CHAPTER

Whether you build a cabinet yourself, turn the job over to a cabinet maker or buy it ready-made, it is best to know something about how furniture is constructed.

There are tricks in every trade, and to start a project without knowing about them is perilous at best. For those who want to buy, remember that some very pretty packages can conceal shoddy or mediocre products. By knowing how good furniture is made you'll be able to be sure that you get your money's worth.

Layout

Before purchasing materials, work out a cutting diagram. This is a miniature layout, to scale, of how you will cut the pieces of your cabinet from the large sheets of raw material. If you've bought a set of plans a cutting diagram is probably included. If not, or if you are starting from scratch, you'll have to make your own.

Consult your plans, and list every part required in categories according to the materials required. For example, some parts will be of %-inch plywood, others, such as backs or control panels, may be 1,4-inch. Still others such as molding or legs, may be solid hardwood and you may require, in addition, some solid soft pine for cleats or glue blocks.

The parts for which a cutting diagram is normally needed are plywood. You need it to be sure that you have enough material for all parts, and to make economical use of your material. Too, the cutting diagram helps to keep the grain of the wood running in the right direction on each piece.

VERTICAL pft tir i r/ort , s/oe

/8"JCJZ-9"

DXOP

fltonr fyxUg

FfíüAT

  • t/fr rrt/rw. /s
  • K/fWfX fM/W
  • ft"*/?'

Fig. 601. The final working or cutting diagram (shown on page 164 and above) is laid out on the plywood sheets.

Cut pieces of paper to a scale of, say l^-inch to the foot, representing every piece of wood you'll need. Then lay them over a rectangle drawn to the same scale and representing an uncut plywood panel. Try a rectangle representing a 4 X 8-foot panel first, since this is the most common stock size. For a big cabinet you may need more than one panel to get all the parts in and keep the grain running in the right direction. With a small cabinet, you can get them all in one piece with space to spare. In this instance try a smaller stock-size panel, 3 X 8, 3x6 or 4x6 feet, and see if you can still get them all in. The smaller the plywood panel the less it will cost. Sometimes a set of parts that will not quite make it on one 4 X 8-foot panel will go very comfortably on two 3 X 6's. Try various combinations until you find the most economical arrangement.

Be careful at this stage to lay out every part with the grain running in the correct direction. The easiest way to keep track of grain is to put an arrow showing direction on each piece of paper representing a part of the cabinet. When making experimental layouts, be sure that this arrow is parallel to one of the long sides of the rectangle representing the panel. The grain on all plywood panels, except counterfront panels, runs parallel to the long sides.

Except in special graining effects, the general rule is that the grain shall run parallel to the longest dimension of a given piece of the cabinet. For example, it will run side to side across the top of a cabinet—not front to back. It will run top to bottom on the sides. However, grain may be either top to bottom or side to side on doors or drop fronts, depending on the effect desired and on the proportions of the cabinet as they influence the proportions of the doors. On a door 2 feet high by 1 foot wide the grain will usually run top to bottom; on a drop front 3 feet wide by 10 inches high it would generally be side to side.

After experimenting with and repositioning the parts until you have located them on the panel diagram, finish your arrangement by either pasting the patterns to the diagram or drawing them in (Fig. 601). Be sure to label each individual part.

An experienced cabinet maker may not need to lay out all parts full scale on a panel before he starts cutting. But if you haven't done much of this sort of work, drawing every part out full scale on the panel before starting to cut is essential for accuracy and economy. Remember to allow ]/8 inch between the parts for the thickness of the saw cut. The pile of sawdust that will accumulate on the floor will no longer be part of your material. It has to come from somewhere!

A hand saw is neither the best nor the most accurate way of cutting a large plywood cabinet panel. Machines do this kind of job better and faster.

Table saw

There are two kinds of cuts you may have to make: straight, and curved. For straight cuts, three methods are worth considering,

Fig, 602. The table saw (tilting arbor circular saw) complete with adjustable fence and mitre gauge. (Courtesy Delta Power Tool Div., Rockwell Manufacturing Co.)

Cutting two good and one fair. The first and preferable method is to use a table saw. The saw (Fig. 602) consists of a circular blade with teeth set around its circumference. The blade is mounted under a heavy steel table in such a way that it protrudes up through a slot in the table top. It is rotated from below by an electric motor. Cutting with this type of saw is done by moving the work across the table top and past the rotating blade, which remains in a

Fig. 60S. The swing saw is a useful and easily manipulated tool. (Courtesy De Walt Inc., Div. American Machine and Foundry.)

fixed position. The saw blade may be raised or lowered, depending on the depth of cut required, and can also be tilted, allowing the cut to be vertical or beveled at any angle up to 45°.

To cut, say, a strip 16 inches wide by 8 feet long from a panel 4x8 feet, some sort of device must guide the work past the saw to keep the cut straight and maintain an even width. This func-ion is performed by a "fence" mounted parallel to the saw on one side and adjustable to various distances from it.

A table saw is also equipped with a mitre guide for cutting various angles on the ends of narrow strips of wood. You would use it to cut the 45° angles on the ends of molding to make a frame, or to cut a 10° angle on the end of a stretcher before attaching an angled leg, or to cut off an angle at the top of the leg itself.

A table saw will cut only straight lines. You cannot cut curves with it. But straight-line cuts at all sorts of angles to each other can be made with the use of appropriate guides and jigs, and these cuts can be simultaneously beveled at any angle up to 45°. Also, by proper adjustment of the saw-blade height, it is possible, instead of cutting through a piece of wood, merely to cut a groove in it. The width of the groove can be altered by the use of various dado blades.

Fig. 604. The portable rotary saw can be used for cabinet work provided a suitable guide and the proper blade are obtained. (Courtesy Porter-Cable.)

Use a table—or any other saw—only for the type of work for which it was designed. Any machine is safe when doing its proper work with proper safeguards. Improper operation can cause an accident to the user or the machine!

Overarm or swing saw

Also widely used to make straight cuts is the overarm or swing saw (Fig. 603). The swing saw has a circular blade similar to that of a table saw, but it operates differently—the table saw works from beneath the material to be cut, the swing saw cuts from above. The swing saw will handle long rips, cross cuts, bevels, dadoes and grooves just as accurately as a table saw. It will also do some jobs such as routing that cannot be done on a table saw. There is, however, one serious limitation to an overarm saw. The length of the arm limits the width of rips or cross cuts that can be made. (A table saw does not have this limitation.) It is one that is inherent in the design of an overarm saw, but there are ways of

Fig. 604. The portable rotary saw can be used for cabinet work provided a suitable guide and the proper blade are obtained. (Courtesy Porter-Cable.)

working around it. You might, for instance, have to make a wide cross cut in two passes with a swing saw where you could have done it in one with a table saw.

Portable rotary saw

A portable rotary saw (Fig. 604) is really made for on-the-job carpentry, not cabinet work, but by using the right blade and feeding the machine carefully, it is possible to make a nice clean cut. The problem is to keep your cut straight in comparison with

Fig. 605. A guide for the rotary saw is easily made from a strip of wood.

the cut you can get with a table or swing saw. It cannot be done by eye. Clamp a straight strip of wood to the panel to act as a guide for the shoe of the portable machine (Fig. 605). Be certain the guide piece is really straight; your cut can be only as straight as the guide.

Because of space limitations, the only practical way of cutting a large panel might be by use of a portable saw. If possible, however, try a table or swing saw.

Band saw

The saws mentioned thus far are designed strictly for straight-line cuts. But what happens if you need to cut a curve? For this you have a choice of three other types. The fastest and most powerful is a band saw (Fig. 606). Simply described, it consists of a pair of large pulleys or drums. One is placed above the other and a long continuous saw blade that resembles a belt runs around both drums. A small steel table is placed between the drums as a rest for the work, and the saw blade passes through the middle of the table. The blade is narrow and made of very thin steel, permitting it to cut quite sharp curves as well as long flowing ones without binding the blade. The table is adjustable, making it possible to cut curves and bevels simultaneously, a feature that is often desirable. A band saw should be treated with extreme caution and respect. Very fast and powerful, they can injure a careless operator before he is aware of what has happened.

Sabre saw

Another good machine for cutting curves is the sabre saw (Fig. 607). For cutting a long curve, say along the front of a cabinet top, it is slower than a band saw, but it is also much more compact, less expensive, and therefore much more likely to be available to the home craftsman.

The sabre saw is portable and cuts by means of a blade that moves alternately up and down like the movement of a hand saw, except that it cuts on the up instead of the downstroke. About half a dozen good makes are on the market, but only a few will simultaneously cut a bevel.

The smoothness and accuracy of a cut with this type of machine depends on how keen an eye you have and the steadiness of your hand. Practice on scrap wood before starting to do serious work.

Fig. 606. The band saw is especially suitable for cutting curves. (Courtesy Delta Power Tool Div., Rockwell Manufacturing Co.)

The sabre saw is a fine tool for making the cutouts for the tuner and amplifier in control panels and for record players or tape machines in mounting boards. If you have any large ventila-

The sabre saw is a fine tool for making the cutouts for the tuner and amplifier in control panels and for record players or tape machines in mounting boards. If you have any large ventila-

Fig. 607. The sabre saw is another machine which is excellent for cutting curves. (Courtesy Porter-Cable.)

tion holes to cut in your cabinet, the sabre is excellent for this purpose and it is also a fine tool for cutting speaker holes and ports in baffle boards.

Power jig saw

A third type of machine for curved cuts is a power jig saw (Fig. 608). Although they will make a nice clean cut, they are slow. Between sabre and power-jig saws, a sabre is preferable. A jig saw, however, will do the job.

Jointing

When your basic pieces of material have been cut to size, it is time to prepare the ends for the joints that will form the assembly. So let's look at the types of joints in common use, and see how they are made. We will start with those that form the "basic case" —the top, sides, bottom and any fixed internal partitions.

0 0

Post a comment