Here is a review of the the Airblade Assault 130mm – a brushless micro quad frame. We will also show you how we built the frame and how she flew.
Get your Airblade Assult 130 frame from 65Drones. This review is done by Konrad.
The frame – Airblade Assault 130
Airblade Assault 130 mini quad frame is made from 3K carbon fibre, both the material and cutting quality is very good with no rough edges. It consists of two plates which are held together with three 20mm nylon standoffs.
This frame is very light at 30 grams only (without FC spacers) thanks to the unibody design. The bottom plate is very stiff, top plate is a bit more bendy (because it’s thinner and has more cut-outs), but the entire frame feels rigid enough when assembled.
Even being this small, it can take standard size 36x36mm flight controllers, such as the Naze32 or CC3D. It should also be relatively easy to stick a mini-sized FC on the bottom plate with double sided tape.
Diagonal motor to motor distance is about 135mm.
It’s a “dead cat” style frame – the motors are placed relatively close to the X-quad pattern, however the front arms are a bit more spread out than the rear. This creates more room for the propellers, yet avoids props to block the FPV camera view. Props are not visible in the footage while using the micro 600TVL camera, of 170° FOV lens.
The frame accepts 1104 or 1306 motors, and it’s able to swing 3 inch props.
The cutout on the top plate allows a RG316 coax wire to slide through. The gap is then closed by the screw. This design makes it very easy to install directly soldered FPV antenna wire.
The package includes:
- 1x 1mm top 3k carbon plate
- 1x 2.5mm bottom 3k carbon plate
- 3x 20mm nylon female-female standoffs
- 4x 8mm nylon female-female standoffs
- 4x 10mm nylon male-female standoffs
- 4x 5mm M3 allen screws
- 10x 8mm M3 allen screws
- 4x M3 nylon nuts
The frame I received was the first version. There is now a new version available with thicker and slightly redesigned plates. The manufacturer seems to be listening to suggestions from the community, for example a FPV antenna pigtail hole is now added.
The manufacturer also designed soem 3D printing parts you can download from thingiverse, to protect components in case of a crash, but I don’t want to add extra weight so I won’t use them.
DYS BX1306 4000kV motors
The DYS BX1306 4000KV motors come in CW/CCW pairs with standard DYS hardware: prop caps, a set of M2 screws, heatshrink and 2mm bullet connectors. They have integrated standard 5mm propeller shafts.
The motor is designed to be used with 3″ propeller on 3S LiPo packs. After some initial 3S bench tests on 3045 bi- and tri-blades, the motor was getting pretty hot after being on 100% throttle burst for just a few seconds. But in real flights, it doesn’t get as hot thanks to the good air flow. It starts getting hot when power is over 140 Watts.
I tested these motors on the Diatone 3045 dual and triblade propellers. I also tried some cut-down props from 5040, 5045 and 6030. Other users of this frame reported that RotorX 3040t triblades to be very efficient and powerful on these small motors. But those props are quite expensive though (about $4,50-$4.99 per set).
Here is the thrust test on this motor with XM20A ESCs and FVT Littlebee 20A.
- Weight: 13g
- M2 mounting holes
- Shaft: 2mm main shaft and 5mm integrated prop shaft
- Recommended voltage: 2S-3S
- Airblade Assault 130 carbon fiber frame
- DYS BX1306 4000kv motor
- DYS XM20A ESC
- Jumper Naze32&OSD, later changed to Naze32 rev6
- Diatone PDB with 5v linear regulator
- Flysky ia6b PPM receiver, depinned
A tiny build like this requires a bit more planning. I had to test fitting components before mounting and soldering. Assembling the frame is pretty straightforward and unibody design makes maintenance easy.
As I’m not using a micro size RX and VTX, so I decided not to use standard FC nylon spacers provided with the kit. Instead, I used only nylon screws, and separated components with nylon nuts and washers so the FC/PDB stack could be as low as possible.
I chose to use a simple stackable Diatone PDB, because most of the PDB on the market are designed for 4S, which provide both 5V and 12V voltage regulators. However 12V is really not needed on a 3S build.
This Diatone PDB has two 5V linear regulators which is pretty much noise-free to my FPV components (switching regulators is more noisy). It also protects the electronics from voltage spikes produced by the ESC’s.
To power the quad, I used a XT30 connector which in my opinion is a better than a JST, the XT30 allows you to conduct more current than the JST. A pair of the XT30 connectors weighs under 2 grams, and they look tiny compared to an XT60.
The only way to mount ESC’s on the arms, is to wrap motor wires around the ESCs. Remember to leave some space between the motor and ESC, so the motor bell doesn’t touch the ESC when spinning.
I use the Flysky i6 radio, but as Flysky doesn’t make any micro-sized receivers, I had to make my own by de-pinning my IA6B RX. This saves space and weight significantly.
Additionally I reinforced the antennas with hot glue as I already found out that they tend to break off the board even when it’s protected by the plastic case. I also shorten the antenna by removing the shielding from both dipoles, so they don’t get sucked into the props.
The de-pinned, heatshrinked Flysky ia6b weights only 6g.
- Micro 600tvl camera
- Micro MinimOSD
- Aomway 32ch 200mw VTX, direct soldered DIY cloverleaf
- Small 0.7A LC filter for the VTX
I removed the copper antenna connector from the Aomway to save weight. It’s not the simplest of things to do as it’s soldered to both sides of the board. There are two way to remove it:
- Cut one side with a hacksaw or thin wire cutters, then de-solder the other side
- The second method is to heat up the whole connector and slide it out, it’s a bit risky as the overheating could delaminate the copper and rip the pads
That’s what I exactly did – the center pad came off, but fortunately it still works. I managed to solder to the bit of the pad that is left on the board. Then I reinforced the coax with hot glue (epoxy would be better).
I find exposed cloverleaf antennas way too fragile for proximity flying, I used my favourite method of protecting it – I took a lid from a Kinder Surprise Egg. It’s more durable than “half ping-pong ball dome” and fits my cloverleaf antennas perfectly.
MinimOSD was prepared with a single row of header pins, but video in and out have the wires soldered on directly. This takes very little space, but yet still makes it possible to easily plug FTDI in for programming. The MinimOSD is fixed to the frame with double sided foamy tape.
Mini FPV camera is secured between the two front standoffs with hot glue:
LC filter in red heatshrink sits below the camera and provides Aomway with clean 3S power. Finished wiring the power and FPV:
Entire FPV system weights about 15g.
Mounting the flight controller
Initially I wanted to use the flight controller provided by 65Drones, the Naze32&OSD (MinimOSD integrated Naze32 board) – but the board turned out to be using M2 mounting holes, and they don’t match the holes on the frame. I settled with a used Naze32 and a standalone micro MinimOSD.
The best solution to save space in a tight build is to direct solder wires to the FC. For a cleaner look I decided to solder them from the bottom. Here I also used a 5mm buzzer instead of 9mm I use on bigger builds. It’s smaller but still perfectly audible.
Finished build, VTX is now sitting in the front narrow part of the frame, the RX on top of the Naze32 FC:
Airblade Assault 130 compared to Demon Ghost 220 mini quad.
This tiny build weights 153g, 228g including a 3s 850mah 45C nano-tech LiPo.
This build easily gives me 6-7 minutes of fast flying through the garden per flight (with DAL 3045BN triblades props). I barely feel any voltage sag in this environment (voltage fluctuate around only +/-0.4V). I reckon flight time could be shortened by half in the field where we normally would push full throttle all the time :)
Overall, this is a fantastic little quad, I’m very satisfied with how well it flies, stock Betaflight PIDs needs a bit of a tuning though. Flying experience is different from standard 210/250 mini quad, since it carries less than half the weight of a regular build, but is still capable of 4:1 thrust-weight ratio, it reacts instantly on sharp turns.
Some footage from flights:
There aren’t many choices for strong 3″ props on the market currently – we have HQ, Gemfan, DAL and RotorX, but pitch choices are very limited. More will probably start appearing soon as small builds are becoming more popular.
You can however use cut-down props from larger propellers that you already have. I did that by using digital calliper, set to 35,42 mm (blade length of the DAL 3045BN), and “scratch-mark” the prop with the sharp tip. This gave me a nice curved line to follow and cut with nail clippers.
The only prop that was difficult to cut with this method was the DAL 5040 “Indestructible” V2 propeller. I suggest using a dremel for it. You could probably 3D print some dremel cutting tool that would make it easier and more accurate.
ESC calibration on a Naze32 rev6 (no-diode version)
Here I used a first version of the Naze32 rev6 that is missing a diode on 5v trace. It passes power into the main line after plugging USB cable in, which is enough to initialize the ESCs. If You try to calibrate using cleanflight motor tab, they will immediately spin at full throttle after plugging the lipo. This makes standard calibration hard to do without tinkering.
Note that this issue is only present if You use a BEC that doesn’t prevent 5v back-feeding into main power line.
You can still setup Your ESCs properly by configuring them using BLHeli or SimonK and setting min and max PPM throttle range manually.
5v back-feeding issue can be fixed by soldering a Schottky diode on 5v pad – more info. You could also temporarily unplug or desolder FC power wire just for calibration.
Naze32 rev6a (and the rev6b which has some further fixes) is a fixed version of the board that has the diode soldered in on 5v line. Beware of rev6 clones marketed as the rev6a – intofpv.com users report that some of them still miss the diode. Some “rev6a” sellers even show pictures of normal rev6 version with the part missing.
With 20mm frame spacers, top mounted lipo can be smashed by props.
During the maiden I managed to scratch 1 lipo, dent another one and make a hole in third – they always move a bit after a crash and on 20mm spacers and get straight into the prop. One of the damaged cells had inner layers exposed, but luckily it didn’t catch fire.
I recommend using 25mm spacers as a minimum, mounting battery on the bottom or use a heavy strap to secure it better.
Note: shorter spacers make the centre of gravity lower in the craft, which means it will handle better. For me it doesn’t justify risking lipo damage.
In the end I decided to use 25mm spacers and a rubberized strap.
Using a smaller FPV kit
Instead of using full featured FPV transmitter, I could build a micro FPV setup powered directly from PDBs 5v pads. This would probably let me get rid of any additional filtering making the build 8-9g lighter.
Author: Konrad Stepanajtys Join us as a guest writer and help move the hobby forward.