  Additive manufacturing (or "3D printing") has become a powerful tool for
rapid prototyping and manufacturing of complex geometries. As technology is
evolving, the quality and accuracy of parts manufactured this way is ever
improving. Especially interesting for the world of particle accelerators is the
process of 3D printing of stainless steel (and copper) parts. We present the
first fully functional IH-type drift tube structure manufactured by metal 3D
printing. A 433 MHz prototype cavity has been constructed to act as a
proof-of-concept for the technology. The cavity is designed to be UHV capable
and includes cooling channels reaching into the stems of the DTL structure. We
present the first experimental results for this prototype.
