Rapid.Tech 3D digital : understanding seeing experiencing : proceedings of the 17th Rapid.Tech 3D Conference Erfurt Germany 22 23 June 2021 Rapid.Tech 3D has developed constantly and consequently over the last 19 years to an absolutely leading event in the field of Additive Manufacturing. The Rapid.Tech 3D specialist conference is aimed specifically at users and developers of Additive Manufacturing technologies. This work contains papers of the 17th Rapid.Tech conference that grant unique insights into latest research developments specialized knowledge of Additive Manufacturing research and applications. Some of the papers are double blind reviewed by a scientific review committee.