First, let me say, I meant no disrespect with my statement "of suitable" to previous replies. I do think there are better ways of doing the job than by calculation alone. Marc needs a means of application. There are truly many ways to do this. I offered one, and I'm unsure of its merits with only one application, but it worked for me. My method assumes one will use the "coopering plane" style of joining. This discussion might be better suited to the builder list.
Best wishes, Chad -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Tuesday, August 14, 2007 3:05 PM To: [email protected] Subject: [LUTE] Re: Facets on a solid lute mould >>> There are very detailed instructions on how to build a bowl mould but no >>> mention on how to facet them addendum. My previous email spoke to how one would design the mold on paper before building it. One can also glue up slabs, shape them into a rounded luteish form, and then carve the facets; as Marc has noted, the challenge then is how to denote the edges of the ribs. All the following assumes that the edge of each rib lies on a plane which is parallel to the axis of the lute. The plane need not include the axis of the lute, nor is it necessary for the several planes to intersect in a common axis. Take a scrap of plywood twice as wide as the mold; cut an opening in it that will pass over the mold as they lay on your work bench. Grab the ends of this board in two clamps to hold it vertically as you slide it on the bench. Position it arbitrarily along the length of the mold, slide a pencil on the face of the board so it marks section lines on the mold. (Assumes circularish form) Use dividers to stepoff equal-sized facets on each section. Rip a thin piece of wood longer than any rib, spring this batten aginast the mold to join the dots, trace the edge to mark the mold, repeat for each ribs edge. Pins and tape may be useful to hold the batten while you adjust so it lies fair to the eye. It may be helpful if you mount the mold to a board that has a slot at one end to take the end of the batten. Alternativly you can mount the mold to a board, tack the board to your bench so that a bench vice is conveniant to take the end of the batten. Maybe you can dragoon a child or some other helper. Another way is to take a piece of stiff plywood longer than the central axis of the solid mold, cut an arch that closely clears the mold on its axis and which will be rotated axially about the mold closely without touching (1" clearance should be fine). Arrange for pivots and mount them to your bench (strap hinges ok). Align the mold so this board projects the plane of each edge you want to draw, then slide a pencil along the board, marking one edge of a rib. Setup again and iterate. This is very much like using a surface guage (or an improvised one - pencil on block serves); sometimes its easier to rotate the mountain, other times the reference plane. I guess I learned something in high school drafting class after all, thanks Mr Boros. -- Dana Emery To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
