Evaluate: Flywoo Explorer LR4 with DJI O4 Professional – The Final Sub-250g Lengthy-Vary FPV Drone

June 4, 2025

7

I’ve been flying the Flywoo Explorer LR4 for five years, and it stays one in every of my favourite drones to take when touring. It’s light-weight and gives distinctive flight time—good for long-range exploration and capturing cinematic footage. So after I heard Flywoo had launched a brand new model that includes the DJI O4 Professional, I knew I had to purchase one and take a look at it out. On this evaluation, I’ll share my ideas on the up to date Explorer LR4, its execs and cons, and how one can optimize its flight efficiency and reliability.

A number of the hyperlinks on this web page are affiliate hyperlinks. I obtain a fee (at no further price to you) if you happen to make a purchase order after clicking on one in every of these affiliate hyperlinks. This helps help the free content material for the group on this web site. Please learn our Affiliate Hyperlink Coverage for extra info.

Study extra about long-range FPV flying on this information: https://oscarliang.com/long-range-fpv-flying-mini-quad/

A number of years in the past I travelled overseas with the Explorer carrying the Vista + Bare GoPro 6 on this compact setup.

And it was capable of produce this stage of footage, very spectacular efficiency. The O4 Professional is barely going to get even higher!

The place to Purchase

You should buy the Explorer LR4 O4 Professional Version from these distributors:

Word: You should buy the Explorer LR4 with or with out the DJI O4 Professional Air Unit. Nevertheless, the model that features the O4 Professional is $270 extra—whereas the O4 Professional alone prices solely $220. That’s a $50 markup! In case you’re comfy putting in the Air Unit your self, it’s cheaper to purchase the drone with out it and set up the O4 Professional individually. I’ll stroll you thru the set up course of later on this evaluation.

Equipment embody:

8 × Gemfan 4024-2 Black Props
2 × Battery Straps (15x180mm)
Screws
Further 3D printed mounts

Specs

Body: Flywoo Explorer LR4 O4 PRO Body Package
Flight Controller: Goku F722 Mini
ESC: Flywoo 45A 32bit 4-in-1 ESC
FPV System: DJI O4 Professional Air Unit
Receiver: ExpressLRS
Propellers: Gemfan 4024×2 Bi-blade
Motors: Flywoo Nin V2 1404 2750KV
GPS: GOKU GM10 Mini V3
Battery Connector: XT30
Weight:
- 171g (with out battery)
- 239g with a 4S 720mAh LiHV (sub-250g)
- 266g with a BetaFPV Lava 4S 850mAh LiPo

Construct High quality & Design

Virtually the Identical because the Authentic Design

Flywoo hasn’t modified a lot concerning the Explorer’s design for the reason that unique model from 5 years in the past. The primary replace is a modification to the body to accommodate the DJI O4 Professional Air Unit.

Flywoo Explorer Lr4 With Dji O4 Pro Long Range Sub250 Fpv Drone Compare Original Version

Left: Explorer O4 Professional; Proper: Authentic Explorer with Caddx Vista

For these unfamiliar with the Explorer, it makes use of a deadcat structure, which helps preserve the props out of the digital camera’s view. The arms are extraordinarily skinny—this drone isn’t constructed for crashing, however slightly for staying mild to maximise effectivity and flight time.

The soldering high quality seems to be nice. The motor wires are soldered vertically, holding the profile low and lowering the danger of wire injury. Antennas are mounted in a V-shape at 90°, which is perfect for sign reception—good consideration to element from Flywoo.

Electronics

Flywoo upgraded the FC/ESC stack from 16x16mm to 20x20mm. The bigger board measurement not solely makes repairs simpler doubtlessly, however the brand new ESC now options 45A 32-bit help—a serious step up from the earlier 13A model. It’s an enormous overkill for this construct (you’ll hardly use 10% of its present score), however hey, having further headroom isn’t a nasty factor.

All of the elements are related to the FC through connectors – no soldering on the FC in any respect.

The receiver is just not hooked up to something, simply left there hanging freely. With the O4 digital camera put in it’s type of being pressed by all of the wires between the stack and digital camera, so it’s not unfastened or something and hasn’t been a priority up to now throughout my testing.

They’ve additionally lastly added a present sensor, which is a giant plus for long-range flying. Voltage alone may be unreliable—particularly with low C-rated batteries that endure from voltage sag. With a present sensor, you get a significantly better thought of battery utilization and may higher decide when to land.

Because of the tight area, Flywoo needed to solder the capacitor on to the XT30 connector, which is a bit removed from the ESC. The capacitor can also be fairly small. Whereas not the simplest setup for noise filtering, it’s higher than nothing. Fortunately, the small motors don’t produce an excessive amount of electrical noise, so this needs to be high quality typically. Study capacitor on this information: https://oscarliang.com/capacitors-mini-quad/

GPS Enhancements

Flywoo continues to mount the GPS module on the rear, slightly below the VTX antennas—a location that I’ve all the time discovered problematic. Within the earlier mannequin, the M8-based GPS would take a very long time to get a 3D repair, and satellite tv for pc counts have been typically low because of interference from the close by VTX antennas. The routing of GPS wires beneath the VTX added much more EMI and made matter worse.

This time round, Flywoo tried to handle the difficulty by:

Shielding the GPS wires with copper tape
Upgrading to a more moderen, extra highly effective M10 GPS module

Whereas I nonetheless want that they had moved the GPS away from the VTX solely, these adjustments ought to enhance GPS reliability.

Receiver Antenna Mounting

One other design alternative I’m not a fan of is how the receiver antenna is mounted.

Whereas this mounting technique is easier for producers and works high quality for short-range flights (inside a few km), it’s not preferrred for long-range. For finest efficiency, antennas needs to be mounted vertically. Study extra about antenna mounting: https://oscarliang.com/antenna-positioning/

DJI O4 Professional

The DJI O4 Professional Air Unit is securely mounted on standoffs, leaving clearance for wires beneath. This setup permits for first rate airflow, serving to to maintain the air unit cool throughout flight. Regardless that the O4 Professional digital camera is barely mounted between easy TPU adapters, I didn’t discover any jello or vibration within the footage, Gyroflow additionally works flawlessly.

One draw back: the digital camera tilt angle is very restricted, with a most of round 15 levels. This restricts how briskly you’ll be able to fly, as increased speeds could have you staring on the floor extra. The restricted angle is because of the body’s compact peak—the O4 Professional digital camera is bodily giant, and rising the lean would require a taller body, which in flip would improve weight, drag and scale back effectivity. That stated, for a sluggish cruiser just like the Explorer, this angle is ample.

Onboard Buzzer

Flywoo features a self-powered buzzer—a uncommon characteristic in BNF FPV drones. In case your battery dies or will get disconnected in a crash, the buzzer will proceed beeping for hours, enormously enhancing your possibilities of discovering the drone.

In case you’ve by no means used one in every of these buzzers earlier than, don’t be shocked when it begins beeping after you unplug the battery—that is anticipated conduct. To cease the beeping, simply press and maintain the button on the buzzer for a couple of seconds to disarm it. In case you’re merely swapping batteries, you don’t must press the button, merely plugging in a brand new battery will mechanically cease the beep.

Flight Efficiency

Right here’s footage from one in every of my take a look at flights:

Battery Selection and Effectivity

Relying on battery weight, the Explorer pulls round 6-7A at 50 km/h and seven–8A at 60 km/h—which is impressively environment friendly.

If you wish to keep underneath the 250g weight restrict, the biggest battery you should utilize can be 4S 720mAh LiHV, which is available in slightly below the brink and gives round 8 minutes of cruising flight time. LiHV batteries are barely extra energy-dense than common LiPo, supplying you with a bit extra flight time, see my testing right here: https://oscarliang.com/lihv-battery/

With some modifications—corresponding to eradicating pointless elements—you would possibly be capable of run 4S 850mAh LiPo and nonetheless keep sub-250g. This might doubtlessly offer you over 10 minutes of flight time and as much as 7 km of complete flight distance.

For max flight time, the 4S 18650 Li-ion battery pack is the way in which to go. It could actually present nearly half-hour of flight time (primarily based on my testing with the earlier model of Explorer), although it will increase the general weight to round 365g. Ideally, you must construct your personal pack utilizing high-quality cells. I like to recommend the Molicel P30B 18650 cells, which I’ve examined right here: https://oscarliang.com/best-18650-li-ion-battery/#Outcomes-and-Suggestions. It’s also possible to purchase pre-built Li-ion packs, however they typically use cheaper cells, right here’s a listing of advisable choices: https://oscarliang.com/li-ion-battery-long-range/#Shopping for-Prepared-Made-Li-ion-Battery-Packs

Personally, I really like cruising at round 40–45% throttle (45–50 km/h) with 4S 850mAh, or 50% throttle (50–60 km/h) with the 4S Li-ion pack. This appears to be the optimum throttle vary for maximizing flight time.

Cinematic Smoothness

This drone flies prefer it was on rail, very locked in and steady. Within the flight footage, I used to be flying in 20 MPH gusts, and whereas the drone did drift fairly a bit (because of its mild weight), it didn’t wobble like many smaller micros do. That stability may be very useful for capturing cinematic footage.

Freestyle Functionality

With hover at 36% throttle and a prime pace of 105 km/h utilizing a 4S 850mAh LiPo, the Explorer is just not a quick drone. Throughout excessive maneuvers, it tends to wobble and expertise instability because of the restricted energy of the motors.

Let’s be trustworthy—the Explorer feels underpowered. The 1404 motors are thought of very small for 4-inch props; they’re generally utilized in 2.5-inch freestyle drones, and in my expertise, they even battle with 3-inch props! However keep in mind, this drone is constructed for effectivity and endurance, not uncooked energy, so it is smart.

Whereas it’s no freestyle beast, it might deal with fundamental strikes like split-S, energy loops, and inverted yaw spins simply high quality. You simply want to regulate your expectations—this isn’t a 5-inch ripper.

Noise

The Explorer is surprisingly quiet. It’s not silent, nevertheless it’s a lot much less intimidating than a 5-inch freestyle FPV drone. This makes it well-suited for flying in parks or city areas with out drawing an excessive amount of consideration.

Sturdiness

As talked about earlier, Flywoo hasn’t modified a lot concerning the Explorer’s body design for the reason that unique model—and primarily based on my expertise, it’s fairly fragile. I’ve damaged arms in mild to medium crashes—not even onerous hits—because of how skinny the arms are. So long as you’re conscious of its fragility and persist with cruising as a substitute of aggressive flying, it’s high quality.

GPS and Rescue Mode

Slight disappointment right here: the GPS takes fairly a very long time to get a repair from a chilly begin—about 6 minutes to accumulate 8 satellites. The max satellite tv for pc rely was round 19. I think the low GPS efficiency is because of its mounting location—it’s underneath the VTX antennas.

That stated, Betaflight GPS Rescue Mode works nicely. I’d nonetheless suggest a couple of adjustments to make it higher—corresponding to adapting “throttle fallback” (see my Rescue mode information for element) and lowering return pace, and many others.

The way to Setup

Putting in DJI O4 Professional

I purchased the Flywoo Explorer with out the DJI O4 Professional Air Unit, so I needed to set up it myself.

Since that is fairly a small quad, engaged on it is a little more difficult in comparison with bigger drones like a 5-inch, nevertheless it’s nonetheless doable with endurance. It took me about half-hour. No soldering is required—simply mount the digital camera, air unit, and antennas, plug within the cable, and also you’re good to go. Listed below are the steps.

Take away the antennas from the DJI O4 Professional Air Unit.

Set up the antennas into the TPU holder.

Set up the 4 standoffs in the back of the body for mounting the air unit.

I most popular to run the digital camera cable underneath the FC, so I eliminated the FC from the stack briefly.

Set up the O4 Professional digital camera within the body.

Reattaching the antennas onto the air unit, plug within the cable from the FC, and mount the air unit onto the standoffs. That’s it!

There’s no must take away the SBUS wire within the O4 Professional cable, as a result of it’s related to UART1 (particularly RX1) on the flight controller. Because the ExpressLRS receiver is related to UART2, there’s no battle so long as you’re not utilizing UART1 for the rest. In case you plan to make use of UART1, you must take away the SBUS wire within the O4 cable.

Earlier than powering the drone for the primary time, plug in a smoke stopper such because the Vifly Shortsaver, and join a battery and take a look at the drone and see if it powers up accurately. It’s best to hear the ESC/motor initiation beeps.

Activate the O4 Professional if you happen to haven’t already: https://oscarliang.com/how-to-setup-dji-o4-pro/#Activation

Pair the DJI O4 Air Unit along with your goggles – Information: https://oscarliang.com/how-to-setup-dji-o4-pro/#Pairing-DJI-Goggles-3-with-O4-Air-Unit-Professional

Firmware

The flight controller (FC) board goal is FLYWOOF722PROV2, and it comes preloaded with Betaflight firmware model 4.5.1. For inventory CLI Diff, see right here. Right here’s the pinout diagram.

ESC Firmware: F4A_4IN1 – AM32 2.16. Listed below are the default ESC settings.

ELRS Receiver Firmware Goal: Flywoo EL24E 2.4GHz RX, firmware model says “merge 481945 CE_LBT”, undecided what model that is nevertheless it binds high quality with my radio which is on ELRS V3.5.

Betaflight Setup

What May Be Improved

By eradicating pointless elements, I’m hoping to scale back the burden by one other 15–16 grams, which might enable me to make use of a 4S 850mAh LiPo and nonetheless keep underneath the 250g restrict. This could enable 10+ minutes of flight time, which is superb for exploring new spots when touring. If there’s curiosity, I can write a put up detailing these modifications—let me know within the feedback!

The FC stack may benefit from utilizing plastic nuts as a substitute of metallic lock nuts. Not solely are metallic nuts heavier, however they’re additionally tough to take away whenever you wish to work on the FC.

As talked about earlier, mounting the receiver antenna vertically can be preferrred. I’m not doing that simply but as a result of I plan to improve to a range receiver, with antennas mounted on each side of the body—identical to I did with the unique Explorer. With that setup and simply 100mW on my T-Lite V2 radio, I used to be capable of fly out 3km and again.

It’s a little bit of a missed alternative that Flywoo didn’t use their GOKU Nano GPS with an onboard compass. With Betaflight 4.6 bringing place maintain characteristic, this might have been a fantastic addition. I’m additionally not a fan of the present GPS mounting location—beneath the VTX antennas. I feel it might be higher positioned on the entrance, above the FPV digital camera, and away from all of the antennas.

Additionally, there’s no guide included, and the screw baggage aren’t labeled for his or her goal—solely by measurement. It will have saved a while in the event that they have been labeled (e.g., M2x7 for propellers, M2x4 for O4 Professional digital camera, and many others.).

Some Betaflight settings might have been configured extra thoughtfully for the Explorer. For instance, GPS and OSD settings have been left at default. Whereas Flywoo did present a customized PID tune, the filter settings have been largely left untouched. There’s undoubtedly room for enchancment in filters, PIDs, and Rescue Mode configuration. I’ll be posting my configuration on Patreon.

Flywoo Explorer Lr4 With Dji O4 Pro Long Range Sub250 Fpv Drone Pid

Inventory PID Settings

Additionally value noting: the present sensor isn’t calibrated correctly – it overestimated present draw. I like to recommend setting the present scale to 440.

Last Ideas

I’ve been a giant fan of the Explorer LR4 from Flywoo for years—it’s a incredible platform with a great deal of potential. There’s nonetheless room for enhancements, I want Flywoo had completed extra than simply improve the FPV system. However total, the Explorer LR4 with the DJI O4 Professional is a incredible long-range FPV drone, particularly for many who journey lots and have weight necessities. I’d completely suggest it.