Free design tools · open-source aircraft
Design your own aircraft — for free.
Wing Builder runs a real vortex-lattice solver in your browser. Draw a planform, get the lift distribution, induced drag, and static margin, then share the result as a link. No install, no account, nothing to pay.
Alpha · wings only · powered by onmoru
XFLR5 came out in 2003. It is still the best free thing we’ve got.
That’s not a dig at XFLR5. It’s a remarkable piece of work and half the wings flying at your field owe it something. The problem is that nothing came after it. If you want to know what your planform actually does before you cut the foam, you either learn a tool built for 2003, or you guess and find out at the field.
So we’re building the thing that should have come next.
Same physics, done properly. A design screen you can actually use, an agent sitting next to it that sets up the sweeps and reads the results back to you, and a link you can paste into a thread so the next person can see exactly what you did. Free, because the people who need it are already spending their money on motors.
Wing Builder
Draw a planform. Get the numbers.
The alpha does wings. That’s the honest scope — no fuselage, no propwash, no control surfaces yet. What it does do is the part you actually agonise over, and it does it with the same method XFLR5 uses for the wing.
- Lift distribution
- Spanwise loading for your planform, against the elliptic ideal. Where the wing is working, and where it will let go first.
- CL and CDi
- Lift and induced drag through an alpha sweep, so taper and aspect ratio changes show up as a number instead of a hunch.
- Neutral point
- The wing’s neutral point and the static margin your CG gives you. For a flying wing that is the answer; with a tail it is only half of one, and we say so in the tool.
- Airfoil data
- A precomputed polar database at launch. On-demand XFoil-grade section analysis comes after.
- Where it runs
- In your browser. The solver is compiled to WebAssembly and executes locally — which is also why it can stay free.
- What you get out
- A shareable report link with the geometry, the plots, and a plain reading of what the numbers mean.
- Not sure yet?
- The blog runs the same solver inside the posts, so you can learn what the plots mean before you trust them with your wing — start with where the lift goes.
Open-source hardware
Aircraft One, designed in the open.
A tool is a claim until something flies. So we’re designing a new aircraft in Wing Builder, building it, and flying it — with every step written up as we go.
Designed in the tool
Every planform decision made in Wing Builder, with the numbers we trusted shown alongside — including the ones that turn out wrong.
Built and flown
Foam, electronics, maiden. The parts where the analysis meets the airframe are the parts worth reading.
Published
Drawings, spec, and BOM go public once it flies, so you can build the same aircraft or take it somewhere else.
The blog
Read it, then go and check it.
Aerodynamics posts run the solver in the page, so nothing has to be taken on faith. The Aircraft One serial follows.
Where your wing's lift actually goeslive solver
Spanload, local cl, and why taper is a trade rather than a default — with the solver running in the page so you can move a slider and watch the tip stall.
Aircraft One: what we're building and why
The brief for the first aircraft, the constraints we're accepting, and what we're trying to prove by designing it in our own tool.
Picking the planform
Span, taper, and sweep for Aircraft One — the trades we ran in Wing Builder, and the numbers we ended up trusting.
Cutting foam
From drawing to airframe. What survived contact with the build, and what the analysis missed.
Get in early
The alpha opens soon.
Wing Builder is being built now. Leave an address and you get it the day it opens — and if you tell us what you fly, it shapes what we build.
A one-click signup is coming. For now the fastest way in is a mail — tell us what you build and you get the alpha when it opens.