Prospects for stellarators based on additive manufacturing: Coil frame accuracy and vacuum vessels

High geometric complexity at high accuracy delays the construction of new stellarators and the related research. Thus, exploring whether additive manufacturing (AM) might provide advantages to the fabrication and design philosophy of stellarators appears valuable. Three coil frame supports were designed, produced by three AM techniques (SLA, FDM, and PolyJet) and measured by a Coordinate Measuring Machine. For FDM (similar to SLA), average of ±0.17% mean deviation was obtained and 68% of the points (one sigma) deviate less than ±0.28%. Three assays were performed for modular stellarator vacuum vessels: 1) a thin copper liner attached to a resin shell cast in an AM mold; 2) a thin electroformed liner for a test vacuum vessel; and 3) electrodeposited coating on an AM shell. The assays showed alternative 3) the simplest and fastest. The results from such studies and assays are reported and integrated with the previous results. Low stiffness and strength of AM plastics was previously tackled with fiber-reinforced resin cast in AM hollow structures (3Dformwork technique). Thus, AM, particularly combined with other fabrication methods, proved to be appropriate for the production of certain unpretentious small- and middle-size stellarators.