Show HN: I made a 3D printed VTOL drone

Original Article ↗ Hacker News Discussion ↗

Performance & Capabilities

  • Top speed is untested; author estimates at least ~70 mph, with commenters speculating much higher is possible, referencing 100+ mph quads and extreme racing records.
  • Battery mass fraction is ~53%; author estimates adding ~0.5 lb payload is feasible given hover motors sit at ~45% throttle.
  • Control range depends heavily on radio protocol: basic setups are under ~1 mile, while ELRS can reach tens to ~100 km.

VTOL Configuration Tradeoffs

  • Design uses separate vertical-lift and cruise motors, simplifying mechanics but introducing drag from idle VTOL props in forward flight.
  • Some see this as a “bad inefficiency”; others argue it’s modest (~5% weight/drag penalty) and offset by:
    • Optimally sizing the cruise motor/prop for forward flight.
    • Avoiding heavy, complex tiltrotor mechanisms and actuators.
  • Similar multi-motor VTOL concepts are used in commercial systems (e.g., delivery drones), implying the tradeoff has been deeply analyzed.

Materials & Airframe Design

  • Airframe is 3D-printed in single-wall foaming PLA: very light but extremely brittle and poor under impact and UV exposure.
  • Compared with foam airframes, PLA is heavier and more fragile but easy to repair by reprinting parts.
  • Alternatives discussed:
    • ABS/ASA (including foaming ASA) for a better weight/durability balance, but harder to print and with unpleasant fumes.
    • TPU variants for toughness, though not used here.
  • Structural techniques: carbon fiber spars, CA glue, dovetails/clips for joining multiple printed wing sections; bed size constraints (e.g., Bambu A1) matter for segmentation.

Electronics, Autopilot & Ground Software

  • ArduPilot handles VTOL out-of-the-box; only parameters and tuning were customized.
  • ArduPilot is described as extremely capable, modular, and mature, but also janky and hard to configure.
  • Mission Planner is powerful but considered poor for configuration UX; alternatives include:
    • MethodicConfigurator for setup,
    • QGroundControl and MAVProxy as other GCS options.
  • Licensing is a major reason many commercial UAS use PX4 (BSD) instead of ArduPilot (GPLv3), to avoid sharing proprietary modifications.

Battery Technology & Cost

  • Bill of materials is roughly $2,000, with the high-end Amprius silicon-anode pack being the dominant cost.
  • Battery pack: ~440 Wh, ~21.6 Ah at ~20.4 V, ~1.33 kg, giving ~330 Wh/kg at pack level and ~360 Wh/kg at cell level.
  • Commenters note this is state-of-the-art gravimetric energy density, though not unimaginably beyond cheaper cells.

Use Cases: Mapping & Surveying

  • A landowner mapping ~200 acres currently uses a DJI quad for 3+ hours of segmented flights and battery swaps.
  • Opinions diverge:
    • Some say no sub-$5k VTOL can match this endurance; DJI plus more batteries is the most practical short-term answer.
    • Others propose DIY or COTS VTOL/fixed-wing systems (e.g., Heewing T2 VTOL, commercial eBee/Wingtra-class drones), but these are:
      • More complex to integrate (ArduPilot/PX4, Mavlink, mission planning over steep terrain).
      • Often much more expensive (tens of thousands of dollars).
  • Suggestions include:
    • Multiple cheaper quads in parallel (blocked by FAA single-pilot rules).
    • Higher-end cameras to fly higher/faster within the 400 ft AGL limit.
    • Fully open-source stacks (ArduPilot + open hardware + OpenDroneMap) for custom workflows.
  • Dense, repetitive pine forest and steep topography make flight planning and photogrammetry unusually difficult, requiring high overlap and complex routing.

Build Process, Sharing & Accessibility

  • Many commenters find the project inspirational, highlighting:
    • Going from limited prior experience (one foamboard VTOL) to a sophisticated platform.
    • Heavy reliance on COTS components, LLMs, YouTube, and forums for guidance.
    • “Building in public” as motivation and as help in debugging and learning.
  • Several request BOM and STL files, plus beginner-friendly plans and tutorials, though producing high-quality documentation is noted as a major extra effort.

Control & Terminology Notes

  • Control surfaces are still viewed as worthwhile despite multi-motor options; using VTOL motors for control in cruise would waste power, with servos being a small mass fraction.
  • Differential thrust is acknowledged as a way to generate roll/yaw, but seen as less efficient than conventional surfaces in cruise.
  • Some clarify terminology: “VTOL” historically contrasts with fixed-wing aircraft; since most multirotors already take off vertically, “winged VTOL drone” would be a clearer description.