Woodworker's Journal 1982-6-6, страница 26
¥ Lyre Clock by Roger E. Schroeder | The basic design of this lyre clock is attributed to the famous clockmaker, Aaron Willard Jr., who was born in the late 1700's and lived most of his life in Boston. The clock I built is made entirely from scrap wood that consisted of maple, Honduras and African mahoganies, pine from a turn-of-the-century pew, mahogany from a broken-up antique sewing table 1 found on a neighbor's wood pile, and striped mahogany and crotch veneers. It measures nearly 38 inches from finial to finial, is 12 inches wide and 5Vi inches deep. Begin this project with the sides, parts A. I chose pine because it would reduce the weight of the clock, and since the mechanism case would be bolted into the end grains of the sides, the strength offered by a hardwood wasn't a critical factor. Two pieces of 13A" thick pine 14" x 3" wide glued face to face will be needed. A cardboard template will help so that each half can be roughed out on a bandsaw before gluing. Be sure to leave extra wood at the top and bottom. A drum sander on a radial arm saw or drill press will finish shaping the contours. Since the sides will be veneered, imperfections can be filled in with wood filler. A smooth surface is necessary, so the final sanding should be done by hand. The bottoms of parts A will have to be cut at 10 degree angles, and rabbets 3A" wide by Vi" deep for the back panel, part B, can be made with a router. The back panel, made from cabinet-grade birch plywood, will have its sides tapered 10 degrees from a base that measures 13A inches wide. To do this, I set my taper jig at 10 degrees, starting with a piece of plywood at least 8 inches wide by 13 inches long. I then ripped the panel on one side. My taper jig goes only to 15 degrees, however. When cutting symmetrical sides, the angle has to be doubled for the jig when the panel is turned over. So I taped the waste piece from the first cut to one side and ran it through the saw again. When finished, I screwed panel B, using V* inch #5 flathead brass screws, to parts A and set the assembly aside. Start on the mechanism case, part C. This too is going to be veneered, so solid mahogany is not necessary, but a hardwood should be used since it has to hold a fair amount of weight. I would recommend two pieces of 13A" thick maple glued face to face with a Vi" thick piece of mahogany glued to the front. The mahogany will eliminate veneering the front. Be sure to run the grains in the same direction. I glued the three laminated pieces to a piece of 3A inch plywood, newspaper between, and attached the wood to a face plate. Once I turned the wood to a 7Vi inch diameter, I used a parting tool to take out the center, leaving the walls of the case about 1 Vs" thick. To get a nicely fitting back panel, part D, I again used a parting tool and cut a rabbet Vi" deep x V*" wide into the back of C. Removing it from the lathe, 1 replaced it with a Vi" piece of birch plywood glued to a piece of 3A" plywood, newspaper between. This I turned to a diameter slightly larger than the diameter of the recess I made in the back of C, and, checking it with C, finished turning it down until I got a snug fit. The front panel, part E, a piece of 3A" plywood that holds the mechanism, does not need as accurate a fit as D, as the bezel will cover it, so the rabbet for it can be made with a router and and a 3A inch rabbet bit. But E should be turned round on a lathe so its exact center can be located. This will determine where the handshaft of the movement will be. Eis held to C with 1" No. 5 flat head screws. A hole will have to be made in C for the pendulum to fit through. This I made 2 inches wide by 2 inches deep. Drawing the outline on the outside diameter, I drilled holes into the four corners and cut out the piece with a jigsaw. Part C can be set aside so work can begin on the carved front, part F. A piece Vi" thick x 11" wide x 13" long will be needed. A solid piece of lumber instead of a laminated one will be more stable and will not show the glue lines. I'd recommend Honduras mahogany since its grain is excellent for carving. Take the waist of the clock, parts A and C, turn them panel side down on the mahogany board, and draw the outline for part F. What you must add, however, are the flares at the bottom. When you cut F to shape, don't go inside the outline. Using 1 Va" wire brads spaced about every 3" along the outline and Vi" in, attach F to the front of parts A. But don't drive the nails all the way in as you'll want to remove F for carving. Take the assembly to the drum sander and flow in F with the sides, using a fine grit sanding sleeve. I taped the lower portion of the sleeve with masking tape so it would not cut into the sides of parts A. Next comes the joining of the mechanism case and the clock waist. Determine the vertical centerline of F and place the lowest portion of C at a point 11 Vi" from the bottom of F on that line. Outline the diameter of C with a pencil. Band-saw along the line, leaving a little extra wood. What I discovered was this: hand tools and repeated passes with the sanding drum could not insure a good fit between the case and waist. What I did was lathe turn a piece of glued-up pine 4 inches thick to the same diameter as the housing, which is IVi inches. Using contact cement, I glued a 4 by 24 inch sanding belt to the pine. I then had a sanding drum the same size as the case. Tne drum had a tendency to kick back the work, but with practice on a thick piece of |
