Build Your Own Washers Sets
Outside box dimensions are 16", so you need 4 pieces of 2x4, 14.5" long (the other 1.5" is the width of the 2x4). Treated wood stands up better, although it is also heavier, so up to you to make that trade-off decision. Screw them together with two 2.25" wood screws to make 4 16" sides.
The base is 3/4" plywood, 16" square. Screw it to bottom of 2x4s with 1.5" screws.
Pipe is 4" PVC (inside diameter), cut 5" high. You need a jigsaw to cut the hole (get a start with a drilled hole), although some people have built sets with a plastic base and glue (no hole). Certainly an option if you don't have a jigsaw, but it changes some aspects of the game.
Washers are 1" (inside hole dimension is 1"). Get extras because they are easy to lose at night. For singles, you'll want to mark at least one set for identification.
