Marble puzzle tiles

Update Oct., 22nd 2017:

Added Box.stl (205x205x11.2mm) as a replacement for the impractical Frame.stl. Since more and more printers with huge print beds become more and more widely available size becomes less of an issue nowadays.

Update Jan., 14th 2017:

Added Frame.stl as a primitive holder for four tiles.

Update Dec., 23rd 2016:

After printing Tile1.stl I noticed a mistake in the intersection between the inner and the outer ring. The flaw is corrected in Tile1_2.stl. If you down