Creative Woodworks & crafts 2003-03, страница 50

SUPPLIES

Wood: cherry or wood of choice—four pieces 5/8" x 5/8" x 8" (for fhe top rails), four pieces 5/8". x 5/8" x 17" (for the bottom rails), four pieces 5/8" x 5/8" x 12" (for the side raiis). two pieces 3/8" x 5/8" x 8" (for the top support members) Toots: table saw with miter gauge arid dado blade, router with router table and rabbeting bit or spiral down-cut bit, 45° chamfering bit, drill press with . l/4"-Dia. bit, spring clamps, square. protractor Sandpaper, assorted grits

PVC :fp

Clear packaging tape

Danish oil finish

Plexiglas, one piece 7" x 36"

Fabric of choice 8" x 36" ,

Spray adhesive {3M Photo Mount or similar product)

Sixteen i/4" round, head screws

Introduction

When I made a matched pair of Arts and Crafts style table lamps, my first impulse was to buy lampshades for them. However, after considerable searching I was unable to find affordable shades that would complement the lamps. Every combination gave the impression of two unrelated items put together. So I decided to make my own. The project which followed turned out to be an interesting exercise in lap joinery and compound mitering.

12 • Creative Woodworks & Crafts March 2003 Base

Calculating fhe dimensions and angles of the panels

Given the top and bottom dimensions of the panels, you can calculate the length of the sides (S), the angle to set the miter gauge for cutting the lap joints (I), and the blade tilt angle (m) to cut the miters along the sides.

S=Jo.5(B-T)²+H⁷ cos(l)=-g- tan(j)=^L

The value of m can then be found by interpolation on Table 1. By way of example using my dimensions, S = 9.65", I = 57.93", j = 51.20°, and m = 33.42°.

INSTRUCTIONS

Making the frame pieces

The side, top, and bottom rails of each panel are made from pieces with a square cross-section. These should be cut to lengths several inches longer than their final sizes in order to make them easier to handle when cutting the lap joints. I began by selecting a piece of clear, straight-grained cherry stock and milling it to a final thickness of 5/8". The rails were then cut to length with squared ends using a stop on the miter gauge extension. It doesn't matter what the oversize lengths are; what matters is that all components of the same type must have exactly the same length to facilitate cutting the lap joinery. Sufficient material should be cut to provide for spares. Scraps of reasonable length should be retained for use in setup. For consistency of color and grain, I used a board that was large enough to provide all components.

Cutting the lap joinery

To facilitate cutting lap joints on the table saw, I attached a piece of MDF to the miter gauge, with sufficient length to extend beyond the dado blade when using either the right or left hand miter slot. In addition to minimizing tear-out, fhe MDF extension provides a convenient reference point for alignment of the cuts

----------Took For The

AITS AMI CRAFTS STYLE IAMKHAM

_______________ISSUE;

by Donald R. Mott

Designing the lampshade

The shape of the lampshade design is a truncated pyramid. Because the sides are trapezoidal, the procedure for making one is the same for lampshades of all sizes. The inside edges of the trapezoidal frames have rabbets to hold 1/8" Plexiglas panels. Fabric, when glued to the outer surfaces of these panels, provides a translucent pattern with colors and figures that can be chosen to fit the desired decor.

Although making the lampshade is relatively simple, choosing the overall width and height for a given application is subjective and requires careful planning and modeling. My approach was to make models using cardboard sides taped together, holding them over the lamp to judge the suitability of various shapes. The dimensions to estimate at this point are the width of the base (B), width of the top (T), and the vertical height (H). For my lamps, which stand 15-1/2" inches from base to bottom of the harp, the dimensions I chose were B = 14", T = 3-3/4", and H = 6-3/8". When choosing your lampshade dimensions, don't be overly influenced by the size of the harp. I found it necessary to bend the harp to hold the shade at the desired height, but that is less important than compromising the aesthetic aualities of fhe lampshade.