Development of a Portable Reaming Tool for the Coil Supporting Structures of Wendelstein 7-X

A portable reaming tool has been developed, manufactured and successfully tested to accurately ream holes in flanged connections for the superconducting coil support structures of Wendelstein 7-X stellarator in areas where clean conditions are required to meet high vacuum requirements. The tool operates in spaces with limited access and is able to ream without lubricant. It is composed of a precise centring bracket, a threaded shaft, a cutting tool, high precision guiding bushes, a driving mechanism and a motor (electrical or pneumatic).