The wings are the last thing to do. Begin by gluing and nailing a 1/4″-thick solid wood edge to one end of the wings. This edging gives the piano hinge some meat to bite into. Finish the wings by applying the 1/2″ x 1 1/2″ trim to the other three edges.
Study the diagram to see how the wings are supported. First apply the upright ledges to the uprights. Cut the 2″ radii on the brackets and then attach them.
Cut the swing arms, braces and flip-out supports. The swing arm and brace need a half lap joint that makes a “T” shape. Attach the continuous hinge to the top of the “T.” The best way to cut this joint is with a dado head in a table saw. Cut a 3/4″ x 3/4″ notch on the end of the swing arms to mate with the flip-out support.
The last thing to do to the arms is to round off the corners: 1″ on the ends and 3 1/2″ on the brackets. Now mount the swing arm assemblies to the underside of the wings using a 10″ piece of continuous hinge, with the notched end of the swing arm 1/4″ in from the point where the wing meets the case. To keep everything from flopping around when the arms are down, use adhesive-backed Velcro between the swing arms and wings. Reinforce the Velcro’s adhesive with staples.
Finish the wings by cutting a 3/8″ x 3/4″ dado down the middle of the wing for the extruded aluminum channel for the stop. Next to that dado, cut a second shallow dado that’s 1/2″ wide and as deep as your tape is thick. Cut the channel to length and screw it in place. Now concentrate on the flip-out supports. After cutting out the mating notches for the swing arms, cut a 3/16″ x 5/8″ rabbet into the end of the support to accept a 4 3/4″-long piece of continuous hinge. Lay out and mount the support to the upright, centered and flush to the bottom edge.
The last step on the wings is to attach the wing assembly to the upright. Do this carefully so that the surface of the wing is flush with the upright ledge. Now, if everything’s OK, your wings should lock flush and square to the upright. If you didn’t get it right the first time, add a flat-head screw to the inside of each notch to adjust the height of the wing.
To attach the wing assemblies, temporarily remove the saw/riser assembly and remove the wing from the upright assembly. Cut a spacer that’s 2 3/4″ plus the height of the saw’s table. Clamp the spacer flush to the upright ledge. Lay the wing assembly on the edge of the case. On the saw/riser assembly, measure from the front edge of the riser to the saw fence. Subtract 1 3/4″ from that number and mark it on the case, measuring from the front. This is where the upright should be mounted. It accounts for the thickness of the 3/4″ saw fence and the distance from the center of the stop to the fence. Mount the upright with the hardware listed. Make sure to counterbore the bolt heads and washers. This allows the flip-out support to fold flat against the upright. Re-attach the wings and flush the saw table up to the wings using a straight piece of lumber. Adjust the saw’s height and lock it down.
The last step is to make the fences and the stop and to attach the tapes. Rip a couple of 3 1/2″-wide sections of plywood from your scrap. Cut them to 1″ longer than the distance from the blade to the outside edge of the upright. That should be about 16 1/4″ if everything was centered correctly.
Cut 3/8″ x 3/4″ dadoes 1″ to the center from one edge. The edge that the dado is closest to is the bottom edge. Repeat the 1/2″ dado for the tape so it’s above the dado. Glue in a 4″-long filler into the groove at the end next to the blade and attach a length of aluminum channel to fill the remaining length. Make a mirror part for the other side. This keeps your hands at least 4″ away from the blade. Attach the fences by lowering the saw (as if you were making a cut) and butting each fence against the blade. Clamp the fence pieces there and screw them in place.
Cut the measuring tape to 16″ and stick it in place. Use a square block to index off the 16″ marks and, after cutting the tapes to length (around 46″), stick them in place, butting the end up against the block on each side.
Finally, make the stop that runs in the channel.The stop is a simple 2″ x 3″ block with a 1/4″ hole in it. Make a guide strip that’s about 5/16″ x 1/16″. It’s easier if you make the strip a little thick and plane it down to the 1/16″ thickness. Drill the 1/4″ hole through and test it with a bolt and star knob. PW
Jim Stuard is a former associate editor for Popular Woodworking.