David Lamb's ring magnet and cylinder setup
ringandrod1
ringandrod2
The above views are representative of David Lambs ring magnet and a inverted polarity cylinder magnet put within the outer ring magnet. The top view has a disc of rounded gas diffusion PG; however its also able to levitate some of the Sci-Toy PG, that is squarish and thin. This was the basis for Davids earliest seismometer, and he added a thin silver plate atop the levitating disc for dampening, and used a laser on the edge of the disc, which from there illuminated a portion of a photodiode. The thickness of the levitated PG disc is 0.020" and is 0.695" in diameter. Circa February 2000.