Circular saw

“ Filing a Circular Saw.—The teeth of a crosscut circular saw point a little ahead. Sometimes they point so nearly straight out from the center that you have to look twice to determine which way the saw should run. There are plenty of rules for the pitch of sawteeth, but they are subject to many qualifications. What interests a farmer is a saw that will cut green poles and crooked limbs into stove lengths with the least possible delay. A saw 20 inches in diameter will cut a stick eight inches through without turning it to finish the cut. ”

“ It is astonishing how much very hard labor may be saved by means of a small circular saw like that shown in Fig. 1. This tool, like many others described in this series of articles, can, in most instances, be purchased cheaper than it can be made, and the chances are in favor of its being a more perfect article. However, it is not so difficult to make as one might suppose. A piece of sheet steel may be chucked upon the face plate, or on a wooden block attached to the face plate, where it may be bored to fit the saw mandrel, and cut in circular form by means of a suitable hand tool. ”

“ A very effective machine for cutting pieces of wood of moderate dimensions is the Circular Saw, represented in Fig. 37. Here there is a steel disc, having its rim formed into teeth; and the disc is made to revolve with very great speed, in some cases making as many as five hundred turns in a minute, or more than eight in a second. On the bench is an adjustable straight guide, or fence, and when this has been fixed, the workman has only to press the piece of wood against it, and push the wood at the same time towards the saw, which cuts it at a very rapid rate. ”

“ They employ a circular saw, made of thin steel-plate, such as is used for sawing veneers, on one side of which is a circular plate secured by rivets or screws, the plate being less in diameter than the saw, which has the effect to stiffen the plate of the saw, and to enable the operator to use a thinner saw than he would otherwise be able to do. ”

“ What building-up does to strengthen the gun has been repeated in the case of the circular saw: driven at a high speed it becomes so highly heated at its periphery that the resulting expansion may crack the metal in pieces. In an improved method of manufacture the saw is hammered to a compression which gradually increases from rim to centre. ”

“ Sometimes the circular saw is provided with apparatus by which the machine itself pushes the wood forwards, and the only attention required from the workman is the fixing of the wood upon the bench, and the setting of the machine in gear with the driving-shaft. ”

“ Suppose that the mischief maker does not drive his spikes in the tree where the cut will be made, but climbs up twenty or thirty feet or so, and drives a dozen or two in different parts of the trunk of the tree. The tree trunk is cut safely and then it is drawn to the sawmill where it is sawed into planks. What happens when one of the big, expensive circular saws rips through a dozen spikes? It’s just goodbye to the saw and goodbye to a lot of money, and means a delay of several minutes until the saw can be replaced with another. ”

“ With nickeled tilting table; roller in table back of the saw which makes it run remarkably true; clamps hold any thickness of saw; clamps adjustable right or left, forward or back so that the blade can be kept in perfect line; with 3-inch circular saw on 3x4-inch iron table capable of cutting half-inch lumber; solid emery wheel; drilling attachment with six Stubbs drills; lathe attachment with iron ways and rests, steel centers and three fine turning tools—length of bed 15 inches, distance between centers 9 inches, swing 3 inches, length of slide-rest 4 inches ”

“ For example, in cutting four boards of one-inch lumber, an ordinary circular saw wastes enough material to make a fifth board, because it cuts an opening that is one-quarter of an inch in width. Band saws, although they do not work at such high speed, are replacing circular saws in many mills because they are less wasteful of lumber. Although sawmills try to prevent waste of wood by converting slabs and short pieces into laths and shingles, large amounts of refuse, such as sawdust, slabs and edgings, are burned each season. ”

“ This machine, being of small size, is worked by hand.
32. The saw-gin is much larger, and is moved by animal, steam, or water power. It consists of a receiver, [22] having one side covered with strong wires, placed in a parallel direction about an eighth of an inch apart, and a number of circular saws, which revolve on a common axis. The saws pass between these wires, and entangle in their teeth the cotton, which is thereby drawn through the grating, while the seeds, from their size, are forced to remain on the other side. ”

“ The height of d from the saw table is sufficiently greater than that of c to give the shank g the correct taper, e f representing the circular saw. t is a plain piece of the full size of the box or frame, and serving simply to close up on that side the mortise in the frame. The grain of t should run at a right angle to the other piece of the frame so as to strengthen it. s is a binding screw to hold the cog on the frame, and h is a guide for the edge of the frame to slide against. ”

“ Hoe himself.
The old method of grinding circular saws, and that still practiced in all other works of this nature, is the application of them horizontally to the great vertically-moving grindstones by the hand ”

“ If it is necessary to hold work in the vise to rip it, hold it slanting, so that the handle of the saw leads the line, as it naturally does when the work is on a saw-horse.
The back-saw, tho a crosscut-saw, may be used in any direction of the grain.
Any saw should be in motion when it touches the wood it is to cut. To guide it to the right place, a workman lets his thumb touch the saw just above the teeth, the hand resting firmly on the wood. A little notch, cut in the edge right to the line where the saw is to cut, will help a beginner to start accurately. ”

“ The more nearly the saw is held at right angles to a board, the greater [Pg 33] is the force which must be applied to it by the hand to cause it to bite into the wood; and, on the other hand, if the saw is laid down too far, as shown in the incorrect way, it is a very difficult matter to follow the working line. Furthermore, it is a hard matter to control the saw so that it will cut squarely along the board, particularly when ripping. The eye must be the only guide in the disposition of the saw. Some boys make the saw run in one direction, and others cause it to lean the opposite way. ”

“ The thinner the blade, the less material will be cut out and wasted, and the less force will have to be applied. In order to have the saw as thin as possible, almost all the people of the world, except the Anglo Saxons, have saws that cut when they are pulled toward the worker. The blade is in tension while cutting and in compression only when being returned for a new cut. German carpenters use a saw like our turning-saw. English and Americans have developed the saw on the opposite principle, namely, that it should cut on the pushing stroke. ”

“ As a matter of fact, the saw has gone through a process of evolution the same as the electric motor, automobile, and aeroplane. New methods of its manufacture are constantly being invented and improvements made in its construction. Some of the steps in the process of making a hand saw are: rolling the steel plate of which the body is made, hardening, tempering, hammering or smithing, grinding, polishing, filing, setting, etching, handling, and blocking. ”

“ First lay out the design on paper. Cut out to the outline, and trace upon the surface of the sheet metal. A metal-cutting saw blade obtained from the hardware store can be fitted into the frame of the coping saw.
With this tool, saw on the lines exactly as in thin wood, and file the edges smooth. The holes for the heavy nails are drilled. If suitable big-headed nails cannot be found, brass screws may be used, and when in position, the heads filed to any desired shape. ”

“ The first thing to do in testing the saw is to take up the end motion of the saw arbor, or if this cannot be done, then a pointed piece of iron or wood should be pressed on the end of the mandrel so as to keep it from moving endways while the saw is being tested. ”

“ The expert workman (and he becomes expert because of it) makes the hammer do its proper work; and so with every other tool.
Fig. 3.
Fig. 4.
About Saws.—There are four well-defined kinds. First, a long, flat saw, for cross-cutting. Second, a slightly larger saw for ripping purposes. Third, a back saw, with a rib on the rear edge to hold the blade rigid, used for making tenons; and, fourth, a compass or keyhole saw.
> [Pg 8]
Cross-cuts.—The difference between a cross-cut and a rip saw is, that in the latter the teeth have less pitch and are usually larger than in the cross-cut saw. ”

“ Press down hard enough on the work to keep it on the table against the up strokes of the saw; as the top of the table is polished it is easy to slide the work around and keep the saw on the line. Run the saw at an even speed and do not feed the wood against the blade too fast.
TABLE OF SCROLL SAW WOODS These woods can be bought of H. L. Wild, 171 Avenue A, New York City, or of J. Gabriel and Company, 672 Grand Street, Brooklyn, N. Y.
Fancy Woods for Scroll Saw Work. —Fancy [37] woods that are planed on both sides for scroll sawing can be bought in thicknesses of 1⁄16, 1⁄8, 3⁄16 and 1⁄4 inch. ”

“ The two then with a dozen half clips of the ax, removed the inequalities of the bark from the saw's path. The long, flexible ribbon of steel began to sing, bending so adaptably to the hands and motions of the men manipulating, that it did not seem possible so mobile an instrument could cut the rough pine. ”

“ They work with double-bitted or two-edged axes, and can so truly guide the fall by means of the under cut that they are willing to set a stake one hundred feet away and guarantee that the descending trunk shall drive it into the ground. With the under cut chopped out to their satisfaction, they remove their spring-boards to the opposite side, and finish the task with a long, two-handed, coarse-toothed saw. ”

“ The eyes of small saws are either made to fit the mandrel an easy sliding fit, or else the mandrel is provided with cones to accommodate various sizes of holes, an ordinary construction being shown in Fig. 3081, in which a is the saw arbor, fast on which is the collar b, s representing a section of the saw, w a washer or loose collar, and n the nut for tightening up w. The cone c is screwed upon a and passed through the saw until it just fills the hole, and thus holds the saw true. ”

“ The turning-saw, Fig. 95, is a narrow saw, set in a frame, which stretches the saw tight, so that it works as a tension saw (cf. p. 62) . The best frames are made so that the handles which hold the blade can revolve in the frame. The turning-saw is used chiefly for cutting curves. A 14 inch blade, 3⁄16 of an inch wide is a good size for ordinary use. The teeth are like those of a rip-saw, so that they are quite likely to tear the wood in cutting across the grain. ”

“ This saw is merely a narrow band of steel, toothed on one edge and running over a wheel like an ordinary leathern band attached to shafting. The exquisite manner in which it fashions the most intricate patterns from thick slabs of wood is really surprising. The felloes, after being thus roughly formed, are stacked to season in a shed by themselves, where they are piled one upon the other in vast pillars, down vistas of which the visitor passes, full of amazement at their number. ”

“ Tinner’s snips are simply large powerful shears and you can cut sheet metal up to 3⁄32 of an inch thick with an ordinary pair. When you cut a sheet of heavy metal with them let the lower blade and handle rest on your bench and you can get a better leverage on it. Metals that are thicker than 3⁄32 inch must be sawed.
(4) While metals can be sawed by using a special saw blade in a scroll saw frame you should use a jeweler’s saw frame with jeweler’s saws for metal—I prefer the Fish Brand for fine work. (5) For heavier work use a machinist’s hack saw ”

“ The object of this is to make the teeth cut a wider kerf than the thickness of the blade, and thereby cause the saw to travel freely. A great many so-called "saw sets" are found in the market, many of them built on wrong principles, as will be shown, and these are incapable of setting accurately. ”

“ The bow saw, known also as the turning saw or frame saw (Fig. 80) , cuts out curved work with or across the grain, the compass, turning, or lock saw (Fig. 81) being used for a similar purpose, and in cases where a large saw could not be employed. A keyhole or pad saw (Fig. 82) is used for small internal curved work.
Appliances for Sharpening Saws.—For holding a hand saw during the process of sharpening, a saw vice (Figs. 83 and 84) is used, there being many designs to choose from. For sharpening English hand saws, the triangular file (Fig. 85) is commonly
Fig. 85.— Triangular Saw File. ”