Intro: Obelisk Table Lamp Base
Make a wooden lamp base in the shape of an obelisk for a table or nightstand lamp.
Materials you need are a 3/4" thick hardwood board 4 inches wide by about 40 inches long; a scrap piece of 3/4" plywood; wood glue; tape; and hardware for the bulb/lamp shade mount.
Tools: table saw and sander
Step 1: Make a Template
Make a template from 3/4” plywood for cutting the tapers. Start with a 3” by 10” piece of plywood. Trim off the taper by using a small 3/4” wide spacer taped to the top corner of the plywood as shown. The spacer/template should slide along the table saw fence together while making the cut. There is nothing special about the 4.3 degrees I used, pick your own angle for your project. Mark the template sides 1 and 2. It will help later on.
Step 2: Cut Four Boards for the Sides
Cut four pieces of 3/4” hardwood to 4” wide by 10” long. On each piece mark the top edge on the outside face.
Tilt the table saw blade to 4.3 degrees. You can set the angle easily by using the template you made in the previous step. Then cross-cut the four hardwood pieces using the table saw miter gauge. Be sure the angles on both ends of each piece slope in the same direction, and all pieces have the same length. Study the diagram and mark your pieces before making the eight cross cuts. It's very easy to get confused here!
Step 3: Cut the Left Taper
On one of the hardwood pieces, lay out the shape of the side of the lamp base. Mark the 45-degree cut lines on the top and bottom edges.
Tilt the table saw blade to 45 degrees. Put the template on the table saw, side 1 up, straight edge against fence, and longer (3") edge towards the blade as shown. Line up the marked hardwood piece against the tapered edge of the template, flush at the top. The outside face of the hardwood piece faces up, and the top edge faces the blade. It is very easy to make a mistake here, so be sure everything is lined up properly. Tape the hardwood piece to the template so they move together during the cut. Now adjust the fence to cut the left side edge of the hardwood piece, based on your layout marks. Repeat for the remaining three pieces with the same fence setting. Save one of the cut-offs.
Step 4: Cut the Right Taper
For the next four cuts, flip over the template. The shorter side of the template will now face the saw blade, and the straight edge is still against the fence. Use one of the cut-offs from the prior step and line its square edge up against the tapered edge of the template, flush at the top. Again, the shorter edge of the cut-off should be facing the saw blade. Securely tape the cut-off to the template. Put the lamp base piece against the 45-degree mitered side of the cut-off and secure with tape. Now you are ready to set the fence to the correct distance based on your layout marks, and carefully make the cut. A push block with a wide flat bottom will hold the three taped-together pieces flat on the saw table while they move past the blade. Repeat this cutting procedure for the remaining lamp base pieces.
Step 5: Assemble, Glue, and Finish
In one of the pieces drill a 3/8” hole near the bottom for the power cable.
The four pieces should fit together well if you simply stand them up on a flat tabletop. Spread glue along the mitered edges of all four pieces. Assemble and use masking or packing tape along the outside edges to hold the lamp base together during gluing. I used some clamps, but it is not necessary; and it can actually mess you up since you don’t have any good clamping surfaces perpendicular to each other. You could make some 4.3 degree wedges to facilitate the clamping; but I recommend: stick with just tape for the glue-up. If I made a larger obelisk I would use biscuits in the mitered joints.
After the glue dries, sand the base with progressively finer grid to 220 or 320. Some light sanding along the sharp edges will keep them from splintering. Finish with stain, varnish, or paint.
Step 6: Hardware Installation
To install the lamp shade hardware make a 3/4” by 3/4” square ‘washer’ from 1/2” or 3/4” plywood. Drill a 3/8” hole through the center. Insert a 1/8-IP threaded lamp nipple through the hole and firmly attach with metal washers and hex nuts. Insert the nipple/square washer from the bottom of the base, then fix it to the base with a large metal washer, the lamp harp holder, and a hex nut from the top. You may have to fine-tune how far the nipple sticks up from the base. Wire the lamp socket, thread the wiring down through the nipple and the hole in the back side, and screw on the bulb socket. Finally, install the lamp shade.
Use the same procedure to make tapered table or bench legs, or a stand for a small tabletop.