In addition to prototypes, many designers like to build scale models of their designs. The models serve mostly a visual purpose, since testing a 1/10th size joint would be futile, if not impossible. Models can be made with a variety of materials, including cardboard, balsa wood, foam-core board or even construction paper. Or, you may want to resaw some of the actual stock you plan to use into thin strips, then use that to build the model. The main benefit models offer is a 3-D view of the project to give you a better sense of how the relative proportions work.
Standard furniture dimensions:
Lounge seating
Seat height: 14 to 17 in.
Seat width: 24 in. minimum per person.
Seat depth: 15 to 18 in.
Arm rest height from seat): 8 to 10 in.
Seat angle tilt backwards: 3° to 5°.
Backrest tilt angle from seat: 95° to 105°.
Bookcases
Depth: 12 in.
Height: 76 in. maximum.
Shelf width: 24 in. maximum width for ¾-in. plywood shelves; 36 in. maximum width for ¾-in. solid wood shelves.
Making Plan Drawings
To visualize and refine finer details such as overall and relative proportions, you’ll need to make “scaled” working drawings. A scaled drawing is basically a shrunk-down, yet correctly proportioned drawing that shows your project’s details and its dimensions. If you were drawing in ¼ scale, every real inch would equal 4 inches. The term “working” refers to the fact that you will follow these drawings closely when you build your project and use these drawings to determine the dimensions of the wood parts you need to cut.
To make professional-quality scaled working drawings you’ll need an architect’s scale, drafting table, T-square, 45° triangle, 30 x 60° triangle, and a compass for drawing circles. French curves are useful for drawing curved shapes. Other more specialized drafting tools are available at graphic design stores.
The architect’s scale. Many scale rulers are available, but an architect’s scale is the one used by most woodworkers. An architect’s scale is a ruler with six sides. Although architects use these scales to draw in feet increments, the architect’s scale is just as easily used to draw in inch increments, which is what most woodworkers do. The side with the number 16 marked at the left end is a full size ruler, meaning 1 inch equals 1 inch. The number 16 label means each inch is divided into sixteenths. The rest of the sides are marked with two different scales per side. One scale runs left to right, and the other runs right to left. To understand how to use an architect’s scale, start by looking at the side marked on the left end with the fraction 3/32. Using that side and working from left to right means that every 3/32 inch equals 1 inch. In this scale, the real measurement of 12 inches would equal 128 inches and those divisions are marked off with the upper row of numbers on that side. On the right end of the same side of the scale, is a fraction label that says “3/16.” Working from right to left and using the lower row of numbers marked on that side is the “3/16 inch equals 1 inch” scale. The other fraction-labeled scales work the same way. The sides with the ends labeled 1, 1½, and 3 are used for scaling at “1 inch equals 12 inches,” “1½ inch equals 12 inches,” and “3 inches equals 12 inches,” respectively.
Accurate, detailed plan drawings not only create a blueprint for your woodworking project, they help you determine part sizes and get a better sense of what your project will look like when completed. An assortment of drafting tools will make drawing scaled plans much easier. A triangle, circle template and an architect’s scale are shown in the photo above. For maximum benefit, draw your project from several different viewpoints.
Drafting tools for making project plan drawings include a smooth worksurface (a portable drafting table is shown here), a variety of pens and pencils including a mechanical pencil, an architect’s scale, a compass, a triangle or two and one or more french curves.
The architect’s scale is virtually indispensible for making scale drawings of your woodworking projects. The six-sided ruler is calibrated to make automatic conversions in several different reduction scales, saving you plenty of math work.
Reading an architect’s scale. To understand how to use an architect’s scale, start by looking at the side marked on the left end with the fraction “3/32.” Using that side and working from left to right means that every 3/32 inch equals 1 inch. In this scale, the real measurement of 12 inches would equal 128 inches and those divisions are marked off with the upper row of numbers on that side. On the right end of the same side of the scale, is a fraction label that says “3/16.” Working from right to left and using the lower row of numbers marked on that side offers the 3/16 inch equals 1 inch reduction scale.
Drawing scaled plan views. When using an architect’s scale, work using a scale on the ruler that allows you to draw the largest scaled drawings on the paper you draw on. This will make it easier for you to interrupt your drawings and see the details and proportions, since your drawings will be as large as they can be. Finding the best scale to use is done by starting with the largest dimension you need to draw. Say your project is longer than it is tall and deep. Then, length is the dimension to use to determine the scale to use. Fit the scale to your paper and allow for all the views you plan to draw on one sheet. Use your T-square to draw horizontal lines, use your triangles to draw vertical and angled lines, and use your compass to draw circles.
Start by drawing two-dimensional plan and elevation view drawings. A plan view can be a top or bottom view, and an elevation view can be a front, right side, left side or back view. Making these drawings will give you a sense of the overall proportions and help you to adjust those proportions that seem wrong. For most everything you build, you’ll draw a front view, top view and one side view. For projects that have different-looking sides, you’ll draw the other side view, too. The back and bottom views can be drawn too, but they’re not needed very often since the details they provide are not usually that important.
When drawn properly, each view projects it’s dimensions onto the other views. You can see this indicated with the lighter lines flowing from view to view. A typical three-view drawing shows a front, top, and right side view. Start by drawing your front view. Project its width dimensions upward onto the top view. Add the depth dimensions to the top view. Now, project the height dimensions of the front view over to the right view, and the depth dimensions of the top view over and down onto the right view. Make drawings showing your overall project as well as the details which can be drawn in a larger scale, closer to their actual sizes.
TYPICAL 2-D VIEWS