Construction of helical coil winding machine for LHD and on-site winding

On-site winding of two helical coils of LHD started at the beginning of 1995, using a numerically controlled winding machine. They are large-scale pool-cooled superconducting coils which are designed to satisfy fully stabilized criterion. The conductor consists of Nb-Ti/Cu strands with a pure aluminum stabilizer and copper sheath. The main demanded values for winding the coils are 2.0 mm and 65 /spl mu/m for the accuracy of coil and the average gap between layers, respectively. A winding method was established by trial of winding.