Whereas many FPV drone producers are busy copying one another and releasing near-identical merchandise lately, HGLRC is without doubt one of the only a few firms nonetheless making an attempt to innovate and do one thing genuinely completely different. I’m genuinely impressed by what HGLRC has achieved with the Rekon35 V2, a 3.5-inch micro FPV drone purpose-built for long-range cruising. It’s clear that a whole lot of thought went into this design. After flying it and tearing it down, I’ve gathered loads of ideas—each good and unhealthy. Right here’s my hands-on overview.
Thinking about flying lengthy vary? Listed below are some sensible suggestions: https://oscarliang.com/long-range-fpv-flying-mini-quad/
The place to Purchase
You should purchase the Rekon35 V2 from these distributors:
What’s Included
- 2 units of propellers (8 in complete)
- USB cable for charging
- screws for mounting the props
- screwdriver
- stickers
- handbook
Specs
- Body: Rekon35 V2
- Flight Controller: HGLRC H743 20A ELRS 2.4G 2S V1 AIO
- FC Firmware: HGLRCH743
- Gyro: ICM42688P
- Motors: Specter 1404 5500KV
- Digital camera/VTX:
- HD: DJI O4 Lite Air Unit
- Analog: HGLRC Zeus Nano VTX 350mW
- Receiver: Onboard ELRS 2.4G (or 915MHz)
- GPS: HGLRC M100 Mini
- Propellers: Gemfan 3630 triblade
- Supported Battery: 2× 18650 Li-ion cells
- Marketed Weight (with out battery)
- HD Model: 180 ±5g
- Analog Model: 174 ±5g
- Energy Equipment Model: 169 ±5g
- Weight (My Measurements)
- DJI O4 model with out batteries: 187.5g
- With 2× Molicel P30B 18650 cells: 278.5g
Design and Construct
The HGLRC Rekon35 V2 is a 3.5-inch, 2S FPV drone.
Immediately, it stands out because of its distinctive building. The drone includes a totally enclosed injection-molded plastic physique that protects all inside electronics, giving it a clear, skilled, and sturdy look.
One frequent subject with the DJI O4 Air Unit is overheating when powered on with out airflow. Fortunately, HGLRC addressed this with a big heatsink mounted beneath the air unit. I used to be in a position to go away the drone powered on the bench for over 5 minutes with none overheating warnings, which ought to be even much less of a priority throughout precise flight with fixed airflow.
HGLRC additionally changed the inventory linear-polarized O4 antenna with an extended circularly polarized antenna, enhancing each vary and penetration. Primarily based on my testing, its efficiency is great.
The flight controller and motors are mounted on a carbon fiber plate, with 3mm-thick arms that really feel very stiff and strong.
There are two rows of vivid RGB LEDs on all sides of the drone. Fly this factor at night time and it genuinely seems to be like a tiny UFO gliding by means of the air. The LEDs are configurable in Betaflight and can be utilized to show helpful data akin to GPS standing, throttle stage, or battery voltage stage. Out of the field, they default to a rainbow impact.
Study configuring Betaflight LED on this information: https://oscarliang.com/setup-led-betaflight/
The drone is powered by two 18650 cells housed in a hinged battery compartment (battery isn’t included). Merely insert the batteries and also you’re able to fly.
Even higher, you’ll be able to go away the batteries contained in the drone and cost them immediately through the USB-C port on the rear like a DJI Mini, which is extremely handy.
The “no uncovered wires” design is considered one of my favourite features—every little thing seems to be clear, glossy, and properly protected.
You possibly can entry the DJI O4 Air Unit’s USB port and bind button from the perimeters of the drone.
To attach the drone to Betaflight, there’s one other USB-C port situated slightly below the charging port. You’ll have to push the spring-loaded antenna mount downward to entry it.
Battery – It Solely Takes 18650!
Open the battery compartment by holding down the 2 locking tabs and lifting the duvet to disclose the battery tray—simply essentially the most fascinating facet of this drone.
The Rekon35 V2 does NOT help LiPo battery. As an alternative, it runs on two particular person 18650 Li-ion cells—sure, the identical cylindrical batteries you’d usually use in radios, flashlights, or vaping gadgets.
At first, this would possibly sound limiting, but it surely’s really the core identification of the drone: long-range.
Li-ion batteries are extraordinarily fashionable for long-range FPV, however they’re normally assembled right into a battery pack and linked to the drone through an XT30 or XT60 connector like a regular LiPo. Instantly inserting particular person 18650 cells into the drone itself is genuinely distinctive. Whereas we’ve seen related concepts earlier than, they had been restricted to 1S setups—that is the primary BNF FPV drone to do it on 2S.
Really useful 18650 Batteries
I’ve examined many various 18650 cells: https://oscarliang.com/best-18650-li-ion-battery/
Listed below are my suggestions:
Best choice
Good Alternate options
Essential: The battery holder solely helps flat-top cells. Button-top 18650s is not going to match.
Tear Down: What’s Contained in the Drone?
Disassembling the Rekon35 V2 is easy. There are solely 6 M2 hex screws securing the plastic physique to the body.
The very first thing that shocked me was the unconventional flight controller design. It seems HGLRC might have designed this board particularly for the Rekon35 V2—it’s lengthy and rectangular moderately than the same old sq. form. That is an all-in-one (AIO) board, integrating the ESC and ELRS receiver onto the identical PCB. The upside is a really compact structure; the draw back is that if any main part fails, you’ll want to exchange your complete board.
The GPS module is the HGLRC M100 Mini, which I examined final yr and located to be wonderful. Regardless of its tiny dimension, it makes use of a u-blox M10 chip, delivering sturdy efficiency. I sometimes get a GPS repair in about 1.5 minutes with 8 satellites, and after 10 minutes it usually locks onto 19 satellites.
The digicam angle is adjustable, however you’ll have to take away the entrance cover to entry the mounting screws. Out of the field, the angle is ready to round 20 levels, which is good for long-range cruising, so I didn’t really feel the necessity to change it. For those who ceaselessly modify digicam angle, you possibly can in all probability drill a small entry gap within the cover to keep away from eradicating it every time.
The drone additionally comes with a small bodily beeper hidden between the 2 USB port within the rear, which is fairly loud. For those who crash in bushes or tall grass, this can be extraordinarily useful for restoration.
Flight Efficiency
Clean, Quiet, and Surprisingly Refined
The very first thing I observed is simply how quiet the Rekon35 V2 is. It’s shockingly low-noise for a 3.5-inch drone—you’ll be able to barely hear it from 100 meters away, even when doing flips and rolls. It’s good for discreet cruising.
The second shock was how steady and clean it feels within the air. It comes with a reasonably aggressive PID and filter tune, which is strictly what I wish to see in a BNF. This actually exhibits that HGLRC put real effort into tuning moderately than transport a generic setup.
However It’s Not Quick
It hovers at round 30% throttle at takeoff. At first, it feels fairly agile—you’ll be able to even do some freestyle strikes like flips, rolls, and split-S maneuvers. Nevertheless, a couple of minutes into the flight, you’ll be able to really feel the drone slowly shedding punch as a result of voltage sag, and it turns into more and more dangerous to aim aggressive maneuvers as you’re always warned about low voltage.
This isn’t a freestyle machine; it’s finest fitted to relaxed cruising.
Prime pace is round 70–80 km/h, and cruising sometimes sits between 40–50 km/h at roughly 40–45% throttle.
Lengthy Flight Time
The marketed 15-minute flight time is pretty correct for sluggish cruising. Realistically, it’s best to anticipate 13–14 minutes in case you fly up and down ceaselessly and blend in some freestyle strikes right here and there, particularly with some wind.
In calm circumstances with regular cruising, protecting 10km or extra is totally achievable.
Not the Greatest in Windy Situations
The Rekon 35 V2 doesn’t deal with wind significantly properly. In 20mph wind, the quad struggled considerably and was barely shifting into headwind.
With LiPo batteries, you possibly can usually simply punch by means of wind, however with Li-ion cells, there’s little throttle response as a result of voltage sag. For those who fly too far out in windy circumstances, there’s an actual threat you could not make it again, so keep away from pushing distance when wind is robust.
GPS Rescue Labored Effectively
GPS Rescue is configured out of the field, and failsafe is ready to Rescue mode.
In my testing setting, GPS Rescue labored properly and introduced the drone again near the takeoff level.
That stated, it’s best to at all times double-check your Rescue mode settings to make sure they fit your flying setting.
Try my information on Rescue Mode: https://oscarliang.com/setup-gps-rescue-mode-betaflight/
Present Sensor Wants Calibration
My Molicel P30B has an precise capability of round 2851 mAh, however the OSD reported 6036 mAh—greater than double the actual worth. The present sensor scale clearly wants calibration.
Limitations and Potential Enhancements
With this quad, battery high quality issues rather a lot. You need to use first rate 18650 cells—low-cost or counterfeit batteries will fully break the expertise. Sadly, faux 18650s are frequent on eBay and Amazon, which might frustrate newcomers who aren’t conversant in sourcing high quality cells.
The drone can also be barely heavy for a 3.5-inch quad, weighing 187g with out batteries. In case your purpose is to remain below the 250g weight restrict, this is probably not the most suitable choice out of the field. That stated, I have already got a couple of concepts to scale back weight and enhance effectivity, and I consider it ought to be potential to convey it below 250g. I’ll attempt to cowl these modifications in a future put up or replace this overview after the New Yr when I’ve extra free time.
Battery Charging
You possibly can cost the batteries contained in the drone through USB-C, with a charging energy of round 11–12W. This implies it takes roughly 2 to 2.5 hours to totally cost two 3000mAh 18650 cells.
Charging seems to cease at round 4.15V per cell, which is definitely an excellent signal—it doesn’t overcharge. Nevertheless, it doesn’t attain the complete 4.20V, so that you’re probably shedding a tiny quantity of capability (roughly 50mAh, or about 10 seconds of flight time). In follow, that is negligible.
For those who favor, you’ll be able to take away the cells and cost them with a devoted 18650 charger, or perhaps a LiPo charger utilizing a DIY holder like this. These strategies are more likely to be a lot quicker and ensures a full 4.2V cost. Nonetheless, charging immediately contained in the drone is extraordinarily handy, good for lazy folks like me 🙂
Tips on how to Setup
Handbook could be very useful.
Firmware
- FC Board: HGLRCH743, comes with BF 4.5.2
- ESC Firmware: Bluejay, 0.21.0 (F-H-40)
- ELRS Receiver: HGLRC Hermes 2.4GHz RX (3.5.3 firmware)
Binding ELRS receiver
Detailed directions might be discovered right here: https://oscarliang.com/bind-expresslrs-receivers/
Pairing DJI Goggles
Comply with the directions right here: https://oscarliang.com/how-to-setup-dji-o4-lite/#Pairing-DJI-Goggles-3-with-O4-Lite. The O4 doesn’t require activation, so you’ll be able to fly as quickly because it’s paired.
Betaflight Setup
- Energy & Battery tab: The settings are left at Betaflight default, that are for LiPo batteries, so low-voltage warnings will set off method too early. For 18650, it’s best to set Minimal Cell Voltage to 3V (will depend on the cells you might be utilizing, some can safely go as little as 2.8V and even 2.7V). Most Cell Voltage to 4.2V. Warning Cell voltage to three.2V. Present sensor scale additionally wants altering – I’ll publish my worth on a later date.
- PID Tuning tab: Arrange your individual charges.
- Modes Tab: Configure your arm change, angle mode, and turtle mode. For steerage, see this tutorial: https://oscarliang.com/betaflight-modes/#How-to-Setup-Arm-Change
- Receiver tab: Allow Telemetry
- GPS tab: My typical settings are to allow “Use Galileo” and “Set Dwelling Level As soon as”, set Floor help Sort to Auto
- OSD tab: Customise to your desire.
Putting in Propellers
Insert the translucent bushings into the prop hubs, mount them on the motors, and safe every prop with two screws.
Essential: The Rekon35 V2 makes use of reversed motor path.
That’s it—your Rekon35 V2 ought to now be prepared for its maiden flight.
Ultimate Ideas: Is the HGLRC Rekon35 V2 Value It?
The HGLRC Rekon35 V2 is a daring experiment—a drone constructed totally round 18650 Li-ion. One essential level is that you should use good-quality cells; poor batteries will lead to irritating efficiency.
HGLRC clearly invested a whole lot of effort into the design. That is essentially the most well-thought-out Li-ion-only FPV drone I’ve examined to this point. GPS Rescue works properly, the quad is environment friendly, quiet, clean, and cleverly engineered.
Get the Rekon35 V2 from:
That stated, I do want HGLRC had made the drone lighter, ideally protecting it below the 250g weight restrict. Because it’s not designed for freestyle or high-speed flight, the cumbersome building feels pointless. I consider a big portion of the plastic might be eliminated to scale back weight.
Even in inventory type, a 5 km spherical journey is totally potential, which is spectacular. Making it lighter would solely improve its potential.
The Rekon35 V2 isn’t good, but it surely’s genuinely fascinating. And in a interest filled with look-alike drones, that alone is refreshing.