One of the objectives of the London Charter on computer-based visualisation of heritage promotes “intellectual and technical rigour in digital heritage visualisation” (London Charter 2009)—yet, in what way should one today digitise Polhem’s <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">Laboratorium mechanicum</hi>? What is the <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">exact</hi> relation between “technical rigour” and virtual heritage in a software culture permeated by constant updates? Within the interdisciplinary Swedish research project, “Digital Models. Techno-historical collections, digital humanities & narratives of industrialisation” (funded by the Royal Swedish Academy of Letters, History and Antiquities) parts of Polhem’s collection has been 3D scanned and 3D reconstructed by <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">different</hi> software. The project set up is part of the trend were heritage institutions are today exploring how 3D technologies can broaden access to, and the understanding of their collections (Urban 2016; Ioannides 2014). Then again, is a 3D scan of a model (in our case) for example more <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">rigour</hi> than a simulation?