommend. If you're planning on soldering header pins onto these connection points, forget it. The frame's forward arm would foul half of the pins sticking up here - another Work Experience Week moment from Tarot:

Tarot TL250A Mini FPV Frame

As you can see, I was very clever and labelled the servo wires appropriately. What wasn't so clever was realising that they were to short to reach my Naze32 in the middle of the frame. Time to warm up the soldering iron again and grab some longer wire:

Tarot TL250A Mini FPV Frame

I initially soldered the wires from my FatShark CMOS camera to the relevant pads on the front of the PDB (as intended by Tarot). The traces run towards the aft of the frame and I intended to break them out (signal wire to my VTX and the power wires to my Naze32 ESC/Servo headers (5V)). The wires however kept snapping at the solder points due to stresses and so I opted to use a 12V board camera (HS1177) which we had in stock instead. The FatShark CMOS camera had performed admirably but as well as needing a 5V power source, it had always been a nightmare to mount. The HS177 however can run straight off the battery and comes in a cracking little case which lets you tilt it up for fast forward flight.

The board cam's case bracket can actually be mounted directly onto the forward silver spar which would be a good option other than being a little exposed and leaving no options for mounting a Mobius. I decided to move the forward battery stay to the underside of the frame and used the centre hex screw to hold down the board cam's case bracket:

Tarot TL250A Mini FPV Frame

The camera is now well behind the front of the frame and needs no additional mounting fixtures, the included square camera mount plate can also be discarded. With 6" props the clearance is 4-5mm:


Tarot TL250A Mini FPV Frame

Tarot TL250A Mini FPV Frame

The Emax 1806 motors went on without a hitch. Both the 12mm and 16mm pitch mounting points were accessible so I opted for the wider spaced 16mm pitch holes (these were admittedly right on the extremities of the motor mount slots in the frame arms but they do fit):

Tarot TL250A Mini FPV Frame

If I'm unhappiest about anything it would be the tidiness of the ESC mounting. I don't have any desire to shorten the ESC or motor wires as this would likely make them useless in another build but I'm well aware of how messy they look. At least they're functional though:

Tarot TL250A Mini FPV Frame

Here's how it was looking before a coffee break:

Tarot TL250A Mini FPV Frame

Next job was to mount the TS351 VTX - it's a little on the heavy side for this sort of build and if I was being picky I'd swap it for the lighter TS5823. Unfortunately though it's January and I can't justify shelling out the best part of £30 to shave off 17g. It's just mounted with self adhesive foam for now - once I've worked out where to run a cable tie or two, I'll get it secured more convincingly:

Tarot TL250A Mini FPV Frame

R615X receiver mounted on top behind the Naze32 - case removed and wrapped in kapton tape. Also added the circular polarized antenna to the VTX. You can see the aft prop clearance nicely in this picture - don't worry, they aren't as close as they look:

Tarot TL250A Mini FPV Frame

With all the essentials happily in their new homes, I was left with a lovely little spot at the front of the frame for the Mobius: You can see that a 1500mAh LiPo fits nicely between my VTX and Mobius - the CG is bang on centre too.

Tarot TL250A Mini FPV Frame

Tarot TL250A Mini FPV Frame

The Mobius' mounting sleeve is stuck down in front of the battery and mounted upside down (I'll flip the video in the firmware). I'll be honest, it's definitely exposed and although the sleeve is a good tight fit, it's not impossible for the camera to come out. It's also got minimal vibration isolation. When I've got a little more time I'll revisit this issue and try to fabricate a vibration isolated plate for a more permanent mounting solution. It will do for now though.

Final Thoughts:
The frame is pretty frustrating to put together with some questionable design choices and if you want to mount anything other than Tarot's own line of parts you'll need to think a little outside the box. Not only are there few/no alternative mounting holes, there is barely any available material to drill your own. 

Don't take all this the wrong way though, I actually really like the frame. I don't see how it could weigh any less, it's a solid construction with high quality materials and aesthetically speaking it's a stunning breath of fresh air. I can't wait for the weather to improve so I can get this quad in the air but until then, here are a few pictures of the final build:

Tarot TL250A Mini FPV Frame

Tarot TL250A Mini FPV Frame


Tarot TL250A Mini FPV Frame

Tarot TL250A Mini FPV Frame

Tarot TL250A Mini FPV Frame

Tarot TL250A Mini FPV Frame

Total weight including Mobius = 494g

Tarot TL250A Mini FPV Frame

How to Use The Naze32 ESC/Servo Headers for 5V Power Distribution

Power distribution is always a major concern when it comes to wiring your multirotor. Did you know that you can use the Naze32 itself as a way to distribute 5V power to components in your build? Here's how to do it...

click any image to enlarge

5V Power Distribution using Naze32 ESC/Servo Headers

5V Power Distribution using Naze32 ESC/Servo Headers

5V Power Distribution using Naze32 ESC/Servo Headers

5V Power Distribution using Naze32 ESC/Servo Headers

1. Remove the PWR / GND wires from the ESC Servo cable connectors leaving only the orange signal wire (fig. A). Use a pointed tool to gently pry open the latch on the plastic connector and carefully remove the crimped wire. It should not need much force. Take care not to damage the plastic latch when doing this as we will be reusing these connectors shortly.

When removing the PWR / GND wires, ensure that they are electrically isolated (not touching) using electrical tape or similar. If these wires touch when in use, the resulting short circuit will destroy the ESC.

2. If using a power distribution board with an adjustable output, use a multimeter to check that the adjustable voltage output
Is set correctly to 5V. If using a 5V/6V UBEC, make sure that the jumper is set to output 5V and check with a multimeter.

3. Observing the correct polarity, connect two dupont wires to the PDB / UBEC (fig. B). Using the same technique mentioned in step 1, remove the plastic dupont connectors from the loose end of the wires (fig. C).

4. Take the crimped wires and insert them into the spare slots in one of the ESC Servo cable connectors (fig. D). Again, be careful not to reverse the polarity of the wires or the Naze32 could be irreversibly damaged.

5. The Naze32 is now receiving 5V power from your PDB / UBEC. You can use any of the other ESC Servo connectors to provide 5V power to other components. This is useful for powering GPS modules, OSDs, Mobius ActionCam, etc. Simply use crimped wires from dupont connectors and insert them into the ESC Servo connectors.

Remember that the Naze32 runs at 3.3V and inputting 5V anywhere else on the board could result in irreversible damage. Be very, very careful not to reverse the polarity (reverse the wires) when connecting them as this could also result in irreversible damage.

This guide is also available in pictorial form here.

HobbyRC RTB 250 Class Quad Kit Battery Testing

HobbyRC RTB 250 Class Quad Kit Battery Testing


Since we don't include a battery with our RTB 250 Class Quad Kit we have decided to do a little bit of testing so you can make an informed decision about which one to buy. Also, it's nice to get a rough idea about how long your quad will stay in the air. Although we made every effort to make this a fair test, variances will always play a part in the results; we have tried to make note of any environmental factors which may have affected with the data.

It's worth noting from the outset that this test is intended to show the relationship between battery capacity, weight and flight time in LiPo batteries and not specific times for specific batteries. Although you might not use these exact batteries in your build, the relationship between capacity, weight and flight time should remain relevant across most LiPos battery models.

The RTB 250 Class Quad Kit is made up of the following components:

  • Diatone G10 FPV250 frame
  • 4x eMax 1806 2280KV motors
  • 4x AfroESC Ultra Light 12A ESCs
  • Naze32 Flight Control Board
  • Gemfan 5030 propellors
  • Power Distribution Board

Also on board was the FrSky Battery Voltage Sensor and the FrSky D4R-II receiver. The total weight without battery was 308g.

Although the ESCs and the Power Distribution Board in this kit can handle 4s batteries, the motors are only rated for 2-3s batteries and so this is all we have included in our testing. Using a 4s battery with this kit is not advisable.

These are the batteries we used for testing:

HobbyRC RTB 250 Class Quad Kit Battery Testing

  • Turinigy A-SPEC 65C 2200mAh (196g)
  • Turnigy A-SPEC 65C 1800mAh (160g)
  • Turnigy nano-tech 35-70C 1500mAh (130g)
  • Turnigy nano-tech 45-90C 1300mAh (120g)

As you can see, we have used different cell chemistries in the testing. This was mainly due to stocking issues and while there is an argument that this might make a difference, when all is said and done it probably doesn't. All of the batteries used are a premium grade of battery and have a higher discharge rate than some others which are available (eg, Zippy Compact, etc.). Due to thicker metal plates in the cells, they are also slightly heavier than those batteries with a lower discharge rate (eg. the Turnigy A-SPEC 65C 2200mAh weighs 196g while the Turnigy 2200mAh 25C 2200mAh weighs 194g).

Two tests were performed with each battery:

  1. Hovering (indoor flight manually kept in the same position)
  2. 'Real world' flying (outdoor flight, gently following a consistent circular route at medium speed)

We used the FrSky Battery Voltage Sensor in conjunction with the FrSky D4R-II Receiver and the FrSky Taranis X9D Transmitter to monitor the battery voltage. Each test was started with a new battery after a full charge and the battery was deemed discharged when the reported voltage dropped below 10.8V. The quad would still fly after this point but discharging the batteries any further would risk causing permanent damage to the cells and you shouldn't really be doing this on a regular basis anyway. After each flight, the battery voltages all rose back up to roughly 11.2V.


Hovering vs 'Real World' Flying Results:

HobbyRC RTB 250 Class Quad Kit Battery Testing



From a purely anecdotal perspective, while the results obviously trended towards a longer flight time with a higher capacity battery, this does not paint the whole picture. The response and handling was very different across the range of batteries. For example, with the 2200mAh battery and to some extent the 1800mAh battery, the quad 'felt heavier' in the air. The controls were dampened almost akin to having a lower RC rate setting and this became increasingly noticeable as the battery discharged. On a positive note though, if you wanted to use the quad for aerial videography the dampened flight characteristics might help with recording smoother footage.

At the opposite end of the spectrum, with the 1300mAh and 1500mAh batteries the quadrocopter felt more sprightly and responsive. There was almost no 'pendulum effect' and it felt as though it was 'on rails'. If you wanted to use this quad for acrobatic flight or racing then these would be the batteries to go for.

While the difference in handling across the batteries was noticeable, it is worth saying that the quad actually flew very well with all the batteries we tested - you certainly wouldn't be disappointed with any of them on this quad.


Potential Factors Affecting Test Results:

Human Input - Since both of the tests were performed under manual control, it is conceivable that inconsistencies in operation could have led to inaccuracies in the results. That being said however, the tests were all performed by the same person in a reasonably short space of time so I think we can say that any effect this factor may have had is minimal.

Wind - The outdoor 'real world' flight tests were obviously performed in the open air and the wind was a factor over which we had no control. Average windspeed at the time of testing in the area was around 5m/s but changeable. In order to stabilise the quad, the flight controller has to tell the ESCs to send power more erratically to the motors which will obviously affect the draw on the battery. Unfortunately, we have no way of telling how much of an effect the wind had on the tests.

Battery Chemistries - This has already been mentioned and not ruled out as an impacting factor. According to documentation the A-SPEC batteries have an additive which causes lower internal resistance. This leads to less heat generated and less voltage sag under load. The way the batteries are constructed also makes them slightly lighter than their nano-spec equivalents. Both of these elements could translate to increased performance aside from the capacity differences.

Although we cannot rule out any of these factors as significant, after looking at the results they still conform to both third party tests and our own expectations. It's fair to say that we think the test results are reasonably accurate, and even if they are not a completely fair test of the differences in capacity, they are still useful when deciding which battery to buy for this particular build.



Here is a price list of the batteries (at the time of testing) and links to where to find them:

Turinigy A-SPEC 3S 65C 2200mAh (£19.83)

Turnigy A-SPEC 3S 65C 1800mAh (£18.73)

Turnigy nano-tech 3S 35-70C 1500mAh (£10.48)

Turnigy nano-tech 3S 45-90C 1300mAh (£9.15)

The above links are for batteries listed on the Hobbyking website. Stocking issues in their UK Warehouse however are almost becoming notorius so if the battery you want is in stock then buy it while you can!

As previously mentioned, our testing was purely based on flight times vs. capacity/weight and was not intended to test different battery types. As you can see however, the difference in price between the nano-tech and A-SPEC batteries is quite considerable. The 1800mAh A-SPEC is almost twice as expensive as the 1500mAh nano-tech. In our testing the flight time vs. capacity relationship was quite linear whereas the price between the two battery types is certainly not.

The A-SPEC batteries are purported to be of a higher build quality and may well last longer but in my personal opinion, when compared to another battery with a similar C Rating, it remains to be proven whether the gains are actually worth the additional cost. Obviously this is a personal view and whether you will buy them or not is down to your own opinions.

As I have already mentioned, the A-SPEC and nano-tech are certainly not the only batteries you could use; we used these batteries for their consistency across the test flights. There are other battery models which are perfectly capable and less expensive. The Turnigy 2200mAh 3S 60C LiPo Pack for example can handle the necessary current draw and is currently only £12.93 as compared to the equivalent capacity A-SPEC model which is £19.83. This difference starts to add up when you start buying multiple batteries.

We happened to have one of these cheaper batteries in the office and just out of interest, decided to give it the same hover test as we gave the other batteries. Here is its time as compared to the more expensive A-SPEC equivelant:

HobbyRC RTB 250 Class Quad Kit Battery Testing

As you can see, the difference is not huge and the cheaper battery was not new like the more expensive ones were.


Choosing Your Own:

When it comes to choosing your own LiPo batteries for your multirotor build, aside from the capacity (measured in mAh) and the voltage (3.7V multiplied by the number of individual cells in series in the battery - 2S, 3S, 4S, etc.) you also need to make sure the battery can handle the current draw from your motors and ESCs otherwise it will get too hot and possibly cause permanent damage.

If we want to work out the nominal constant current draw from these components we have to add together the ESCs' current rating. In this case we have 4 x 12A ESCs so a reasonable estimate for the maximum constant current draw is 48A. 

To find a battery's maximum constant discharge rate, multiply its capacity (in Amps) by its C rating (always use the lower number - the higher number indicates the maximum 'burst' output rather than the 'constant' output). The result is measured in Amps.

Let's use this calculation to test a couple of batteries. Firstly, the Turnigy A-SPEC 3S 65C 2200mAh (which we used in our testing):

HobbyRC 250 Class Quad Kit Battery Testing

As you can see, the maximum discharge rate of the battery is 143A which is well over the 48A maximum constant draw of the battery. This battery is fine to use. Now let's work out how whether the Zippy Compact 3S 25C 1300mAh battery is a suitable choice:

HobbyRC 250 Class Quad Kit Battery Testing

The 32.5A maximum discharge rate of the battery is lower than the maximum draw from the ESCs so this battery is very likely unsuitable for this quad. I should mention that the combination of motors and props also affects the maximum draw from the quad but you should be fine just using the ESCs constant current rating for your calculations. Add on a little margin and you can't go too far wrong.

At the end of the day, which type of battery you buy will come down to your own personal preference based on price, capacity, build quality and availability. Just make sure that you pick a 3S battery with a capacity roughly between 1300mAh and 2200mAh and a C rating which allows a sufficient discharge rate for your build.



If you want to fly for a long time regardless of how this quad flies, get a 2200mAh battery. If you want to race the quad or otherwise fly it acrobatically, get a 1300mAh battery. Always, always make sure the C Rating of your battery is high enough to handle the current draw of the ESCs and motors though. Remember, the HobbyRC RTB 250 Class Kit has a nominal maximum current draw of around 48A. 

Better still, get one of each. You'll probably end up buying more than one anyway since 11-12 minutes of flight time doesn't make for a day out! If you plan to upgrade this build for FPV flight, don't forget that you'll be adding more weight anyway and perhaps a lighter battery would be preferable in this situation.

[Video Tutorial] How to solder 2mm bullet connectors for ESCs and brushless motors

When you buy our eMax motors, the wires do not come terminated with connectors. Although we do offer a soldering service, you may want to solder bullet connectors onto them yourself. If that's the case and you're not completely confident then here's the best way to do it.

2mm Bullet Connector Soldering

For our 1806 and 2204 eMax motors we recommend 2mm gold plated bullet connectors. They are quite small and can be tricky to solder if you don't know what you're doing. The best way to do this is to hold the connectors in a piece of wood. This helps to steady the connector and also stops the heat conducting away while soldering.

2mm Bullet Connector Soldering

The video below shows you the process from start to finish:

Don't forget to finish your connectors with appropriately sized heatshrink tubing - we found that 1/8" heatshrink works well for 2mm bullet connectors.

2mm Bullet Connector Soldering

When you're finished your connectors should look a little like this - electrically isolated and aesthetically pleasing:

2mm Bullet Connector Soldering

I hope this has been helpful to you. As I mentioned earlier, we do offer a soldering service with our eMax motors if you'd rather we did this for you. The motors, bullet connectors and heatshrink are available from our shop below:

Emax MT1806 2280KV Motor

Pack of 12 x 2mm Gold Plated Bullet Connectors (12 x M + 12 x F)

1/8" x 500mm Heatshrink Tubing (Black)

CC1333 Board Cam Case Installation Tutorial

This tutorial concerns the CC1333 board cam and its corresponding plastic case. They are available to buy in our shop here:

CC1333-B Board Camera with Sony Super HAD CCD and 600tvl

Ultra light plastic case for CC1333-B and CC1333 board cameras


PLEASE NOTE: If you have bought your board cam from HobbyRC and decide to cut it down to fit in our plastic case, you will be invalidating the warranty since this is a destructive process. This tutorial is provided purely for informational purposes and you undertake the installation at your own risk.



click on any image to enlarge

As always, lay out all the parts and tools you will need in front of you before you begin. In addition to the CC1333(B) Board Cam and the Plastic Case, you will need a tool for snipping the board cam's PCB (we used a pair of wire cutters), a small Phillips head screwdriver and some sandpaper for cleaning up the edges of the PCB (not pictured).

CC1333 Board Cam Case Installation Tutorial



The PCB comes with holes for two mounting options - 34 x 34mm and 28 x 28mm. The first step is to remove the outer portion of the PCB leaving only the 28 x 28mm holes in order to make it fit into the plastic case. 

CC1333 Board Cam Case Installation Tutorial

CC1333 Board Cam Case Installation Tutorial

Before cutting anything it is important to ensure that you keep the protective cover on the lens to prevent any damage. You should also take every precaution not to damage any components on the PCB during the process.

Carefully cut off the long strips which run along each side of the PCB. Once you have done this, you can more easily remove the remaining material on the corners. You can offer the board cam up to the plastic case to see whether it fits at this point and continue sanding until it does. Take a little time to remove any loose material and make sure the edges are finshed smoothly.

It is better to cut off a little less material than you need to and then file and sand it down rather than cut off too much. Make sure you have cleaned the PCB and your work area before moving on. You will be exposing the image sensor and the inside of the lens assembly both of which are very sensitive to debris.

CC1333 Board Cam Case Installation Tutorial 



Once you have trimmed down your board cam, you will need to remove the lens assembly from the PCB. Remove the two small screws on the underside of the board, keeping them to one side:

CC1333 Board Cam Case Installation Tutorial

CC1333 Board Cam Case Installation Tutorial

Once again, it is very important not to touch the image sensor or the inside of the lens assembly as they are both very sensitive to debris.



Now you have removed the lens assembly, you can install the PCB in the plastic case. The back cover of the plastic case has a specific orientation which aligns with the pins on the PCB. Make sure that when in the case, the cover fits on with the writing reading left to right. This way your image should remain aligned with the horizon as you would expect (obviously, the case allows for the camera to be flipped vertically). Use four of the longer screws provided with your case to attach the back cover onto the main housing.

CC1333 Board Cam Case Installation Tutorial

CC1333 Board Cam Case Installation Tutorial




The opening on the front of the plastic case which aligns with the image sensor is threaded - this is where the lens assembly fits. Separate the two parts of the lens assembly and screw the part which contains the lenses into the plastic case as shown below:

CC1333 Board Cam Case Installation Tutorial

CC1333 Board Cam Case Installation Tutorial

CC1333 Board Cam Case Installation Tutorial

CC1333 Board Cam Case Installation Tutorial

The plastic ring on the lens assembly is used to limit the range of movement on the thread and focus the lens on the image sensor - you will need to adjust this yourself to find the optimum position.

Your board camera is now installed and ready to fit onto your multirotor.

CC1333 Board Cam Case Installation Tutorial





HobbyKing Brushless Gimbal Assembly Tutorial


As with any kit assembly, it is best practice to lay out all the components and fixings. The HobbyKing Brushless ActionCam Gimbal is no different. This helps you know whether or not you are missing anything and also makes it easier to find the components you need for each step:

It is worth nothing that there are five different types of spacers supplied with this kit:
 9x 10mm 
 1x 10mm w/external thread
 3x 30mm
 3x 20mm
 2x 21mm
You also have three different types of screws:
 6x M2 Socket Head cap screws
 4x M2.5 Socket Head button screws
38x M3 Socket Head button screws
Take the parts shown above and 2x21mm spacers. Assemble the parts and spacers as shown in the image below - they are held together with 4xM3 screws. Take care to fit the motor mounting plate in the correct orientation as the motor does not mount centrally on to the plate.
Take the parts shown above and 3x30mm spacers. Assemble the parts and spacers as shown below - they are held together with 3xM3 screws. In a later step the motor will mount to this plate centrally so the orientation is not important.



Take the parts shown above and 3x10mm spacers. You will not need the 3xM2 screws which are bagged separately with the motor however these will be used in STEP 6 so keep them to hand. Fix the motor to the circular/triangular mounting plate with 2xM3 screws.
Take the component you assembled in STEP 2 and fix the motor and mounting plate to it as shown below. You will need 3x M3 screws. Take care to ensure that the motor is oriented so the wires are more easily routed to your controller board.
Take the parts shown above, 2x10mm spacers, 1x10mm spacer w/external thread and 3x20mm spacers. Assemble the parts and spacers as shown below - they are held together with 8xM3 screws. 
Take note that only one of the 10mm spacers is sandwiched between the plates. The 10mm spacer w/external thread appears in the image below as the furthest to the right protruding from the reverse of the component and in the second image as the closest to the bottom. 
Visible from the front of the component here is a hole to the other side of the motor mounting plate which is intentionally left empty. This is a slightly larger hole and is simply used as access to reach the M3 screw which fixes the 10mm spacer w/o external thread to the reverse of the component.
Take the parts shown above and the component you assembled in STEP 4. Fix the motor to the mounting plate in the same way as you did in STEP 3 using 2xM3 screws. Again, make sure you will be able to easily route your wires to your controller board.
Secondly, take the two remaining pieces and fix them to the protruding spacers either side of the rear of the motor using 2xM3 screws. These are the arms which you can mount your controller board to if you wish to. (If you would like to mount your controller board somewhere else then these arms are not necessary.)


You should now have three assembled components. The resulting component from STEP 1 fixes on to the resulting component from STEP 3 using 3xM2 screws through the bell of the motor.
Next, the resulting component from STEP 5 fixes on in the same way using 3xM2 screws. Once these components are fixed together they should look like the image below:
Take the components in the image above and 4x10mm spacers. Using 4xM2.5 screws, fix the "hook and rod" mounting brackets to one of the plates. Take care to ensure the orientation is correct in this step or else the gimbal will not be able to be mounted in the correct way. (If you would rather not use the "hook and rod" mounting method, you can skip this step and mount the plate directly to your multirotor frame.)
Secondly, fix the 4x10mm spacers onto the other plate using 4xM3 screws. Now fit the two plates together using the rubber vibration dampening balls. These balls help decrease the vibrations transferred from the multirotor frame to the camera gimbal giving you a more steady picture.


Finally using 4xM3 screws, fix the resulting component from STEP 7 onto the rest of the gimabal. Your gimbal should now look like the images below and is ready for you to fit your camera.
How To Build Your RTB 250 CLASS QUAD KIT

This guide will walk you through building your HobbyRC Ready To Build 250 Class Quad Kit. If this is your first build then we'll try to make everything as easy to follow as possible. If you've made a quad before then that's fine too, just ignore anything you already know. You will need to be able to use a soldering iron - if you've never used one before, it's not too difficult and with a little practice you should be fine (here is a good resource for learning to solder:

Things You'll Need:

- HobbyRC Ready To Build 250 Class Quad Kit

- A soldering iron and some solder

- A Transmitter (TX) and Receiver (RX) (suggested TX / suggested RX)

- A Battery (suggested battery)

NB - It's worth nothing that in our kit we don't include a transmitter, receiver or battery and you'll need these to fly your quad. Since people often have more than one multirotor build, they tend to use the same TX/RX/batteries on multiple builds. For this reason, we decided to let you buy your own (or use one you already have). In either case, you need any 6 channel transmitter and compatible receiver (probably of the same brand) and a 2200mAh 4S battery (LiPo or LiFePo4).

Step One - Mounting Your Motors

For this step you will need the 4 x Emax 1806 2280kV motors and the Diatone G10 FPV250 frame. Take one of your motors and one of the circular mounting plates which came with your frame. Screw the mounting plate to the motor as shown in the images below.




Ready To Build

What is Ready To Build?

Building an RC multirotor is a rewarding yet daunting task. Before you can even begin to start assembling your model, you need to decide which components it will be made of. There are thousands of different combinations of frames, motors, ESCs, etc. All of these will produce a model which performs slightly differently to the last and some that won't even fly at all!

So how do you decide which parts to buy? You could spend hours trawling through forum posts on the Internet reading about other people's builds. This can take a lot of time and although you will undoubtedly gather some useful information, you will often be left with more questions than answers. In addition to this, people's experience differ and rarely will you find real qualitative data. 

To this end, we have put together and tested a few different builds which we think are a great starting point for building your own multirotor. We have filtered through many different combinations of components and found a few decent builds which meet these requirements:

- Straightforward construction

- Simple and enjoyable to fly

- Good value for money

By choosing one of our Ready To Build kits, you can be confident that (if assembled correctly) the final product will fly pretty well! There may well be an aspect which you would like to change, that's fine. Having built your multirotor, you now have the skills to tinker away to your heart's content.

If you have never built an RC multirotor model before or if you have simply had trouble sourcing your own components, then we would highly recommend purchasing one of our Ready To Build kits.

It's worth briefly mentioning that we don't include any batteries, or radio systems as standard with our kits. People often reuse these parts between builds and as such they are a treated as an interchangeable item. If you don't have batteries or a radio then don't worry, we still recommend solid options for all our builds and will show you the best places to buy them (whether it be it from our own shop or somewhere else).