Great to see this. It reminds me of the original toy. If I had the time/inclination, a kickstarter based on the original toy that rendered on paper and screen might be an interesting plaything. Another future angle could clearly involve 3d-printing of the disks. Good stuff.
You might also want to check out http://GeoKone.NET, which is kinda similar, but not trying to imitate the original spirograph. But I hear many people have compared the two.
GeoKone is much more complex though and allows much more flexible geometry to be created.