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A 3D PRINTED DRONE THAT FLIES ON A SINGLE PROPELLER, STEERED BY AIR VANES

One propeller, four servo-driven air vanes, and no other spinning parts — thrust vectoring at model scale, printed in PLA.

by abritten

FULL CAD BOM FIRMWARE DOCS

RoboticsWorkshop

difficulty
●●●●○
time
a weekend-plus
license
GPL-3.0
repo
repo ACTIVE35 stars

WHAT YOU’LL NEED

  • 3D printer + filament — printable parts — files are in the repo
  • Electronic parts — full list with part numbers in the repo BOM
  • Dev board / microcontroller — runs the project firmware
  • Soldering kit + basic tools — one-time buy, serves every future build

Partner

Reach your Pi from anywhere — Remote desktop to the machine running this build — no port forwarding, works right from the browser.Try Getscreen.me
1

COMPAREE VERDICT

Almost every hobby drone turns by making one pair of rotors spin faster; this one has a single propeller and steers by deflecting the airflow with four micro servos. The concept is a graduate thesis at model scale, and the repository gives you everything to build it: STL files, the twelve-part BOM with links, and firmware ready to flash. The catch is that tuning a thrust-vectoring monocopter is not like tuning a quadcopter — the PID loops fight against a gyroscopic precession you do not get with symmetrical layouts, and the README says outright that the first flights will be twitchy. You will spend more time on the bench adjusting servo throw and control surface deflection than you will printing parts. The propeller is unshrouded and the aircraft weighs enough to require operator registration in the EU, so first flights belong in a net or a large indoor space until the loops settle. The single thing most likely to go wrong is launching before the control vanes are trimmed: a misaligned servo will turn stable hover into an instant cartwheel. If you want a stable FPV platform, build a quad. If you want to see thrust vectoring work on something you printed, and you are comfortable with an R/C transmitter and a logic analyser, this is the honest weekend project.

NOT IN THE REPO

  • —All STL files are in the repository, split by subassembly (vanes, motor mount, ball halves, servo arms).
  • —The bill of materials lists twelve parts with supplier links and model numbers for the motor, servos, gyroscope and Teensy.
  • —Firmware is the upstream dRehmFlight flight controller by Nicholas Rehm, forked and tuned for the monocopter — you flash a Teensy 4.0 over USB.
  • —Assembly instructions are a photo walk-through in the README with servo horn orientations and vane alignment steps.
  • —Published under GPL-3.0, which permits commercial use with the same licence for derivatives.
  • —No official video walkthrough — the repository links to a brief hover test, the rest is community posts.

Can I build this?

PrintBall halves, motor mount, vane assembly, servo arms — everything structural is PLA, no support-free orientation required
BuyTeensy 4.0, MPU-6050 gyroscope, STORM TL2306 2300 kV motor, four SG90 micro servos, 7.4 inch propeller, 1300 mAh 3S LiPo, R/C receiver compatible with dRehmFlight
Tools3D printer, soldering iron, Arduino IDE or PlatformIO for flashing the Teensy, R/C transmitter (6+ channels), multimeter, logic analyser or oscilloscope helps for servo debugging
SkillsR/C aircraft experience and basic PID tuning — this is not a first drone, it is a control theory experiment that flies
TimeA weekend to print and assemble, then another weekend tuning the flight controller before stable hover — first-time PID tuning on a monocopter can double that
Cost$$ — the Teensy 4.0, motor and battery dominate the bill; servos and filament are under twenty dollars total
SafetyUnshrouded propeller spinning at several thousand RPM — first flights must be in a net or large indoor space. 3S lithium polymer pack requires a LiPo-safe charging bag and a balancer. Drone regulations apply: EU operator registration and open category rules, equivalent rules elsewhere.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

A desktop 3D printer that prints in full colorPartner · Kickstarter
A desktop 3D printer that prints in full color

HeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.

See how it prints

Gallery

https://github.com/abritten/dRehmFlight-Monocopter
https://github.com/abritten/dRehmFlight-Monocopter
https://github.com/abritten/dRehmFlight-Monocopter
https://github.com/abritten/dRehmFlight-Monocopter

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the dRehmFlight documentation (The upstream flight controller README explains the PID architecture and channel mapping — you need to understand it before you tune the monocopter fork.)
  2. 2.Print the ball halves and vane assembly(Start with these while you wait for parts to arrive — print the servo arms last because they are the most likely to need reprinting during fitment.)
  3. 3.Flash the Teensy 4.0 with the monocopter firmware(Arduino IDE or PlatformIO — the README has the board config and library dependencies.)
  4. 4.Bench-test the servos and control surface deflection before first power-up(A misaligned vane will cartwheel the aircraft the moment it lifts off — check throw and neutral position with the transmitter before you spin the motor.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

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KNOWN ISSUES

  • Buying SG90 clones with different gear ratios — the servo arms are sized for the standard SG90, and a taller stack will foul the ball interior.
  • Skipping the upstream dRehmFlight README and jumping straight to the monocopter fork — the PID tuning guide and failsafe setup are in the upstream docs, not repeated in this repo.
  • First flight outdoors in wind — a monocopter has much less control authority than a quad, and a gust will flip it before the PIDs can respond. Start in a net.
  • Using a 4S battery because you have one — the README specifies 3S, and the motor KV is chosen for that voltage. Overvolt and the propeller will overspeed the vanes' slipstream range.
  • Assuming the default PID values will work — they are a starting point, and the README says outright that the first hover will be twitchy. Plan to spend a session on the bench with a logic analyser.
  • Not registering as a drone operator (EU, UK, or equivalent jurisdictions) — the aircraft is over 250 grams and has a camera mount, so open category rules apply even if you never fit FPV.

Can I use a different flight controller instead of the Teensy 4.0?

Not without rewriting the firmware. dRehmFlight is written for Teensy and uses its hardware timers and pin mappings — porting to an STM32 or ESP32 is a separate project.

How does it compare to a quadcopter for flight time and stability?

Worse on both. A single motor at high RPM is less efficient than four at moderate speed, and the control authority from vanes in a slipstream is lower than direct rotor thrust. This is a proof of concept, not a practical platform.

What is the actual flight time on the 1300 mAh pack?

The repository does not state it, but monocopter designs typically see 4-6 minutes of hover — shorter than a quad with the same battery.

Do I need a ham radio licence to fly this?

No — the R/C link is in the ISM band, same as any consumer drone. You do need operator registration in jurisdictions with drone rules.

Community builds

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Discussion1

FROM THE COMPAREE TEAM

Twelve parts, all published, and the entire control system is four micro servos deflecting air. What would you try to tune first — the vane throw or the PID gains?

CompareeTEAM15d ago

Practical notes from our verification: the repository is a fork of the dRehmFlight project, and the upstream README is where the PID tuning guide and failsafe setup live — the monocopter repo does not repeat that documentation, it assumes you have read it. There is no official build video; the linked hover test is under ten seconds and shows stable flight but not assembly or tuning process. The bill of materials is complete with supplier links, but the README does not state actual flight time or whether the default PID values are flyable out of the box — the honest read is that you will spend a session on the bench before the first stable hover. The single biggest gotcha is not mechanical: it is launching before the control vanes are trimmed, which turns stable hover into an instant cartwheel.

abritten

Built on the dRehmFlight flight controller by Nicholas Rehm, a researcher and open-source maintainer who published the original VTOL and fixed-wing monocopter stabilisation code. abritten's repository is the mechanical airframe and tuned firmware fork.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
GitHub repo