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 downloaded the previous version, please use the updated file.

Update Dec., 20th 2016:

- Replaced Tile1.stl with a repaired, manifold version.

Update Dec., 11th 2016:

- Added tile 3.

Notes:

You need four tiles. The combination is up to you. Place them in a flat 20x20cm cardboard box, add marbles (15mm diameter), have fun.

Inspired by Selecta's Infinello marble puzzle. Get the original it, it's great!