Many thanks to ZOHD for sending us their latest and greatest FPV wing for the review – the Dart XL Extreme FPV Wing. Let me take you through my experience of this model, and give you my honest feelings and thoughts in this review.
This review is written by guest writer, Greg McKean.
This is a PNP (plug and play) kit which means it includes everything you need to fly except the radio receiver. Here is the spec:
- Material: Biodegradable BEPP
- Wingspan: 1000mm (39.37”)
- Length: 596mm (23.46”)
- Flying speed: 25-100+km/h
- Motor: 2216-1300KV
- ESC: 30A w/5V 3A BEC
- Servos: 9g Metal Gear Digital
- Prop: 9X4.5
- Recommended Battery: 4S 3300mAh
- Wing area: 19.8dm²
- Wing load: 60.6g/dm² (Max.)
- Recommended Max. Flying weight: 1200g
- Max. Flying time: 40 minutes (with recommended battery)
First off the bat, this came from China, so where are the dents in the packaging?
From past experience, it’s not unusual to see big dents in the boxes and ripped packaging when you ship a parcel this big from China… But no, I received this with minimal damage. Fist thumbs up of the review!
You can see that the Dart XL Extreme is shipped in 2 boxes, the main product box and the shipping box. This is great as the shipping box takes all the bumps and knocks that goes with the nature of shipping from the other side of the world.
As you can see by the images, the product box has slight damage that is not even worth mentioning, I would even say I received the Dart XL in mint condition when considering the journey it has been on.
Open the box and you will find three individual boxes inside, containing all the parts required to get this bird in the air (with the exception of radio receiver).
Box 1 contains the main wings, vertical stabilisers and instruction manuals.
The first thing I noticed was that proper English grammar was used in the instructions manual, which gave me great hope that I was on to a good thing here! Good start!
Then as I pulled out the first wing, wrapped in sealed bubble wrap, my initial thought was, “these guys have thought about this”.
Box 2 contains the main fuselage and main wing spar, again with all foam parts well protected in sealed bubble wrap.
Box 3 contains all the final pieces to complete the minimal build. This includes
- a 9×4.5 APC style propeller
- HD camera mounts
- HD camera plate adaptors
- vortex generators
- flight controller standoffs
- wing bolts
I will go through all parts of the aircraft in detail.
Beware that the Dart XL I received is a “review sample”, so anything I say here may or may not reflect the finished production version…
But SonicModell (or ZOHD, same company really) has confirmed the sample I received would be roughly 90% of the finished production version. The remaining 10% I guess relies on what reviewers like myself and community feedback have to say about it.
Now with the disclaimer out the way, let’s crack on!
As mentioned, the wings come in really nice bubble wrap bags. Getting my hands on the naked foam, I can say the foam resembles something similar to the Nano Talon foam.
I must say when it comes to foam quality, I am a bit of a snob. I have a background of flying Ritewing Mini Drak and E-wings Vortigaunt (probably two of the best FPV wings out there), so I am used to flying aircraft with very high quality foam.
Comparing the foam directly with these guys would be slightly unfair as they both fall in different price brackets. SonicModell has officially confirmed that the production model of the Dart XL will retail at $199.99 (around £155) for this PNP model. This is around the same price bracket you would pay for JUST the Mini Drak airframe without any components, so please bare that in mind.
I have since contacted Sonic Modell about the foam quality, and they replied that the foam of the production version will be “smoother for sure” and the “strength will also be optimized after the first mass production”. For what you get for £150 I am willing to overlook this foam and consider it value for money. Only the test of time and the inevitable “unexpected landings” will confirm this for sure.
Also on the subject of foam, the Dart XL is the first to come to market with BEEP foam (Biodegradable EPP foam) as I am aware. Save the planet while flying FPV at the same time, nice! I have also been assured by them even though it is biodegradable, it isn’t going to shrivel into a tiny wing every time it gets wet or exposed to elements as it will still take 100 years to degrade!
Each wing comes with a ZOHD branded 9g metal gear servo.
The installation of the servo looks really nice and sits flush with the wing profile. I have no experience with these particular servos but based in the size of the elevons that it is required to move, I believe this will be a good match providing the gear quality and resolution is where it needs to be.
Based on my initial look at the build, I reckon ZOHD wouldn’t have “dropped the ball” on something this basic. So I will stick my neck out and say these will be good and up for the job.
My first immediate concern that springs to mind is the quality of the clevis and control horns.
To me these look a bit underwhelming… Come on ZOHD, you considered and included vortex generators! Let’s beef up these “bread and butter” components a bit?
For the sake of a few more pennies, I would like to see these improved and would be willing to pay a bit more for something I consider one of the most important aspects of the build.
I can confirm that these control horns and linkages will be the ones used on the production model. However Sonic Modell have since confirmed that “these have been tested to the extreme and up to standard”.
Don’t get me wrong, I am sure they will do the job… but for how long? My feedback to them would be to upgrade the rods, clevises and horns to something a bit more substantial. Especially as these are mounted on the underside of the wing and will be subject to hard landings and snagging. And this leads to my next suggestion: top surface mounting may have been a better approach in hindsight.
Each elevon comes with a pre-installed carbon fibre spar to add more strength and rigidity to the elevon. This is such a nice touch and shows the attention to detail they do have, but again slightly let down by the elevon’s foam hinge.
This is putting the reliability of the hinge purely down to the quality of the foam and its properties. Something I am sure they are advocating. Unfortunately I am unable to comment on how well this would work until I had some flight time with this model. I am happy to put my faith in their previous experience in the meantime.
A really nice touch is the detachable wing mechanism. This basically allows you to run your servo, VTX and receiver cables to a quick release adaptor/plug for quick wing attachment for transport. Big thumbs up from me on this one.
This is a much welcomed addition and I hope other manufacturers take note of this. This is what us consumers are wanting and I believe only ZOHD have delivered this convenient feature so far (in the hobby industry).
Don’t like cutting into foam to install your receivers and video transmitters? Relax, these guys have thought this through by pre-cutting exclusive bays already in the wings for these components.
It also allows excellent air flow and more than adequate separation to help eradicate interference. Thanks goodness for this, imagine having to actually cut through the foam yourself in this build! Great thinking again by ZOHD!
If you thought that the wing release adapter is the most unique aspect to this wing, you would be wrong.
ZOHD have include inverted wingtips. They claim the reasoning behind this is “to provide more lift force and ensure a super efficient wing surface”. I’m not entirely sure what they mean by this, nor do I really care, all I know is that they look cool! I’m an easy sell on this I guess!
This leads nicely on to my next “i’m not really sure why but don’t really care” point… The vortex generators!
There are slots near the leading edge of the wing to allow you to install the vortex generators which are included in the kit. To be brutally honest, I don’t believe these will scale down from full scale to model scale level to have any significant impact on performance.
They do look awesome and that’s fine with me and enough for me to actually install them. I am more than happy to proved wrong about them in my flight testing.
Protected Leading Edges
Final thing to mention regarding the wings are the nice impact-resistant protection covers on the leading edge of the wings. Again, a nice touch. Or is this a required feature due to the quality of the foam?
Let’s talk about these vertical stabilisers. These are also made from moulded BEEP foam which is a really nice change from the standard correx based solutions you get with many FPV wings.
I did notice they opted for an offset, V-tail style vertical stabiliser, not too long after the release of another plank wing design to the market with similar vertical stabiliser setup.
Whether this was intentional or not, the design choice is in line with the “push the design envelope” philosophy in which ZOHD have clearly decided to adopt. I can also confirm from past experience, this stab setup is more than adequate for vertical stabilisation.
Like the wings, the fuselage comes shipped in a bubble wrap bag and arrived in perfect condition. The foam used seems to be the exact same as the wings.
The fuselage has two removable parts: the forward battery bay door and the aft hatch bay door. The battery bay door is held down with a wedge on the front and rare-earth magnets on the back, making a very solid and flush connection.
The aft hatch door is also held in place with a wedge on the front, but wood screws at the back. This is obviously designed to be removed less often than the battery battery.
The aft hatch door has some really nice honeycomb cooling vents at the front and the back to ensure adequate airflow over the ESC and flight controller.
Starting at the front and working our way back, the fuselage comes with really nice plastic molded nose that is capable of accommodating a wide range of FPV and HD cameras. These include cameras like the Runcam HD, Runcam 2, Runcam 3S, Swift, Split, GoPro Hero4, 5, 6, 7 and the Session series. Simply use the provided camera mounting molds and faceplates for cameras of different shapes.
Looking inside the battery bay, I can say it was a pleasant surprise. This is huge considering the wingspan of the aircraft is only 1000mm. They recommend flying a 3300mah 4s battery, which I will initially test with but I believe this would be able to accommodate a 5200mah 4s which would open a lot of doors and allow for pilots to do longer range with this aircraft. Something I am willing to try and see if it can handle these heavier wing loads.
Also in the battery bay you will find a plywood plate with CG markers, again a nice touch and indication that they want you to experiment with different battery setups. On this plywood plate, there is also an included battery strap – GREAT STUFF!
Rear Hatch Bay
Moving onto the aft hatch bay, you will find more plywood parts, these are mainly for reinforcing the foam at stress points like the main spar joint and motor mount. Also included is a plywood flight controller mount that can accommodate the included 30.5×30.5mm standoff mounts, allowing you to mount standard flight controller boards.
Located in the rear of the hatch bay is the included ZOHD branded 30amp ESC, which has integrated 5V/3A BEC to power your flight controller and servos.
I do not have any previous experience with this speed controller, however I feel 30A may be on the low side especially if you are planning on flying this with larger batteries, or planning to fly this aircraft as ZOHD state in their marketing material as “fly like you stole it”.
Again, similar to the control linkages, I would have been happy to pay a bit more to have an equivalent 60A ESC in there just to give you plenty of head room if you decide to wide open throttle it all the time! But I am happy to be proven wrong on my flight testing where I can monitor the amp draw.
Finally we come to the motor. My first thought was the supplied 2216-1300KV motor seems a bit under-spec’ed for this aircraft, especially as it will be swinging a 9 inch prop.
My concern is that it may lack the grunt to push things to the edge. If you are aiming on cruising and battery conservation then this could still be a great option for you.
Here are what I had to do before the maiden flight.
I began on the starboard wing. I will be installing the receiver in this. Begin by removing the pre-cut bay foam.
I lined up roughly where I wanted the antenna to be installed and marked on the foam where the cut is to be.
Bore a hole for the antenna through the foam and score a channel to allow the antenna cable to sit nicely in the foam.
Once happy with the fit, secure the receiver in the bay. I used some hot glue in this case.
Locate the female servo connector found near the wing root. Run a servo extension cable from this to the video transmitter. There is a pre cut channel in the foam to run the servo extension wire through. Ensure the black wire goes to the receiver’s ground, red wire to the receiver’s 5v and the white wire to the receiver’s sbus.
Moving onto the port wing, I will be installing the video transmitter in it. Like the starboard wing, begin by removing the precut bay foam. Mark on the foam where you plan to feed your antenna through.
Similar to the receiver, score in the foam where you wish to run the antenna cable in the foam and feed the antenna through.
Attach the video transmitter to the antenna and secure video receiver in place. I use hot glue in this case.
Again, locate the female servo connector in the wing root and run a servo extension from here to the video transmitter using the precut channel. Black wire to VTX ground, red wire to vtx power and white wire to vtx video in.
Attach the vertical stabilisers by sliding them into the pre cut hole on the wing.
Once pushed in, simply flip the plane over and locate the locking nut located in the skid.
Turn the locking nut 90 degrees to lock stabiliser in place.
Now run a very small bead of glue (I am using CA glue) in the vortex generator slots found on the leading edge of the wing.
Gently slide the vortex generator in the slot, ensuring it is pushed all the way to the front of the slot.
Repeat this process for all of the remaining vortex generators.
Your wings are now completed.
Start building the main fuselage. Using a standard sized HS1177 type FPV camera, insert this into the nose of the wing. I found this was a nice tight fit however based on what camera you are using you may need to glue or tape in place.
Once camera is installed, run camera wire down pre cut wire channel in fuselage.
For HD camera, I will be using a Runcam 2. Locate the best suited HD mount for your camera. Embed your camera in the mount, then securely push the mount into the nose of the plane.
Ensure that the camera’s lens are seated properly with the front panel.
If needed, take the provided faceplate and seat the plate over the front of the nose plate, ensuring it is stuck securely to the nose.
I chose to cut the pre installed speed controller power cable in order to direct solder the speed controller to flight controller/power distribution board.
Taking the XT60 side, I soldered this to the flight controller’s main power in.
The flight controller I am using is the Matek F405 Wing FC: http://bit.ly/2CBYdvK
Then I solder the speed controller directly to the flight controllers speed controller pads.
Secure the flight controller to the aircraft using the provided velcro.
Now permanently secure the speed controller to the aircraft using a zip tie.
Attach the speed controller to the flight controller. For my particular flight controller, I was required to change the wire order to attach the speed controller correctly. Please follow your flight controller instructions.
The servos are connected to the bottom rail (flat bottom) of the wing connectors.
Trace the servo wires to inside the fuselage. Once identified the correct servo wires, attach them to your servo inputs of your flight controller.
Now attach your video transmitter to your flight controller video out. Connect your camera to your flight controller video in and finally connect your receiver to your sbus and 5v/ground rail.
Slide the main spar through the fuselage, allowing equal distance on both sides.
Slide one wing on, ensuring the main spar goes through as far as it can into the wing.
Make sure everything lines up correctly before fully seating the wing.
Do the same for the other wing.
With both wing fully seated into the fuselage, screw wing bolts from inside the fuselage and ensure they engage with wing and tighten.
Loosen both wood screws located at the aft of the aircraft.
Seat the aft hatch in.
Once seated correctly, tighten both wood screws directly into the hatch.
Well done your model is now built!
I must admit, this was the quickest aircraft I have ever built. I have come from a kit building background where you need to endure time hungry tasks such as laminating, hinging elevons and installing servos etc… I finished this build in one short evening.
During the build you can clearly see the attention to detail and the thought involved as to how all parts come together. The ONLY time I used glue was for attaching the receiver and video transmitter to the wings. However this could have been done using double sided tape. I also reckon you could also get away without having to glue the vortex generators in as the pre cut slots make for a very tight friction fit.
I really love the way the wings attach to fuselage. Running the receiver, servos and video transmitter cables to a central connector makes for a very tidy install, not to mention the ability to quick release the wings on and off.
I love the simplicity of how the vertical stablisers attach with a simple locking nut, again allowing you to quickly add and remove them.
Pre cut receiver and video transmitter bays and servo cables channels. As a kit builder I can’t express how happy this makes me!
The only negative thing I can say about the build experience was that I was forced to use a flight controller. My initial plan was NOT to use an FC in this build, however due to the wing connectors, I was unable to run 3 servo cables to the receiver (2 x servos and 1 x ESC) without heavy modification to the wing.
Using just one servo cable means that you have to use PPM or SBUS on a flight controller instead of direct receiver inputs (PWM). The option to remedy this would be to house the receiver in the fuselage but that would impact the amount of separation, thus increasing the chance of RF issues. Not a biggie but would have been nice to run 3 cables to the receiver on the wing for those that fly “bareback”.
Setup the flight controller, calibrate the speed controller and set up your radio failsafe, CG etc…. With 3300mah LiPo and 5200 and their CG markers…
More coming soon…