We need to rout the pockets for the magnets. Turn the plywood panel over. If you used through holes, the location of the magnets will be easy to determine, if you drilled blind holes, you will need to measure. We created the pockets an 1" (25mm) or so beneath each column at the bottom of the display.

For the magnets to work effectively, the pockets need to be made with a very thin bottom. If they are made too thick, the magnets will not be able to catch the falling pucks. We recommend about 1/16" (1.5mm). You can jump ahead and make a puck to test out the depth of the pockets.

We used a 3/4" (20mm) straight bit in a plunge router. It may be tempting to rout out one large pocket for all of the magnets, but this would endanger the strength of the panel. To avoid putting too much strain on the router bit, we made three successive passes progressively getting deeper until we reached the depth stop (lock the stop tightly!) we set on the router. We simply marked the locations and clamped a board to the plywood and our workbench to act as a fence. You can complete all of the pockets by setting up the fence only three times.

Once you have completed the routing step, you can chisel out any areas that prevent the magnets from sitting without obstruction at the bottom of the pocket. If you do need to use a chisel, make sure it is very sharp and that you have clamped the plywood firmly to a flat surface - the bottom of the pockets are very thin and delicate. If you do mistakenly plunge through, you can patch the hole from the other side.