LIBRARY OF CONGRESS. Chap,.: Copyright No... ' Shelf„_i.C_5. r c /-&2L7 UNITED STATES OF AMERICA. A Treatise MILLING AND Milling Machines The Cincinnati /Hilling Machine Co. CINCINNATI. OHIO, U. S. A. Cincinnati^ Ohio : The Cincinnati Milling Machine Company. April, 1897. \%% w -C - ' Copyright 1897, BY The Cincinnati Milling Machine Co. PREFACE. This treatise is published in answer to a demand from those wishing to become more familiar with the construction and use of milling machines. The important parts of the Universal and Plain Milling Machines are clearly and concisely described. A number of examples of milling operations are shown to illustrate the advantages which these machines possess for manufacturing purposes. INTRODUCTION THE use of Milling Machines during the past few years has been largely extended, as the advantages they possess for certain classes of work have become better understood. At the same time, great improvements have been made in the construction of these machines to adapt them to a larger variety of work. The constant aim of the designer has been to increase the range of these machines with the result that to-day they are used on work that a few years ago was thought not possible to be done on milling machines. Specialization in their manufacture has also contributed to this result. For many years w T e have confined our attention exclusively to that type of milling machines which is known as the pillar and knee type, comprising two classes, viz., Plain and Universal. In this way it has been possible for us to develope every detail of design and workmanship to a high degree of excellence. Our buildings are modern and well lighted and of ample size to afford an economical arrangement of machinery. Our machinery is modern, much of it being of our own design and especially adapted to our particular requirements. Jigs and special fixtures are employed throughout to insure both economy in manufacture and interchangeability of parts. * We extend a cordial invitation to any one interested in metal working machinery to visit us. This will afford an opportu- nity of becoming more familiar with the use of milling machines, as developed on our own work, and at the same time, permit intending purchasers of milling machines, to thoroughly ac- quaint themselves with the merits which our machines possess, both as to design and workmanship. The Cincinnati Miixing Machine Co. THE CINCINNA TI MILLING MA CHINE CO. CONTENTS. PAGE. Preface, 3 Introduction, 5 Contents, 6-7 Description of No. 1 Universal, 8-14 Description of Universal Indexing and Dividing Head, . . , 15-17 Description of Sector, 18-19 Table of Special Divisions, 20 Description of Tail Stock, 21 Description of Spindle for Back-Geared Machines, .... 22-23 Section of Front Box, 24 Description of Gear Box, 25-27 No. 1 Universal Milling Machine, 28-29 No. iy 2 " " 30-31 No. 2 " " 32-33 No. 3 " " 34-35 General Dimensions of Universal Milling Machines, ... 36 Plain Milling Machines, 37 No. o Plain Milling Machine, 38-39 No. 1 " " '* 40-41 No. 2 " " " 42-43 No. 3 " " " 44-45 No. 2 " " " (showing all Automatic Feeds), . 46 General Dimensions of Plain Milling Machines, .... 47 Attachments for Milling Machines, 48 Universal Indexing and Dividing Head, 49-50 Plain Indexing Centers, . . . 51 Rack Cutting Attachment, 52 and 68 High Speed Milling Attachment, 53 Vertical Spindle Milling Attachment, 54 Cam Cutting Attachment, 55~56 THE CINCINNATI MILLING MACHINE CO. PAGE. Rotary Milling Attachment, 57 Vises, 5^ Arbors for Milling Machines, ........ 59 A New Milling Machine Dog, ........ 60-61 Cutters, 62-67 Examples of Mining : Miscellaneous, .......... 69-81 Cutting Bevel and Miter Wheels, 82-84 Worm Wheels, 85-86 Spiral Gear Cutting, 87-90 Special Jig Milling, 94-103 Change Gears for Cutting Spirals, . 91-93 Erection and Care of the Machine, ...... 104-106 Design, Features, Workmanship, 107-112 Tables : Tables of Angles and Gearing for Spirals, . . . 113-116 Table used for Making Standard Spiral Milling Cutters, . 117 Table used in Connection with the Universal Indexing and Dividing Head, 118-119 Table for Cutting Racks, 120-121 Table showing Depth of Space and Thickness of Tooth in Spur Wheels, 122 Comparative Table of Circular and Diametral Pitch, . . 123 Table of Decimal Equivalents, .124 Table of Decimal Equivalents of Millimetres and Fractions of Millimetres, 125 Speed of Cutters for Cast Iron , 126 THE CINCINNA TI MILLING MA CHINE CO. FIG. 1. THE CINCINNATI MILLING MACHINE CO. No. I UNIVERSAL. The name ' ' Universal ' ' applied to Milling Machines is now understood to designate a machine adapted to n,versa • the automatic cutting of spirals. The swivel carriage in this machine swivels on its saddle, permitting the table to be turned to any angle. The following description applies to the No. i Uni- versal Milling Machine. We select this small machine for detail description as it embodies nearly all the features found in our other universal machines. This machine is completely universal in all its movements. The table may be completely revolved through 360 degrees, allowing spirals to be cut beyond 45 degrees. The feeds are automatic in their horizontal directions, Automatic are reversible without crossing the feed-belt, and can Feeds, be automatically tripped in either direction. This size finds its greatest usefulness in the tool- room, as ever} T kind of operation can be performed upon it, which can be performed upon the larger sizes of the Universal machines. Owing to its small size, it is quickly handled, and is therefore a favorite for tool- room work. An overhanging arm is provided for the better sup- over= port of the outer end of the cutter arbor. In case an han s in s end mill is used, or where the character of the work does not require the overhanging arm, it is easily turned up out of the way. The end of the arbor, which is cutter made cylindrical and ground after hardening, has its Arbor - support in the phosphor bronze bearing secured in the Bearing in overhanging arm. The bearing is so constructed to 0ver= admit of being concentrically closed in as wear takes Arm. place. This feature is of no secondary importance, as by means of this improved bearing a close adjustment on end of arbor is obtained, firmly supporting it and permitting therefore heavy and accurate work to be done. THE CINCINNA TI MILLING MA CHINE CO. 13'..., FIG. 2. THE CINCINNATI MILLING MACHINE CO. Two friction pulleys are furnished on countershaft, Counter- both running in same direction and at different speeds, p„n* giving double the usual number of spindle speeds. All spindles revolve in a right hand direction, permitting the use of turret machine, lathe and drill press tools. The double speed countershaft affords two speeds for the cutter without shifting the belt on cone pulley or changing the gearing, thus giving a roughing cut at one speed and a light finishing cut at a higher speed, very often a convenience to the operator. The main spindle is made of crucible steel and has a spindle. |4" h°l e bored through its entire length ; the front end is bored to receive a No. 10 B. & S. taper shank on cutter arbors. The end of spindle is threaded for re- ceiving the 6 inch universal chuck. The thread on the front end of the spindle is protected when not in use by a guard-collar. The 6-inch universal chuck furnished is also made to Universal fit the spindle of universal indexing and dividing head. uc Besides the numerous uses on the dividing head, it may be used on the main spindle of machine for holding straight shank reamers, drills, special milling cutters and boring bars, as w 7 ell as for cutting up stock from the bar passed through the hollow spindle. The front box for spindle is solid and has a taper Front Box seat in the column. It is made of cast-iron and is lined with genuine Babbitt metal, thoroughly compressed and secured. The superiority of such a bearing is well recognized. Both front and back bearings are provided with lock nuts for taking up wear. The back bearing is made of phosphor bronze, turned Back Box. to fit a taper bored seat in the column. The taking up of the end wear of main spindle is Taking up provided for in the construction of the front box S 2 , Boxes° f Fig. i ; on the rear end of this box is a threaded lock collar S 3 , wdiich may be screwed back against the hub of the cone pulley as wear takes place. THE CINCINNATI MILLING MACHINE CO. Oiling of The two spindle boxes are oiled through a wick from a reservoir or chamber surrounding each journal, afford- ing at all times ample lubrication. Column. The main frame or column A, Fig. i, is of box form Knee, with its face side planed to receive the knee F, which slides vertically upon it and is raised and lowered by vertical the screw G. Screw G is operated by a pinion shaft screw, ^/hjck j ias on ^ ou t er enc [ a detachable clutch handle 13, Fig. 2, conveniently located for the workman. Saddle. On top of the knee F, Figs. 1 and 2, the saddle H is placed. It is operated by the transverse feed screw 1 , Fig. 1, in a line parallel to the axis of main spindle. Swivel The swivel carriage J, is placed on top of saddle. amage. j^ g j ar g e b ear i n g on the saddle provides a substantial support for the table K, at whatever angle the table ma}^ be placed. The swivel carriage is circular in form. This feature is of special value when cutting spirals or any work requiring the setting of the table to an3 r considerable angle. The angular positions of the table are indicated by easily read graduations. Clamping The swivel carriage is firmly clamped to the saddle a a "j ge by means of T-head bolts, which engage in a circular saddle. T-slot in swivel carriage. These bolts extend through the saddle and the nuts for tightening are easily ac- cessible. Oil The table has oil-channels along both sides which drain all oil drippings to the pockets at its ends. These oil -pockets are provided with plugs for draining the oil. Channels. Table The power for driving the table is obtained from the Feed. "*" four step cone pulle} T on the rear end of the main spindle B. For the slower feeds, this pulley is clutched directly to the spindle, and for the faster feeds, runs loose on the spindle. While loose on the spindle, the cone pulley is driven by a gear arrangement which increases the rate of feed between two and three times. For this heavier duty of rapid feeding, a higher belt speed is obtained. THE < 7M 7\.\ . I II MILLING M I < /// WE i '< >. Feed Mechan= ism. By the one operation of raising' handlever ze> 8 , these gears are thrown out, and at the same time, the clutch on the cone pulley W, is engaged with the clutch w 4 on end of spindle, or vice versa. There are eight changes of feed, varying from .004" Feed to .070" travel of the table to one revolution of the an ^ es - cutter spindle. A dial on the guard for the feed mechanism indicates in plain figures the rate at which the machine is feeding. The arm X, which carries the lower feed cone Y, can Feed Beit. be conveniently adjusted on the column to keep the feed belt (which may be made endless), at a proper tension. Motion is transmitted from cone Y, by means of the universal, jointed, telescope shaft to the stem gear b, Fig. 2, which has its bearing in the back of the knee F ; thence, to the splined shaft /, Figs. 1 and 2. The direction of the power feeds is changed by operating the tumbler gears through the crank k, Fig. 1. These tumbler gears control the direction of rotation of shaft /. The automatic operation of the cross feed is as follows. The splined shaft /, Fig. 2, has a clutch k 1 , pinned to its outer end for engaging with another clutch g 1 , attached to a pinion/ 1 . The automatic cross feed is thrown in or out by means of hand-lever M 1 , Fig. 2, engaging or disengaging clutch h 1 . This feed may be thrown out automatic- ally by means of trip-dogs which act on pitman 24, Fig. 2 , to disengage h l . The cross-feed screws I, receives its power feed from the pinion/ 1 , by its attached gear d l , Fig. 2. A clutch-handle 15, Fig. 2, on end of cross-feed screw, mounted loosely on it, is shifted into engagement for operating this feed by hand. The motion for feeding the table is taken from the same splined shaft /, Fig. 1, which has upon it a sliding bevel gear M, engaging into its companion on a vertical shaft, on the upper end of which is formed a spur Power Cross- feed. Power Table= feed. THE CINCINNATI MILLING MACHINE CO. pinion q. Gear q engages with the large gear r on shaft s, centrally located within the carriage J. On the upper end of this shaft is a bevel gear meshing with gear U 1 . Gear IT 1 is journaled in the carriage and has clutch teeth for engaging a feathered clutch U, Fig. 2, sliding on the feed screw L, and operating it. The hand lever b 1 , engages and disengages clutch U, for starting and stopping the automatic table feed. Dog In the T-slot on the front side of the table is an ad- on Table. j ust able feed tripping dog, 10. This dog has two wedge surfaces, either of which as it approaches the stud ii on the lever b 1 swings the lever b 1 which disengages the feather clutch U, and instantly stops the table-feed. Back Back-lash in the table feed screw is overcome by the Lash, use of a compensating nut. Handles There is a handle provided on each end of the table on Table. for f ee ding it by hand. The handle 12, Fig. 2, on left end of table, is used for fine feeding, the other 13 1 , Fig. 2, on right end is used for rapid feeding and also for a quick return of the table. Elevating The shaft M for vertical motion is placed at an oblique Shaft, angle, and carries a clutch crank 13. This arrange- ment of shaft in connection with permanent handles on screws for cross and longitudinal adjustments of table, gives the operator easy control of every adjustment without the necessity of changing his position or shift- ing the handles. Adjust= Two adjustments may be made simultaneous!}'. All adjustments are indicated in the thousandths of an inch by large readable dials, 20, 21, 22, Fig. 2. THE CINCINNATI Ml 1.1. IXC MACHINE CO. UNIVERSAL INDEXING AND DIVIDING HEAD. Change Gears. Lead. The Universal Indexing and Dividing Head is used Use for cutting spiral work such as twist drills, spiral teeth on cylindrical and conical milling cutters, and teeth in spiral gear wheels, etc. It is used to the greatest ex- tent for indexing and dividing the periphery of cylin- drical work into a large range of a number of equal divisions. When cutting spirals, suitable gears are attached from the lead screw to the dividing head. These gears are mounted on the segment plate Q, Fig. 3. When the table is driven by its lead screw, these gears pro- duce rotation of the dividing head spindle. On most spiral w T ork, for every revolution of the dividing head spindle, the table travels more than one inch. Therefore, instead of designating the spiral by its pitch, the lead is given in inches, which means that the table has traveled a certain number of inches (called lead) while the dividing head spindle has made one revolution. For example, a 6-inch lead is one in which the dividing head spindle makes one turn in 6 inches travel of the table. The manner of determining the gears for various spirals is explained under the head of Change Gears for Cutting Spirals, in this treatise. Fig. 3 shows the various parts of the head. The housing E rests on the table of the milling machine, and has two feathers which fit in the T-slot of the table and two slotted holes in its base for receiving two clamping bolts. The swiveling block carrying the spindle S, is fitted s W j V eiing in the housing E. This block is always fully contained within its bearings at whatever angle the spindle is held. Housing. Block. THE CINCINNA TI MILLIXG MA CHIXE CO. /Zitrn in 70 /fa inc/z- FIG. 3. THE ( V.\ t INh , I 11 Mll.l.l.\ (1 M. I ( III VE ( ( >. A circular T-slot, similar to that of a planer head, is turned in one side of the swiveling block. This slot is concealed, and can not become clogged with chips. By means of two T-bolts in this slot and an additional clamping device B, on the other side, the swiveling block is firmly held at any desired angle. The end of the spindle is not raised to an excessive height when it is in a vertical position, because the axis of the swivel- ing block is central with the housing. The swiveling block is as rigid when the spindle is vertical as in any other position. The same arbors which fit the main spindle of the spindles. milling machine will fit the spindle S. The spindle S will take work through its entire length i T y diameter. The front end of the spindle is threaded to receive a 6-inch universal chuck. When not in use, the thread on the spindle is protected by a guard-collar. The chuck fitting this spindle also fits the main chuck. spindle of the machine. The spindle of the head is provided with a clamping device U, by means of which clamping it can be firmly locked during cutting operations, thus s P' nd,e - relieving the worm, worm wheel and index pointer of all strain. On the spindle, there is formed a worm gear having 40 teeth. For dividing work into a number of equal parts, the side index plate P 1 , and index pointer N, are i n d ex = provided. A complete description of the method of plate and making divisions is given in the article on the use of pointer, the sector, page 18. The sector is shown at V, Fig. 3, and more plainfy s ec tor. in Fig. 4. To cut left hand spirals on the Nos. 1, ij4 and 2 Universal Machines, and right hand spirals on the No. 3 Universal Machine, the idle gear C is meshed between Direction the change gears by shifting the holder A. This of spiral. holder is marked for each machine, with the direction of the spiral which can be cut when the idle gear C is jn mesh. iS THE CIXCINNATI MILL IX G MACHINE CO. 38 Circle /OJ^o/e.y. FIG. 4. SECTOR. Fig. 4 shows how the sector is adjusted for counting off holes in the index-plate. This example shows the sector in position to cut 152 teeth which requires that the index pointer move over a series of 10 holes for each division. Mistakes are frequently made in setting the sector only 10 holes apart, which is incorrect. The hole in which the index-pointer rests, which is indi- cated by black spot, should never be counted when adjusting the sector for any number of holes. After the sector is set and tightened by the screw a, no further counting of holes is necessary in cutting the w T heel of 152 teeth, because the sector as set is moved against the index pointer for each division. THE CINCINNATI MILLING MACHINE CO. The index-plate is drilled from both sides, the circles t8j 24, 2$, 30, 34, 37, 38, 39 and 41, being drilled in one side and circles 42, 43, 46, 47, 49, 54, 58, 62 and 66 in the other. With these circles, the greatest possible variety of divisions up to 360 is obtained as shown in table in the latter part of this book. The following rule may be applied for finding the Rule. number of turns or number of holes required to divide the periphery of cylindrical work into any given number of equal parts. Forty revolutions of the index-pointer holder P, Fig. 3, are required to make one revolution of the dividing head spindle ; therefore, to make an} 7 part of a revo- lution of the spindle, 40 divided by the number of divisions required, will determine the number of turns or part of a turn to be made by the index pointer. For example, suppose it is required to cut 96 teeth ; then 40 divided by 96 is equal to ff ; according to the index chart furnished with each dividing head, this division can be made by using the 24 hole circle ; since ■ff is equal to ^i, the index pointer must make 4-J of a turn or be moved 10 holes in the 24 hole circle for each division. We are prepared to furnish index plates to make the special divisions shown on page 20, in addition to those which are shown on our regular table. On account of the greater number of holes in these plates, the holes must be drilled smaller than in the regular plate, and an index-pointer of smaller diameter is also required. THE CINCINNATI MILLING MACHINE CO. SPECIAL DIVISIONS. n H B B B i i i B B b B a I- r- 1 c- 1 {H B B w B a en a B •Ji a* ■i. o B o j W O ►J B o a B (J ►J CJ a O J o J 6 & o 6 OS o 6 <£ O 6 a O £ X Z o W £ U X z o X 51 51 40 102 51 20 204 51 10 408 51 5 53 53 40 106 53 20 212 53 10 424 53 5 57 57 40 114 57 20 228 57 10 456 57 5 59 59 40 118 59 20 236 59 10 472 59 5 61 61 40 122 61 20 244 61 10 488 61 5 63 63 40 126 63 20 252 63 10 504 63 5 67 67 40 134 67 20 268 67 10 536 67 5 69 69 40 138 69 20 276 69 10 552 69 5 71 71 40 142 71 20 284 71 10 568 71 5 73 73 40 146 73 20 292 73 10 584 73 5 77 77 40 154 77 20 308 77 10 616 77 5 79 79 40 158 79 20 316 79 10 632 79 5 81 81 40 162 81 20 324 81 10 648 81 5 83 83 40 166 83 20 332 83 10 664 83 5 87 87 40 174 87 20 348 87 10 696 87 5 89 89 40 178 89 20 356 89 10 712 89 5 91 91 40 182 91 20 364 91 10 728 91 5 93 93 40 186 93 20 372 93 10 744 93 5 97 97 40 194 97 20 388 97 10 776 97 5 99 99 40 198 99 20 396 99 10 792 99 5 101 101 40 202 101 20 404 101 10 808 101 5 103 103 40 206 103 20 412 103 10 824 103 5 107 107 40 214 107 20 428 107 10 856 107 5 109 109 40 218 109 20 436 109 10 872 109 5 111 111 40 222 111 20. 444 111 10 888 111 5 113 113 40 226 113 20 452 113 10 904 113 5 117 117 40 234 117 20 468 117 10 936 117 5 119 119 40 238 119 20 476 119 10 952 119 5 121 121 40 242 121 20 484 121 10 968 121 5 123 123 40 246 123 20 492 123 10 984 123 5 125 125 40 250 125 20 500 125 10 1000 125 5 127 127 40 254 127 20 508 127 10 1016 127 5 128 128 40 256 128 20 512 128 10 1024 128 5 129 129 40 258 129 20 516 129 10 1032 129 5 131 131 40 262 131 20 524 131 10 1048 131 5 133 133 40 266 133 20 532 133 10 1064 133 5 137 137 40 274 137 20 548 137 10 1096 137 5 139 139 40 278 139 20 556 139 10 1112 139 5 141 141 40 282 141 20 564 141 10 1128 141 5 143 143 40 286 143 20 572 143 10 1144 143 5 147 147 40 294 147 20 588 147 10 1176 147 5 149 149 40 298 149 20 596 149 10 1192 149 5 151 151 40 302 151 20 604 151 10 1208 151 5 153 153 40 306 153 20 612 153 10 1224 153 5 157 157 40 314 157 20 628 157 10 1256 157 5 159 159 40 318 159 20 636 159 10 1272 159 5 161 161 40 322 161 20 644 161 10 1288 161 5 163 163 40 326 163 20 652 163 10 1304 163 5 167 167 40 334 167 20 668 167 10 1336 167 5 169 169 40 338 169 20 676 169 10 1352 169 5 171 171 40 342 171 20 684 171 10 1368 171 5 173 173 40 346 173 20 692 173 10 1384 173 5 175 175 40 350 175 20 700 175 10 1400 175 5 177 177 40 354 177 20 508 177 10 1416 177 5 179 179 40 358 179 20 716 179 10 1432 179 5 181 181 40 362 181 20 724 181 10 1448 181 5 183 183 40 366 183 20 732 183 10 1464 183 5 187 187 40 374 187 20 748 187 10 1496 187 5 189 189 40 378 189 20 756 189 10 1512 189 5 191 191 40 382 191 20 764 191 10 1528 191 5 193 193 40 386 193 20 772 193 10 1544 193 5 197 197 40 394 197 20 788 197 10 1576 197 5 199 199 40 398 199 20 796 199 10 1592 199 5 THE ( '/.Y< 7 \ Y / II MILLING M I ( III \ I C( ». FIG TAIL STOCK. Fig. 5 illustrates the tail-stock. The housing is shown at D. The slide E is dove- tailed into the housing and is moved forward and backward by turning the knob A. The clamping bolt C holds the slide E firmly in any position. The double center-bar F in tail-stock is dove- tailed into the front of the slide E. This center-bar is adjustable up and down by means of a rack and pinion operated by the knob B. The clamping bolt G, holds the center-bar firmly in any position. One center has the top milled off to allow small work, such as taps, reamers, etc., to be milled ; the other end is left as full as possible for milling heavy work with large centers. The change from one end of the center-bar to the other is easily and quickly made. Fig. 6 shows a special tail- stock center-bar. One end A is milled off on the side as well as on the top. This permits the use of an end mill very close to the center. The other end of this center- bar is provided with a female >" I center B. Housing. Slide. Clamping Bolt for Slide. Center- bar. Clamping Bolt for Center= bar Small Center. Large Center. m mm Special Centers. FIG. 6. THE CINCINNA TI MILLING MACHINE CO. THE CINCINNATI MILLING MACHINE CO. SPINDLE FOR BACK-GEARED MACHINES. Fig. 7 shows the method of fastening the face-gear F. with its collar H, to the spindle by means of the notched feather C and spline in the spindle D. The knurled knob L is used for connecting and dis- connecting the face-gear F and the driving cone E. When the back-gear is not required, the face-gear and driving cone run together. To accomplish this, the knurled knob L is turned to the left, and by turning the driving pulley belt by hand, the driving stud J is pushed into one of the holes in the driving cone head K, by the spring M. For disconnecting the face-gear from the cone, the driving stud J is withdrawn by turning the knurled knob L to the right, and the back-gear can then be thrown in. This knob avoids the use of a wrench, and enables the operator to make these changes without the necessity of feeling his way. To Adjust the Spindle. — For taking up the wear on the taper of the spindle, and to take out end play, turn the lock-nut G toward the face-gear F. After a number of adjustments of the spindle, the driving cone may become crowded against the back box. To move the cone forward, the notched feather C is withdrawn by turning screw B until it comes to a stop. Turn the lock-nut G away from the face- gear. Then move the face-gear and driving cone to- ward the nut G. Screw down the notched feather C, which will now 7 engage in other teeth in the notched spline nearer the front of the spindle. To TAKE THE MILLING MACHINE SPINDLE D Ollt of its bearings, insert wrench A through the largest step of the cone pulley into screw B, and withdraw feather C, until it comes to a stop, and after unfastening the gear on back end of spindle the spindle may be withdrawn. The Cone Pulley E should have about ^V of an inch lateral play after the spindle is adjusted. THE CINCINNA TI MILLIXG MA CHLXE CO. FIG. 8. SECTION OF FRONT BOX. Fig. 8 shows a section of the front cast iron box, with its Babbitt lining. After the box has been bored, dove- tail slots are planed lengthwise in it. Two dove-tail circular grooves are turned in it to keep the Babbitt metal from shifting length- wise. The Babbitt metal is thoroughly compressed by a rolling process, then turned out true, and treated as though it were a solid box. Babbit lined bearings have been used for many 3-ears on lathes, screw machines, and other fine and accurate machinery, and better results have been obtained from its use than from any other material. THE CINCINNATI MILLING MACHINE CO. GEAR-BOX. All back-geared machines are made with a gear-box, providing a stronger and wider range of feeds for the heavier duty resulting from the use of cutters of larger diameters and wider faces, which may be used, owing to the increased range of spindle speeds. Figs. 9 and 10 show the construction of the gear-box. A small and large pinion O and P, are secured on the rear end of the milling machine spindle B, which pro- jects beyond the column. Pinions R and S, which mesh either with or P, are fastened to shaft Q. The gears T, U, V and shaft Q drive the cone pulley, W. From this pulley, power is transmitted to uni- versal-jointed telescope shaft in the same manner as described on page 13. On top of the gear-box is fastened a plate, I 3 , show- ing the rate of feed in thousandths of an inch to one revolution of the main spindle. The gears T and V are change gears, which may be transposed for slower or faster feeds. Twelve distinct changes in the rate of feed are obtained by the use of the cone pulleys, sliding gear and change gears. The gear, U, is an intermediate gear running loose on an eccentric bushing. No fine adjustment of the inter- mediate gear is necessary in transposing gears T and Y, because the eccentric bushing is simply turned one- half revolution to bring the gears into proper mesh. The dial plate, I 3 , and the pointer, H 3 , are shown below. The rate of feeds is read from the plate as follows. When the small gear V is on the upper shaft Q, and the belt is on the smallest step of the cone pulley, W, the left hand figure in the upper row, on the side to THE CINCINNA TI MILLING MA CHINE CO. which the pointer directs, should be read ; if the belt is on the second step of the cone pulley, W, the second figure, and if on the third step, the third figure in the upper row is read. When the large gear, T, is on shaft, Q, the lower row of figures is read in the same manner. For example, when the feed belt is running on the small step of the pulley, W, and the pointer, I 3 , points to the left, this would indicate that the feed advances yo'W of an inch to every revolution of the milling cutter. Throwing the lever to the left, thereby shift- ing the sliding gear inside the box, and changing the direction of the pointer to the right, the rate of feed indicated will be t Mtt of an inch. 10 (TO" By placing the belt on the second step of the cone pulley, the second number, 9 is read, and by throwing the lever over, the pointer indicates T |f ^ of an inch feed to every revolution of the spindle. This rapid change in the rate of feed by simply throwing the lever, G 3 , from one side to the other is quite an advantage because coarse and fine feeds can be applied on some work for roughing and finishing cuts without rechucking the piece. Feed in Thousandths io one Revolution of Spindfe. O 9 12 16 22 41 57 \78 98 i 146 187 THE CINCINNATI MILLING MACHINE CO. MILL.MACH SPINDLE. FIG. 10. lS THE CINCINNATI MILLING MACHINE CO. Table Feed, . 20 in. Cross " . 6 in. Vertical " .17 in. No. \ Universal Milling Machine. FIG. 11. THE CINCINNATI MILLING MACHINE CO. No. 1 UNIVERSAL. The No. i Universal is well adapted for the tool-room. Its size per- mits a rapid adjustment of the machine for the great variety of work usually performed there. The Spindle is bored to receive a No. 10 B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole -Jf" diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 3" belt. The largest diameter is 12 inches. The Overhanging Arm is 3^ " diameter. It can be turned up out of the way or put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 6*4 inches. The Table over all including oil pockets is 35" x6>^ // . The work- ing surface is 33" x 6^ r/ . There is one T-slot y%" wide. The top of the table can be lowered 17" below the center of the spindle. The Swivel Carriage which forms the housing for the table is graduated in degrees on its circular face. A T-slot is turned in the bottom, near the outer edge, to receive two T-bolts which pass down through the saddle and are used for firmly clamping the swivel carriage to the saddle. The Feed of the table is automatic in either direction through 20^. The cross motion in line with the spindle is 6 /r , and is automatic imeither direction. Both of the above feeds are reversed by a lever on the front of the machine, without crossing the feed belt There are 8 changes of feed which vary from .004" to 070" travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. The Index Cutters furnished with this machine swing io // diameter and take in length 15 inches. The Vise can be swiveled to any position, the angle of which is shown on the graduated base. The jaws are 6" wide, i^rV' deep, and will open 3^ // . The Countershaft has two 12 inch friction pulleys for 3" belts, which should run at 80 and no revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is 69 x 58 inches. Net Weight of machine is 1900 pounds. THE CINCINNA TI MILLING MA CHINE CO. Table Feed, . 20 in. Cross " . 6 in. Vertical " . 17 in. No. \y 2 Universal Milling Machine, FIG. 12. THE CINCINNATI MILLING MACHINE CO No. VA UNIVERSAL. The No. i l 2 Universal Milling Machine closely resembles the No. i Universal. It is provided, however, with back-gearing and the feed gear- box described on page 25. This machine is well adapted for tool-room work where more spindle power and a larger range of spindle speeds is required. The Spindle is bored to receive a Xo. 10 B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole || // diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 2 X / Z // belt. The largest diameter is 10 inches. The Overhanging Arm is iK" diameter and can be turned up out of the way or put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 6 1 /. inches. The Table over all including oil pockets is 35" x 6 l / 2 n '. The work- ing surface is 33" x 6)4 // . There is one T-slot y% ,f wide. The top of the table can be*lowered iy // below the center of the spindle. The Swivel Carriage which forms the housing for the table is graduated in degrees on its circular face. A T-slot is turned in the bottom, near the outer edge, to receive two T-bolts which pass down through the saddle and are used for firmly clamping the swivel carriage to the saddle. The Feed of the table is automatic in either direction through 20". The cross motion in line with the spindle is 6 /7 , and is automatic in either direction. Both of the above feeds are reversed by a lever on the front of the machine, without crossing the feed belt. There are 12 changes of feed which vary from .oo6 // to .150" travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. The Index Centers furnished with this machine will swing io // diameter and take in length 15 inches. The Vise can be swiveled to any angle, where its position is shown by the graduated base. The jaws are 6 // wide, ijV' deep, and will open $%". The Countershaft has two 12 inch friction pulleys for 3" belts, which should run at 90 and 150 revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is 69 x 58 inches. Net Weight is 1980 pounds. 32 THE CINCINNATI MILLING MACHINE CO. Table Feed, . 23 in. Cross " . Q)4 in. Vertical " . 18 >£ in. No* 2 Universal Milling Machine. FIG. 13. THE CINCINNATI MILLING MACHINE CO. 33 No. 2 UNIVERSAL. The No. 2 Universal is adapted for tool-room work and can be placed to good advantage in jobbing shops. It is heavier than the Nos. i and and i ';> Universal and has a larger range throughout. This machine is back-geared. The Spindle is bored to receive a No. io B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole || // diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a i% /f belt. The largest diameter is io inches. The Overhanging Arm is 4" diameter. It can be turned up out of the way or put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 5^ inches. The Table over all including oil pockets is 38" x 8^ // . The work- ing surface is 35" x $>/%". There are two T-slots yi" wide. The top of the table can be lowered i8^ 7/ below the center of the spindle. The Swivel Carriage which forms the housing for the table is graduated in degrees on its circular face. A T-slot is turned in the bottom for one of the T-head clamping bolts. The Saddle has a T-slot turned in its upper face which, in con- nection with the T-slot in the swivel carriage, permits the use of four strong bolts for firmly clamping the swivel carriage and saddle together. The Feed of the table is automatic in either direction through 23". The cross motion in line with the spindle is 6 l / 2 // , and is automatic in either direction. Both of the above feeds are reversed by a lever on the front of the machine, without crossing the feed belt. There are 12 changes of feed which vary from .006 " to . 150" travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch An automatic vertical feed can be fur- nished with this machine to order. The Index Centers swing io // diameter and take in length 17 inches. The Vise can be swiveled to any position, the angle of which is shown by the graduated base. The jaws are 6" wide, 1 r 7 6 // deep, and will open 3K 7/ - The Countershaft has two 12 inch friction pulleys for 3^" belts, which should run at 90 and 150 revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is 82x68 inches. Net Weight is 2125 pounds. THE CINCINNA TI MILLING MA CHINE CO. Table Feed, . 28 in. Cross " . 7^ in. Vertical " . 19 in. No- 3 Universal Milling Machine, FIG. 14. /"///■- CINCINNATI MILLING MACHINE CO. No. 3 UNIVERSAL. The Xo. 3 Universal is much heavier and is more powerful than the smaller sizes. It is intended for a heavier class of tool-room work and is very useful for general manufacturing purposes where a Universal Machine is required. This machine is back-geared. The Spindle is bored to receive a No. n B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole {§" diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 3" belt. The largest diameter is 1 1 % inches. The Overhanging Arm is 4^ 7/ diameter and can be turned up out of the way or put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 6 r T g inches. The Table over all including oil pockets is 46" x ^Yz n ' . The work- ing surface is 43 // x9>£ // . There are 3 T-slots y%" wide. The top of the table can be lowered 19" below the center of the spindle. The Swivel Carriage which forms the housing for the table is graduated in degrees on its circular face. A T-slot is turned in the bottom for one of the T-head clamping bolts. The Saddle has a T-slot turned in its upper face which, in con- nection with the T-slot in the swivel carriage, permits the use of four strong bolts for firmly clamping the swivel carriage and saddle together. The Feed of the table is automatic in either direction through 28". The cross motion in line with the spindle is'j}4 // and is automatic in either direction. Both of the above feeds are reversed by a lever on the front of the machine, without crossing the feed belt. There are 12 changes of feed which vary from .oo6 // to .150" travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. An automatic vertical feed can be furnished with this machine to order. The Index Centers furnished with this machine swing i2 // diameter and take in length 21 inches. The Vise can be sw T iveled to any position, the angle of which is shown by the graduated base. The jaws are 7" wide, i T % // deep, and will open <\%". The Countershaft has two 12-inch friction pulleys for y/ z n belts, which should run at 90 and 150 revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is 98^ // x72 // . Net Weight is 2800 pounds. 36 THE CLXCINXA TI MILLING MA CHLXE CO. GENERAL DIMENSIONS. UNIVERSAL MILLING MACHINES. Net weight Shipping weight about Length of automatic feed to table Cross motion in line with spindle Vertical range Size of table over all Working surface of table Largest diameter of driving pulley Number of steps on driving pullej^ Number of spindle speeds Width of driving belt Number of feed changes Variations in feed to 1 rev. of spindle. . Width of feed belt Center of spindle to overhanging arm. . Diameter of overhanging arm Back-geared No. of vise furnished No. of B. & S. taper hole in spindle Diameter of hole in spindle Speeds of countershaft Size of countershaft pulleys Floor space Dimensions of box for export Index centers swing Index centers take in length Page 28 Page 30 Page 32 Page 34 No. 1. No. iy 2 . No. 3. No 3. 1900 lbs. 1980 lbs. 2100 lbs. 2800 lbs. 2400 lbs. 2500 lbs. 2700 lbs. 3400 lbs. 20" 20" ■ 23" 28" 6" 6" 6%" 7%" 17" 17" isy 2 " 19" 85x6%" 35x6%" 38x8%" 46x9%" 33x6%" 33x6%" 35x8%" 43x9%" 12" 10" 10" n%" 4 4 4 4 8 16 16 16 3" 2%" 2%" 3" 8 12 12 12 .004 to .070 .006 to .150 .006 to .150 ,C06to.l50 IK" i%" i%" 1%" 6K" 6K" 5rs" 6 tV 3K" 3K" 4" 4%" No. Yes. Yes. Yes. 1 Swiv. 1 Swiv. 1 Swiv. 2 Swiv. 10 10 10 11 1 3 T6 13 T6 13 Te- 1 3 16 80 & 150 90 & 150 go & 150 90 & 150 3x12" 3x12" 3%xl2" 3%xl2" 69x58" 69x58" 82x68" 98%x72" 56x37x62 56x37x62 63x46x62 66x50x66 10" 10" 10" 12" 15" 15" 17" 21" THE CINCINNATI MILLING MACHINE CO. 37 PLAIN MILLING MACHINES. The Plain Machines are built the same in size as the Universal Machines of corresponding numbers. They have all the move- ments of Universal Machines, with the exception that the table of a Plain Machine has no swivel movement, which is neces- sary in cutting spirals. It is often thought that the swiveling of the table produces angular work, such as long key-shaped pieces or similar work. This, of course, is a mistaken idea. The Plain Machines are simpler in construction and are built for more severe and heavier duty than the Universal Machines. The table is fitted directly into the saddle which slides on the knee, and is larger on the Plain than on the Universal Machine. All Plain Machines, except No. o, are furnished with strong braces combining the knee and the overhanging arm very rigidly. These can be taken off very quickly when not required, by unscrewing the nut on the outer end of stud and releasing the clamp screw on the bridle which straddles the knee. A number of these machines can be operated at the same time by a workman of limited skill, as the operations are usually very simple on work produced in large quantities. Owing to their simplicity and greater capacity for turning out work, this type of machines is to be preferred for manufac- turing purposes, and is best adapted for the majority of shops. In connection with the universal head and other attachments, every operation, except cutting of spirals, worm wheels or any other work requiring the swivel movement of the table, can be performed on these machines. 38 THE CINCINNA TI MILLING MA CHIXE CO. Table Feed, . 18 in. Cross " . 5^ in. Vertical " . 14 in. No. Plain Milling Machine. FIG. 15. THE i 7.\ "( 7.V.V. / 77 MILLING M. I ( IIIM- ( '( >. 39 No. PLAIN. This machine is well adaped for light rapid milling, such as the manufacture of bicycle parts, electrical fittings and appliances, type- writers, etc. The Spindle is bored to receive a Xo. 9 B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole \\" diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 2^" belt. The largest diameter is 10 inches. The Overhanging Arm is i%" diameter. It can be turned up out of the way, or it can be put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 5^ inches. The Table over all including oil pockets is 32>< // x 8". The working surface is 27^ // x8 // . There are 3 T-slots ~y%" wide. The top of the table can be lowered 14" below the center of the spindle. The Feed of the table is automatic in either direction through i8 // . This feed is reversed by a lever on the front of the machine, without crossing the feed belt. The cross motion in line with the spindle is 5%". There are 8 changes of feed which vary from .005" to ,ioo // travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. The Vise can be swiveled to any position, the angle of which is shown by the graduated base. The jaws are 6" wide, iyV' deep, and will open 3 j£". The Countershaft has one 12-inch friction pulley for a 3" belt which should run at 130 revolutions per minute. The Floor Space necessarv to permit the extreme limits of travel *"x 5 i". Net Weight is 12S0 pounds. THE CINCINNA TI MILLING MA CHINE CO. Table Feed, . 21 in. Cross " . ft in. Vertical " . 19 in. No* 1 Plain Milling Machine. FIG. 16. THE ( INI 'INN. I II MILLING M. I ( 7//A I < \ '. No. 1 PLAIN. The No. i Plain is very convenient in model shops. It is well suited for manufacturing small articles, such as gun parts, sewing machine parts, etc. The Spindle is bored to receive a Xo. 10 B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole -j-f " diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 3" belt. The largest diameter is 12 inches. The Overhanging: Arm is 3^ 7/ diameter. It can be turned up out of the way, or it can be put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 6% inches. The Table over all including oil pockets is 36 // x9 // . The working surface is 30" x a/'. There are 3 T-slots y% /f wide. The top of the table can be lowered 19" below the center of the spindle. The Feed of the table is automatic in either direction through 2\" '. This feed is reversed by a lever on the front of the machine, without crossing the feed belt. The cross motion in line with the spindle is 6". There are 8 changes of feed which vary from .005 " to ioo' 7 travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. The Vise can be swiveled to any position, the angle of which is shown by the graduated base. The jaws are 6'' wide, 1 r 7 g /y deep, and will open ^Yz° . The Countershaft has two 12-inch friction pulleys for 3'' belts, which should run at So and no revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is 76 x 6r inches. Net Weight is 1800 pounds. THE CINCINNA TI MILLIXG MA CHTXE CO. Table Feed, . 24 in. Cross ' ' . 1% in. Vertical " .19 in. No. 2 Plain Milling Machine, FIG. 17. THE CINCINNATI MILLING MACHINE CO. No. 2 PLAIN. The No. 2 Plain is, without doubt, the best machine for machine tool builders. It takes in a great range of work, and in general jobbing shop operations, it has become a very important tool. This machine is back- geared. The Spindle is bored to receive a No. 10 B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole ^f" diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 2S±" belt. The largest diameter is 10 inches. The Overhanging Arm is \" diameter. It can be turned up out of the way or it can be put in from the rear of the machine to receive various attachments. It is provided with an adjustable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 5 T 9 g inches. The Table over all including oil pockets is 4o^ // xio // . The working surface is 34 y%" x io // . There are 3 T-slots ^i // wide. The top of the table can be lowered 19" below the center of the spindle. The Feed of the table is automatic in either direction through 24". This feed is reversed by a lever on the front of the machine, without crossing the feed belt. The cross motion in line with the spindle is 7}4 // . There are 12 changes of feed which vary from .oo6 // to .187" travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. This machine can be furnished with automatic cross and vertical feeds to order. The Vise can be swiveled to any position the angle of which is shown by the graduated base. The jaws are 6" wide, iyV 7 deep, and will open 3J£". The Countershaft has two 12-inch friction pulleys for a 3 }i^ belt, which should run at 90 and 150 revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is S2' / x6S // . Net Weight is 2100 pounds. THE CIXCIXXA TI MILLING MA CHIXE CO. Table Feed, . 32 in. Cross " . 9 in. Vertical " . 20 in. No* 3 Plain Milling Machine, FIG. 18. THE CINCINNATI MILLING MACHINE CO. No. 3 PLAIN. The No. 3 Plain is designed for a heavier class of milling, and is well adapted for machine tool builders, engine and railroad shops, and large jobbing work. This machine is back-geared. The Spindle is bored to receive a No. n B. & S. taper shank on cutter arbors and collets. From this taper bore, a hole }| // diameter is drilled through the remaining length of the spindle. The front end of the spindle is threaded and is provided with a guard-collar. The Driving Cone has four steps for a 3" belt. The largest diameter is 11 1 : inches. The Overhanging Arm is ^% /f diameter. It can be turned up out of the way, or it can be put in from the rear of the machine to receive various attachments It is provided with an adjxistable phosphor bronze bushing to support the cylindrical end of the arbor. The distance from center of spindle to overhanging arm is 6 r 7 ff inches. The Table over all including oil pockets is 5i 7/ x 12" '. The working surface is 45" x 12". There are 3 T-slots Y% n wide. The top of the table can be lowered 20'' below the center of the spindle. The Feed of the table is automatic in either direction through 32". This feed is reversed by a lever on the front of the machine, without crossing the feed belt. The cross motion in line with the spindle is 9". There are 12 changes of feed which van- from .006" to .i&Y' travel of the table to one revolution of the cutter spindle. All feed adjustments are indicated by dials in thousandths of an inch. This machine can be furnished with automatic cross and vertical feeds to order. The Vise is flanged and can be clamped to the table with the jaws parallel to the table slots or at right angles to the table slots. The jaws are 8" wide, 2^ // deep and will open 6 // . The Countershaft has two 12-inch friction pulleys for a 3 j£ /7 belt, which should run at 90 and 150 revolutions per minute. The Floor Space necessary to permit the extreme limits of travel is 9H inches high. Weight, So pounds. THE CINCINNATI MILLING MACHINE CO. VISES. Vise shown in Fig. 28 swivels, has a graduated base and ends of jaws open for better clamping long work in an upright position. The base is provided with tongues which fit T-slot in table. The jaws are made of steel. The No. 1 Swivel Vise is fur- nished with Nos. o, 1 and 2 Plain and Nos. 1,1% and 2 Universal and the No. 2 with No. 3 Univer- sal M i 1 1 i n g Machines. The plain Vise shown in Fig. 29 is flanged for clamping. It may be held parallel or right angular to table as tongues are detachable. The No. 1 may be used with Nos. o, 1 and 2 Plain or Universal Machines. The No. 3 is regularly furnished with the No. 3 Plain Milling Machines. FIG. 21). DIMENSIONS. SWIVEL. PLAIN. Size. Depth of Jaws Width of Jaws 6" 7 Jaws Open. Weight. Size. I 3 Depth Width of Jaws of Jaws Jaws Open. Weight. I 2 its if* 4 l 4" 50 75 i T % 6" 2/s 8" 3'A" 35 90 THE CINCINNATI MILLING MACHINE CO. ARBORS FOR MILLING MACHINES. We carry in >tock Arbors as listed below. The large hexagon nut shown at E, Fig. 30, is used for backing out Arbor, by forcing this nut against the end of spindle. 1-1 ; '- ! — B -w D 1 hf * HnF *d " Af,V GROUND FIG. 30. length B Xo. Diameter A from Shoulder to Nut. Xo. Machine Where Used. Xo. of Taper. 04 V IV Xos. 0, I and 2 Plain and t, 1 'i and 2 Universal. 7 07 4" 9 oS Xo. Plain. 9 09 I" 6" 9 1 w 4" -10 2 w 4" 10 3 I " 4" 10 4 1 A" 4" 10 5 itf" 4" No. 1, r *-,' and 2 Universal 10 6 w 6" 10 - I " 6" and 10 ^v 6" 10 9 iX" 6" Xos. [ and 2 Plain. 10 10 8" 10 11 I // 8" 10 12 ijV 8'' 10 15 *X" s" 10 15 16 1 " iX" 8" 8" io // 10" Xo. 3 Universal and Xo. 3 Plain. 11 11 11 11 6o THE CINCINNA 77 MILLIXG MA CHIXE CO. A NEW MILLING MACHINE DOG. FIG. 31. Often taper work is done on a milling machine between centers, and an ordinary dog with a bent taper tail is used for carrying the article to be milled. Referring to Fig. i, it will be noticed that the action which takes place by revolving the work is a continuous gaining and losing one. This is due to the fact that the bent tail continuously changes its position at the point of driving. It can readily be seen that it twists right and left, and at the same time slides forward and back as the dog changes from the vertical to horizontal position in turning over. Now if the set screw which holds the tail to the dog carrier is not released for every partial revolution, the tendency is to either spring or bend light work, or it will throw an enormous strain between centers on heavy work, so that it is almost impossible to revolve it, causing uneven divisions. Figs. 2 and 3 represent a milling machine dog in which the above defects are overcome. The tail of the same is turned cylindrical, and is offset, so that the center line through the cylindrical part is in line with the end of the work when the dog is set flush. In addition to the dog there is an adjustable clamp attached THE CINCINNATI MILLING MACHINE CO. to the regular dog driver, which firmly holds any size dog and at the same time admits the tail to swivel either way or slide forward and backward. With a dot; and clamp of this design, taper or straight work may be revolved between centers and held firmly in any position without any strain whatever. The same arrangement can be used on lathe work, and it is especially advantageous for thread cutting, for two reasons. First, where taper threads are cut between centers with the old style dog, the action of losing and gaining on the thread takes place the same as in the milling machine work, and produces what is called a drunken thread ; by using the improved dog this trouble is entirely avoided. Second, there is no back lash in reversing the lathe, and a dog of this pattern is always on time. All sizes from )\" to 2> 2 /// are made and furnished with a well- finished tool steel screw (threaded in the lathe) with a tempered point. Sizes made are #", y % " ', y 2 " , #", %", i", i%" , \)/ 2 " , 2" and 2^". THE CINCINNA TI MILLING MA CHINE CO. FIG. 33. FIG. 35. THE LY.VCY.Y-Y.-J 77 MILLING MACHINE CO. CUTTERS. Milling Cutters may be classified in four distinct types. The first and probably the most common form is known as the axial. Fig. 32, in which the surface cut is parallel to the axis of the cutter. This cutter has teeth on its periphery only ; these may be straight or spiral teeth. Cutters of this character, made in appropriate widths, are used very much for milling broad flat surfaces, and for cutting key- ways in shafts. For deep cuts, or for slitting metal, they are made of large diameter and thin. These are called metal slitting saws and are ground hollow on the sides for clearance. The second class of cutters is known as the radial, Fig. 33, in which the surface cut is perpendicular to the axis of the cutter. These cutters are called radial because their teeth are used in a plane parallel to the radii of the cutter. End mills, face mills, butt cutters, etc., are all tools in this class. The third class of cutters is the angular, Fig. 34, in which the surface cut is neither parallel nor perpendicular to the axis of the cutter, but is at some angle with this axis. Frequently, cutters are made with two different angular cutting edges, in which case the angle is marked on each side. The fourth class of cutters is the form cutter, as shown in Fig. 35. The cutting edge in this class is of an irregular out- line. When properly backed off, these cutters can be ground 64 THE CINCINNA Tf MILLING MA CHIXE CO. and retain their original form. Gear cutters, tools for grooving taps, etc., are all classed as form cutters. Fig. 36 shows an inexpensive method of attaching the tool- steel cutter, A, to the taper shank, B, which ma}- be made of a cheaper grade of steel. A rod can be screwed into the tapped hole C from the back end of the spindle to hold the taper shank tight in the spindle. The three following pages illustrate a number of cutters which are used on milling machines. In most cases, it is advisable to use a cutter of small diameter rather than of large diameter. Cutters from 1% to 2 inches in diameter are the most economical for general milling:. THE CINCINNATI MILLING MACHINE CO. GANG OF MILLING CUTTERS. FIG. 36. THE CINCINNA TI MILLING MACHINE CO. GENERAL FLAT SURFACE MILLING. FOR KEY-SEATS. SLOTS, AND STRADDLE MILLING WHEN USED IN PAIRS. FOR SAWING AND SLITTING. RIGHT-HAND CUTTER. FOR RATCHET TEETH, TEETH IN MILLING CUTTERS. RIGHT-HAND CUTTER. FOR CUTTING TEETH IN SPIRAL MILLING CUTTERS. HOW TO ADJUST CUTTER TO WORK FOR CUTTING SPIRALS THE C1XCIS \AT1 Mil l.l\i, .!/./( lll\ I C'< CONCAVE AND CONVEX CUTTERS FOR MILLING HALF CIRCLES. FORMED MIFFING CUTTER FOR MILLING PARTS OF MACHINERY. FOR TAPS AND REAMERS. FOR TEETH IN GEAR- WHEELS. FOR GROOVING STRAIGHT-LIPPED TWIST-DRILLS. RIGHT-HAND CUTTER. T-SLOT CUTTER. FOR END-MILLING, DIE-SINKING. AND MILLING SLOTS. 68 THE CINCINNATI- MILLING MACHINE CO. RACK CUTTING ATTACHMENT AND VISE. (See Page 52). EXAMPLES OF MILLING THE CINCINNATI MILLING MACHINE CO. LH ^s |5jl MS By THE Cf.VC/.V.y \TI MILUXG MACHIXl ( EXPLANATION OF CUTS ON OPPOSITE PAGE. Figure i. Illustrates milling hexagon nuts or heads of bolts with a single cutter. Fig. 2. How a number of nuts, strung on a mandrel, may be milled at the same time with two cutters. Fig. 3. How to mill a lot of caps, accurately finishing the sides and bottom at the same time. Fig. 4. How to mill a T slot having the groove milled to proper depth. Fig. 5. How to mill a V slot. Fig. 6. How to mill the guides of a housing. This can be done with a cutter the width of guide, or with a saw about J 4 -inch thick, finishing one side and then the other. A small cutter should then be applied to finish inside bearings. The housing requires but one chucking. Fig. 7. How to turn out a hole with a boring bar arbor. Various work can be drilled and bored out to advantage in this way, by either bolting the work on the table, holding it in a vise or between centers. Fig. 8. How to mill a key seat. This may be done holding the shaft in a vise or between centers. Fig. 9. How to mill a taper reamer with center bar in tail stock elevated. Fig. 10. How to cut a number of gear wheels when strung on a mandrel. Fig. 11. How to mill a tap. Fig. 12. How to hob a worm wheel after the teeth are cut. This operation gives the teeth the proper shape, so that the shafts will work at right angles to each other. THE CINCINNA TI MILLING MA CHINE CO. Mil 23 (r a 1 i THE CINCINNATI MILLING MACHINE CO. EXPLANATION OF CUTS ON OPPOSITE PAGE. Fig. 13. How to cut off pieces of metal. Fig. 14. How to mill a thread chasing tool. The milling cutter is to be V shaped and 60 degrees. Mill one side first, and then the other, without re-chucking. Fig. 15. How to mill an angle, finishing sides and bottoms at the same time. Fig. 16. How to mill a slot with a small cutter. Fig. 17. How to mill a fork true with its round shank. One end is held in a universal chuck, which is screwed on the spindle of the indexing center, and the other held in a steady rest. How to cut a rack. How to mill boxes perfectly true with the hole. How to mill an angular cutter. How to index dial plates. In this case the tool does not revolve. Fig. 22. How to mill a cam. Fig. 23. How to mill a friezing bit for wood work. First, the sections are milled out with a square faced cutter, and then the cutting edges are milled by placing a right and left angular cutter on the milling arbor. These bits can be milled complete before removing them from the mandrel. Fig. 24. How to cut off round or square stock, 03^ placing the universal chuck on the main spindle, and using the over- hanging arm for a length gauge. Fig. 18. Fig. 19 Fig. 20, Fisr. 21 THE CINCINNA TI MILLIXG MA CHIXE CO. FIG. 37. THE CINCINNATI MILLING MACHINE CO. EXAMPLES OF MILLING. Fig. 37 shows how the two cutting edges of the angular milling cutter A, may be cut without removing the work from the spindle. In the position shown in full lines, the dividing head spindle is set below the horizontal 23^ degrees, which allows a horizontal instead of a vertical cut to be taken. A vertical cut would be necessary if the spindle could not be deflected as shown. The dotted lines indicate the position necessary for milling the end teeth. In setting the dividing head spindle from one angle to another, the spindle is slightly revolved on its axis due to the action of the worm on the worm wheel. Therefore, before cutting the end teeth, revolve the dividing head spindle slightly by moving the index pin one or more holes forward or back- ward, as the case may require. 76 THE CINCINNA TI MILLING MA CHINE CO FIG. 38. THE CTNCINNA TI Mil. I. IXC, MACHINE CO. 77 EXAMPLES OF MILLING. Fig. 38 shows the manner of cutting teeth in a Cutting Double- double angular milling cutter A, without reversing the A ngie angular cutter on the main spindle or taking the work C u tt '" r g off the mandrel. The angular cutter, on the main spindle, runs only in the right hand direction. The double angular cutter blank A, on the work spindle is elevated to the required angle on the right side of the head, in order that the cut may be of a sweeping nature and to prevent the cutter from gouging into the work. To cut the teeth on the other angle of the cutter, the dividing head spindle is swiveled 30 degrees below 7 the horizontal line. This completes all the operations without removing either the work A or the cutter. These operations could be performed with the work on the left side instead of on the right side of the dividing head, and without removing the w r ork or changing the cutter ; but the direction of the cut would have a tendency to drag the work deeper into the cutter and spoil it. Similar work can be done in the same manner by setting the dividing head spindle to the required angle to the right and left of its vertical position. It may be convenient in such a case to use the automatic vertical feed, wdiich should always be in a direction to allow the cutter to push the work aw r ay from it. 78 THE CINCINNA TI MILLING MA CHIXE CO. EXAMPLES OF MILLING. at Fig. 39 shows the use of the adjustable center bar in a lowered position for supporting the end of the cutter A, and similar work. This affords the advantage of a free passage of the cutter over the tail-stock. THE CINCINNATI MILLING MACHINE CO. EXAMPLES OF MILLING. The facility with which the table and its swiveling carriage can be turned to any degree of angularity with respect to the cutter spindle, offers some important advantages. One example is illustrated in Figs. 40, 41 and 42, which shows the facility with which this job has its opposite sides milled parallel. These illustrations also show the manner of milling the three T-slots in the work without re-chucking it. The piece is clamped with the finished surface A, on the table K. In Fig. 40, the table K is shown in its ordinary position. In this position, one cut across the work with the face mill, will finish the surface B. Then the swiveling carriage J, and the table K, with the work can be turned through 180 degrees, or half way around, as shown in Fig. 41. in which position the face C is milled. The two faces B and C, will become true and perfectly parallel to each other and perpendicular to the base surface A. Turning the table half way around does not in any way interfere with the automatic operation of the feed and the hand lever. After milling the faces B and C, the three T-slots can be milled parallel and in their proper location without re-chucking the work. In Fig. 42, the operations of the end mill F and So THE CINCINNATI MILLING MACHINE CO. the T-slot cutter G are shown. Slots of suitable depth and proper width are first milled in the face C, with the cutter F in either one or two cuts, according to the accuracy required. A similar slot is cut in face B, after the table is revolved. Then the head of the T-slot in the side B, is milled with the cutter G, after which the table is revolved and the T-slots are finished in the face C, with the same cutter G. It will be observed that the table has been swiveled three times to complete the eight operations on the two sides without re-chucking the work. On such work where the chucking is complicated, this feature is of a decided advantage. THE CINCINNATI MILLING MACHINE CO. SI E=0 FIG. 40. R H 3 0=3 II p ^ H rji 1.0 2,0 3,0 4,0 S.0 6,0 7,0 8,0 9,0 l.-illll'lllMlliillllNlllllllllllllllllllHIlIll r^ \^ FIG. 41. i FIG. 42. THE CINCINNA TI MILLING MA CHINE CO. ~~£7eT B nti Cut FIG. 43. FIG. 44. THE I IN( 'INN. I II MILLING M. 1 1 HINE c O. S3 CUTTING BEVEL AND MITER WHEELS. Iii cutting bevel and miter gear wheels on a Universal Milling Machine, the swivel housing is set at zero and is not swiveled for any operation. Cutting Operations. First adjust the work so that the center line A B, Fig. 43, of the wheel to be cut coincides with the center line of cutter, and cut two or three teeth of the proper depth. For the succeeding operations which are explained in the example given below, no fixed rule can be given as wheels of different diameters, faces, and pitches require different settings. The following miter wheel has been taken as an example. \2 Pitch. 32 Teeth. ff" Pitch Diameter. 2 rf" Outside Diameter. T V" Face. The index chart which is furnished with every dividing head shows that for cutting 32 teeth, the 28 hole index circle should be used, and to advance one revolution and 7 holes for every succeeding tooth. After the first two or three teeth have been cut, proceed to take second cut, Fig. 43, after slightly revolving the miter wheel by advancing the index pointer five holes, and also shifting the wheel twenty thousandths out of center by moving the cross slide this amount out from the column. After this cut has been taken, proceed to third cut as follows : turn the index pointer back ten holes and move cross slide back towards column forty thousandths. These operations completed will produce a tooth of the proper form, and the remaining teeth can be cut by simply using the second and third operations. These figures are correct only for the above wheel and will vary with each wheel. The cutter, if properly made, will leave the small end of the THE CINCINNATI MILLING MACHINE CO. tooth of the proper thickness, and care must be taken in the second and third operations that the cutter does not make the space already cut wider on the small end of the tooth. If wheels must be duplicated, it is advisable to note figures for future reference. For the proper thickness of the tooth on the large pitch diameter, see table, page 122. It is best to set the pointers at zero on the cross slide and vertical slide after the machine has been adjusted for these operations. The depth of the teeth in miter and bevel wheels should be measured at the large end of the tooth and is the same as the depth of teeth in spur wheels, see table, page 122. Care must be taken that the back lash in the index pointer and the cross slide screw is taken up. In ordering cutters for miter and bevel gears, state pitch, number of teeth, and the length of the face of tooth. For a pair of bevel gears, two cutters of different shapes are required on account of the difference in the number of teeth in the large and small gears. Fig. 44 shows the direction of motion of the cutter and the table. A paper was read at a meeting of the American Society of Mechanical Engineers, held in December 1896, on cutting bevel and miter gears. This paper was prepared by Forrest R. Jones and Arthur L. God- dard, and was published later in the Ameri- can Machinist of January 21, 1897. Their experimental investigations were made to find a graphical method for determining those operations which must otherwise be fixed by trial. THE ( TNt INNA Tl MILLING M. I ( 7//.\ E i \ >. 85 WORM WHEELS. In cutting worm wheels, the work is fed up vertically into the cutter to the proper depth. It is also necessary to swivel the table. Before swiveling the table, the cutter is set central with the work. The angle to which the table must be set depends upon the pitch and the diameter of the worm. Fig. 46 shows a graphical method for finding this angle. For example, take a worm whose pitch is 7 threads per inch and whose outside diameter is one inch, see Fig. 45. Lay off the distance A B, Fig. 46, equal to T of an inch. The dis- - tance A C at right angles to A B is the result obtained by multiplying the pitch diameter of worm, .902 by 3.14. Connect points C and B with a straight line, and the angle A C B shows the number of degrees through which the table must be swiveled, which is 3 degrees in this example. 3 1 .000 inch = outside diameter. 5 ln -098 " = depth of tooth. FIG. 45. \° is III,/ .902 3.14 = diameter of pitch circle. ~v3" FIG. 46. 2.83228 inch — length A C of pitch circle. For right thread worm wheels, swivel the table to the right, for left thread worm wheels, swivel the table to the left, facing either end of fig. 47. milling machine table. The angle of the thread of the worm should be 29 , as shown in Fig. 47. S6 THE CINCINNA TI MILLING MA CHINE CO. To find the diameter of a worm wheel at the throat, Fig. 48, when the number of teeth in the worm wheel and the number of threads per inch on the worm are given : Add 2 to the number of teeth in the worm wheel and multiply by .3184 and divide this result by the number of threads per inch on the worm, and the result will be the diameter of the worm wheel at the throat. Example : Worm wheel has 40 teeth. Worm has 6 threads per inch. 40 + 2 = 42 42 X .3184 = 133728 13.3728 = 2.2288 inches = diameter at the throat a of the worm wheel. J)lJ^f*tTaf b/oR M . 3oTM ofTMf&l To find the number of teeth in a worm wheel, when the diameter at the throat and the pitch of worm are given. Mul- tiply the diameter at throat by the num- ber of threads per inch on the worm, and then multiply this product by 3. 141 ; then substract 2 and the result will give the number of teeth. Example : Diameter at throat = 2.2288 inches. Worm has 6 threads per inch. 2.23 X 6-= 13.38 I3-38 X 3.14 = 42.026 42.06 — 2 = 40 = No. of teeth. FIG. 48. TABEE SHOWING DEPTH OF TEETH FOR WORM WHEELS. Threads Per Inch on Worm. I 2 2/2 Depth. Thi-eads Per Inch on Worm. Depth. Threads Per Inch on Worm. Depth. Threads Per Inch on Worm O.6866 0-4577 0.3433 O.2746 3 4 5 6 O.2288 O.1716 O.I373 0.1 144 7 8 9 10 O.0980 O.0858 1 O.0762 O.0686 II 12 Depth. O.0623 O.0572 THE CINCINNATI MILLING MACHINE CO. B7 SPIRAL GEAR CUTTING. Some of the following articles on normal pitch, addendum, etc., relating to spiral gears, have been taken from INIr. George B. Grant's Hand-Book on Gears, with his kind permission. Normal Pitch. — " The real pitch of the spiral gear is measured on a section that is normal to its axis, and, as in the case of the spur gear, it is found by dividing the number of teeth by the pitch diameter ; but the shape of the tooth must be regulated by the normal pitch, or pitch of its normal section. The normal pitch is found by dividing the real pitch by the cosine of the angle made by the tooth spiral with the axis of the gear. Thus, if the real pitch is 5.65 and the angle of the spiral is 45 , the normal pitch is 5.65 divided by .707 or 8." The normal pitch can also be found graphically by the following method. Lay off A B, Fig. 49, to any con- venient scale equal to the real pitch. Draw another line A C, making the angle at A equal to the angle of the spiral. Draw a line perpendicular to A B from B and let it intersect A C. The length of this oblique line A C measured to the same scale as A B will be the normal pitch. In this example Real pitch A B = 5.65 Angle of spiral = 45 ° Normal pitch A C = 8 Addendum. — ' ' The addendum of the spiral gear should not be deter- mined by its real pitch, but by its normal pitch, for it is then usually possible to mill the tooth with a milling cutter that is made for a standard spur gear. A gear of 11.3 normal pitch and 45 ° angle should have an addendum of yy-j = .089." ' ' If the addendum is determined by the true pitch when the angle is considerable, the tooth will be long and thin." Shaping the Tool. — "When the spiral gear is cut in a milling machine or turned in a lathe, it is necessary to give the tool the shape of the normal section to be cut, and this is most readily accomplished by shaping it for the spur gear that most nearly coincides with that normal section. "The number of teeth in the gear that is osculatory to the normal spiral, and therefore most nearly coincides with it, is found by dividing ss THE CINCINNA IT MILLING MA CHINE CO. the actual number of teeth in the gear by the third power of the cosine of the spiral angle. "For example, if we are to cut a gear \" diameter, 6 pitch, and 24 teeth, at a spiral angle of 45 , the cutter should be shaped to cut a spur- gear of .yff 3 = ff = 69 teeth of T £ T = 8.5 pitch. " If the gear has 28 teeth of 4 pitch, and an angle of io°, the equiv- alent spur-gear has 29 teeth of 4.08 pitch, as the gear varies but little from a spur-gear. If the gear is of 5 pitch, and 15 teeth, with an angle of 8o°, the equivalent spur-gear has 2830 teeth of 28.7 teeth, and in general, when the gear has a great angle it is a worm, the section is practically that of a rack. Care must be taken, when the gear is a screw, and is turned in the lathe, that the tool should be set with its cutting edge normal to the thread of the screw, if it is shaped by the above rule. If the tool is set in the axial section of the screw, and it generally is, it should be shaped to the axial section of the worm and have the axial pitch and addendum. But when the lead of the thread of the screw is small compared with its diameter, the difference between the normal and axial sections is not noticeable." When spiral gears are to be used, there are several things to be con- sidered in their design. Sometimes a certain distance must be main- tained between the centers of the two gears. In some instances, it is not necessary to put the centers of the two wheels any certain distance apart, because there is ample room for the gears to work in, and in such a case, a spur-gear cutter on hand may be used, and the problem is to determine what spiral gears can be cut with a given spur-gear cutter. The following example shows, when the distance between the centers of the spiral gears is given, see Fig. 50, how to find 1. The Real Pitch. 2. The Normal Pitch or Pitch of Cutter. 3. Number of Teeth in Spur-Gear which is oscu- latory to the spiral. 4. Outside Diameter of Gear. 5. Depth of Cut. 6. Ratio of Change Gears on Dividing Head and Lead Screw. Distance between centers = 3 T V' Therefore pitch diameter = 3 I 3 g // Circumference at pitch line = 3.1S75 X 3- I 4 I 6 = 10.013 or IO - Assume 18 as the number of teeth. 18 1. _ FIG. 50. Then the real pitch 5-65 pitch diameter THE CINCINNATI Ml 1.1. ISC MACHINE CO. The Norn a i. Pitch = / v -V = 5 — =8 pilch. .-. S pitch = pitch of Cos. 4s .707 r r ^ cutter to cut gear. NUMBER OF TEETH in spur gear which is oscillatory to the spiral U ._ 5S+-5I teeth. Outside Diameter = pitch diameter - _ = * T 3 , -i_ \ [ = 7 " Normal Pitch Depth of Cut = 2I 5/ — = .267 Normal Pitch Ratio of Change Gears on dividing head and lead screw. The lead of a spiral of 45 ° always equals the circumference of the pitch diameter. In this case, the circumference of the pitch diameter is 10 inches. Therefore, the lead of the spiral is 10 inches. Gears of the same size on both lead screw and worm shaft will cut this spiral. In order that the gears may have a possible number of teeth, it is necessary that the lead shall be a number which will work in readily. For example, if the lead is 9. 6132", then use 9.6 inches lead and change the pitch diameter. The ratio of the gears in this case is 1* or ;. 6 9 6 4 S 24 6 V 4 TOO. 1 5 2 5 5X5. Multiplying both numerator and denominator of a fraction by the same number does not change its value, therefore the product | X ! is not changed in value when expressed £§ X If after multiplying both, terms of I by 12 and both terms of f by 8. Again, if the lead is 7.962 use 8 for the lead and the ratio of gear on head to gear on lead screw would be j%. It sometimes occurs that it is not necessary to maintain a certain distance between the centers of spiral gears. In that case, spur gear cutters on hand may cut the spiral gear. With any given spur gear cutter, it is possible to cut some spiral gear. The following example may be used as a guide for finding the spiral gear which can be cut. In this example, a cutter 10 pitch Xo. 3, cutting from 35 to 54 teeth in a spur gear will be used. Multiply the pitch 10 by the cosine of the spiral angle .707 to find the real pitch = 10 X -JOJ = 7.07. Xo. of teeth in spiral gear = Xo. of teeth which cutter will cut in spur gear multiplied by the cube of the cosine of the spiral angle. Xo. of teeth in spiral gear = 35 X .707 3 = 35 X -3533 X = 12. Xo. of teeth in spiral gear = 54 X .707 3 — 54 X -3533 + = J 9- This cutter will cut from 12 to 19 teeth in a spiral gear with a real pitch of 7.07. Suppose that 15 teeth are cut in the gears, then ^- == 2. 121 = diam- eter at pitch circle. go THE CINCINNA TI MILLING MA CHINE CO. Total depth of tooth = tlii = .2157". Outside diameter of wheel = 2. 121 + fo 2.321. 2.12 X 3-14 = 6.656 — lead of required spiral, use 6.6" lead then the ratio is ^§ or T 6 ¥ V f 55 teeth Given cutter 20 pitch. No. 2. < to ( 134 teeth. 20 X .707 = 14- 14 = real pitch. No. of teeth in sp. gear= 55 X -353 — = J 9- No. of teeth in sp. gear = 134 X -3533 = 47- ■ x ±\± = 2.828 = diameter of pitch circle. Depth of cut = ^4|^ = .1078. Outside diameter = 2.828 .-f -.£, =2.928. 2.828 X 3- 14 = 8.879 — = *ead of spiral, then the ratio is -|=| = ^ = i£. THE CINCINNATI MILLING MACHINE CO. CHANGE GEARS FOR CUTTING SPIRALS. The worm wheel in the universal indexing and dividing head has 40 teeth ; therefore, 40 revolutions of the worm are required to make one revolution of the dividing head spindle. The table lead screw has 4 threads per inch ; therefore, 4 revolutions of the screw are required to move the table forward one inch. If gears of equal size were put on the lead screw and the worm shaft, to produce one revolution of the dividing head spindle, the worm shaft must be revolved 40 times. The gears being of the same size, the lead screw would also revolve 40 times and the table would travel 10 inches and these gears would give a lead of 10 inches. To determine gears which will give a spiral of any other lead, multiply the required lead in inches by 4 ; this number will be the re- quired number of revolutions of the lead screw for every 40 revolutions of the worm, necessary for one revolution of the dividing head spindle. «, , . number of teeth in driven gears .. 4 times the lead The ratio r- rz — nr^ — ^—- must equal number 01 teeth in driving gears ^ 40 For example, to cut a spiral with a lead of 10 }4 inches, multiply io x 2 by 4=42. The lead screw must, therefore, make 42 turns while the worm makes 40 turns. To accomplish this with gearing, the number of teeth in driven gears . . 9 ,-, . ". ... ratio 7- j— — -T-. — -r-T—. must equal t§. This ratio £# can number of teeth in driving gears n * u 4 " be divided into two fractions without changing its value, that is J§ = - . Multiplying both numerator and denominator of these fractions by some number does not change their value, that is \ X f = % I a "d - :-lo- The ratio \% is not changed in value if it is written in this form \ % X If- Gears with these numbers of teeth are found among the set of change gears furnished with each universal machine. The gears having 56 and 4S teeth are the driven gears and ma}- be arranged to have either driven from the screw, in which case, the other must be put on the worm shaft. The gears having 64 and 40 teeth are the driving gears, and either gear may be put on the lead screw, in which case the other must drive the gear on the worm shaft. 92 THE CINCINNA TI MILLING MACHINE CO. From these examples, the following rules may be deduced : Multiply the required lead by 4. The number thus obtained will be the numerator and 40 will be the denominator of a fraction which .„ ... ,. , ,, , . the number of teeth in driven gears will give the ratio required, that is -r t- 7— — ^—-. — -5-5-3 5 & ^ ' the number of teeth in driving gears. Resolve this fraction into two fractions. Multiply the numerator and denominator of each fraction by some number (not necessarily the same number for each fraction) so as to give numbers corresponding to the number of teeth in the change gears furnished with the machine. The numbers in the numerators will represent the number of teeth in the driven gears, and the numbers in the denominators will represent the number of teeth in the driving gears. Instead of using compound gearing, it is frequently much simpler to drive from the table screw to the worm shaft, as shown in Fig. 51. For example, to cut a spiral with a lead of 12 inches, the ratio of the number of teeth in driven gear to the number of teeth in driving gear is |f. If the 48 gear is fastened on the worm shaft, and the 40 gear is fastened on the table screw, the desired spiral of 12 inches lead will be produced. Always withdraw the index plate stop before starting to cut spirals, because the index plate must be free to revolve with the index pointer. The dividing head should be placed in that slot of the table which is directlv over the lead screw. THE CINCINNATI MILLING MACHINE CO. 93 FIG. 51. 94 THE CINCIKNA TI MILLING MACHINE CO. Ji &tr ; - G, 52, ,*£?***> THE CINCINNATI MILLING MACHINE CO. SPECIAL JIG MILLING. When large quantities of pieces are to be milled, the cost of milling can be greatly reduced by using some special jig or device for either holding the work securely, or indexing the work rapidly. Very often, it is necessary to provide for both rapid and accurate indexing, and for firm and convenient chucking. The saving in time will more than pay for the cost of such jigs and devices. A number of illustrations are given showing some of the methods in practical use on milling machines. Two vises, Fig. 52, can be clamped side by side and used to good advantage. After the piece in the vise on the left is milled, the piece in the second vise can be brought up to the cutter, and while the second piece is being milled, another piece can be clamped in the first vise. In this manner, a con- siderable saving in time is effected. Pieces to be milled in this wa3^ are shown on left end of table. A similar use of two vises is shown in Fig. 53. The vertical milling attachment is used here, however. While the cut is being taken on one piece, another can be clamped in the second vise. 9 6 THE CINCINNA TI MILLING MA CHINE CO. FlC.54- THE c INC 'INN. I 77 MILLING M. 1 1 HINE CO. Fig. 54 shows a device for chucking and indexing bevel gears. The gear is shown at A. Two index plates B and C. are used for the first and second cuts. The proper adjustment of the cross slide must be made for these cuts. The index pin D, can be adjusted up and down to work in either plate. The hub of the gear is let down into the jig, and in this way, the gear is well supported against the strain of the cut. Xote. — These gears are 12 pitch and are fed to the cutter at the rate of .057 inches per turn of the spindle. It is difficult to cut accurately on a gear cutter the pinion of a back gear when both gears are cast in one piece, because the pinion is at the outer end of the arbor and not well supported. Fig- 55 shows a method of cutting the pinion of a back gear on a milling machine. The spindle of the dividing head stock is made long enough to extend through the back gear for holding it. Suitable collars are provided at B to accommodate different lengths of back gears. The pinion A is thus brought very close to the dividing head stock and accurate work can be done at a high rate of feed. In this manner, a 6 pitch pinion can be cut at the rate of .076 inches for one turn of the cutter spindle. THE CINCINNATI MILLING MACHINE CO. Fig. 56, THE CINCINNATI MILLING MACHINE CO. Rack-cutting is illustrated in Fig. 56. Three cutters are used on the cutter spindle. An indexing attachment is fastened to the table. To move the table to the right for new cuts, the pin B is withdrawn, the large gear wheel is turned by the crank C until the pin B again enters the slot. When the pin strikes the end of the slot, the table will have been moved to the right, the required amount for a series of three teeth by one turn of the crank C. A devise for milling the two sides of a form for bullet molding is shown in Fig. 57. The two sides B, B, of the form are held by screws to the jaws A and F. By revolving the intermediate gear E, the gears which are fastened on shafts C and D are revolved, bringing both jaws up to the cutter at the same time. On the shafts C and D are turned both right and left hand threads which mesh in nuts under the jaws A and F. ioo THE CINCINNA TI MILLING MA CHIXE CO. FlG. 59 THE CINCINNATI MILLING MACHINE CO. A number of shafts can be splined at one time by clamping them as shown in Fig. 58. A vise Y, large enough to take in the four shafts, s, s, s, s, is clamped to the milling machine table. The four cutters are placed on the arbor at the proper distances from each other. The overhanging arm braces, B, B, combines the outer support of arbor with the knee. The back box, B, Fig. 59, for the milling machine spindle is made of phosphor bronze. It has a groove milled in the out- side for an oil wick and through this same groove is cut a narrow saw slot to allow the oil to pass through. The box is split through its entire length on the side opposite the groove. These three operations are performed with one chucking of the work and without removing the cutters from the arbor. The box B is put on a spindle K which revolves in the head A, and is clamped firmly by the washer D and the bolt C C. The index plug F is used to bring the box to its proper position for a cut. The thumb screw G is used for clamping the spindle E firmly in the head A. The table must be moved in or out to bring the cutter to be used central with the work. THE CINCINNA TI MILLING MA CHINE CO. Fig. 60. Fig, 6i, THE CINCINNATI MILLING MACHINE CO. The angles A, A, A, Fig. 60, are used to hold the milling machine tables while cutting the T slots. The angles are made large enough to take in all the different widths of tables. The lower part of each angle has a 45 degree V planed in it, to correspond with the V's on the tables. The gibs, G, G, G, which are made to take in different widths of tables, are used to clamp the table firmly to the angles. A tedious and lengthy operation is the planing of taper gibs. To overcome a very unsatisfactory process on the planer, the jig shown in Fig. 61 was devised for milling taper gibs. This jig is simply an angle A with a recess B, B, planed in it to hold the gib at the proper angle. Two clamping screws D, D, are used to clamp the gib on the angle. THE CINCINNA TI MILLING MA CHINE CO. ERECTION AND CARE OF THE MACHINE. Position of Counter^ shaft Cone Pulley. Shifter. Driving Belts. Diameter of Pulleys. The machine should be set level and upon a founda- tion as solid as can be secured. The countershaft cone pulley should be directly over the milling machine driving cone, so that the driving belt does not strike the cylindrical brace between the upright supports for the overhanging arm. The handle of the shifter should be to the left of the machine and near the middle of the driving cone. Both driving belts should run in the same direction. To find the diameter of pulley to be used on the main shaft, multiply the diameter in inches of pulley on countershaft by the specified number of revolutions per minute of the countershaft, and divide this product by the number of revolutions per minute of the main shaft ; the result will be the diameter in inches of the pulley required on the main shaft. For example, the pulleys on the countershaft of the No. i Universal are 12 inches diameter and run at 80 and 150 revolutions per minute ; a certain main shaft runs at 140 revolutions per minute. Then^^° = 6-« I40 inches, or about 7 inches is the diameter of pulley to be used on the main shaft to obtain 80 revolutions per minute of the countershaft. The other countershaft pulley runs at 150 revolutions per minute, and hence the diameter of the pulley required on the main shaft is 12 X 150 140 i2f inches or about 13 inches. A blue print similar to Fig. 62, showing the arrange- ment of the countershaft is sent with each machine. /•///■■ CINCINNATI MILLING MACHINE CO, 105 FIG. 62. 106 THE CINCINNA TI MILLING MA CHINE CO. On both disks of the countershaft clutch pulleys, the word "oil" is cast in raised letters. Xear these letters, an oil hole is drilled to permit the oiling of the pulleys while running. The durability, accuracy, and efficiency of a fine machine, depends to a great extent upon proper lubri- cation. Therefore, the operator should become ac- quainted with all oiling places and be careful not to neglect those plainly in sight. The interior working parts and the table bearings are oiled through holes in the table marked ' ' oil ' ' when the table is run to the right its full length. We advise the use of a good grade of mineral oil, as animal oils contain more or less gummy substances, which in due time clog up in the oil channels. The ends of the arbor collars should be kept per- fectly clean. As all machines are carefully adjusted before ship- ment, no adjustment will be necessary for some time. When the spindle is adjusted, it should turn readily by hand. To obtain the best results when adjustment becomes necessary, the construction and principles of the machine should be carefully studied and understood before re- moving or taking up the wear of any part of the machine. It is necessary that the bushing in the overhanging arm should be closely adjusted to the outer end of the arbor, and that the arbor should be of as large diameter and as short as possible. The cutter should be as close to the nose of the spindle as the work will permit. THE CINCINNATI MILLING MACHINE CO. DESIGN, FEATURES, WORKMANSHIP. The true principles of design were inquired into when the construction of these machines was undertaken. The proper selection of material and a correct disposal of it to the best advantage, the relative efficiencies of the different kinds of gear transmission especially for the operation of the feed mechanism, were made subjects of separate and extensive inquiry, which required much tedious and costly experimentation. The power required for driving a machine is frequently an important item of expense, especially ,c,enc y- where a shop rents power or uses an electric motor to drive the machine. Power is sometimes limited, and must be used economically. This fact makes it important that the machines used in such shops should be designed with a careful consideration of their, power efficiencies in each particular. The feed mechanism has always been regarded, even Feed. with the fine-feed practice of the past, too weak and ineffi- cient. Since such surprising advantages have been shown with coarser feeds, the former feed mechanisms have proven entirety inadequate. The great variety of work now done on milling machines, requiring both coarse and fine feeds, demands a wide range of feed. Recognizing this fact, the back-geared machines, with their greater number of spindle -11 1 i--i ■ ■, r- ,- -. r- Number of speeds, have been designed to give 12 changes of feed for changes each spindle speed, and those machines without back gears of Feed - have 8 changes of feed for each spindle speed. The table feed is given in thousandths of an inch travel for each turn of the spindle. The Nos. o and 1 Plain have a range from .005" to .100" ; all other Plain machines have a range from .oo6 // to .187". The No. 1 Universal has a range from .004" to .187" and all other Universal machines have a range from .005 /y to .150". 10S THE CINCINNA TI MILLING MA CHINE CO. A pointer on the end of the lever on the gear box in- dicates on a dial the feed at which the machine is being operated. Throwing this lever from one side to the other, increases or diminishes the rate of the feeds between two and three times. Heretofore, with the narrow range of feeds on milling machines, it was impossible to accommodate the large range of cutter diameters which are required in every day practice. These cutters may range from less than y%" to more than 6" diameter. A very large part of the total power required for the machine is used in feeding the work to the cutter, and hence careful attention to the character and efficiency of the gearing and transmission devices used for the feed, is of high importance. Worm gearing is largely used for the transmission of on power to the feeds. For fixed speeds of small range, worm gearing may serve certain purposes, accompanied, how- Gearing. ever, by sacrifices of power. But where the power as well as the speed of transmission must have a large variation, especially where the coarsest feed is more than thirty times as fast as the finest feed, the use of worm gearing would waste an enormous amount of power. Geo. B. Grant, says : "The combination known as worm gear and worm is much used for obtaining slow and power- ful motions. It is also too much used for wasting power and wearing itself out, for its friction is very great, and con- sumes one-quarter to two-thirds of the power received." The efficiency of worm gearing is lowest for slow speeds (often not more than 40 per cent.) while the highest speed is soon reached by the tendency to abrasive cutting of the teeth. Cast Iron worm gears should not have a sliding speed for their teeth greater than two hundred feet per minute, and with the most favorable metals in contact, this speed should not be increased too much. THE CINCINNATI MILLING MACHINE CO. The practical usefulness of speed range is therefore limited. On the other hand, the efficiency of spur gearing usually ranges from S6 to 99 per cent, at almost any speed which might be used." Perhaps the most extensive experiments ever made to determine the relative efficiencies of worm and other toothed gearing, were those by Win. Sellers & Co., and these have been very careful ly described in a paper by Wilfred Lewis, printed in the Transactions of the American Society of Mechanical Engineers, Vol. VII. A very comprehensive extract from this paper is given in George B. Grant's "Treatise on Gears," from which the following abridg- ment and chart have been taken. We are indebted to Mr. Grant for this matter. Veloc f?/ «< Pitch Line in Feet per minute. 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X X X X X -M8J3 S JO i JB8Q CO cm CM 00 co CM CD CM CM © CD CD 00 CO CO jeaj) 8»B|p 3U1J8 » U IPC © © CO © cm Of CO cm cm i—l CM O CM X 00 00 ee 23 X CM CM X X OS X oc a *© CO CM CM cm CM cm OS OS >* 00 J> X CO X CO X 1—1 X X o OS 00 35 X CO cm X CO *© i© X X X CO X CO a g OS 00 00 fr- t> X CO X CO X *© X »© -* ^ X CO X CO CO X CM a 00 X fr- i> CO CO CO X 1© »© i© X tH CO X CO CO X CM X CM - K CO CO CO la *© m X X X X CO X CO CO CO X CM X CM CM X ^5 i© X »© i© 1© X -* X ^ X CO X CO X CO X CM X CM CM X CM CM X a rfr X ^ Tt< Tji CO X CO X CO CO CO X CM X CM CM CM r— 1 X 1—1 X 1— 1 a CO CO CO CO CM X CM CM X CM CM CM X X X X X a CM cm cm CM N* X X 5 2 X X X :* X X -Maj3§ JOJ JBSry CO CO 1© CO 00 CO 00 o o ee •** o O * CM 00 CM CM CO 00 CM CM CO CM co 00 CM 00 CM CM 00 CM CM •OIJ0/V\ U0 JB8Q CM fr- fr^ frl CO CM CO co CM fr- CM fr- CM CM CM 3> CM . TABLE USED IN CONNECTION WITH THE UNIVERSAL INDEXING and DIVIDING HEAD For Dividing "Work from 2 to 360 Spaces. u - O d Z * o Z V u '0 X V o = O z V a a; c d Z (LI "3 ■z 05 6 z V O T. V — 86 43 20 115 46 16 155 62 16 192 24 5 245 49 8 88 66 30 116 58 20 156 39 10 195 39 8 248 62 10 90 54 24 120 66 22 160 28 7 196 49 10 260 39 6 92 46 20 124 62 20 164 41 10 200 30 6 264 66 10 94 47 20 130 39 12 165 66 16 205 41 8 270 54 8 95 38 16 132 66 20 168 42 10 210 42 8 272 34 5 96 24 10 135 54 16 170 34 8 215 43 8 280 28 4 98 49 20 |136 34 10 172 43 10 216 54 10 290 58 8 100 30 12 140 28 8 176 66 15 220 66 12 296 37 5 104 39 15 144 18 5 180 54 12 224 28 5 300 30 4 105 42 16 145 58 16 184 46 10 230 46 8 310 62 8 108 54 20 148 37 10 185 37 8 232 58 10 330 66 8 110 66 24 150 30 8 188 47 10 235 47 8 360 54 6 112 28 10 152 38 10 190 38 8 240 66 11 THE CINCINNA TI MILLING MA CHIXE CO. o: 00 ^ CO »ra Tf CO O? p_i © - ~ saaaSaa OS Cfi ^ TP CM OS as ■^ ■^ Tp CM ^ ** r « •2 ~ ~ ir s ■A3-S - - he X o CO — — -N? »o X _ •rP l<- © "J >, x^ o — S39J§3CI TP CO i> i> — o Tp CO X „ ■fl CM > '- 00 w X -r Q ~ "A3"H - X " 5 > Oc d gj 00 ?^ fQ iC •rp CO CM ^ c — S33JS3CL OB Tp OS T -rP CX tP Ot "^ ^T ^. ~ — w ^ u r>i ^ H '"^ cm - ^* C^3 — x W r rt r - — ^ £ •A3-S ~ 1—1 ^ — ~ — — — — — X — - E O "^f 00 CM CO c -I. 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OS cc CO © B > aj ~ CM CM CO "^p ^p >o CO *- — ^ J*! ^ x ~ . — C* M CN v £ A3« iC l0 iO iC UO iG iC iC lO la ,r - V ^c > aj X u -~ cm 00 ■* o ZC CQ X ^p © .' ^ o •^ X S39Jx>3CI t ■<* 00 X CO Oi Oi cc -x> CM «3 t "K I aj ^ < S CN - - X 11 x - r •-WH *C iO lO lC lO lO lO »c \C iC 3 H _, <*? CO r* »o cc 1> X OB © - = s33j.Saa i> Tf cm CO o i> CM x; ™ 1-* — .s be 3 CN •— i - —• — ._ — i _z: •A9H X!COCOCOCOCOCDCOCOCO THE CINCINNATI MILLING MACHINE CO. fJ 00 >C o xo o xo o xO o XO © O u a saaaS^a co CO a. 1-H i> o CM CM 00 XO ■^ a) F* CvJ 13 c u £ y o as oo i> CD 1© •^ CO (M 1—t © 3 01 be X C sasaSaa r- xO CO CD "* CM XO CO 1-H •<* »-H CM 1-H CM '"" ' CM rZ o CO .2 o ^ _ , c ^ as 00 CM o y—i as 1-H CO - ^ ^ cu bn c 3 {N 00 CO ^* CM o 00 CO T* CM © 'Z a; CJ "o a. as t* Tf Tf 00 00 CO CO CO o C/2 «i — tn H 5 ~ Z o xo o XO O \G> o xO o xO s S93J§3a o CD ^ CM co CO as as ^d - CJ r< /-> — H CM 1-H 1—1 CV i-H j5 aJ ^^ - aj CO "* CM +•> -rr ,i^ CM 1-H nj ~ O H a X U CO t cn _j CM CO -* ID CD i> 00 at © O OJ o C S33.I.§3a cm -^ 1-H CO O CM as 00 •>-> +- 1 +- 1 VH — ' CM 1—1 CM i-H CM CM CM o ^Cj +J ,_- ►> M o c bjo o > _ o ^ 3 ** — -t CM CO ^ XO CO t^ 00 as © o '> CO Q S33JS3Q CO -* CM XO CO CD "tf *> CD be Ih 1-H 1-H ^-i CU ~ £ ■| H "^ ^ * u c 3 rsi CO CO as CM xC 00 ^H ^* 2> © -'-' _c — M E- S33.IxS3Q m CO t- i> i-H o •^ CO 00 -M r~ ,J2 b/) ^ H ' —l CM ,_H l-H r ^ •1—5 c ? .t! c ■A ? o J> rf ^ 00 xO CM as CD CO © u D S33JS3Q xo CD CM CM CM CO as as CD i> a o o" CO t- rt U ~- xO O xO o XC o XO o xO © of rt i^ '-d ^ i- °° S33.l§3(7 i> o CM o CM XO CM xO £- XO 13 (U aj o T 7 1 — 1-H I— 1 CM 1-H CM i-H CM b£ X S 5? ■J - 'p, 0) CM CD i-H CM o o ON o 7 w -* 00 CM CD o -^ 00 CM CD © O cu > ^ cu H H ^ saaaSaa o* as 2> -tf CM as CD "^ Tf a3 en g 2 H r CM i-H y—t i-H T—t CM ,_, _ p l 00 as © CM J5 a; , "- 1 J H 2* 1-1 *"^ * O CO CM 00 -* © 1 2 6 2i CJ 1 g J ~ saaaSaa CO S> o T* 00 CO J> 1 "c6 "^ ^ CM X cu -) r 1 — O S z 4-i Q ^h" cu 3 •A3>I ~* i— l 1-H 1-H i-H "* 1-1 1-1 i-H "^ o CO Oi 1-H J> ^ =.625 ft = .28125 & = . 140625 f| = .640625 f = .750 i-i = .34375 ii = .171875 ff=. 671875 •-.875 i : J = .40625 if = .203125 H=. 703125 16ths. H = .46875 i| = . 234375 £| = .734375 h = .0625 H = .53125 H = . 265625 || = . 765625 rv, -.1875 3 1 = .59375 if = .296875 |i = . 796875 •>, -.3125 |i = . 65625 fi = .328125 ff =.828125 ft = .4375 If = .71875 f| = .359375 If = .859375 i 9 6=.5625 || = .78125 f| = .390625 fl=. 890625 1 1 =.6875 II = .84375 fl =.421875 If = .921875 i 1 — .8125 || = .90625 || = .453125 |4- = .953125 If = .9375 H = - 96875 fi-=. 484375 ff = .984375 THE CINCINNATI MILLING MACHINE CO. 125 TABLE OF DECIMAL EQUIVALENTS OF MILLIMETRES AND FRACTIONS OF MILLIMETRES. nun. Inches. mm. Inches. mm. Inches. ,V = .00079 ft = -02047 2 = .07874 ft = -00157 ft = .02126 3 = .11811 ft = .00236 11 = .02205 4 = .15748 5 ^ - = .00315 ft = .02283 5 = .19685 ft = .00394 ft = .02362 6 = .23622 ft = .00472 U = .02441 7 = .27559 ft = -00551 II = .02520 8 = .31496 ft = -00630 ft = .02598 9 = .35433 ft = .00709 1* = .02677 10 = .39370 H> = .00787 ft = -02756 11 = .43307 B = .00866 ft = .02835 12 = .47244 if = .00945 ft = .02913 13 = .51181 H = .01024 ft = .02992 14 = .55118 M = .01102 ff = .03071 15 = .59055 H = .01181 U = -03150 16 = .62992 ft = .01260 f£ = .03228 17 = .66929 H = .01339 ft = .03307 18 = .70866 H = .01417 U = -03386 19 = .74803 U = .01496 ft = 03465 20 = .78740 U = .01575 ft = .03543 21 = .82677 H = .01654 ft = -03622 22 = .86614 ft = .01732 ft = .03701 23 = .90551 If = .01811 ft = .03780 24 = .94488 ft = .01890 f| = .03858 25 = .98425 ft = .01969 1 = .03937 26 =1.02362 10 mm. = 1 Centimeter = 3937 inches. 10 cm. = 1 Decimeter = 3.937 10 dm. = 1 Meter =39.37 25.4 mm. = 1 Fnglish Inch.