This frame is reviewed by Artur B. Liquid frame from FlyingLemon is a mini quad frame designed for 5” props.
Get your Liquid frame from FlyingLemon.
Frame set contains:
- 3mm unibody bottom plate
- 1.5mm top plate
- 1.5mm camera plate
- FPV cam mounting plate
- 2 x side mounting plates for FPV cam
- 6 x golden aluminium standoffs
Assembled frame weights 81g which is remarkably light for a 5″ frame.
Liquid is an X frame with motor-to-motor distance of 235mm. However the body is not symmetric. It extends more to the front than it does to the back.
There are multiple cut outs to help with putting components inside the frame. On the bottom plate there are cut outs for securing FPV cam, flight controller and battery strap if battery is mounted on the underside of the frame. At the very back there are fixing holes for LEDs that can be purchased from FlyingLemon shop (not supplied for this review).
On the top plate there are cutouts for protruding FPV cam lens, FPV cam (if mounted to the top plate), battery strap, dip switches on VTX, VTX antenna and XT60 lipo cable.
Motors mounts are made for 3mm bolts, so it takes 22XX motors.
Mounting GoPro can be done with or without the HD cam plate. There are cut outs in the FPV cam side mount plates that can accommodate a velcro strap.
These were the parts I used in this build:
- Cobra 2204 2300kv motors
- LittleBee 20A ESC
- Naze32 Rev6 with Betaflight 2.2.0 (later replaced by a Dodo, because of the problems)
- Lemon Core PDB standard version (supplied for review)
- FrSky X4R-SB (SBUS)
- TS5823 32ch 200mw VTX
- HS1177 25mm Sony Super HAD FPV cam
- Spironet antenna
Started with soldering cables to Lemon Core PDB. Took some measurements for the cables lenght and soldered them onto the PDB. Lemon Core has LC filters and power regulators. I’ve set both outputs for FPV cam and VTX to 12V.
Motors and ESCs
Motors were bolted to the frame. Soldered ESC to the motors and trimmed ESC power cables before soldering them to PDB
Flight controller and PDB
Installed Naze32. Instead of going for servo plugs I decided to solder signal and ground wires from the ESCs and all other cables directly to the flight controller. This is the best way to save some weight and to have a nice and neat build. At first connected SBUS cable to the wrong pin No 1 instead of 4 but quickly spotted the mistake :)
Supplied PDB does not come with any OSD so decided to use telemetry. On Naze32 rev 6 had to use Soft Serial by bridging pin 5 and 6 together (yellow cable pictured below).
As always, I prefer to keep radio receiver and video transmitter under the top plate. This helps when top plate is removed when doing upgrades etc.
Boscam VTX had RP-SMA connector and I had to use 90 degree adapter screwed directly through the the top plate cutout. Turned out to be a really nice solution. Tried to shorten RX and VTX cables as much as possible for saving the quad weight.
Mounting FPV cam
With two side plates for FPV cam, mounting it was really easy. Used second hole so that the cam was still securely hidden inside the main frame body. I remember from my previous builds with HS1177 25mm cased fpv cam that the bracket holding the cam is pretty weak and often had some oscillations on the cam itself thanks to the bad mount.
Last few bits to do including connecting the top plate to the bottom and bolting everything together.
XT60 cables can be put through the cut out on the top plate and it can be securely hold there during the flights.
With VTX attached to the underside of the top plate, it is easy to access the dip switches too.
After about 4 hours quad was ready. The biggest problem I had with this build had nothing to do with the frame. It was Naze32 rev 6 issue. I have the very first version of it and this board supplies 5V to ESC and buzzer over USB connection. Because of that I couldn’t calibrate ESCs with the default Cleanflight method. Had to manually put Min and Max throttle values in BLHELi suite. Not a big deal but still annoying. As late found out, there was more problems with Naze32 Rev6, including quad falling off the sky after the flip.
Total AUW with DroneLabs 1400mah 4S lipo and GoPro was only 505g – very impressive!
Great things about the Liquid
- Frame is very light!
- Compact X design, minimising cable lengths in the build, making it even lighter
- Side plates for mounting FPV camera. Very effective solution
- Extra cut outs for velcro straps holding GoPro
- Very well thought cut outs for VTX
- Not much bigger than some 180 frames but accommodating 5” props can give much more power to the quad
Things can be improved on the Liquid 220
- The 3mm unibody bottom plate could break easily in my opinion. Would be good to have 4mm as an option for those who prefer durability over weight saving
- The frame only fits 1300-1500mah batteries. It’s possible to put 1800mah lipo but that leaves no space for the HD camera
- Not everyone likes gold standoffs :) But this is a matter of a personal preference rather than frame functionality
With mini quad market being pretty stuffed with frame options, Liquid seems to be an interesting one because of the light weight. In fact, it was by far the lightest build I’ve ever done. I am a little bit concerned about how durable this frame will be in the long run but I was not able to actually test it yet outdoor. The Naze32 Rev6 board gave me a headache and turned out to be faulty. FC was replaced later with Dodo but the proper maiden is yet to be done.
Flight video with this build: