As soon as the child displays an aptitude for self-propulsion, some sort of curb will be required to restrain the young hopeful from contact with various danger zones, and elders from nervous breakdowns. Suitable for either indoor or outdoor use, the conventional folding type of play pen illustrated in Figure 2.1 makes use of forty-two 1/2-in. maple or birch dowels 23 in. long, set 1/2 in. deep into the thinner sides of J in. by 1 1/4 in. top and bottom rails, which are 39 and 37 in. long, respectively. In the longer rails the dowels are spaced on 3 13/16 centers, while in the shorter rails, which are later cut in half, the centers are spaced 3 9/16 in. apart.

Fig. 2.1. Folding play pen.

Two templets will simplify the matter of accurate spacing. These may consist of two strips of wood with two 1/2-in. holes bored on 3 13/16 in centers in one case, and on 3 9/16in. centers in the other. If the strips are thick enough to act as stops after the bit has penetrated 1/2 in., so much the better. Otherwise a gauge can be improvised from scrap wood or a measured length of rubber hose. Use a try square as a guide when boring by hand. On the 39-in. rails the first and last holes are centered 7/17/16 in. from the ends; they are 3 1/8 in. from the ends of the 37-in. rails. Using the proper templet, bore the first hole, remove the bit, and replace it with a J-in. dowel. Bore the second hole and repeat the operation.

Lumber List

Before gluing and clamping the sides of the pen, be sure to chamfer the ends of all dowels, and cut a 1/2-in. channel at both ends to permit the glue to escape as it comes under pressure.

In the absence of bar-clamps, a side of the play pen which has been assembled and glued can be laid flat on an old level floor, with one rail butted against a wall or other solid base. A 3-f t. piece of 2 x 2 or other solid stock is laid against the other rail and a hardwood cleat or cleats screwed to the floor a slight distance from and parallel to it, so that slim wedges can be hammered between the two in order to exert the necessary pressure. To prevent buckling, one or more boards must be nailed or weighted across the rails of the play pen. An automobile jack can often be blocked fiat on the floor to exert the required pressure.

While the glue is drying, two pieces of 1/4-in. plywood are cut a scant 18 1/2 by 37 1/4 in. to form the floor of the pen. Three cleats 1 in. deep are screwed or nailed from the underside of each floor section, to raise the floor flush with the upper edges of the bottom rails as indicated in the drawing. Finger holes bored with an expansive bit in the two center edges will facilitate lifting the hinged floor when folding the pen.

After all four sides have been glued up, the 37-in. sides are cut exactly in half, and narrow butt hinges screwed to the outside. Rigidity is retained by the installation of a simple latch on the inside. As indicated in the detail, this can be made from a flat metal mending plate which has a notch hack-sawed in one end. If this notch is cut at a slight angle, it will be tight enough to foil exploring fingers. The latch swings on a bolt and washer which passes through one of the hinge holes, where an extra lock nut can be added if desired.

Eight more narrow butt hinges are added, one to each inside corner; the two sections of the floor are then hinged to the tops of the two lower long rails, as shown. Stain or enamel to suit. To fold away, lift both floor panels against their sides, unfasten the latches, and press both ends inward until the whole pen is flat.