Most woodworking machines and hand tools are designed for making caseworks and joinery with straight, square cuts. Turning is different; it requires a more 3-dimensional perspective, most lines are curved and more precise hand-work is usually needed but still, a lathe is designed to accomplish this. However, combining an 8-sided shape with graceful sweeping arcs over a long span is altogether different and absent large automated machinery, it can be accomplished by precise handwork and patience..... and that's what this story is all about.... making this elegant, contemporary floor lamp with its deceptively simple flowing lines, inset stripes.... and its surprising complexity. It's a challenge I'm really look forward to, here is the design:
Let's begin with the lamp stem and come back to the base and finial later in this story. The stem is nearly 46" long and a cross section mirrors the 8 sided shape of the base. It has smooth, flowing arcs which range from approximately 1 3/8" diameter at the top to 6" diameter near the base and it has 2 sets of inset stripes, each set at approximately a 45 degree incline. Although these measurements and angles may change slightly, the arcs need to be smooth and continuous so, the stem needs to be shaped as a single piece.
The stem will be built up as a long square block, the stripes will be set into the block and then the block will be rough cut to the approximate shape of the stem. More on each of those steps as the stem progresses but once they are done, it then needs to be shaped accurately into the final shape which will be done by hand. After the block has been rough cut, it's most important to be able to work it lengthwise to create the smooth flowing arcs, and around the diameter from all clock angles so that each of the 8 sides can be shaped equally along the arcs. To do this, a special holding fixture is necessary and you can see this below.
This is a highly engineered fixture which is sufficiently robust to withstand lateral and longitudinal forces from hand-planes, spoke shaves, scrapers and chisels. One end of the fixture is fixed, the other end slides and the threaded steel rod runs through the center of the stem in the wire-chase. The stem is held in place by friction against each end of the fixture; when the ends of the stem are against the ends of the fixture, the sliding end of the fixture is tightened so it won't slide further and the threaded rod is tightened to increase friction between the ends of the stem and the ends of the fixture. To rotate the stem for working each side, tension is reduced, the stem is rotated and tension is increased to hold it in place. This allows rotation of the stem to infinite positions, it allows each side of the stem to be worked flat without inducing twist and it allows access to all parts of the stem without needing to move it. Here are a couple photos of the fixture.
It's also most important to maintain the same consistent arc on each of the 8 sides of the stem. To accomplish this, ends of the fixture are fitted with small saddles to hold matching profile templates of the arcs, one template fits on each side of the fixture and here you can see a couple photos with the blanks for the templates in place on the fixture, the actual arc still needs to be cut into these templates.
So, as the stem is shaped, a straightedge is placed across the templates to gauge where the stem needs additional shaping. This will be easier to see once the shape of the arc is cut into the templates. Because the stem is actually held in the fixture through its center, it can be rotated for identical shaping of each side.
Next up is cutting the templates to the shape of the arc.
Here you can see the first template laid out and ready to cut. The shape is actually transposed from a drawing then outlined with fine painters tape.
The shape is then cut out on the band saw and the edges are sanded to smooth the curve then the first template is used to create the second so they are identical. Since only one side of the stem will be shaped at a time, the template is actually half of the profile (lengthwise) of the stem.
Here are a couple photos showing both templates finished and in place on the fixture with the straight edge resting on the templates.
The templates are really intended as a guide for shaping the stem, they will go off an on the fixture frequently as the stem is being shaped. When they are removed there is unobstructed access to the stem for hand tools. The templates are also marked so they can be installed on the fixture in the same position each time.
Next is getting the wood and a trip to the mill didn't disappoint (never does). Here you can see the walnut and maple which will go into the lamp. The maple will be used for the white stripes.
... and here are a couple photos that include the bloodwood which will be used for the red stripes. The bloodwood finishes to a rich crimson color and should compliment the walnut and maple nicely.
The woods need a couple days to acclimate before working; once they are ready, the blocks for the stem and the base will be built up.