41 - Fold-Down Drafting Table, страница 13

compass. In addition to a . circle template, you'll also need a compass for drawing large circles and arcs. To produce accurate results, the important thing is to get a compass with legs that adjust easily and lock in place.

I'd recommend the type that has a threaded rod connecting the legs and a center adjustment wheel, see bottom photo on page 12. The center wheel lets you "tweak" the compass to the exact radius that's needed. And the threaded rod keeps the legs from spreading farther apart (or squeezing together).

As simple as it sounds, the way the lead in the compass is sharpened can affect the quality of the line. To produce a fine line, I sand the lead to a "chisel edge" instead of a point.

french curve. A circle template or compass works great for drawing a simple curved line (one with a single radius.) But you may need to draw a line that's made up of a series of flowing-curves — each one with a different radius.

That's when a french curve comes in handy. It's a template

IN THE SHOP

with a series of curves that make it look like a plastic scroll saw project, see lower photo on page 12. The important thing about this template is that the radius of the curves changes continuously from one point to the next. So you can use it to draw freeform curves.

The idea is to draw one section of the curve at a time. What works well is to draw the curved line freehand first (very lightly). Then find a portion of the template that matches the shape of the line. After darkening that part of the line, move the template and repeat the process.

SCALE & PROTRACTOR

All it takes to round out a basic set of drafting equipment is a scale and a protractor.

scale. It's a cinch you won't be able to draw every project to actual size — some are just too large to fit on the paper. So a scale provides an accurate way to reduce the size of the drawing without changing the proportions.

The type of scale I use is called an architect's scale. Basically, it's

a triangular "ruler." Each face of the ruler has measurements drawn to a different scale.

For example, if you want to make a drawing that's half as large as the project, measure directly off the half-scale (V2). If that's still too large, you could use the quarter (V4) or eighth-scale (Vs). (There are twelve scales altogether.)

Regardless of the scale, the nice thing is there's no arithmetic involved. You simply mark the length of a line directly off one of the scales.

protractor. Finally, it seems there's always a project that requires drawing an "odd" angle (one you can't draw with either of the drafting triangles). So I always make it a point to keep a protractor on hand.^k

PROTRACTOR

Drafting Supplies

The best way to end up with a crisp, clean drawing-is to start with supplies used especially for drafting.

paper. One important thing is a high quality paper. I use a 100% rag paper called marker-paper. It's more expensive, but it erases well. And if you get the type that's translucent, you can trace through it.

tape. The paper is attached to a flat surface (hardboard is fine) with drafting tape This tape has enough "tack" to hold the paper, but not enough to tear it when you peel it up.

pencil. Another thing to consider is the pencil. To produce a fine, consistent line, I get the best results with a mechanical pencil. A hard (2H) lead isn't as apt to smudge the drawing as a softer lead.

fixes. Finally, a plastic eraser and metal shield will let you fix mistakes without removing lines you want. And don't forget a brush to sweep off dust.

No. 41

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