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:
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.
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!
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’.
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).
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.
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.
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.
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.
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: