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| Handmade Dulcimer, Part 2: Cutting the Components |
From "Handmade Music" episode DHMM-108 |
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 The dulcimer is constructed from seven components: the peg head, tailpiece, fret board, top, back and two curved sides.
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In this segment, Professor Gary Mahoney and his assistant Brian Hartzog prepare the wood components to create a dulcimer out of walnut stock. Thus far, they have cut and glued the stock for the dulcimer's back. In this segment they create the other components including the curved sides, fret board and peg head. Materials: Design blueprint and templates Table saw Jointer Power planer Band saw Scroll saw Drill press Bending form Propane torch and aluminum pipe (for bending device) Container of water Fret jig Fret saw Wire cutters Polished-end hammer Straight edge Carpenter's pencil Woodworker's glue Clamps Safety Alert: When working with wood stains, finishes, varnishes, solvents and other harmful chemicals, work in a well ventilated area. In some circumstances, a ventilator mask may be required.
Curved SidesBrian cuts the walnut stock for the sides. The stock pieces for the sides are 32 inches long and 1-1/2 inches wide. The thickness will be 1/8-inch, and the stock is sliced with the band saw to form a book matched pair (figure A), just as was done earlier with the back piece. The flat pieces of walnut will be transformed into curved sides to give shape to the dulcimer. From his design plan, Gary has built bending forms that replicate the shape of the dulcimer's sides (figure B). Personal preference will determine the shape and plan choosen. Gary chose this particular shape because it's traditional.
After soaking the strips of walnut, Gary carefully bends the wood against a heated pipe and checks the evolving shape against the form. "I also like to over-bend it a little bit," Gary says, "This is a shape that was traced from the pattern we're going to build. I over bend [the wood] so when I put it in the forms, I'll be straightening it out. So when I glue it later, I'll have a lot less spring-back and it will be closer to the shape I'm looking for." Gary keeps his thumbs close together and uses gentle, even pressure to rock the walnut back and forth (figure C). The moisture and heat allows the wood to bend without a lot of stress. When both sides match their forms (figure D), Gary clamps them and set them aside for later assembly.
Fret Board and Top- The next major step is the creation the fret board. Brian and Gary cut a piece of the walnut stock 1-1/2 inches wide and 3/4-inch thick. The length is 30 inches, so it matches the back. A 3/4-inch groove is cut on the underside of the fret board using a dado head on the table saw. The length of the cut is the same length as the dulcimer's fret scale. So Gary marks with chalk 26-1/2 inches and keeps the cut within that boundary. Also, the depth of the cut will be half the thickness of the fret board so the blade is set to 3/8-inch (figure E).
- Now the fret board is rolled over and a pick area is cut out using the band saw (figure F). This area will prevent players from scratching the surface of the fret board when they use picks to play the dulcimer. Sanding is also required in the pick area.
Next, Gary cuts the frets into the fret board using sawing jig (figure G) and fret saw. Gary custom-built the sawing jig to make sure that the frets are spaced properly and to make sure cuts are true. Jigs like this, as well as fret saws (figure H) are available through luthier supply shops.
The spacing is determined by the fret scale, and Gary makes the cuts for the 15 fret slots using the fret saw. Since the depth of each cut should be precisely 1/16-inch, he marks the depth on the blade's face with masking tape. He cuts only to the mark, and follows the jig as a guide, as he works down the fret board (figure I). After cutting 15 fret slots, he uses a set of diagonal cutters to prepare 15 lengths of fret wire. He cuts each piece them at least as long as the fret board's width (figure J). He'll trim away the excess later.Tip: It's a good idea to add a little before into each slot before you drop each piece of wire into position. The water expands the groove slightly and insures a snug fit when the wood dries.
A hammer with a polished end is used to tap each fret into place (figure K). The polished end of the hammer keeps the frets free of marks that could diminish the look of the dulcimer.When all the frets are installed (figure L), the excess wire is trimmed from the edge of the fret board and filed smooth.
Once the fret board is finished it needs to be glued to the top. Gary cuts two more book-matched pairs from the walnut stock. As with the pieces cut earlier to make the back, these should be 4 inches wide, 30 inches long and 3/16-inch thick. He sands both pieces down after cutting until both pieces are 1/8-inch thick. He then sets 3/4-inch spacers between the book-matched pair. He centers the fret board over the space between the top pieces. He puts a thin bead of glue down the edge and carefully places it on the top (figure M). When he is sure the fret board contacts both pieces symmetrically he locks it all down with clamps until it's dry. By bridging the two pieces with the fret board Gary created a channel that improves sound quality (figure N).
With the glue dry, Gary can cut out the dulcimer's shape. Using an instrument's blueprint as a guide, Gary created a template of the dulcimer's top. After tracing the pattern onto the left and right side of the top (figure O) he cuts along the outline with a band saw (figure P) to reveal the dulcimer's shape (figure Q).Next, Gary retrieves the back piece that was glued up earlier. He marks it for cutting, but this time uses the newly made top as the template. That way, even if a slight cutting mistake was made on the top, the back will still match.
With the top and back both cut, decorative patterns can be added to the top of the dulcimer. These are not sound holes. These designs are not actually sound holes, like the familiar one in acoustic guitars. These are added strictly for appearance, and the pattern and postion chosen have no effect on the tone of the instrument. Heart shapes have been chosen for this dulcimer. The shapes are traced onto the top using a template (figure R). The shape is cut out by drilling two holes side by side to form the upper portion of a heart. A scroll saw is then used to complete the design (figure S).
Assembly can't continue until a peg head and a tail piece have constructed. First the stock is cut large enough to accommodate the patterns for both and it's run through a jointer and planer. The stock must be as thick as the width of the sides -- 1-1/2 inches thick. The patterns are traced from the design plans for the dulcimer (figure T). A band saw delivers the best results when cutting out these shapes. Relief cuts will be needed when it's time to cut the extreme curves of the peg head and tailpiece. The peg head must be hollowed out after cutting, and a jig (figure U) makes the job of drilling easier, helping to make consistent, straight cuts in spite of the peg head's odd shape.
With a 5/8-inch bit, a channel down the center of the peg head (figure V) is created at the drill press-- one hole at a time. A chisel will clean up the sides when the drilling is complete.Gary makes an angle cut across the top of the peg head for a decorative touch and a taper jig simplifies this cut. He cuts one side with the band saw, then flips it over after one pass to repeat the cut on the other side. He also adds a couple of kerfs in the peg head and tailpiece (figure W). The tips of the sides will slip into these cuts later when he assembles all the components.
At this point in the process, Gary has constructed every component he needs to complete the dulcimer. In the segment that follows, the instrument is glued up and a wood finish is applied.
RESOURCES :
Stewart MacDonald's Luthier Supply Shop
Website: www.stewmac.com
Luthier's Mercantile International, Inc.
Website: www.lmii.com
Pioneer Valley Luthier Supply Company
Website: www.pioneervalleyluthier.com
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