The sound of a hammered dulcimer is exquisitely beautiful. The word dulcimer means 'sweet sound' after all. The materials to build one are readily available and won't cost more than about $25.00, but that doesn't mean it is easy.Building a hammered dulcimer is not something to do casually. It takes much delicate and dedicated work. But when you are finished you have a work of art.
Choose your wood wisely. The most important wood is the one you choose for the pin blocks. It must be strong, so it can grip the tuning pins and endure the stress of the strings. Maple is a good wood to use for the pin blocks. Use pin blocks made from 2 by 4 stock, though it could be difficult to obtain. If so, you can make your own by joining three 3/4-inch by 31/2-inch planks to produce a block that's 2-1/4-inch thick. Then use 2-1/4-inch-wide pieces for the frames and inside braces as well. Make the dulcimer's top (soundboard) and bottom can be made from plywood, if you choose.
Round off the top edges of the inside treble and bass bridge braces. Glue the pin blocks, outside frames and all four inside braces to the bottom panel. Make all the joints flush and square. Use clamps to hold the components in place while the glue is setting. When the interior is complete, finish it with paint or varnish, except for the top edges of the frames, braces and pin blocks.
Cut out the soundholes and glue the soundboard in place, including the rounded top surfaces of the treble and bass bridge braces. After measuring and aligning them carefully, glue the side pieces to the soundboard. When the adhesive has dried, sandpaper and paint or varnish the entire instrument.
Drill the tuning-pin holes with a 3/16-inch bit, and install the tuning pins by driving (not screwing) them into their holes. Leave 1/4 inch of space between the string hole in the pin and the soundboard, to allow room for the winding of the strings. Drill the 9/64-inch holes for the hitch pins, and install the pins at an outward angle of about 30 degrees.
String the dulcimer, with No. 10 music wire for the four bass courses, No. 8 for the lower five treble courses, and No. 6 for the upper five treble courses. Allow enough slack to wind two or three full turns of wire around each tuning pin.
Using a sharp knife, make a straight, shallow groove in each bridge to hold the wire capping material in place. Cut the coat hanger to size and lay it in the groove. Install the treble and bass bridges under the strings. The pressure of the strings, when tuned, will hold them in place.
Ensure that the strings make solid contact with the side bridges by lowering the height of the three or four treble strings. Lower the treble bridges at the rear of the instrument to make the strings contact the bridge. The bass strings will not contact the right side bridge, so don't worry about it. The most critical measurements involve the placement of the treble bridges. They must divide the strings crossing them into tones a fifth apart. The distance between the left side bridge and the treble bridges must be two-thirds of that between the right side bridge and the treble bridge. When you complete this critical stage, you are finished. You can now make sweet sounds with your hammered dulcimer.