A height system using the inner of kitchen paper rolls or toilet paper rolls. The cardboard rolls have an inner and outer diameter of 42 mm and 43 mm. The height is about 14.5 and 24cm. The lower part has a hole for dropping a marble and a little arrow to align top and lower part. The floors can be pushed on the rolls ... beware of the balance ... The bigger floors can also be used as single floors independent of the system. The ring inset can be found eg here: https://www.thingiverse.com/thing:4900813

For use of the "pillars" on a board, you have to print a pair of GraviRolleO.stl and GraviRolleUPfeil.stl and one ring inset