Reduction of disk flutter by decreasing disk-to-shroud spacing

Faster rotation speed in hard disk drives has increased disk nutter which c auses head-positioning errors. The nutter reduction effects of various disk -to-shroud spacings in order to reduce disk nutter amplitudes have been inv estigated. In the experiments using 3.5 and 2.5 inch disks, we confirmed th at the nutter amplitudes decrease when the spacing is less than about 0.5 m m, This effect was also confirmed when we changed the disk rotational speed and the shroud length.