Modern Machine-Shop Practice Novel Chapters
List of most recent chapters published for the Modern Machine-Shop Practice novel. A total of 286 chapters have been translated and the release date of the last chapter is Apr 02, 2024
Latest Release: Chapter 1 : Modern Machine-Shop Practice.by Joshua Rose.PREFACE.MODERN MACHINE-SHOP PRACTICE is pres
Modern Machine-Shop Practice.by Joshua Rose.PREFACE.MODERN MACHINE-SHOP PRACTICE is presented to American mechanics as a complete guide to the operations of the best equipped and best managed workshops, and to the care and management of engines and boiler
- 86 [Ill.u.s.tration: Fig. 1237.]The term "compounded" as applied to the change gears of a lathe, means that there exists in it a shaft or some equivalent means by which the velocity of the wheels may be changed. Such a shaft is shown at R in Fig. 1
- 85 In the case of a ring too thin to permit this, and of too large a bore to warrant making a mandrel for it, the ring may be held on the outside and bored, and both radial faces turned to within a short distance of the chuck jaws; at the second chucking, th
- 84 [Ill.u.s.tration: Fig. 1218.]Figs. 1218 and 1219 ill.u.s.trate this method of setting. A represents a piece of work requiring to be turned taper from B to C, and turned down to within 1/32 inch of the required size at E and F. If then we place the tool po
- 83 [Ill.u.s.tration: Fig. 1210.]If it be attempted with steel tools to take a very fine cut, as, say, one of sufficient depth to reduce a diameter, say 1/500 inch, the tool is apt to turn an uneven surface. There appears, indeed, to be a necessity to have th
- 82 [Ill.u.s.tration: Fig. 1209.]When the pressure between the tool and the work is sufficient, from the proportions of the work, to cause the work to spring or bend, the length of acting cutting edge on the tool should be reduced.As the diameter and rigidity
- 81 To prevent the weight of the work from causing the countersinking being out of true with the hole, the work should be occasionally allowed (by relaxing the grip upon it) to make part of a revolution, as explained with reference to centre-drilling without
- 80 [Ill.u.s.tration: Fig. 1173.]In Fig. 1174 is shown a device for guiding the centre punch true with the axis of the work, so as to avoid the necessity of finding the same by lines for the centres. It consists of a guide piece B and a parallel cylindrical c
- 79 If the live centre does not run true the following difficulties are met with.[Ill.u.s.tration: Fig. 1156.]If one end only of the work requires to be turned and it can be completely finished without moving the work driver, the work will be true (a.s.suming
- 78 Lathe Number 2.--Turning tool steel 2 inches long and 1/2 inch diameter, reducing diameter 1/8 inch. Revolutions of work 100 per minute. Feed 200 lathe revolutions per inch of tool travel.Lathe Number 3.--Turning tool steel 4 inches long and 7/8 inch in d
- 77 The considerations, therefore, which determine the shape of a cutter to be employed are as follows: Cutters for use on a certain and unvarying size of bore should have no clearance on the diametrical edges, the cutting being performed by the end edge only
- 76 A boring tool holder suitable for holes of from 2 to 4 or 5 inches is shown in Fig. 1118, in which A represents a round bar shaped at the end B to fit into the tool post of the slide rest, and having a groove across the diameter of the end C D to receive
- 75 Three or more washers may thus be used for every standard size, their thickness varying to suit the nature of the fit required.[Ill.u.s.tration: Fig. 1103.]It will be noted that it is mentioned that three _or more_ washers may be used, and this occurs bec
- 74 1083. The reamer is fed end-ways into the work at a cutting speed of about 15 to 18 feet per minute.[Ill.u.s.tration: Fig. 1081.][Ill.u.s.tration: Fig. 1082.]The main considerations in determining the form of a reamer are as follows:-- 1. The number of it
- 73 Referring to a 1/2 inch twist drill, it is said: "The time occupied from the starting of each hole in a hammered sc.r.a.p-iron bar till the drill pierced through it varied from 1 minute 20 seconds to 1-1/2 minutes. The holes drilled were perfectly st
- 72 " 5 " " 2-1/32 " 2-1/2 " "These sockets are manufactured ready to receive the drills, but are left unturned at the shank end so that they may be fitted to the particular lathe or machine in which they are to be used, no stand
- 71 If, for example, a piece of work requires the use of two or more such tools, and the holder is once set, the tools may be removed and interchanged with a certainty that each one put into place will stand at the exact angle and position required, not only
- 70 [Ill.u.s.tration: Fig. 1011.]Since, however, it is impracticable to measure male threads at the root, it becomes a problem as to the proper size of hole to bore for any given diameter and pitch of thread. This, however, may be done by the following rules:
- 69 But in the case of a tool holder, or of a chaser holder, the tool may be ground on the top face, and adjusted for height by any suitable means, the top of the holder serving as a guide to set the tool by.[Ill.u.s.tration: Fig. 986.]The line of the cutting
- 68 When the tool is very narrow at _c_, Fig. 960, or long as in Fig. 961, it may be strengthened by being deepened, the bottom B projecting below the level of the tool steel, which will prevent undue spring and the chattering to which this tool is liable.[Il
- 67 Both these guides, however, can only be applied to metal not unusually hard, and to tools rigidly held, and having their cutting edges sufficiently close to the tool point or clamp that the tool itself will not bend and spring from the pressure of the cut
- 66 In Fig. 921 let W represent the work having a cut C being taken off by the tool T; let E represent the slide rest, and F the extreme point at which the tool is supported; then the pressure placed by C on the top face of the tool will be at a right angle t
- 65 [Ill.u.s.tration: Fig. 912.]The inside faces of the cheeks are turned to the dotted lines shown in Fig. 909, and the outside faces being turned each to the proper thickness measured from the outside ones, the job will be complete and true in every directi
- 64 [Ill.u.s.tration: Fig. 889.]It is obvious that the pin may be pa.s.sed through one of the radial slots in the chuck, and set the required distance from the centre, but in this case the pin would be liable to become moved in its position in the slot.Side p
- 63 [Ill.u.s.tration: Fig. 870.]This could be held as shown in Fig. 869, in which C is the chuck plate, W the work, S a strap plate, and B, B are bolts and nuts, a face view of the work already chucked being shown in Fig. 870. The surface of the work being bo
- 62 [Ill.u.s.tration: Fig. 852.]The Judson patent chuck is designed to overcome this difficulty, and is constructed as shown in Figs. 851 and 852, the former being a face view and the latter a sectional edge view of the chuck.The jaws A of the chuck are hollo
- 61 Fig. 829 also represents a two-jawed chuck, the body being cylindrical, and having a [V]-groove at A to receive the work. The screws C, D may act independently of each other, or a continuous screw may be used, having, as in the figure, a left-hand thread
- 60 The set-screws are so adjusted upon the work, that the outside runs quite true from end to end. The jaws of the steady rest are then set to just touch the circ.u.mference of the sleeve, care being taken that their pressure does not spring the axial line o
- 59 [Ill.u.s.tration: Fig. 795.]When a mandrel is fitted to the sockets for the lathe centre, it should have a thread and nut, as shown in Fig. 795, so as to enable its extraction from the socket without striking it, as has been described with reference to la
- 58 [Ill.u.s.tration: Fig. 771.][Ill.u.s.tration: Fig. 772.]When a piece of work to be turned between the lathe centres is of such a form that there is no place to receive centres, provision must be made to supply the deficiency.[Ill.u.s.tration: Fig. 773.]In
- 57 [Ill.u.s.tration: Fig. 746.]Fig. 745 represents a lathe dog, driver, or carrier D, in position to drive a piece of work in the lathe. It is obvious that the work is secured within the carrier or driver by means of the set-screw shown.The tail of the drive
- 56 [Ill.u.s.tration: Fig. 734.]3rd. The rest for traversing single pointed screw cutting tools or chasers (for internal threads) is at the back of the lathe where it is out of the way.4th. In place of the usual change wheels required to operate the lead scre
- 55 When the tools, cutters, and belts are all properly adjusted in position to cut to the required respective diameters or lengths the operator has simply to place a stick of wood in the lathe and operate the respective handles or levers in their proper cons
- 54 [Ill.u.s.tration: Fig. 705.]Fig. 705 is a sectional and end view of the core A of the chuck, and Fig. 706 a sectional and end view of the sh.e.l.l D.[Ill.u.s.tration: Fig. 706.]Fig. 707 represents a sectional side view and an end view of the cross slide,
- 53 When, however, K is operated from left to right L moves back, and when it has traversed a certain distance, the head F rotates 1/7 of a rotation, and becomes again locked so far as rotation is concerned. Now the relation between the seven holes in F is su
- 52 The manner in which these results are accomplished is as follows: The headstock B and the tailstock are attached to the bed or table A, which is pivoted at its centre to a table beneath it, this latter table being denoted by C. This permits table A to swi
- 51 The construction of this sliding-spindle head is shown in Fig. 666, in which a wire chuck is shown in position in the spindles; L is the live spindle pa.s.sing through parallel bearings, so that it may have end motion when the nut M is operated. The inner
- 50 The lathe is made in many special or limited forms, to suit particular purposes, the object being to increase its efficiency for those purposes, which necessarily diminishes its capacity for general work.In addition to this, however, there are machine too
- 49 The tailblock of a lathe should be capable of easy motion for adjustment along the shears, or bed of the lathe, and readily fixable in its adjusted position. The design should be such as to hold the axial line of its spindle true with the axial line of th
- 48 By continuing the table for other pitches we shall find that in the first vertical column the denominators diminish by 4, the second column by 5, and the third by 6; and it is seen that by diminis.h.i.+ng the pitch of the lead screw, we have rendered nece
- 47 A lead screw should preferably be as near as possible to the middle of the lathe shears, and as close to the surface as possible, so as to bring it as nearly in line with the strain on the tool as possible, but on account of the cuttings, which falling up
- 46 Fig. 594.Fig. 595.Fig. 596.Fig. 597.Fig. 598.Fig. 599.Fig. 600.Fig. 601.Fig. 602.Fig. 603.Fig. 604.Fig. 605.Fig. 606.]Fig. 608 shows the tool in position, held by a single screw, for work requiring the tool to be close up to the work driver. In Fig. 609 a
- 45 A similar locking device is provided for the pinion B for actuating A; thus in Fig. 582 B is the lever, the spring pin being at R"; or referring to Fig. 584, X is the lever fast at _x_ on the pin driving B, and R" is the spring pin.The nut for t
- 44 With the lever L in the position shown, neither B nor E engages with A, hence they are at rest; but if lever L be raised as in Fig. 567, B will gear with wheels A and C, and motion will be conveyed from A to C, wheel E running as an idle wheel, thus C wil
- 43 The actual diameters, when thickness of belt = 0.20 in., are: 5.8 11.8 17.8 23.8 on cone A.29.8 25.36 20.08 13.7 " B.And the length of belt will be: [3.5080 - (3.5080 - 3.4137) 0.04] 40 in. = 140.17 in.EXAMPLE 3. Given the effective diameters: 12 in.
- 42 +-------------+-----------+-----------------------------+ | Average | Adjacent | DISTANCE BETWEEN THE CENTRES| | difference | steps, | OF CONE PULLEYS. | | between | whose +----+----+----+----+----+----+ | the | diffe- | | | | | | | | adjacent | rence is
- 41 In some cases, as in spinning lathes, the order of the steps is reversed, the smallest step of the cone being nearest to the live centre, the object being to have the largest step on the left, and therefore more out of the way.The steps of the cone should
- 40 [Ill.u.s.tration: Fig. 545.]The face plate is 12 feet diameter, cast with internal gear at the back.It is provided with [T]-slots and square holes for fixing work. It is bolted to a large f.l.a.n.g.e in one piece with the spindle, and fitted with four ste
- 39 [Ill.u.s.tration: Fig. 530.]Wood turners sometimes have their lathes so made that the headstock can be turned end for end on the lathe shears, so that the face plate may project beyond the bed, enabling it to turn work of large diameter. A better method t
- 38 [Ill.u.s.tration: Fig. 515.]All these parts are enclosed in a tight cast-iron tail-block, which serves as an oil well to insure constant and perfect lubrication. The surfaces which confine the revolving collar back and front are so adjusted as to allow pe
- 37 Fig. 503 represents the change wheel swing frame, an edge view of which is partly shown at W in Fig. 494. S is a slot narrower at _a_ than at _b_. Into this slot fit the studs for carrying the change wheels.By enabling a feed traverse in either direction
- 36 [Ill.u.s.tration: Fig. 495.]The thread on S at Z, Fig. 494, is to receive and drive the face plates, chucks, &c., which are bored and threaded to fit over Z. To cause the radial faces of such face plates or chucks to run true, there is provided the plain
- 35 [Ill.u.s.tration: Fig. 480.]The sizes of lathes are designated in three ways, as follows:--First by the _swing_ of the lathe and the total length of the bed, the term _swing_ meaning the largest diameter of work that the lathe is capable of revolving or s
- 34 If two set screws are placed diametrally opposite they will drive by the contact of their ends only, and not by reason of their inducing frictional contact between the bore and the shaft.A very true method of securing a hub to a shaft is to bore it larger
- 33 The proper angle of the jaws to the centre line of the jaws may be determined as follows:--The most desirable angle is that which will enable the wrench to operate the nut with the least amount of wrench-motion, an object that is of great importance in ca
- 32 [Ill.u.s.tration: Fig. 433.]In cases where nuts are placed under rapid vibration or motion they are sometimes detained in their places by pins or cotters. The simplest form of pin used for this purpose is the split pin, shown in Fig. 431. It is made from
- 31 [Ill.u.s.tration: Fig. 404.]A plain tap bolt should be turned up along its body, because if out of true the hole it pa.s.ses through must be made large enough to suit the eccentricity of the bolt, or else a portion of the wrench pressure will be expended
- 30 TABLE OF THE FRANKLIN INSt.i.tUTE STANDARD DIMENSIONS FOR THE HEADS OF BOLTS AND FOR THEIR NUTS, WHEN BOTH HEADS AND NUTS ARE OF HEXAGON FORM, AND ARE POLISHED OR FINISHED.+------------+-------------+-----------+---------------+-----------+ | Diameter | D
- 29 To insure that a tap shall tap a hole straight, the machinist, in the case of hand tapping, applies a square to the work and the tap, as shown in Fig. 361, in which W represents a piece of work, T a tap, and S S two squares. If the tap is a taper one the
- 28 A defect in taps which it has been found so far impracticable to eliminate is the alteration of pitch which takes place during the hardening process. The direction as well as the amount of this variation is variable even with the most uniform grades of st
- 27 Another form of free cutting tap especially applicable to taps of large diameter has been designed by Professor Sweet. Its principles may be explained as follows:-- In the ordinary tap, with the taper four or five diameters in length, there are far more c
- 26 The teeth for adjustable dies, such as shown in Fig. 293, are cut as follows:--There is inserted between the two dies a piece of metal, separating them when set together to a distance equal to twice the depth of the thread, added to the distance the faces
- 25 For cutting external or male threads by hand three cla.s.ses of tools are employed.The first is the screw plate shown in Fig. 292. It consists of a hardened steel plate containing holes of varying diameters and threaded with screw threads of different pit
- 24 So far as the diameter of a thread is concerned it may be measured by calipers applied between the threads as in Figs. 280 and 281, a plan that is commonly practised in the workshop when there is at hand a standard thread or gauge known to be of proper di
- 23 [Ill.u.s.tration: Fig. 267.]So far, however, we have only considered the wear tending to round off the sharp corners of the teeth, which wear is greater in proportion as the corners are sharp, and less as they are rounded or flattened, and we have to cons
- 22 CHAPTER IV.--SCREW THREAD.Screw threads are employed for two princ.i.p.al purposes--for holding or securing, and for transmitting motion. There are in use, in ordinary machine shop practice, four forms of screw thread. There is, first, the sharp [V]-threa
- 21 [Ill.u.s.tration: Fig. 229.][Ill.u.s.tration: Fig. 230.][Ill.u.s.tration: Fig. 231.][Ill.u.s.tration: Fig. 232.]To compare the motions of the respective rollers along the line of motion A A we proceed as in Fig. 232, in which the two dots M and N are the
- 20 To obtain the forms of the teeth, therefore, take any convenient describing circle, and employ it to describe the teeth of the pinion by rolling within its pitch circle, and to describe the teeth of the wheel by rolling within and without its pitch circle
- 19 "But these circular arcs may be rectified and subdivided with great facility and accuracy by a very simple process, which we take from Prof.Rankine's "Machinery and Mill Work," and is ill.u.s.trated in Fig. 195. Let O B be tangent at O
- 18 Second, 72/47.1 = 1.53 inch equal to the pitch.This is nearly 1-1/2-inch pitch, and if possible the diameter would be reduced or the number of teeth increased so as to make the wheel exactly 1-1/2-inch pitch.Rule 3.--Given ---- pitch and pitch diameter; t
- 17 The following table gives the safe working pressures for wheels having an inch pitch and an inch face when working at the given velocities, S.W.P. standing for "safe working pressure:"-- +------------+------------+------------+------------+-----
- 16 [Ill.u.s.tration: Fig. 172.]It now remains to draw in the top of the thread upon the curved surface of the half pattern; for this purpose take a piece of stiff card or other flexible material, wrap it around the pattern and fix it temporarily by tacks, we
- 15 [Ill.u.s.tration: Fig. 154.]The error in the set of the compa.s.ses as shown by the distance apart of the two marks E and I on the circle in Fig. 152 is too fine to render it practicable to remedy it by moving the compa.s.s legs, hence we effect the adjus
- 14 Each of these parts is marked with the number of teeth the wheel is to contain, and with the pitch of the teeth as shown in Fig. 140, which represents part C full size. Now suppose it is required to find the thickness at the root, for a tooth of a wheel h
- 13 From these tables may be found a tabular value which, multiplied by the pitch of the wheel to be marked (as stated at the head of the table), will give the setting number on the graduated edge of the instrument, the procedure being as follows:-- For the t
- 12 [Ill.u.s.tration: Fig. 127.]To overcome this objection the template may be made to equal half the thickness of a tooth and its edge filed to represent a radial line on the wheel. But there are other objections, as, for example, that the template can only
- 11 The method of using the table is as follows:--Suppose it is required to make a set of wheels, the smallest of which is to contain 50 teeth and the largest 150, and it is determined to use but one cutter, then that cutter should be made correct for a wheel
- 10 Rule.--Multiply the number of teeth in the smallest wheel of the train by the number of cutters it is proposed to have in the set, and divide the amount so obtained by a sum obtained as follows:-- From the number of cutters in the set subtract the number
- 9 100 " " " " 87 to 123 "150 " " " " 123 to 200 "300 " " " " 200 to 600 "Rack " " " " 600 to rack.[6] For wheels having less than 12 teeth the Pratt and Whitney C
- 8 [Ill.u.s.tration: Fig. 107.]A cast steel disk is turned in the lathe to the required form and outline. After turning, its circ.u.mference is serrated as shown, so as to provide protuberances, or teeth, on the face of which the cutting edges may be formed.
- 7 Involute teeth possess four great advantages--1st, they are thickest at the roots, where they should be to have a maximum of strength, which is of great importance in pinions transmitting much power; 2nd, the action of the teeth will remain practically pe
- 6 It may here be shown that a worm-wheel may be made to work correctly with a square thread. Suppose, for example, that the diameter of the generating circle be supposed to be infinite, and the sides of the thread may be accepted as rolled by the circle. On
- 5 Internal or annular gear-wheels have their tooth curves formed by rolling the generating circle upon the pitch circle or base circle, upon the same general principle as external or spur-wheels. But the tooth of the annular wheel corresponds with the s.p.a
- 4 [Ill.u.s.tration: Fig. 47.]But if a pair or a particular train of gears are to be constructed, then a diameter of generating circle may be selected that is considered most suitable to the particular conditions; as, for example, it may be equal to the radi
- 3 [Ill.u.s.tration: Fig. 30.]In Fig. 30 _a_ _a_ and _b_ _b_ are the pitch circles of two wheels as before, and _c_ _c_ the pitch circle of an annular or internal gear, and D is the rolling or describing circle. When the describing point arrived at _m_, it w
- 2 revolutions of the 40 wheel, the discrepancy of 1/100 being due to the 6.66 leaving a remainder and not therefore being absolutely correct.That the amount of power transmitted by gearing, whether compounded or not, is equal throughout every wheel in the t
- 1 Modern Machine-Shop Practice.by Joshua Rose.PREFACE.MODERN MACHINE-SHOP PRACTICE is presented to American mechanics as a complete guide to the operations of the best equipped and best managed workshops, and to the care and management of engines and boiler