LIBRARY OF CONGRESS. §^tp t ©ajiijn$Ijt If xu Shelf.. UNITED STATES OF AMERICA. SAWS; HOW TO Straighten and Gum ALL KINDS. BY A. K. WILBUR, ONEONTA, N. Y. Colegrove, Job Printer, oneonta, n. y. TS'SSI ,\V5 ENTERED ACCORDING TO ACT OF CONGRESS IN THE YEAR 1888, BY A. E. WILBUR, IN THE OFFICE OF THE LIBRARIAN OF CONGRESS AT WASHINGTON. 5 I* $< 1 I i INSTRUCTIONS is^ ON Straightening and taming Saws, Owing to a universal want among mill-men for a plain, practical and comprehensive treatise on the art of straightening saws, the author has, in the following pages, endeavored to set forth the general principles by illustration so that any me- chanic of ordinary ability can by diligent practice do that class of work which needs to be done in mills using circular and other kinds of saws. SAWS. Many attempts have been made to give the users of saws full directions by which they can do their own smithing, but many of them have fallen far short of what they intended to accomplish. Although the author of the following pages does not claim that a k ' green ' ' man can take up this particular trade, and by the aid only of these pages get to be an expert in a very short time ; he does claim that by close application of principles herein shown, he can quickly be enabled to do good and practical work. All experienced mill- men will allow that if they could properly ham- mer their own saws it would not unfrequently happen that they could effect a great saving in time and expense by doing this class of work themselves. The mill-owner's best friend is a true working saw. If he has good machinery and good, prac- tical men to operate and keep in order he will find that the quality of his work will soon have favor in the lumber market where competition is very strong and good work favored at the present time. The gumming of saws is often entrusted to in- experienced men who, by their inability to prop- erly do the work, cause the plate to become out of true and unlit for practical use until further repairs are made upon it which oftentimes cause much unnecessarv delay and loss of time that SAWS. 5 might be obviated had the operator had proper instructions placed before him. To chamber the teeth upon a good and true plate without effecting its tension is a feat that requires much knowledge on the part of the operator as to the effect given the plate by the action of the cutter or gimiraer. The writer in the following pages has striven to give sawyers and other mechanics, to whom this class of work may come, full and plain instruc- tions in this branch of saw repairing, and if the rules and principles herein given be well followed, the result will be highly satisfactory. The sawyer to operate successfully a circular saw must observe the following points : The plate should have a tension adapted to the speed applied ; it must be free from Haws, blisters and kinks ; its teeth must have sufficient room to carry the dust from the kerf ; it must be tiled and swaged properly ; it must have the teeth formed so as not to k ' heel ' ' when in the cut ; its width of kerf must be governed by the condition and kind of timber to be sawn ; it must be per- fectly round and in balance ; its mandrel must run cool and have a slight end play ; it must be in line with the carriage and stand perfectly plumb and at right angles to the bed of its head- 6 SAWS. blocks ; it must not be crowded between the guides ; it must not have a feed stronger than it can work under ; it must have power enough applied to maintain an equal speed the whole length of cut ; it must be favored in large knots and in timber that has a tendency to spring and bind the plate. Although the log band saw is coming largely into use it will not, on account of its large expense, more difficult management and slowness of feed, displace but comparatively few of the many hundreds of circular log mills now in use. Owing to the great improvements of late years in the manufacture of saws their quality has largely been improved while their cost has been some- what reduced by many factories of this country. Natural gas for heating, pressure disks used in tempering, and improved machinery for grinding and polishing are among the most important im- provements now adapted. The purchaser of a new saw should exercise much care in his selection as there are on the mar- ket goods of this class varying in quantity like other wares manufactured and sold. Usually a trial of thirty days in actual use is .the best test of truth in all form of saw plates. SAWS. ®eg@rif\\®¥i ©f fSooIg. STRAIGHT-EDGES. To straighten a saw of any kind but few tools are needed. By referring to Fig. 1, you will iind illustrated three sizes of steel straight-edges that are used in doing work of this class, as well as in factories and general repair shops. The largest size is forty-eight inches long, three inches wide, seven gauges thick, tapered at the ends and planed on both edges. This size is nsed principally in tensioning saws on their mandrels with burr tightened and guides in place. It is also a very handy tool about the mill for leveling frames, plumbing uprights, straightening shafting, etc. The medium size is twenty-four inches long, two inches wide, about twelve gauges thick, and planed on both edges. The smallest size is twelve inches long, one and one-half inches wide, tapered and planed in the same manner. These sizes are used on all kinds of circulars, band, mill, cross-cut, drag and gang saws. SAWS. ammerg. For ordinary tensioning, the common pene hammer, shown in Pig. 2 at B, is principally used. This hammer, as well as all of the rest, should be made of good tool steel. The pene hammer should weigh about 2& pounds, and have its corners and face quite well rounded. At C is shown the form of a dog-head hammer which has a weight of 3£ pounds. It is rounded con- siderably on the face, and has its handle set at an angle of 80° to the head. The use of this ham- mer is for stretching unequal places in plates, as its blow is a dead om, being delivered in a direct line. At D is shown a blocking hammer weighing about live pounds. This hammer is made with two faces, one on each end and at opposite angles. The faces are at an angle of 95° to the handle. Thus you will see that the opera- tor can by striking a blow with each end deliver them at right angles without moving the plate or changing his position, and forming by striking- one blow over the other a perpendicular cross. Referring to E. , another form of blocking hammers is illustrated. This is made the same as the other with the excei)tion that one face is parallel with the handle and the other at right angles. This hammer when used will, on reversing ends, form by its marks on the plate an oblique cross. By the use of these different hammers the smith can deliver just such a blow as lie pleases without moving his plate upon the anvil. 10 SAWS. Qnuifg. For ordinary mill work the anvil represented at A, Fig. 3, is usually sufficient. This anvil is made of hard cast iron eight inches in diameter, octagon in shape, and about two and one-fourth inches in thickness. It is planed perfectly fiat on one side and turned about one-sixteenth oval on the other. In tensioning the larger sizes of circu- lar saws, they are commonly left upon the man- drel, and the hand-anvil held by one hand on the opposite side of the plate from which the opera- tor intends to deliver his blows. At B is shown an ordinary saw-maker"' s anvil used in all saw factories and general repair shops. This anvil is made in the form represented with a cast-iron body and a heavy cast-steel face, nicely rounded and polished. Its weight is from one hundred and fifty to two hundred pounds. It should be mounted upon the upper end of an upright post running down tli rough the floor and bedded in the ground with a large stone beneath it. By being thus arranged there is very little spring or re-bound to blows delivered upon the plates lying on the anvil, providing they lay flat upon the face. 12 saws. §iffe.@tg ©f tfie Ifcaoimer. Before the smith delivers a blow upon his plate he should know how that blow is going to effect the plate in the locality of its delivery. If he goes at it in any other than a systematic method he will soon find that he is not straightening, but distorting and warping from any and all degrees of trueness. A blow delivered by the round- faced pene or dog-head hammer in a perpendicu- lar line will effect as shown in plate A at N. Its effect being equal on all sides at the point of con- tact. The same effect takes place by a perpen- dicular blow as shown at A with the blocking hammer, excepting that which is changed by the form of the hammer itself. At R and S the effect is very much different. This represents a blow falling on a slant, thus producing more expan- sion beyond the point of contact and in direct line of hammer stroke. In delivering blows upon a saw the smith must pay particular attention to the manner in which he delivers them. Unless the nature of his work requires a slanting blow it is always best to hammer in a perpendicular and direct line. Referring to B, Fig. 4, the effect of many blows delivered by a round-faced ham- mer on the central portion of a plate is to expand that section, and to accommodate this expansion the plate must dish. It is now out of true and to equalize again to its original tension the section at C must be expanded in order to take up the slack at B. The operator should bear in mind 14 SAWS. ;ffe@ts ©f tfie jammer. that in doing this he must reverse the plate, and do equally as much hammering on either side, otherwise the surface of one side will receive more strain than the other ; consequently a true plate cannot be obtained until both are equally ex- panded. The plate shown at A, Fig. 5, has repre- sented each end bent or sprung from a true line. In order to again straighten the smith should use the blocking hammer and deliver blows as shown on the plate B. The expansion from these blows is nearly all in the line indicated by the arrows shown upon the plate. Referring to plate A, Fig. 4, at S one can readily comprehend why the plate under treatment will soon assume its original form. By delivering the blows from the blocking hammer on the convex side the expan- sion takes place on the contracted parts of the plate and thus throws it again back gradually in a straight line. The operator must bear in mind that any and all of these principles and methods are applicable to saw plates under treatment. In hammering a plate the operator must use great care and judgment in regard to heft of blows delivered. The quality of steel, different de- grees of temper, thickness and size of plates, have all to be taken into consideration. For in- stance, the smith is hammering a sixteen or twen- ty gauge saw, he must not use as heavy and strong blows as if he were hammering a rive gauge large circular. 16 SAWS. \ound, A circular saw constantly heated and cooled about the center will soon expand permanently in that locality in such a degree as to cause the plate to become loose, or in other words, out of tension. Referring to Fig. 6, the plate A, represents a rim-bound saw. At B and C is shown how the plate stands off from the straight edge when stood upon one side. A saw in this condition cannot work well as the looseness of the plate will not allow of any but a very slow feed. If the saw be run at a high rate of speed a por- tion of this slack will be equalized by the expan- sion due to the speed itself. If the saw be run at ;i slow rate of speed it should have a tension that will cause the plate to be quite stiff and rigid. In order to equalize the tension on a rim-bound saw, lay it out by marking across the plate with a piece of chalk from D to E and from L to Gr, then on the opposite side midway between the others, from H to I and from J to K. If the operator wishes to use the hand anvil, leave the saw upon the mandrel with burr tightened and guides loosened. Commencing at the center hold the anvil on one side while delivering blows, at first very light and increasing in heft and force as he approaches the rim. (See represented upon lines drawn across the plate, Fig. 6.) After going over the saw in this manner on all the lines, care being- taken not to hammer too much on the concave side, try the plate with the straight edge and if not effected sufficiently draw another set of lines in the same manner between those previously drawn and proceed as before until the rim is suffi- ciently stretched or expanded. 18 SAWS aa5 ©eater §om Usually when a sawyer attempts to run a cen- ter-bound saw successfully lie finds the trial a complete failure. A saw in this condition cannot be run with any degree of accuracy. It is seldom a solid toothed saw will get in this condition unless it is roughly used while gumming or has been unduly heated at the outer rim. One of the greatest difficulties in running an inserted toothed saw is due to the expansion given the outer edge of the plate by the teeth being sprung or riveted in their sockets. Unless this expansion be nicely adjusted the plate will become center bound, and consequently cannot cut in a straight line. By referring to Fig. 7, at A, is shown a plate that is center bound and one can easily see the form it assumes. In order to correct this, lay the saw out, as shown on plate B, with a piece of elm Ik. drawing a set of lines as explained on plate A, Fig. 6. Next place the saw upon the anvil, or if the operator choose to use the hand anvil, leave the saw upon the mandrel holding the anvil in the left hand. Proceed by commencing at* the outer rim hammering towards the center, veiy light blows at first and gradually increasing the heft and force as shown by hammer marks on the plate. Go over the set of lines drawn on one side and then reversing go over the other in a like manner. If you have not the desired tension by going over in this manner on both ^ides then draw a new set of lines between tin se previously drawn and proceed in this way until the desired tension is obtained. Care should be taken not to over expand the center, causing the ] late to be- come rim bound. 20 SAWS. am IB fi stored. This is a common term applied especially to large circular saws that have been accidentally, carelessly or otherwise over-heated and bulged in different places upon the plate. It is evident that a saw in this condition cannot be depended upon for accurate work. The prominent parts of* the plate will when passing continuously through the cut come in contact with the side of the kerf, thus expanding more and more by the friction and heat. To remove these loose places the plate must be expanded by the hammer in a locality that will take up and equalize the tension again. By referring to Fig. 8, at B. plate A, you will see represented one of these blisters, and in order to effectually remove it, lay out the plate as showed by the lines from D to E and P to G on both sides and hammer with the blocking hammer as shown, care being taken not to hammer more on one side than the other. This being done deliver a few blows with the round faced hammer upon the convex side of the blister. After trial if it be not all removed repeat the operation until the tension be again equalized. 22 saws. ©insofar $< The rapidity with which this form of glimmer will cut into steel plate is suprising. By referring to Fig. 14, the general arrangement for gumming a circular saw is shown. The plate is suspended by the center as with the emery wheel, the edge resting upon the support D, a tub of water is placed as shown at C, with faucet and tube con- nected, directing a stream upon the stone and plate at the point of contact, thus facilitating the rutting action and keeping the metal cool. The stone should be run at about 275 revolutions per minute, and be covered by a wooden or sheet metal covering to prevent water from flying upon the operator while at work. To secure the best results, the rest supporting the saw should be lowered about one inch below the center of the stone, thus cutting a very little obliquely across the plate. The writer has with this form of gummer gummed a large circular saw, cutting out from each tooth about three-fourths of an inch in depth of metal, in less than thirty min- utes without injury to the plate. In using this form of gummer care must be taken not to run at an overrate of speed, as the centrifugal force is liable to burst the stone and do much damage. A good burr gummer may be used without injury to a plate if the operator chooses to be at the extra expense, apply his muscle, and follow well the the directions given with the machine. Press glimmers should be used only in saw factories. 34 saws. »e:etfi UJelT ©fiambered. It is not economy for a sawyer to use a saw without gumming until the throat or sawdust chamber be filled as shown in Fig. 15, at B, plate A. It is obvious that a plate with teeth in this condition cannot stand up under heavy feed, as the sawdust by more than filling its space will crowd itself out at the sides, consume a large amount of power, cause the plate to heat and, as a consequence a poorly sawed lot of lumber will be produced. By frequently gumming and keep- ing the form of teeth as shown on lines F and C, the liability of stretching the plate upon the rim by cutting out a large amont of metal at one gumming is avoided. Teeth in this form are very easily dressed, as the iile has free action by not coming in contact with any of its corners. By producing, with the file, press glimmer, or any other device, square corners at the base of teeth, there is danger of the plate eventually cracking, as shown at E. Band saws should be hied or gummed on a circle at the base of their teeth, as the action over wheels tends to bend and crack them in that locality. 36 saws. l^epeurmg §roK©Fi (Seetfi. Till ess the operator understands well the art of brazing steel, he should repair a broken tooth by inserting a removable point or tooth accordingly as the shape and circumstances will allow. If broken, as shown on the plate A, Fig. 16, at line B, the spike tooth, as shown at C, is a very good way of repairing the break. As the saw becomes smaller the inserted tooth will soon wear back to the point at D, and then by removing the stub and gumming out the metal on the line E, a new and perfect tooth is again formed. To insert a tooth of this form, cut the metal out within three- thirty-seconds of an inch from the lines around the tooth C. File the edge as shown at F in a V shape. Form the tooth, C, the desirable size and cut a groove around it as shown at G ; slide it into place, care being taken not to have it fit too tightly, drill two small holes at H, H, and insert- two rivets, countersinking and upsetting them below the surface of the plate. All breaks will not be of the form shown, hence a tooth must be formed and inserted that will be best suited for the occasion. Solid toothed saws may in this way be - converted into removable or inserted toothed ones in the same manner by placing the needed tension upon the plate after the teeth are in place. 38 saws. Repairing a f^raetMredt Plate. If by accident or otherwise a plate becomes fractured at the outer rim extending inward, the break, if not too deep, may be effectually re- paired as follows : Trace the fracture to the ex- treme end and drill a small hole through the plate at that point to prevent it from going- deeper or extending farther. Lay out the plate A, Fig. 17, as shown at C, D, across the break B. Drill two f inch holes through the plate and countersink them from both sides, thus forming a V about the rim of both sides. Cut out the space I, with an emery wheel or file, leaving the sides square. Form from a, plate of wrought iron about two gaiiges thicker than the saw a a dovetail in form as shown at E, that will fill the socket, giving it a slight draw endwise and after heading down put it upon a stone or emery wheel and reduce the thickness to that of the plate. This, if properly done, is a very satisfactory way to repair a fracture of this kind. If a circular plate be cracked near the eye or midway, it should be discarded, as it is unsafe for further use. 40 SAWS. fBr^iFig gand |>@ajg. At A, Fig. 18, is shown a very convenient form of clamp to be used in brazing band saws. The plate, if it be a large one, should have its ends beveled at least 1J inches back and be placed in the clamp so as to form the thickness of the plate at the joint after it is brazed. Feed a small quantity of muriatic acid all the small pieces of zinc it will consume, and dilute with the same quantity of soft water. Place a thin strip of silver solder between the ends and cover all with the flux. Heat to a bright cherry red a large pair of tongs with jaws long enough to reach across the width of the plate. Remove all scale and clamp the lap between the jaws and have a helper clasp the farther ends with another pair and squeeze tightly until the plate be sufficiently heat ; then gradually pull off the hot tongs, following up with another pair slightly warmed. When cooled, if properly done, the splice will have a temper equal to that of the plate. File off all surplus solder, smooth off the lap and the plate is ready for use. 42 saws. ^ru\nne .32 Teeth well chambered 34 Repairing broken teeth 36 Repairing a fractured ri.ate 38 Brazing band saws 4o Truing up collars 42 Lug pins 44 Filing and swaging 4*> LIBRARY OF CONGRESS 017 002 022 4