Blueprints for the machine in your head.

Yes, to start. The 10 worked examples on this page are free with no account: every part, wire, step and file. Your first build of your own is free too: new accounts get 5 BuildBux, and a build costs 5. Opening your own build is always free, except builds our check marks Not checked or Concept, which get no parts cart. The Pricing page has the rest.

Yes. Every line of the parts list is a real, orderable component with a current price, and the build email carries a one-click Amazon cart for the whole list. Builds our check marks Not checked or Concept get no parts cart, and on a build of your own the flight parts stay out of the cart: the list names them for you to find. The 10 free examples link every part. You buy the parts yourself, on Amazon, with your own card and address: we never see either.

The numbers are worked out in code, not written by the AI: weight, current draw, battery runtime, motor strength, wire gauge and tip-over angle. Where we know a part, its weight comes from our parts table. Where we don't, we use a rough guess. Drones also get a flight check: lift against weight, battery load, speed controllers, prop fit and flight time, ending in Checks pass, Almost, Concept or Not checked. If we can't check a machine, it says "Not checked" instead of pretending. It's math, not a test flight, so check it before you build.

Not to start. The firmware is written for you and the steps are numbered in order. Every build carries a difficulty rating from 1 to 5, and the easy end is chosen to need no soldering, so you can filter the Market down to what you can finish.