The rumba box, also known as the cajon, is a percussion instrument that’s used in Latin, flamenco and African music. It’s essentially a wooden box on which the player sits, hitting the front and sides with his hands to produce a variety of tones. A hole at the back of the instrument allows the sounds to escape. Guitar strings are place behind the front panel to give a crisp snare sound when the panel is struck.
Cutting The Box
Measure and cut a piece of 3/4-inch plywood, 16 inches by 24 inches, to make the bottom of the rumba box.
Measure and cut two pieces of 3/4-inch plywood, each 24 inches by 30 inches to make the sides of the rumba box.
Measure and cut one piece of 3/4-inch plywood, making it 17 1/2 inches by 30 inches; this will be the back of the rumba box.
Making The Box
Mark the center point on the back piece of the rumba box and use a compass and pencil to draw a circle 6 inches in diameter around it. Cut out the circle with a jigsaw.
Line up one of the side pieces along the 24-inch side of the bottom on the rumba box. Apply glue where the two pieces join, and then screw the side to the bottom to create an L shape. Attach the other side in the same way, then glue and screw on the back of the rumba box; viewed from above it will resemble a squared-off U shape.
Cut two pieces of 1 inch by 1 inch lumber, each 23 1/4 inches long. Glue these in the corners where the back of the rumba box meets the sides.
The Front Of The Box
Measure and cut a piece of 1/4-inch plywood that is 24 inches by 17 1/2 inches for the front of the rumba box. On one side of the plywood measure and draw lines 3/4 inch in from each of the long sides and one of the short sides. Cut two pieces of 1 inch by 1 inch lumber and glue and screw them inside the lines you’ve drawn. Cut two 20 1/2 inch lengths of the 1 inch by 1 inch lumber. Glue and screw one of these pieces in place along the line you’ve drawn along one of the short sides of the plywood.
Mark point 6 inches, 8 inches and 9 inches from each edge along the remaining 1 inch by 1 inch lumber. Hammer in nails at these points (six nails in all), leaving 1/4 inch of the nail showing. Chisel a small groove at each of the marked points on the sides opposite and above the nail.
Completing The Rumba Box
Tie a classical guitar string to each of the nails and run each string through the grooves you made on the wood. Fit the piece of wood in place on the plywood, between the two side pieces, the top of the piece against the line you drew earlier. Glue and screw in place so that each of the guitar strings dangles free.
Measure and mark points 12, 14 and 16 inches along the inside of each of the long pieces of lumber. Hammer nails at each of these marks, leaving 1/4 inch of the nails showing. Wind one guitar string tightly around each nail and tie in place to make the snares.
Fit the front in place on the rumba box, with the snares inside. Glue and screw in place.
Measure the outside dimensions of the top of the rumba box and cut a piece of 3/4-inch plywood to size. Glue and screw in place – only use screws to attach to the back and sides of the rumba box.