About this 3D model

Here's gyroscope with 4 concentric rings and a durable loop for a keyring. Each ring is spaced with a tolerance of .25 mm, and thus spins best if printed in FDM with a layer height of .1 mm. Edit: the t_300um file contains the same gyro but with a .3 mm tolerance for printers with lower accuracy than the Ultimaker 3 I used.