For the most part, developing a woodworking project plan will involve scale drawings, but there are times when only a full-size drawing can give you the visualization necessary to work out construction and design issues. Let's look at when full-size drawings are useful and review a practical setup for producing them.
When to use a full-size woodworking project plan:
As an instructive example, consider designing a 3' x 6' dining table. Drawing the entire front and side elevations and plan view to full scale would obviously be impractical unless you're Paul Bunyan making the table for your little friends. The solution is to use the magic of the architect's scale. Using a scale of 1 1/2" to equal 1', all three views could fit on an 11" x 17" drafting sheet using a compact drafting board, like the one shown below.
The scale drawings would give a good sense of the general look and proportions, show the lumber requirements and serve as a ready reference while building. However, this project can also demonstrate some of the most common circumstances where full-size drawings come into play, made on a setup like the one shown below.
The first is joinery. Let's say this is a trestle-style dining table using a large wedged, through tenon to attach the stretcher to the trestle. The details of this joint are far easier to accurately work out with a full-size rendition. Relationships, thicknesses and angles are much easier to grasp this way. In fact, it may be useful to make a full-size drawing of the side elevation of the entire trestle assembly. The key point is that you can select particular areas of a large project to draw full size.
The second most common situation is curved components. Let's say the stretcher is curved in one plane and meets the trestle at an angle. This important junction and the curve itself are best worked out in a full-size elevation. If the curve were in two planes, a plan view would also be necessary. Since the scale drawing gives you an overall sense and this is a big table, it is only necessary to draw one half of the symmetrical structure to full size. These drawings will also give a direct measure of the stock thickness required to cut out the curves.
Other common situations where full-size drawings are invaluable include:
- Curvaceous table legs. Subtle curves are most accurately worked out at full size.
- Frame and panel. Full-size sectional drawings easily show the thickness relationships.
- Chairs. Here full-size drawings are likely essential because most of the angles involved are not 90°. As with other pieces involving special geometry, angles can be transferred with a bevel gauge directly from the drawing to the wood.
- Special hardware installation, such as a sliding stay for a cabinet door, can get confusing without reference to a full size drawing.
- Any purpose-built housing, such as a cabinet to house a specific collection of ceramic pieces, is most safely worked out on paper at full size.
In short, when in doubt, clear up any visual or mental confusion with a full-size drawing on paper before making sawdust.
Assess the size needed
Let's say you wanted a full-size plan view of that trestle dining table to better appreciate how far the top extends beyond the base assembly to assess the balance of the structure and the legroom available. There is no need for a Bunyan-size drawing on giant paper. One half of the plan view would give you all the information you need because it is a symmetrical structure. In fact, a one-quarter view of it would probably suffice.
The simple idea is to draw what you need to make the piece.
Referring to an earlier post , keep in mind that full-size drawings are not a replacement for mockups. The mockup gives you real hands-on, eyes-on, body-on senses of size and space relationships. Finalize those with precision in your measured drawings.
Tools for creating project plans
An inexpensive, ad hoc setup will work just fine for full-size drawings. The drawing surface can be a sheet of 3/4" medium density fiberboard. Sheets up to 4" x 8" are available at home centers and can be cut to the size needed. The fiberboard is very smooth and incredibly flat, unlike most plywood, though it is rather heavy. It may be helpful to elevate the back edge a few inches with beveled blocks.
An art supply store is the source for the following gear. A T-square ($10 to $20) with a 36" or 48" blade is held against a straight edge of the fiberboard to make parallel lines. Large 30/60/90 and 45/45/90 clear plastic drafting triangles are held against the T-square blade to make perpendicular and basic angled lines. A protractor or direct geometry is used for other angles.
You'll also want to use 16 lb. vellum, available in rolls up to 42" wide, which takes erasures well. Secure it to the fiberboard with blue Painter's Tape. I prefer 2H lead in a 0.5 mm mechanical pencil because it makes a consistent line and does not require sharpening. An alternative is 2 mm lead in a lead holder, which requires frequent sharpening with a lead pointer.
Use a thin steel ruler, 24" or a set of 18" and 36", for measurements. A plastic eraser makes clean erasures. Sweep the crumbs away with a drafting brush to avoid smudging your work. Use an eraser shield for neatness and accuracy.
Accu Arc flexible plastic curves, from 18" to 48", are superb for drawing fair curves. A supply of French curves is also helpful.
Imagine, sketch, think, mockup, draw and build!