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Blog posts of '2015' 'January'

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

* * * MISSED A FEW ASSEMBLY STEPS HERE - COULDN'T HOLD CAMERA AT THE SAME TIME AS STABBING PALM WITH HEX DRIVER * * *

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