This is a magnetic chess set I designed. Quick video of it in action here.

I made it so each 2x2 set of squares are fixed together permanently with glue. I used hot glue, but you could easily epoxy it.

Each side of the 2x2 set has 2 pockets for magnets, and each square has a pocket in the middle. Each piece has a pocket built in as well.

You will need to PAUSE the print to insert the magnets in most of these, as they are embedded. Unless you are unusually quick and / or dexterous. I used super glue for the magnets so they don't get picked up by the hot end.

The magnets I used were 6mm in diameter by 2mm in thickness. Make sure to be careful of your magnet polarity. It's easy to get them reversed - see the graphic.