Both Chris and I have made and taught a lot of six-board chests over the years, and typically we lay out and cut a “boot-jack,” (inverted V”), simple arc or ogee on the ends. Those are easy to lay out and all three are relatively easy to cut…and and don’t hurt our brains or the brains of students too much.
So when working on “Good Eye” the latest artisan geometry book from Jim Tolpin and George Walker, we were both rather dumbstruck with the clever way the authors reverse-engineered the layout of a fancy-looking but simple-to-cut six-board end panel – a layout I have never produced, but have now added to my mental design library. It’s not that I couldn’t have made this shape through measuring – it just wouldn’t have occurred to me to do so; I try to always teach a layout that is scalable without numbers and requires just a few tools, such as a straightedge and compass. That way, you’re teaching the process not the result.
That’s the approach of this entire book – looking at a piece of furniture and showing how the relationships between and among its proportions, and how you can use this knowledge in the real world as you design your own pieces. (Or how to better understand what makes an exiting piece “good.”)
I’ve excerpted this section of “Good Eye” for you below.
– Fitz
Next, let’s turn our attention to the end panels. In addition to the decorative pattern covering the entire surface, the end panels have a triangle cutout (Fig. 3.23). This is not just decorative; it gives the piece four feet to improve stability.
If you look closer, you’ll notice it’s not one, but two triangles, one nested inside the other. The smaller triangle provides that space to carve some relief at the bottom of the decoration. Notice also that this smaller triangle is notched with a right-angle cutout near the floor. It’s likely that the bulk of the decorative linenfold on both end panels was executed on a single board. It was then cut in half, one for each end. So we’ll lay out a mirror-image pattern on the backside of the board and then saw them out after the linenfold is complete.
Because we are making the end panels from a single board we begin with a board that’s two units wide. Instead of three units high, we double it to six units high to have enough length for both ends (Fig. 3.24).
It’s two mirror-image triangles with a pair of smaller triangles nested inside them (Fig. 3.25). The lines and circles that create this pattern look complicated at first glance (Fig. 3.26). Yet, if we walk through it step by step, you can see the logic unfold and the genius of this deceptively simple design.
Begin by drawing a pair of diagonals across the corners (Fig. 3.27). This provides our centerline for the decorative linenfold pattern as well as the apex for our large triangle cutout. It also marks the halfway spot to mark a saw line to separate the two pieces later on.
The first large decorative triangle is centered on the board. The bottom corner of the triangle is inset one-fourth the overall width of the board. We can find that one-fourth width with another pair of diagonals (Fig. 3.28).
Note that we used diagonals just like we did before when locating one-third of a rectangle. Again, these intersections locate one-fourth of our rectangle on both the vertical and the horizontal.
The larger decorative triangles are equilateral. To locate the apex, set a pair of dividers to span the width of the base of the triangle and scribe a pair of overlapping circles (Fig. 3.29).
These two circles define our two mirror-image triangles. A line that runs from the center of one circle to the other establishes the base of our triangles. The intersections, top and bottom, where our circles overlap, locate the apex of both triangles. Strike lines to connect the width of the base with the apex on both top and bottom. These two back-to-back triangles create a diamond shape.
To define the smaller triangles that are nested inside, draw a line from the corner of the board that passes through the apex of our triangle until it crosses the saw line (Fig. 3.30).
Draw three more diagonals, one from each corner to complete the two smaller triangles. Finally, the small notch at the base of the smaller triangle. It’s simply two side-by-side squares, or you could picture it as a rectangle that’s one unit high by two units wide (Fig. 3.31).
The layout for the decorative linenfold carving is similar to the front panel. The width of the tools themselves step off the repetitions across the board using the centerline as the starting point.
One final note on these geometric layouts. For the sake of clarity, we show all lines and circles in their entirety. When you see these layouts in historic books or even remnants left on old work, the actual layout lines are abbreviated. You might see only a few intersections and tick marks. If I were laying this out, being familiar with lines, it would look something like Fig. 3.32. It’s abbreviated, but still has the information needed.
These two authors never cease to amaze me.