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Henry Ford did it, Karl Benz did it – and now you can build a car yourself.

The Tadpole 3-wheeler is a tiny two-metre-long electric vehicle that was designed by Spaniard Gonzalo P. Chomon to be open-source.

That means the blueprints and all instructions to build the EV and assemble it from scratch are available to anyone, free of change.

This tiny one-seat machine has modest cargo space and no roof, so drivers will need a pair of goggles and a protective cap.

Designed to powered by a 2kW brushless electric motor and a 2kWh battery pack, the super-light sub-100kg car has a range of up to 70km and a top speed of around 50km/h (30mph).

Charging time is claimed to take about five minutes.

The body and structural framework of the Tadpole 3-wheeler, or Jellybean3D as it’s also called, can be made with “standard hobby printers”, says Chomon, using around 40kg of PLA (polylactic acid), a plant-based plastic material, and “some off the shelf components” such as wheels, an electric motor, battery pack, screws, nuts, washers and so on.

Australia’s cheapest car is currently the MG3, a compact five-seat petrol-powered hatch priced at $16,990 drive-away.

By comparison, the cost of the fully-assembled Tadpole 3 is estimated to be around €3000 ($A4600).

But how do you build a car with a standard hobby 3D printer?

Well, the vehicle shell and structure is made up of lots of smaller parts. Chomon has even developed a chemical welding system to join the parts of the car together, which you can see on this YouTube tutorial, mainly using dichloromethane.[Ed: Is that safe?]

It’s not clear how the Tadpole 3-wheeler would drive, nor has it been homologated for road use in Australia under our stringent design rules, despite the fitment of headlights, indicators, simple suspension, disc brakes, mirrors and various other parts required to do so.

Vehicle safety is also another potential hurdle for those wanting to create a cheap fleet of mini cars.

“This is an experimental project that aims to explore the limits of hobby 3D printing,” said Chomon.

He also cautioned: “This project does not aim to reproduce a standard vehicle construction.”

While Volkswagen, Tesla, Toyota, Ford and other major car-makers are unlikely to be concerned that their automotive empires may be under threat from millions of backyard cars potentially hitting the road, the project is well documented and very thorough.

However, the idea of open source is not new.

Toyota, for example, has opened its hybrid vehicle R&D to all and sundry, removing all royalty payments usually charged to other companies using its petrol-electric technology.

Toyota’s open-source hybrid powertrain pact is set to end in 2030.