X210 FPV Racer

This new racer is the 2017 FPV racer upgrade. I'm still flying the ones I built two to three years ago and alot has happen in terms of performance.


X210

Parts

The Realacc X210 is a clone/near clone of the Lumenier QAV-X "CHARPU" frame. As usuall with Chinese copies the frame comes priced at about 1/4th of the original product. And as usual you can expect some differences, shortcomings and quality issues. The initial feel of the frame is fairly good. The sharp edges needs some sanding, but it the milling quality is over expectation. There are some slots that have not been milled properly.


Realacc X210

The kit comes with a completely unlabeled but is sold as a CC3D REVO. There is not such thing as CC3D REVO but the name implies that it is a Librepilot Revolution. It is not that either, the hardware specs match, but not the board layout. It is more correctly a Flip32 F4, which is more or less a Revolution with a different board layout. The board comes flashed with Raceflight which is more or less the only option for running this FC.

The motors looks fine but later when spun up they turned out quite unbalanced.

Build

I began by soldering motors to the ESCs and attaching them to the frame. The ESCs has uncovered soldering pads, which is nice, and the motor leads are not lackered, which would always be a really bad surprise.

When mounting the motors it turns out the milled slot in the frame is half a millimeter to far from the center of the motor mount. The screw can be screwed in with a little fiddling and a bit of force. But be careful, I managed to damage the threads on one of my motors.


X210 with motor, pdb and FC

PDB

The power distribution board is not really necessary but does very much provide the nice and clean build i terms of wiring. This board comes with 5V and 12V regulators which will come in handy later on. As I am using EC3 and not XT60 I soldered cables to the PDB power pads. I recommend doing this even if you're using XT60 as a crash may cause the battery to rip your PDB to pieces otherwise. The power leads to the ESCs are soldered to the PDB.


PDB and ESCs


ESCs

The ESCs (Racerstar RS30A V2) comes flashed with BLHELI_S and pre-configured for Multishot. I did as I have always done and soldered them with the wires straight from the motors knowing that I would need to configure the rotation direction later on for two of the motors. I intended to use a DYS USB Linker that I had from before. But that didn't work. I don't know why but after an hour of trying I gave up and ordered a Racerstar USB Linker right away. This turned out unnecessary a few days later as I figured out how to program the ESCs from Betaflight.

Flight controller

The flight controller that comes with it is remarkably unlabeled. Banggood claims it to be a super combo of CC3D REVO F4 Raceflight. In fact, it is a Flip32 F4 which also goes under the name Airbot F4. I spent a lot of time with Raceflight trying to set it up but the GUI was buggy and I had to reflash the firmware multiple times. I also couldn't get OSD, SBUS and the LEDs working at the same time. After some time I turned to Betaflight. Choosing target Airbot F4 solves just about everything, setup is easy as a normal cleanflight setup.

When it comes to mounting the flight controller space is very limited, maybe not at this stage but later on. I recommend soldering all the cables to the flight controller to avoid the rather cumbersome servo pin headers and connectors.


Telemetry sensor

I'm flying a Futaba system and I have fallen in love with using telemetry to record flight data and to monitor voltage and power consumption while flying. To do this I need to have a telemetry sensor installed in the model. The flight controller has built in voltage monitoring and I know that newer PDBs also have current sensing, but until I switch to FrSky I'm stuck with the Futaba system.

Futaba receivers and sensors are quite expensive and I tend to try to get them second hand. This was the case this time as well. Unfortunately the seller did not inform me that the sensor he sold was of the larger kind. I had to rip one from an older model instead since even the smaller sensor is a tight fit in this frame.


E-Fuel gauge pro with Realacc X210
E-Feulgauge PRO sensor, no-go in this frame.

Camera and OSD

I got an OSD board which fits on the back side of the camera. It is a mwosd compatible device which gives much more functionality than my old favourite the "super simple". The devices needs to be programmed with mwosd, preferable before installation. I used a FTDI Serial USB adapter to set it up. I usually use this device when programming Arduinos. Luckily (or maybe by design) the pinout on the adapter matches with the pinout on the osd board.


OSD board monted on camera
OSD board on the backside of the camera


Programming the OSD
Programmer connected to the OSD

When mounting the camera on the frame I managed to break it. I attached it will two screws that turned out too long and I scraped off one connection to what seems to be a voltage regulator. I managed to repair it by re positioning the damaged circuit and measuring to check that everything is ok.

Damaged camera board
Damaged camera board

Receiver and video transmitter

Once again, I'm stuck with Futaba for now. I'm using a R7003SB for this build. I'm using this receiver for all my telemetry enabled models in fact. Fitting the receiver and the video transmitter inside the frame is impossible. Instead, I have the transmitter mounter on top of the top plate, and the transmitter on the inside. The receiver itself will prevent mounting any GoPro-ish camera on top. But I can live without that for now.

LED board

The kit comes with a LED board which is mounted on the backside of the frame. The is fitted with an array of NeoPixel style LEDs and easily configured from the flight controller. However, the board comes with a pin header which is mostly impractical and I removed it and soldered cables directly between the board and the FC.

20170324_214513


The inside

I had a lot of problems getting the camera to work correctly and every time I need to open up the model and unscrew the OSD board. Needless to say, I was exposed to the snakepit of wires on the inside of the frame every time.

IMGP9743


Flight results

I never really got the camera performing as I had hoped, especially in low light conditions, but during the day it is working "good enough" at the moment. When I finally took the first full FPV flight I was not disappointed. I knew it was "overpowered" and hovered at about 30% throttle. Knowing this, I had already taken the precaution of adjusting the hover point and throttle expo in betaflight. This makes it much easier to hover.

Flying an overpower quad is fantastic. It never lets you down. It does exactly what you tell. It spins as fast as you want and it gives you the throttle control when you want it. This setup is no different, it doesn't let you down. It won't let you reach the points when you start getting "strange" feelings. Unless you're a very advanced pilot of course.

Here's the video from the full flight. Unedited. And bare with me, I'm a bit rusty.




No comments :

Post a Comment