This portable version of the classic tic-tac-toe game board enables kids to take it wherever they go.
One row of squares on the game board swivels open to reveal two storage holes for marbles, and two pairs of rare-earth magnets (optional) help to keep the swivel closed. To build the project, you’ll need a piece of hardwood stock measuring 5 1/4 in. wide, 5 1/8 in. long and 1 1/8 in. thick. The holes are sized to store 10 standard game board marbles. Here’s how to build this project.
Step 1: Install a 1/8-in.-kerf saw blade in your table saw, and outfit your miter gauge with a long auxiliary fence. Mark the workpiece to cut a 1 5/8-in.-wide slice off of the blank, cutting along the grain (which should initially be the wider of the two dimensions of your workpiece). Use a stop block to register your blank with the saw blade before making this cut (see Photo 1). The cutoff piece forms the swiveling row of game squares. Making this cut should now reduce the overall size of your blank to 5 1/8 in. square with the cutoff piece held in place.
Step 2: Install a 5/8-in.-diameter Forstner bit in your drill press, and set up the machine to bore a pair of 3-in.-deep holes into the edge of the larger game board blank for marble storage. Position these holes 9/16 in. in from the ends of the blank and centered on the thickness of your stock. Back up your workpiece with a clamped fence on the drill press table. When laying out these holes, choose the edge of the game board that matches up with the cutoff swivel you made in Step 1. Bore the marble holes in a series of deepening passes to help clear the waste as you work (see Photo 2).
Step 3: The swiveling piece of your game will turn on a screw, but two pairs of 3/8-in.-diameter magnets can help hold it closed if the screw should loosen over time. If you choose to install these magnets, drill shallow holes to recess the magnets into the game board and swivel now (see Photo 3). Position them 1/4 in. further in from the marble holes.
Step 4: Fasten the magnets into their recesses with little drops of epoxy or cyanoacrylate glue. Press them into the holes so their contact surfaces are flush with the surrounding wood. Make sure the polarity between each pair of magnets draws them together when the swivel is in place.
Step 5: Mark a center point on the outside edge of the swivel for locating the pivot screw. Clamp the swivel into position on the game board, and drill a countersunk pilot hole for a 3-in.-long wood screw (see Photo 4).
Step 6: Install the pivot screw to attach the swivel to the game board. A dab of paste wax on the tip of the screw can make it easier to drive home (see Photo 5).
Step 7: Now you can create the grid pattern on the playing surface of your game. Return to the table saw and lower the blade to make a 1/8-in.-deep cut. Set your rip fence so it is exactly 1 5/8 in. from the blade (the blade should align with the sawn edge separating the swivel from the larger board. Make two cross grain cuts to form two grid lines, turning the game from one end to the other between passes. Follow up with two long-grain cuts to finish the grid pattern. Use a push pad when making all four cuts to keep your fingers clear of the blade (see Photo 6).
Step 8: Draw a pair of diagonal lines across each of the playing squares to find their center points, and drill a 3/8-in.-diameter hole here (see Photo 7). Make the holes about 3/32 in. deep, which should be sufficient to keep the marbles from rolling off the board during game play.
Step 9: Plug the screw counterbore if you wish, and sand the wood plug flush when the glue dries. Next, head to the band saw to round the corners of your game with 3/4-in. radii. Ease the top and bottom edges of the wood with a piloted chamfering bit in a trim router (see Photo 8).
Step 10: Sand your new game up through the grits to 180 or 220 to thoroughly smooth it. Apply a protective topcoat and, when the finish dries, you’ll be ready to load it up with marbles and find a worthy opponent (see Photo 9). Enjoy your new game.