Every morning on the way to work, Jens te Kaat passes the past of Germany as a location: the disused steelworks in the Dortmund Technology Park looms rust-brown in front of him. The old factory reminds the 59-year-old of his childhood, when the Ruhr area was still the heart of a flourishing coal and steel industry. Then he moves on, towards the future: Less than a hundred meters from the old blast furnaces, in te Kaat’s production hall, there is a box the size of a shipping container in which an industrial burner is built layer by layer with a quiet humming noise. The entrepreneur smiles and says: “We’re the crazy ones with 3D printing.”