HackSpace magazine

3D printing in metal

By Andrew Gregory. Posted

Urwahn Engineering is a German company that specialises in steel-framed bicycles. Schmolke Carbon is a German company that specialises in carbon-fibre bicycle components. Together they’ve come up with this bonkers, brilliant city bike.

Urwahn has done away with the seatpost tube, integrating it into the rear forks to create a flexible back-end that takes inspiration from the hind legs of a fox.

Ramon Thomas, co-founder of Urwahn, says that 3D printing made sense from a functional as well as aesthetic perspective: “After we continued with precision casting, we realised that the walls where too thin for this production procedure,” Thomas continues. “Therefore, we switched to selective laser melting, and managed to get very good surfaces and repeatable quality”.

Selective laser melting is where instead of filament, the initial material is a powder bed (hence its other name of laser powder bed fusion). Lasers heat the powder at a given coordinate, and a solid metal form takes shape. Using this method, Urwahn has been able to integrate the rear forks with the seat tube, making the whole rear end of the frame flexible.