Arch Forms
The function of the tools I use and how they work are explained here. Specific tools used are noted in bold.
The arches are formed by gluing together multiple laminate plies. The plies are bent over a convex form, and held in place within a vacuum bag.
The first step is to build the forms. Because this is a new version of the table, and new form was made for the main arch. The form is made by joining multiple solid sheets of MDF (medium density fiberboard) together with spacer blocks between the sheets. The arch is traced onto the MDF sheet using a thin piece of wood that naturally bends into a pleasing arch. Grid lines are drawn on the MDF to ensure the arch is balanced and symmetrical. One side of the arch is cut and sanded to shape. A pattern cutting bit on the shaper is used mass product the arch on the other sheets. The pattern cutting bit has a bearing that is flush with the cutter head. The bearing rides against the pattern sheet, and the cutter duplicates the cut on the other sheet, which is temporarily attached to the pattern. Once the sheets are cut, the spacer blocks are nailed in place and trimmed using the pattern bit. The sections are then screwed together. The outside curve is fine tuned by sanding, and a thin cover sheet is installed.
Our shop has a large “library” of forms. We seldom throw away forms, as making the form is often more work than making the laminated piece. An existing form is used for the down sloping top arches.
