Slipstream

Towing a conventional caravan behind an electric car is close to the worst thing you can do to its range. The trailer is a brick, the brick has to be pushed through the air, and the battery pays for all of it. The camping trailer market has largely responded by ignoring the problem.

Slipstream is an attempt to design one that doesn’t. Aerodynamics first, all-electric, built openly so the design can be checked, argued with and copied.

How it’s structured

The platform is deliberately split: roughly eighty percent of the parts are an invariant core shared by every build, and the remaining twenty percent are configurable. That means one set of engineering has to be right once, and the variation happens in the parts where variation is cheap.

Builds are tiered by complexity, not by range — because complexity is what actually determines whether a given person can build one. The entry tier is a foam-and-plywood build in the low thousands. The flagship, “Range-Neutral,” is a salvaged-EV-battery build an order of magnitude up.

Tiering by difficulty rather than by spec is the unusual choice here, and it’s the right one: it tells a reader what they can actually attempt, instead of what they can afford to dream about.

Licensing

Deliberately split three ways — hardware under CERN-OHL-S (reciprocal, so improvements come back), code under MIT, documentation under CC-BY. Each part gets the licence that fits it rather than one compromise licence for everything.

Status

Pre-build, flagship-first. The engineering, the subsystem documentation and the configurator exist; Build #1 is in progress. The configurator’s numbers are researched estimates and are labelled as such — they get replaced with measured values as the first build produces them.