Rate L40Pro: Sub‑250g 4-inch Long‑Range FPV — Cheap, Quiet, Fragile?
Rimzler tested the Rate L40Pro because it promised sub‑250g 4 inch performance at a surprisingly low price. The machine aims at efficient long range and cinematic cruising rather than raw five inch punch.
Hook
This matters because the L40Pro undercuts established long range models while delivering excellent handling and tuning. The catch is spare parts and support remain thin.
TL:DR
Rate’s L40Pro is a stiff, well tuned 4 inch sub‑250g craft that cruises quietly and efficiently. It ships without camera or GPS, needs minor setup, and currently risks being hard to repair if crashed.
Quick spec summary
The L40Pro runs 1505 motors at 2800KV, an internal RAID F4 flight controller with USB‑C, and a 30A all‑in‑one ESC. Carbon plates use 2mm top and bottom and 4mm arms for rigidity.
What’s in the box
The box supplies battery straps in two lengths, a single set of HQ 4x2.5 props, a bag of screws, zip ties, service tool bits, and a bag of 3D printed accessories including camera mounts and an M10 adapter.
Design and build notes
Rate uses an aluminium front canopy that accepts three camera mount styles for O3, O4, and legacy cams. The dead cut design eliminates props from camera view, which simplifies framing for cinematic shots.
Electronics and layout
The stack is RAID branded. The F4 flight controller exposes USB‑C and microSD access. The 30A AIO ESC sits below, and a buzzer tucks under the rear stack. The build leaves ample room for O4 Pro and cable routing.
Motors and props
Motors are 1505 size, identical to the smaller S30 Pro but set to 2800KV for 4 inch efficiency. The drone ships with low pitch bi‑blade HQ props that prioritise silence and endurance over top speed.
Camera compatibility and installation
Installing the O4 Pro requires only a few screws and the cable connector—no soldering. If using DJI O3 or O4 receivers, the user must switch protocol from Crossfire to S‑Bus and remap the serial port to port 3 or 4.
Weight and battery choices
Dry weight with an O4 camera sits at around 180 grams. That limits battery choices to stay sub‑250g. Rimzler flew a 720mAh 4S HV at 248g total and an 850mAh 4S at roughly 275g.
First flight — 720mAh HV 4S
Rimzler reports a super silent first arm with the supplied bi‑blades. The craft felt very stable in angle mode. Power felt moderate but tuning controlled motion tightly, unlike looser Flywoo Explorer setups.
Flight impressions — stability and efficiency
The L40Pro cruises quietly and efficiently. Rimzler observed roughly 60 to 70 km/h cruising while monitoring amps and altimeter. The internal FC altimeter tracked altitude reasonably well during tests.
Noise and vibration
Noise levels stayed low thanks to the low pitch props and symmetric tuning. Rimzler found no jello and only light flutter under aggressive bashing. For cinematic work, the machine produced clean footage.
Flight endurance and range
On the 720mAh HV pack Rimzler flew 5 minutes 30 seconds and covered significant ground. He estimates 7 to 8 minutes possible on a slower throttle curve. The 850mAh offered a heavier feel with slightly more noise.
Tuning compared to competitors
Rimzler states the L40Pro feels better tuned than the Flywoo Explorer. The controls felt natural, the craft held flat descents, and the OSD layout shipped in a sensible place—though the fly timer was missing.
GPS, safety and legal bits
The L40Pro ships without a GPS module. Rimzler recommends a tiny M10 nano GPS to stay close to 250g after installation. He also avoided long range flights in his test area due to hunters firing shotguns nearby.
Repairability and support concerns
The biggest caveat remains spare parts and support. The L40Pro currently sells via Banggood only, and replacement arms or frames were not yet available. Rimzler warns that crashes could leave owners stranded until parts release.
Practical notes for builders
Arms are replaceable without removing the center stack, which speeds repairs once parts release. The dual stack electronics add a few grams but keep costs low and simplify manufacturing.
Final verdict
Rimzler recommends the L40Pro wholeheartedly—conditional on spare parts appearing. The drone balances efficiency, silence, and tuning quality. Buy it if you accept the current parts risk and enjoy building your rig.
Where to buy and accessories
At the time of testing the L40Pro was available through Banggood. Use small HV 4S packs to stay sub‑250g. Consider buying a set of spare replacement arms and an M10 GPS once vendors list them.
Short setup checklist
- Install O4 Pro with screws and connector. - If using O3/O4 receivers, change Crossfire protocol to S‑Bus. - Set the serial port to port 3 or 4, then map modes. - Install a tiny M10 GPS to enable GPS features while staying under 250g.
Is the Rate L40Pro ready to fly out of the box?
No. The L40Pro ships without camera, GPS, or receiver setup for O3/O4. It requires camera installation and minor serial port and protocol changes for some receivers.
What batteries keep the drone under 250 grams?
A 720mAh 4S HV pack brought Rimzler to about 248 grams with O4 installed. Small HV 4S batteries offer endurance while staying under 250 grams if fitted carefully.
Are spare parts available?
Not reliably. Replacement arms and spares were not available at test time. A manufacturer comment on the retailer page promised parts soon, but buyers still face a risk if they crash.
How does it compare to Flywoo Explorer?
Rimzler reports the L40Pro feels more tightly tuned and less loose than the Flywoo Explorer. It offers quieter operation and cleaner OSD placement, with similar range potential on light packs.
Takeaway box
- Sub‑250g performance, quiet cruise, and solid tuning make the L40Pro a rare bargain for builders. - The platform requires a camera and optional GPS; assembly and minor CLI changes are needed. - Spare parts scarcity remains the main downside—buy if you accept that gamble. - Swap to higher pitch tri‑blades to chase more top end speed if desired.
This article was based from the video Incredible sub 250g 4" Long Range FPV Drone! Rate L40Pro