A few years ago, I went on creating heavy playing boards for the go game, actually made half a dozen of them.
In another project, I describe how I took large chunks of wood, turned them in thick boards and made custom tools to draw the grid, ie lines & hoshis.
My first experiments were a little more hackish, since go stones were not easy to find, I used black and white marbles, that needed holes to stand still on board.
In this project, I use a 30 years old, 50cm large and 4cm thick oak board. I drew the holes positions and use a variety of drill bits do make the pockets.
Too bad marbles aren't as easy to play as flat stones.