Major project of mine, a tour-de-force of my design work: 3D printed folding-wing VTOL aircraft design I've made from scratch.
If you're interested at all please, I need collaborators/testers/fans to help dial everything in. My discord is set up for this exact thing, please join and say hi: [discord invite]
Are you a developer or moderator for ArduPilot? Amazing, thank you for your work– but you're all banned from my discord and may not have this full design of mine until this issue is resolved.
Update 2025-05-09: Successful VTOL transitions by 5prop! My edited reel on instagram and youtube!
Update 2025-04-26: AeroFold V2 is almost ready! Major redesign of the fuselage– testing now. If you'd like to beta-test join my discord!
Update 2025-04-20: Made an assembly build video to help: [youtube]
Update 2025-04-19: Testing redesigned fuselage, called AeroFold V2. More to come! Also reprinted after crash (full details in discord!)
Update 2025-04-09: Maiden forward flight success! Flew incredibly. Made a short youtube video and IG post. Also added a few missing things to the Parts list! Next steps are quad-mode dialing-in and then transitions.
Update 2025-03-31: Recreated the whole 3MF archive here on makerworld with the latest r2 version. Don't want anyone getting started with an old design. If you're printing anything please do get the latest beta version over in my discord!
Update 2025-03-27: New V2 wing design is finished, printed, and soon to be tested! Larger, (storage/payload for batteries) better flight dynamics (CG & CG movement when folding), stronger, and yet LIGHTER parts. Fuselage changes still ongoing, will be flight-testing soon! If you're interested stay tuned! Follow here, join my discord, and follow my Instagram.
Specs:
Wingspan 1.6m
Minimum battery weight (to fit CG): 50Wh. Maximum TBD.
Stall speed, max speed, etc: TBD with testing
Dry weight (as configured below): ~800g (still to be finalized)
Aerofoil Profile: NACA-4414 at root tapered to NACA-4412. High aspect ratio, ultra efficient.
Wing Incidence Angle: 2deg
Features
4-motor, works with standard 5" FPV quad motors (I used 7" Eco2 motors)
Four servos for control surfaces (V-Tail + ailerons)
Novel wing folding mechanism with only 1 additional servo
Print-in-place tube clamping system for rigid carbon spar utilization
Socketed printed wing segment fit inside each-other for perfectly flush & strong results
Modular nose allows for easy vtx/camera system swaps or choices.
Ailerons use fully printed axle pivoting system
V-Tail control surfaces attached with TPU inserts
All printable on an A1 Mini
Folding mechanism
Novel approach for folding mechanism is to use a dual-side pulley system using kevlar line– driven by a sail-winch servo situated forward of the CG. Very strong, perfect transition speed, nearly no play, light weight, and has closed loop control (can be commanded to any mid-transition position).
Flight Characteristics Simulation
Simulated flight dynamics using ecalc, results screenshots:
Steel z-pushrods (for control surfaces– can use piano wire) [ali-search]
Wiring
FEP Wire for power & servo lines
FEP Wire is stiffer, low friction, and smaller diameter. REQUIRED for routing through the hinge area. Silicone barely works, only when wrapped in kapton tape (see below)
Kapton Tape: you should have some handy. Useful for wrapping around wire bundles for low-friction through the hinge as well as building batteries, thickening carbon spars, etc. AKA High Temp Polyimide Tape. [ali-search]
More documentation coming soon.
Batteries
This is designed to be very flexible with batteries! Many options work great.
For the motors I've specified it's intended for 4S packs. Other motors/props can handle different voltages.
Minimum-sized: ~1200mAh 4S lipo pack, mounted in the center fuselage. Flies efficiently for 10 to 15 minutes.
Min-size means minimum weight. Minimum weight means minimum stall speed. Always fly your first test flights with a lightweight option.
Motor Nacelle Pod Mounted battery options:
Under development! Currently designed to fit either:
Maximum capacity: 8x 21700 cells, 2 in each motor nacelle for a 4s2p setup. Recommended cell: Molicel P45B [imr]
Maximum power: 4x Tattu 4S 750mAh lipo packs, one in each nacelle. Will be testing these as well.
This is till under testing for CG, wiring, etc.
Slicing & Printing:
The 3MF is set up with extensive use of modifiers to make perfect ultra lightweight and ultra strong parts, important for aircraft printing.
→ Only the fuselage and first nacelle section are included in this 3MF .. Everything is changing fast. ←
This project is still under active development! To make sure you've got the latest design join my discord, follow my Instagram, and follow the design here on Makerworld!
Happy to export STL and/or STEP files for everything as-is right now, just per person on my discord so I can get feedback, tips, problem reports, and improve the project while it's under development.
Filament: Lightweight filament for most parts. See the exploded diagrams below and the parts list.
Infill: Cubic, 6% (not adaptive cubic!)
Walls: 1 perimeterin most places for most parts.
Seam positioning: Nearest. Helps lots for LW filament
Wall generator: Arachne. Enables thin walls that actually print well.
Support: None for most parts. See exceptions.
Exceptions:
The bottom and top ~8mm have modifiers to double the infill (to 12%) and use 2 walls.
All layers where bolts thread into also use 2-walls & 2x infill.
All nacelle parts (w1 & w3) require support and I prefer them with 2 walls. For now. Working on some changes.
Please use Orca Slicer and refer to my 3MFs for all settings and ask me any questions/clarifications!
When you switch printers to non-bambu options it may reset settings! Use a second window as reference.
Build Video
Made a video walking through the build process. Happy to make future videos on things like tail assembly, wiring, winch setup .. let me know!
Organization & Assembly
All parts are named for alphabetical sorting:
fuselage * have all fuselage parts
w* are all the wing parts. Must be mirrored and printed again for the right wing.
tail * Are all the fin parts that also are mirrored and printed for the right side.
vtail * Is the joiner base that the fin parts slot into.
shuttle * Moves along the main boom to drive the actuation.
Fuselage Parts
This is for the V1 fuselage. This needs redoing for V2, please ask if you'd like me to update this!
Green is glued with CA glue.
Body clamp is NOT glued into the fuselage. This means the winch servo remains removable.
Not pictured:
Hatch latch mechanism is now part of the design
Fuselage nose is available with several different camera setup designs. O3, O4 Pro, Pan mount servo, and gimbal mount is WIP.
Wing Parts
Green is glued with CA glue.
If non-glued parts are too loose add a loop of kapton tape around the ends of the spar that goes through that part to add thickness.
Not labeled:
Aileron hinge parts
Aileron servo cover/holder
Join tabs
Tail
Green is glued with CA glue.
Not labeled:
Join tabs
Servo linkage
Things will change! Don't print out-of-date gear– Keep up to date and give feedback in my discord!
Carbon Spar Sizing
Using a simple hacksaw cut your carbon spars to size.
It's recommended to wrap tape around the cut area to stabilize the outer fibers and mark the cut position.
Double check the length of each in the airframe before cutting.
Each Wing
1x 14mm x 500mm main wing spar
1x 6mm leading edge wing carbon spar can be a maximum of 687mm long. 500mm is plenty though, that's what I used.
1x 6mm trailing edge wing carbon spar needs to be 180mm long
4x 4mm nacelle support spars are 98mm long, 2x per motor.
Fuselage
1x 14mm x 330mm main fuselage-to-hinge spar
1x 6mm x 274mm secondary fuselage-to-hinge spar
Fuselage V2 has
1x 6mm 298mm (maximum) spar to support the bottom of the fuselage. I recommend cutting it at 274mm to match above.
Fuselage V1 had
1x 4mm bottom support spar is 245mm long
2x 4mm side support spars are 190mm long each
Tail
1x 14mm x 500mm main tail boom
2x 4mm carbon spar 230mm each (one left, one right side)
Shuttle system
2x 4mm carbon spar pushrods are 317mm each
Winch servo / kevlar rope installation process
Center the winch servo at 1500ms
Cut the rope to-length. Safe over-estimates are 0.6m and 1.2m (get TODO accurate lengths)
anti-fray: it's impossible to melt the ends of kevlar rope! use a drop of CA glue instead, using a paper towel to pull flat.
tie one end of each rope to an M3 nut. This terminates the rope so they stay captive on the pulley.
Install the ropes into the pulley. Shorter rope on the inside slot, closer to the servo. Longer on the outside.
Wind 4 turns of rope on both sides of the pulley.
clockwise on the inside, closest to the servo
counterclockwise on the outside
use a piece of tape or a small clamp to temporarily hold the wraps in place
Feed the rope out
inside|shorter|clockwise rope feeds through the small exit hole in the fuselage back part
outside|longer|CCW rope feeds through the tail boom exit (later goes through the whole boom)
press fit the servo into position in the fuselage wing part
install the rope-redirection standoffs
Install the boom, shuttle, and vtail part at the end.
install the vtail insert, feeding the rope through the gap between the part and the bearing&wheel
Shuttle setup
center the shuttle
Feed the rope though the pathways for each rope
Pull the rope tight, wrap the rope around your M3 bolt, tighten bolt to hold in-place
Carefully run the servo back and forth. The rope will loosen– so re-tighten by re-bolt tightening one end once or twice to get the system tight.
Carefully set your autopilot endpoints to values that don't over-actuate in either direction
Autopilot Setup
Documentation is a TODO. Right now it's successfully flown with full transitions with iNav.
Center of Gravity, CG/CoG
The CG is marked on each wing with a balance point bump. This is the standard way to mark and test CG on models.
Sharing & License & Such
The LAST thing I want to do is restrict anyone from sharing. But. PLEASE share links to this makerworld page, not any 3MFs or STLs. Here's why:
This is under active development. The STLs WILL CHANGE and get better.
The documentation is really important here, and I'm sure there's stuff I'll be adding as feedback comes in.
The community is important, I want people to reach out and join the discord not download some STLs and go it alone.
It's just a super dick move to repost designer's stuff. I've spent a long time making, testing, and documenting this and my only reward is that little stupid ‘like’ counter, download counter, and photos/stories from users. DON'T DEPRIVE ME OF MY ONE SENSE OF SELF WORTH
The specific license is Creative Commons (4.0 International License) Attribution—Noncommercial—Share Alike. If you'd like to print this commercially then reach out by opening a new thread on discord and we can talk. Flying professionally using my designs is fine– though please do consider donating a proportionate amount to support my work!
Tim O'Brien
