Carpentry for Boys

J >> J. S. Zerbe >> Carpentry for Boys

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[Illustration: _Fig. 256._]

[Illustration: _Fig. 257._]

Fig. 255 represents a mission type of writing desk for a boy's use. All
the posts, braces and horizontal bars are of 2" x 2" material, secured
to each other by mortises and tenons. The legs are 27 inches high up to
the table top, and the narrow shelf is 12 inches above the top. The most
convenient size for the top is 26" x 48". The top boards may be 1 inch
thick and the shelf the same thickness, or even 3/4 inch. It is well
braced and light, and its beauty will depend largely on the material of
which it is made.

[Illustration: _Fig. 258._]

The screen (Fig. 256) represents simply the framework, showing how
simple the structure is. The bars are all of 1-1/2" x 1-1/2" material,
secured together by mortises and tenons.

Fig. 257 represents a mission chair to match the desk (Fig. 255), and
should be made of the same material. The posts are all of 2" x 2"
material. The seat of the chair should be 16 inches, and the rear posts
should extend up above the seat at least 18 inches.

[Illustration: _Fig. 259._]

[Illustration: _Fig. 260._]

[Illustration: _Fig. 261._]

Fig. 258 is a good example of a grandfather's clock in mission style.
The framework only is shown. The frame is 12" x 12", and 5 feet high,
and made up of 2" x 2" material. When neatly framed together, it is a
most attractive article of furniture. The top may be covered in any
suitable way, showing a roof effect. The opening for the dial face of
the clock should be at one of the gable ends.

A more pretentious bookcase is shown in Fig. 259, in which the frame is
made up wholly of 2" x 2" material. The cross-end bars serve as ledges
to support the shelves. This may be lined interiorly and backed with
suitable casing material, such as Lincrusta Walton, or fiber-board, and
the front provided with doors. Our only object is to show the framework
for your guidance, and merely to make suggestions as to structural
forms.

[Illustration: _Fig. 262._]

Another most serviceable article is a case for a coal scuttle (Fig.
260). This should be made of 1-inch boards, and the size of the door,
which carries the scuttle shelf, should be 12" x 16" in size. From this
you can readily measure the dimensions of the case itself, the exterior
dimensions of which are 15" x 20", so that when the 1-inch top is placed
on, it will be 21 inches high. The case from front to rear is 12 inches,
and the shelf above the top is 11 inches wide, and elevated 10 inches
above the top of the case. This is a most useful box for culinary
articles, if not needed for coal, because the ledge, used for the coal
scuttle, can be used to place utensils on, and when the door is opened
all the utensils are exposed to view, and are, therefore, much more
accessible than if stored away in the case itself.

[Illustration: _Fig. 263._]

A mission armchair. Fig. 261 is more elaborate than the chair shown in
Fig. 257, but it is the same in general character, and is also made of
2" x 2" stock. The seat is elevated 16 inches from the floor, and the
rear posts are 28 inches high. The arms are 8 inches above the seat. A
chair of this character should have ample seat space, so the seat is 18"
x 18".

The dog house (Fig. 262), made in imitation of a dwelling, is 24 inches
square, and 18 inches high to the eaves of the roof. The opening in
front is 8" x 10", exclusive of the shaped portion of the opening.

[Illustration: _Fig. 264._]

[Illustration: _Fig. 265._]

Fig. 263 shows a simple and easily constructed settee with an under
shelf. The seat is 16 inches from the floor and 24 inches wide. The back
extends up 24 inches from the seat. The lower shelf is midway between
the floor and seat, and is 19 inches wide. This may or may not be
upholstered, dependent on the character of the material of which it is
made. If upholstered, the boards may be of second-class material,
preferably of pine or other light, soft wood.

A towel rack (Fig. 264) is always a needed article in the kitchen. The
roller may be an old curtain roller cut down to 18 inches in length. The
top piece is 2-1/2 inches wide and 21 inches long. The vertical bars are
each 1-1/2 inches wide and 9 inches long. The brackets are 1-1/2 inches
wide and made of 3/4-inch material.

Fig. 265 represents the framework of a sofa, the seat of which is 16
inches high, the front posts up to the arm-rests 24 inches, and the rear
posts 38 inches. From front to rear the seat is 18 inches. The posts are
of 3" x 3" material. This makes a very rigid article of furniture, if
mortised and tenoned and properly glued. The seat is 6 feet long, but it
may be lengthened or shortened to suit the position in which it is to be
placed. It is a companion piece to the chair (Fig. 261).

CHAPTER XVIII

SPECIAL TOOLS AND THEIR USES

In the foregoing chapters we have referred the reader to the simple
tools, but it is thought desirable to add to the information thus given,
an outline of numerous special tools which have been devised and are now
on the market.

BIT AND LEVEL ADJUSTER.--It is frequently necessary to bore holes at
certain angles. This can be done by using a bevel square, and holding it
so one limb will show the boring angle. But this is difficult to do in
many cases.

[Illustration: _Fig. 266. Bit and Square level._]

This tool has three pairs of V slots on its back edges. The shank of the
bit will lie in these slots, as shown in Fig. 266, either vertically, or
at an angle of 45 degrees, and boring can be done with the utmost
accuracy. It may be attached to a Carpenter's square, thus making it an
accurate plumb or level.

MITER BOXES.--The advantages of metal miter boxes is apparent, when
accurate work is required.

The illustration, Fig. 267, shows a metal tool of this kind, in which
the entire frame is in one solid casting. The saw guide uprights are
clamped in tapered sockets in the swivel arm and can be adjusted to hold
the saw without play, and this will also counteract a saw that runs out
of true, due to improper setting or filing.

[Illustration: _Fig. 267. Metal Miter Box._]

A second socket in the swivel arm permits the use of a short saw or
allows a much longer stroke with a standard or regular saw.

The swivel arm is provided with a tapering index pin which engages in
holes placed on the under side of the base. The edge of the base is
graduated in degrees, as plainly shown, and the swivel arm can be set
and automatically fastened at any degree desired.

[Illustration: _Fig. 268. Parts of Metal Miter Box._]

The uprights, front and back are graduated in sixteenths of inches, and
movable stops can be set, by means of thumb-screw to the depth of the
cut desired.

Figure 268 shows the parts of the miter box, in which the numbers
designate the various parts: 101 is the frame; 102 the frame board; 104
frame leg; 106 guide stock; 107 stock guide clamp; 109 stock guide
plate; 110 swivel arm; 111 swivel arm bushing; 112 swivel bushing screw;
113 index clamping lever; 115 index clamping lever catch; 116 index
clamping lever spring; 122 swivel complete; 123 T-base; 124-1/2
uprights; 126 saw guide cap; 127 saw guide cap plate; 132 saw guide tie
bar; 133 left saw guide stop and screw; 134 right side guide stop and
screw; 135 saw guide stop spring; 136 saw guide cylinder; 137 saw guide
cylinder plate; 138 trip lever (back); 139 trip lever (front); 141
leveling screw; 142 trip clamp and screw; 146 T-base clamp screw.

[Illustration: _Fig. 269. Angle Dividers._]

ANGLE DIVIDERS.--This is another tool, which does not cost much and is
of great service to the carpenter in fitting moldings where they are
applied at odd angles.

To lay out the cut with an ordinary bevel necessitates the use of
dividers and a second handling of the bevel, making three operations.

THE "ODD JOB" TOOL.--A most useful special tool, which combines in its
make-up a level, plumb try-square, miter-square, bevel, scratch awl,
depth gage, marking gage, miter gage, beam compass, and a one-foot rule.
To the boy who wishes to economize in the purchase of tools this is an
article which should be obtained.

[Illustration: _Fig. 270. "Odd Job" Tool._]

Figure 270 shows the simplicity of the tool, and how it is applied in
use.

BIT BRACES.--These tools are now made with so many improved features
that there is really no excuse for getting poor tools.

The illustrations show merely the heads and the lower operating parts of
the tools. Fig. 271 shows a metal-clad ball-bearing head, so called, as
its under side is completely encased in metal securely screwed to the
wood and revolving against the ball thrust bearing.

D represents a concealed ratchet in which the cam ring governs the
ratchet, and, being in line with the bit, makes it more convenient in
handling than when it is at right angles. The ratchet parts are entirely
enclosed, thus keeping out moisture and dirt, retaining lubrication and
protecting the users' hands.

The ratchet mechanism is interchangeable, and may be taken apart by
removing one screw. The two-piece clutch, which is drop forged, is
backed by a very strong spring, insuring a secure lock. When locked, ten
teeth are in engagement, while five are employed while working at a
ratchet. It has universal jaws (G) for both wood and metal workers.

In Fig. 272, B represents a regular ball bearing head, with the wood
screw on the large spindle and three small screws to prevent its working
loose. This also has a ball thrust. E is the ratchet box, and this shows
the gear teeth cut on the extra heavy spindle, and encased, so that the
user's hands are protected from the teeth.

The interlocking jaws (H), which are best for taper shanks, hold up to
No. 2 Clark's expansion, and are therefore particularly adapted for
carpenter's use.

[Illustration: _Fig. 271. Fig. 272. Fig. 273. Types of Bit Braces._]

In Fig. 273 the plain bearing head (C) has no ball thrust. The head is
screwed on the spindle and held from turning off by two small screws.
The open ratchet (F) shows the gear pinned to the spindle and exposed.
This has alligator jaws (J), and will hold all ordinary size taper shank
bits, also small and medium round shank bits or drills.

[Illustration: _Fig. 274. Fig. 275. Fig. 276. Steel Frame Breast Drills._]

STEEL FRAME BREAST DRILL.--These drills are made with both single and
double speed, each speed having three varieties of jaws. The single
speed is very high, the ratio being 4-1/2 to 1, which makes it
desirable to use for small drills, or for use in wood.

A level is firmly set in the frames of these tools to assist the user to
maintain a horizontal position in boring. Each of the forms shown has a
ball thrust bearing between the pinion and frame. The breast plate may
be adjusted to suit and is locked by a set screw. The spindle is kept
from turning while changing drills, by means of the latch mounted on the
frame, and readily engaging with the pinion. The crank is pierced in
three places so that the handle can be set for three different sweeps,
depending on the character of the work.

Figure 274 has a three jaw chuck, and has only single speed. Figure 275
has an interlocking jaw, and is provided with double speed gearing.
Figure 276 has a universal jaw, and double speed.

PLANES.--The most serviceable planes are made in iron, and it might be
well to show a few of the most important, to bring out the manner
employed to make the adjustments of the bits.

In order to familiarize the boy with the different terms used in a
plane, examine Figure 277. The parts are designated as follows: 1A is
the double plane iron; 1 single plane iron; 2 plane iron cap; 3 cap
screw; 4 lever cap; 5 lever cap screw; 6 frog complete; 7 Y adjusting
lever; 8 adjusting nut; 9 lateral adjusting lever; 11 plane handle; 12
plane knob; 13 handle bolt and nut; 14 knob bolt and nut; 15 plane
handle screw; 16 plane bottom; 44 frog pin; 45 frog clamping screw; 46
frog adjusting screw.

[Illustration: _Fig. 277. Details of Metal Plane._]

RABBETING, MATCHING AND DADO PLANES.--Figure 278 shows a useful form of
plane for the reason that it is designed to receive a variety of irons,
adapted to cut rabbets.

The detached sections of Fig. 278 show the various parts, as well as the
bits which belong to it. 1, 1 represent the single plane irons; 4 the
lever cap; 16 the plane bottom, 50 the fence; 51 the fence thumb screw;
61 the short arm; 70 the adjustable depth gage; 71 the depth gage which
goes through the screw; and 85 the spurs with screws.

MOLDING AND BEADING PLANE.--A plane of the character shown in Fig. 279
will do an immense variety of work in molding, beading and dado work,
and is equally well adapted for rabbeting, for filletsters and for match
planing. The regular equipment with this tool comprises fifty-two
cutters.

[Illustration: _Fig. 278. Rabbet, Matching and Dado Plane._]

As shown in Fig. 279, the plane has a main stock (A), which carries the
cutter adjustment, a handle, a depth gage, a slitting gage, and a steel
bottom forming a bearing for the other end of the cutter, and slides on
arms secured to the main stock.

This bottom can be raised or lowered, so that, in addition to allowing
the use of cutters of different widths, cutters can be used having one
edge higher or lower than the edge supported in the main stock.

[Illustration: _Fig. 279. Molding and Beading Plane._]

The auxiliary center bottom (C), which can be adjusted for width or
depth, fulfils the requirement of preventing the plane from tilting and
gouging the work. The fence D has a lateral adjustment by means of a
screw, for extra fine work. The four small cuts in the corners show how
the bottoms should be set for different forms of cutters, and the great
importance of having the fences adjusted so that the cutters will not
run.

The samples of work illustrated show some of the moldings which can be
turned out with the plane.

[Illustration: _Fig. 280. Dovetail Tongue and Groove Plane._]

DOVETAIL TONGUE AND GROOVE PLANE.--This is a very novel tool, and has
many features to recommend it. Figure 280 shows its form, and how it is
used. It is designed to make the dovetailed tongue as well as the
groove.

It will cut any size groove and tongues to fit with sides of twenty
degrees flare, where the width of the neck is more than one-quarter of
an inch thick, and the depth of the groove not more than three-quarters
of an inch. The tongue and groove are cut separately, and can be made
with parallel or tapering sides. The operation of the plane is very
simple.

[Illustration: _Fig. 281. Fig. 282. Router Planes._]

ROUTER PLANES.--This is a type of plane used for surfacing the bottom of
grooves or other depressions parallel with the general surface of the
work.

The planes are made in two types, one, like Fig. 281, which has a closed
throat, and the other, Fig. 282, with an open throat. Both are
serviceable, but the latter is preferable. These planes will level off
bottoms of depression, very accurately, and the tool is not an expensive
one.

DOOR TRIM PLANE.--This is a tool for making mortises for butts, face
plates, strike plates, escutcheons, and the like, up to a depth of 5/16,
and a width of 3 inches. The principal feature in the plane is the
method of mounting the cutter, which can be instantly set to work from
either end of the plane or across it.

[Illustration: _Fig. 283. Door Trim Plane._]

The cutter, as shown in Fig. 283, is cushioned by a spring which
prevents taking a heavier chip than can be easily carried. A fence
regulates the position of the cut and insures the sides of the cut being
parallel. The depth of the cut is governed by a positive stop. By
removing the fence and locking the cutter post with the thumb screw,
instead of using the spring, a very superior router plane is obtained.

CHAPTER XIX

ROOFING TRUSSES

The chapter on Bridge Building gives some suggestions as to form of
trusses, the particular types there shown being principally for wide
spans. Such trusses were made for one purpose only, namely, to take
great weight, and they were, as a consequence, so constructed as to
provide strength.

But a roofing truss, while designed to hold the accumulated materials,
such as snow and ice, likely to be deposited there, is of such a design,
principally, so as to afford means of ornamentation. This remark has
reference to such types as dispense with the cross, or tie beam, which
is the distinguishing feature in bridge building.

The tie beam is also an important element in many types of trusses,
where ornamentation is not required, or in such structures as have the
roofed portion of the buildings enclosed by ceiling walls, or where the
space between the roofs is used for storage purposes.

In England, and on the Continent of Europe, are thousands of trusses
structured to support the roofs, which are marvels of beauty. Some of
them are bewildering in their formation. The moldings, beaded surfaces,
and the carved outlines of the soffits, of the arches, and of the
purlins, are wonderful in detail.

The wooden roof of Westminster Hall, while very simple in structure, as
compared with many others, looks like an intricate maze of beams, struts
and braces, but it is, nevertheless, so harmonized that the effect is
most pleasing to the eye, and its very appearance gives the impression
of grandeur and strength.

Nearly all of the forms shown herein have come down to us from mediaeval
times, when more stress was laid on wooden structures than at the
present time, but most of the stone and metal buildings grew out of the
wooden prototypes.

Now the prime object of nearly all the double-roofed trusses was to
utilize the space between the rafters so as to give height and majesty
to the interior.

A large dome is grand, owing to its great simplicity, but the same plain
outlines, or lack of ornamentation, in the ceiling of a square or
rectangular building would be painful to view, hence, the braces, beams,
plates, and various supports of the roofed truss served as ornamental
parts, and it is in this particular that the art of the designer finds
his inspiration.

Before proceeding to apply the matter of ornamentation, it might be well
to develop these roof forms, starting with the old type Barn Roof, where
the space between the rafters must be utilized for the storage of hay.

[Illustration: _Fig. 284. Gambrel Roof._]

_The Gambrel Roof_, Fig. 284, requires a tie beam, (A), as shown, but
the space above the beam is free of all obstructions, and gives a large
storage space. The roof has two sets of rafters (B, C), and of different
pitch, the lower rafters (B) having a pitch of about 30 degrees, and the
upper ones (C), about 45 degrees.

A tie bar (D) joins the middle portion of each of the rafters (B, C) and
another tie bar (E) joins the middle part of the rafter (B), and the
supporting post (F). The cross tie beam (G) completes the span, and a
little study will show the complete interdependence of one piece upon
the other.

[Illustration: _Fig. 285. Purlin Roof._]

_The Purlin Roof_ is a type of structure used very largely throughout
the United States, for wide barns. (A) is the cross beam; (B, B) the
purlin posts; (C, C) the purlin plates; (D, D) the rafters; and (E, E)
the supporting braces.

The rafters (D) are in two sections, the distance from the eaves to the
comb being too great for single length rafters, and the purlin plates
are not designed to make what is called a "self-supporting" roof, but
merely to serve as supports for the regular rafters.

_The Princess Truss_, on the other hand, is designed to act as a support
for the different lengths of rafters (A, B, C), and as a means for
holding the roof. It is adapted for low pitch and wide spans.

[Illustration: _Fig. 286. Princess Truss._]

The main truss is made up of the cross beam (D), rafters (E, E) and
thrust beam (F). Purlin posts (G, G) are placed at an angle intermediate
the ends of the rafters, and the purlin plates (H, H) support the roof
rafters (A, B, C); I, I are the vertical tie rods.

This type is probably the oldest form of truss for building purposes,
and it has been modified in many ways, the most usual modification being
the substitution of posts for the tie rods (I, I).

Following out the foregoing forms, we may call attention to one more
type which permitted ornamentation to a considerable degree, although it
still required the tie beam. In fact the tie beam itself was the feature
on which the architect depended to make the greatest effect by
elaborating it.

This is shown in Fig. 287, and is called the _Arched_, or _Cambered, Tie
Beam Truss_. It is a very old type, samples of which have been found
which take it back to a very remote age.

[Illustration: _Fig. 287. Arched, or Cambered, Tie Beam._]

The tie beam A, in wide spans, was made in two sections, properly tied
together, and sometimes the outer ends were very wide, and to add to the
effect of the arch, it might also be raised in the middle, something in
the form shown by the dotted line (B).

_The Mansard_ is what may be called a double-mounted roof, and it will
be seen how it was evolved from the preceding types. It will be noted
that the simple truss formed by the members (A, B, C) is merely
superposed on the leaning posts, the tie beam also being necessary in
this construction.

[Illustration: _Fig. 288. The Mansard._]

But the most elaborate formations are those which were intended to
provide trusses for buildings wherein the tie beams were dispensed with.

The simplest form known is called the _Scissors Beam_, illustrated in
Fig. 289. This has been utilized for small spaces, and steep pitches.
Each rafter (A) has an angled beam or brace (B), springing from its
base, to the opposite rafter (A), to which it is joined, midway between
its ends, as at C.

Where the two braces (B) cross each other they are secured together, as
at D. As a result, three trusses are formed, namely, 1, 2, 3, and it
possesses remarkable strength.

[Illustration: _Fig. 289. Scissors Beam._]

BRACED COLLAR BEAM.--This is a modification of the last type, but is
adapted for thick walls only. The tie rod braces (A, A) have to be
brought down low to give a good bracing action, and this arrangement is
capable of considerable ornamentation.

The steeper the pitch the higher up would be the inner and lower brace
posts (B, B) which were supported by the top of the wall. This form is
not available for wide spans, and is shown to illustrate how the
development was made into the succeeding types.

[Illustration: _Fig. 290. Braced Collar Beam._]

THE RIB AND COLLAR TRUSS, Fig. 291, is the first important structural
arrangement which permitted the architect to give full sway to
embellishment. The inwardly-projecting members (A, A) are called _Hammer
Beams_. They were devised as a substitute for the thick walls used in
the Braced Collar Beam Truss, and small brackets (B, B) were placed
beneath as supports.

[Illustration: _Fig. 291. Rib and Collar Truss._]

The short tie beam (C), near the apex, serves as the member to receive
the thrust and stress of the curved ribs (D, D). It forms a most
graceful type of roof, and is capable of the most exquisite
ornamentation, but it is used for the high pitched roofs only.

[Illustration: _Fig. 290-1/2. Hammer Beam Truss._]

The acme of all constructions, in which strength, beauty, and capacity
for ornamentation are blended, is the _Hammer Beam Truss_. Here the
hammer beam projects inwardly farther than in the preceding figure, and
has a deeper bracket (B), and this also extends down the pendant post
(C) a greater distance.

The curved supporting arch (D), on each side, is not ribbed, as in the
Rib and Collar Truss, but instead, is provided with openwork (not shown
herein), together with beadings and moldings, and other ornamental
characteristics, and some of the most beautiful architectural forms in
existence are in this type of roof.

What are called Flying Buttresses (E) are sometimes used in connection
with the Hammer Beam Truss, which, with heavy roofs and wide spans, is
found to be absolutely necessary.

CHAPTER XX

ON THE CONSTRUCTION OF JOINTS

In uniting two or more elements, some particular type of joint is
necessary. In framing timbers, in making braces, in roof construction
and supports, in floor beams, and in numerous other places, where
strength is required, the workman should have at his command a knowledge
of the most serviceable methods.

Illustrations can most forcibly convey the different types; but the
sizes must be determined by the character of the material you are
working with. Our aim is to give the idea involved, and the name by
which each is known.

[Illustration: _Fig. 292. Bridle Joints._]

Reference has been made in Chapter X, to certain forms of scarfing and
lapping pieces. This chapter has to do with a variety of other
structural forms, but principally with such as are used in heavy
building work, and in cases where neither fish plates nor scarfing will
answer the purpose.

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