Then use this pointed tool to scribe a light line along the side of the tailstock ram remove burr. This line will serve as a guide to set the tool, even when the work is in position between centers. The harder the metal, t h e less t h e depth of cut should be. Ordinary turning does not dem and unusually deep cuts- more met al per minute can usually be removed by turning at recommended speed w ith a roughing cut of between.
T he work can be roughed down to within approximately. T h e si x mo st common carria ge feeds are shown on the lathe Il t h rea ding cha r t:. Ordinary cutting, w h ere t h e final fini sh can b e touched up by filing and with emery cloth, should be done w ith the. Gear set-u ps f or the va rious carriage feeds a r e given in Part 7. During th reading opera tions t he us e of a cutting comp ound, oil or fluid results in a b etter class of work.
L a rd oil or anyone of the general purpose cu t ting fluids shoul d b e kept han dy for this purpose. Continuous prod u ction work usually requires the use of liberal quantities of a cutt ing compound t o carr y the heat away from the tool bit. They are p urchased from the w a reh ouse by their S. Society of Automotive Engineers numbers, listed in detail in Part The tool angles and cutti ng speeds given in Figure 59 are a pproximate and will be found suitable for average work.
Speed Side Front Description of S. The finished tool is also shown. These steels can be machined b est with rake angles as large as t h ose recommended for S. Cuts should be deep enough to cut t h rough the scale. The structure of this metal causes the chips to break out in small sections, not in a continuous chip. Rake angles must be smaller than for the softer steels.
The tool nose sh ould be sharper than for steel. These steels are often used where corrosion must be avoided. The addition of this alloy makes stai. Two grades. Stainless steel is a tough, draggy metal and requires more rake than would be expected. Small rake angles will invariably cause hogging, and the material will "work-harden" badly, that is. To prevent r u bbing. Chips produced when turning stainless steel are stringy and hard to manage and should be pulled away from the work.
They will be hot and sharp and should be handled with heavy cotton gloves or a thick cloth. Tool angles suitable for most grades of stainless steel: Front Clearance.. The depth of cut fo r roughing can be. Rath er deep cuts at rated speed will generally b e most sat isfactory. T o produ ce a smooth finish on copper, tools sh ould be honed to as keen a n edge as possible. Chips are tough and stringy and should be pulled away from the work-wear gloves or use a thick cloth to prevent burning your hands.
N o lubricant is necessary, b ut it is suggested t h at lard oil or paraffin oi l be used for threading. U sin g t h e cu t-off too l on soft copper is unusually difficu lt, due to t h e ten dency of t h e ch ip to spread and ja m in the groove.
A m ethod recomm ended by many machin ists is to start a g roove wider than the cut-off blade and m ove the cut-off t ool back and forth conti n ually as it is fed int o t h e w ork, allowing the chip to clear the work wi thout ja mmin g.
Allowance for the extra width of t he groove should b e made wh en laying out t he work. Phosphor bronze and silicon bronze are in this class. Experiment with tool angles for these metals if large amounts of work are to be done. Pag es If hogging occurs. Speeds may vary from 80 to feet per minute. A feed of. Take cuts of. Some of these alloys have a small percentage of lead in their composition which improves their machinability. It is used for such p urposes as non-sparking wrenches and tools and has many applications where inflammable materials are handled.
Its strength is comparable to tempered mild steel. Tool bits should be ground to these angles: Front Clearance.. Use the. No lubricant is necessary. If chatter occurs, decrease the radius of the tool poi n t. While surface speeds for t urning steel vary between 75 and feet per min ute, aluminum is t urned best at speeds from feet to as h igh as fee t per minute.
F or general work, it is recommended th at wrought aluminum alloys such as 17S-T and 11S-T3 be cut at surface speeds of to f eet per minute, while cast aluminum should be turned between and feet per minute, de pending upon th e composition of the casting. To determine actual spin dle speeds for various diameters of work refer to Figure Both Alcoa 17S-T and llS-T3 can often be turned dry, but for best results on all al uminum some form of cutting oil should be used.
E qual parts of kerosene a nd lard oil or equivalent m ake a ver y satisfactory cutting compound. On finishing cuts, the edge of the tool bit should be ho ned very sharp and smooth. E ven slightly rough tool edges will leave marks on the w ork. One of the earliest plastics was celluloid - it has been followed by various other plasti cs, moulded and cast from such materials as phenol.
For machining purposes plastics can be divided into two groups: Group I includes molded Bakelite, Formica and Durez, all of which are phenol plastics moulded under heat and pressure. Group II includes all of the cast and formed plastics of var ious bases, sold under such trade names as Catalin. For a small amount of machining, high speed tool bits may be used, although it may be FIG. Note the ished. The tool should be ground stringy appearance of the chip.
No lubricant is necessary or advisable. Take rather heavy cuts. Because of the heat generated when d rilling plastics, the finished hole becomes smaller than the drill.
For an exact sized hole. High sp eeds around to feet per minute are recommended, using the. Machine dry. A v ery kee n edge must be maintained and special tool b its should be used if any quantity of t his material is to be machined.
Cutting speed should be around feet per minute when using high speed tool bits and feet per minute w ith special tool bits. I t is not commonly termed a p lasti c. T ools should be ground w ith these a n gles : Front Clear ance Keep the t ool edge honed sharp with a rat h er broad nose at the point. M achine dry. High speed tool bits a re perfectly satisfactory. Speeds of ab out feet per minute should be used when cutting dry, b u t care must be taken that the work does not become too warm.
The four Jines have been scribed to m ark the appro xim ate center position. W h en the cent er h ead is used, set the center head as shown in Figure 73 and scribe two lines approximat ely at right a ngles. Use a sharp scriber and keep the lines as close t o the edge of the scale as possible. Then hold the w ork in a vis e a nd center punch at the in ter section of t he two lines. If the rough stock i s lar ge enough to p ermit a t rueing cut, the en ds may be counters u nk aft er punching.
H old a p iece of chalk so that it just touches t h e high spots of the w ork as it is rotated by hand. A t ool bit moun ted in the too l post can be u sed in place of chalk. Make m arks close to each end, then remove t h e work. Hold the work in a vise a nd drive the t wo center-punched marks toward the chalk marks by striking at an angle with the cent er punch and t hen slow ly b ringing it back to a straigh t p osition.
The center punching is t ested for trueness with chalk, tool bit or dial gauge. The right end can be tapped lightly w ith a h ammer until the work runs true. Do not make the centers t oo large. Another method of countersinking is illustrated in Figure The countersink drill is chucked in the headstock and supports the left end of t he work. The right end is supported by the tailstock. W ith the spindle turning at or R. Do not force the drilling or feed too fast-the advance can be felt when turning the tailsto ck hand wheel.
If the countersink is forced and break s off, the simplest way to remove the broken pi ece is to cut about one-half inch from the end of th e stock.
The latter method r equires light cuts, a rat her loose tailstock center and is not recommended as st andard practice. The two sizes of clamp t ype d ogs h old st ock up to 3Yz inches i n size and have several other advan tages. They drive work of many different shapes Fig. This method of adapting large work to a dog is not advisable for general turning. In such cases it is customary to mount the work on a face plate or h old it in a ch u ck, a device with jaws which grip the work rigidly while it is being machined.
If only one chuck is t o be purchased, it should be the four-jaw independent chuck shown in Figure It is easily the most versatile typ e of chuck. T he four jaws are adjusted separately and a r e r ever sible so that work of any shape can be clamped from the inside or t he outside. For extremely accur ate work, check for trueness with chalk and place shims over one of the jaws until the work runs true.
To insure accuracy, the piece being machined should never be removed or reversed until all operations have been completed. The teeth of the jaws are cut in a circular shape to mesh with the scroll threads. Consequently, the universal chuck jaws cannot be reversed. An extra set of jaws, carefully fitted to the chuck, is furnished so that large diameters can be held from the i nside or outside.
T o change univers al chuck j aws, first remove jaws from slots by turning wrench. II ja ws stick tap lightly with a piece o f wood or a brass hammer. Note that each jaw and j aw slot is marked "1 ," "2," or "3. See that jaws, jaw slots, and scroll are free from dirt.
Turn scroll until the outside start of the scroll thread is pu st ready to pass the No. S lide No. Turn scroll until jaw is en gaged.
Adv ance scroll and repeat for Nos. S the universal chuc k. Note that jaws are 2"rip. Its own. Put the chuck wrench in its hole and pull as shown in Figure If necessary, tap the jaws with a piece of wood or a brass hammer. Do not remove the chuck carelessly. You may damage the spindle or chuck threads or drop the chuck on the bed ways.
Before mounting work, clean the threads in both the chuck and the lathe spindle with a piece of bent wire. Clean the face of the shoulder on the spindle nose and the back face of the chuck.
Put a few drops of oil on spindle nose. Mount the chuck carefully and not too tight, first removing the center and sleeve from the spindle.
The soft thud indicates a good firm seating against the shoulder. Be careful when tightening work in the chuck jaws. Too much pressure on the jaws will affect t he accuracy of the chuck and may spring the work if a light piece is being turned. Try to have the jaws tighten around the more solid parts of the work. Always use the wrench which comes with the chuck. When chucking work in the universal or headstock chuck, turn the work as the jaws are tightened-an accurate "form fit" will result.
Small diameter work should not project from the chuck jaws more than four or five times its diameter-cuts should be short and light. Heavy cutting pressures will often cause small work to spring out and "ride the tool. The an gle plate shown in F igure 93 is bolt ed to any point on the face plate for machinin g irregular shapes and for off-center drilling and boring.
Figu res 94 and 95 show two typical jobs. Whenever ex treme accuracy is required on small diameters, t h e draw-in collet chuck attachm ent is the logical method of chucking. Some typical collet work: precision tools. The collet attachm ent , as shown in Figure 96, include s a hollow draw-in spindle w h ich exten ds t hrough th e lath e headstock spindle, a tapered holdi ng sleeve and t h e split h oldi ng collets. Cast iron, with hardened tool steel plugs for the ends, is often used in making a mandrel for large work.
The mandrel should be tapered about. When finished, the mandrel diameter should be a force fit for the h ole in the work and the tailstock end should be.
To make removal easier, put a drop or two of oil on the portion of the mandrel which will gr ip the work. Never drive a mandrel with a steel hammer without protecting the end. The best tool for forcing a mandrel in or out of the work is an arbor press, or mandrel press Fig.
Be sure the work is started perfectly straight and on the entering end of t he mandrel. Drill with proper lip clearance. The c utting lip an d h eel, S, H eel line. B, is lower than cutting are in th e same plane. Checks bo th length and angle of drill li ps. Reaming a cast iron h an dwhee l.
Figure shows a typical reaming job on the lathe. For best results, follow the same rules in reaming as in drilling and general turning. Use slow speeds, feed in evenly and be sure there are no burrs on the reamer teeth. The type of reamer shown in Figure is generally used in the lathe. A reaming allowance between. Bot h are mounted in the tailstock r am as shown in Figur es and The drill pad serves as a table for flat or square work and is especially valuable for drilling large holes when a drill press is not available.
The crotch center automatically centers round work for cross drilling. The work is held in the left hand and advanced against the drill by turning the tailstock handwheel. The met al s tan d has a h o le for each drill with the drill size and its decimal equivalent clearly m arked.
The drills can also be purchased separately. Note high-spe ed boring tool mounted directly in tool post fo r maxi m um rigid ity. Boring operation s require only slightly differe nt tools and methods than those for external turning. T he b ig problem is t hat of tool rigidity, beca use m ost internal tools project considerably from their support.
Fi gure shows a typical b oring operation. There are several types of boring tools and m ounting methods. The tools shown in Figure 11 9 are mounted directly in the tool post.
The exact amount of front clearance depends up on the size of the hole being b ored. F igur e sh ows how a f ront clearance angle can b e too small for one hole b u t satisfactory for a larger h ole. HE EL. Side Cl earance: Same as for external tools. Back and Side Rake: About half of external angle s-in some cases, less than half.
Then b y putting the cuttin g edge on exact center, the correct amount of back rake is p rovided. The general rules for the use of external tools apply to boring tools. For maxim um r i gidity. This g r adual process avoids spring in the tool- the final finish cut should be continuous. In Figure the lines representing the diameter "PD," are located so as to make spaces "aa" and "bb" equal.
On a 60 0 Vee-type thread and on National Form threads, the pitch diameter is simply the major diameter less t he depth of the thread. Thus, knowing the major diameter required, subtracting from it the double depth of thread for the required pitch, gives the minor diameter.
Information on double depths of National Form threads for different pitches will be found on page PITCH-The distance from a point on a screw thread to a corresponding point on the next thread, measured parellel to the axis see Fig.
In Figure , the distance between points X and Y represents one inch. T hread Gauge. The form of this tool also provides ample clearance for even the coarsest threads. The tool is resharpened by simply grinding the top edge, adjusting the tool as it wears. I FIG. The beginner often finds it h elpful to turn the grooves C and D Fig. In F IG. With the point of the tool about an inch to the right of the start of the thread. Start the lathe and engage the half-nut lever on t h e carriage. Appply plenty of lub ri cant to t h e work.
W hen t he p oint of the tool reaches the groove at t h e end of the thread groove D in Figure , raise t h e half-nut lever on the ca r r iage, b ack out the cross feed a tu r n or two, and return t h e carriag e by h and t o the starting point. Advance the cross feed to its original posit ion at 0, advance t h e compound rest for the desired d epth of cut, and engage the half-nut lever for the second cut.
All feeding is done with the compound rest. A final pass through the thread with no advance whatever will often clean up any remaining high spots. Take the last cuts with extreme care. H eavier cuts can b e taken on soft metals such as brass or aluminum, but if a fine finish is desired, the last cuts should be very l ight.
W ith other metals use the type of lubri cant recommended for g eneral turning operation s. If the thread is to be cut with a sharp pointed 60 0 tool, the major diameter is equal to the minor d iameter plus the Vee-form Double Depth of Thread Table I, page When the tool point has cut to the depth of groove C, the thread has been finished. Groove D should be about twice as wide as the thread pitch and a few thousandths larger than the major diameter.
This groove provides a brief interval at the end of each cut during which the work can revolve freely while the half-nut lever is disengaged. The grooves C and D can be omitted after the operator has learned internal thread cutting operations. Acme Screw Throad and Formulas. T h e A cm e screw thread Fig is often found in power transmi ssions, wh ere heavy loads necessitate close-fitting threads.
Anot her common application is in the lead screws and feed screws of precision m achine tools. T h e very light cuts w hen turning or boring a square t hread. Dra w line "a b" equa l to the circumference of the thread 3.
Then draw line "ac " at right angles to flab" :J a nd eq ml in len gth to th e th r ead pitch o r lead, if a multi ple threa d. Draw lin e F IG. If the stock FIG. F i gure shows a typ e of pipe center recommended for s up port ing the stock w hil e cut ti n g p ip e type L. This procedure is n ecessary b ecause metric th reads have no definite relation to the t hreading dial. Tool Ve! The position of t h e lever is indicated at the left end of the row of numbers in wh ich you find the thread or feed desired.
Righ t H and Quick-Change L ever - shifts to nine positions. They are numbered on bottom row of chart beneat h carriage feeds. T h e indexing position of the lever is always directly below the thread or feed des ired. See Controls, Step "D", for location of gear positions. The position of the sliding gear is indicated on the chart in the same row as the thread or feed desired.
These positions are marked on chart directly above left hand group of indexing holes in gear box. The lever position for a thread or feed is shown in same row as thread or feed desired. The indexing position of the lever is always directly below the thread or feed desired. When writing specify thread or feed required - for coil winding f eeds, give name, type and size of wire. The positions of the gears on the stud assemblies are denoted as "N"and " F" i n the gear set-up tables. Cross section of chan!
Gear clearance does not reduce the accuracy of a thread cutting operation, because all play in t he gears is taken up in one direction. A small amount of grease, preferably graphite grease, applied to gear teeth will often aid in obtain i ng smoother. All the lubrication cups on the gear housing are shown in illustration at right.
Put a few drops of oil in each oil cup once a week if lathe is used constantly. Qu ic k-Change lever bear in gs a nd shaft oil once a week. Occasionally apply a small amount of heavy outer gear lubricant to the feed gears and tumbler gears-it will aid in obtaining smooth er, more quiet operation.
Extra gears, stub assemblies, and spacers necessary to make up the gear train are available from factory at nominal cost.
Left Ri. These designations will be found on the lathe threading chart as well as in all of the following gear data. Gear bracket positions. The outer end of the longest bracket slot is called "Position A," the inner portion of the same slot is "Position B. The gear bushing has a double key which fits into the keyways in the gears. The gear bushing and two gears fit over a stud bushing, and the assembly is bolted to the gear bracket. The washer is a bearing for the outer end of the gear bushing.
Cross section of c hang e gear stud as sembly. N oti c e t h at in o rder to make this assembly complete, two gears m us t be m ount ed on the gear bushing at one time.
When both of th e g ears on a g ea r bushing mesh with other gears in the train, they fo r m a " com p ound " g ear assembly. When only one of two gea rs on a gea r bushing m eshes with the other gears in the train, It is called an "idle r.
A method often used to ob- P ro p e r ge a r clearance. A small am ount of g rease, p r eferably graphite grease, applied to gear teeth wi ll oft en aid in obtaining smoother, more quiet operation. Whenever a n ew gear train has been set up, shift the reverse fee d leve r t o t est th e dir ection of the carriage travel.
The fancy new clothes were pretty complicated to get into. Bartlett and ask their forgiveness for prematurely acting without permission. Fairmont if you have peace about it. She was just a woman in love who had her pride hurt bad enough that she showed poor judgment. Manual of Lathe Operations and Machinists Tables. For inch Quick Change Lathe. This manual is printed in it's original size 5.
See "Which manual works with my lathe" section below for explanations. All CDs come shipped with everything you need to view, print, zoom, and search. You can zoom in on anything, print anything, search for any keywords, and quickly flip through the information finding what you need.
No clunky paper manuals to keep up with. Email to friends Share on Facebook - opens in a new window or tab Share on Twitter - opens in a new window or tab Share on Pinterest - opens in a new window or tab. PDF Atlas Lathe Manualnumerous screwcutting charts, clear instructions for common turning and other machining operations, diagrams, photographs and much useful general lathe-work advice.
This gives an exhaustive description of the machine's potential together with numerous screwcutting charts, clear instructions for common turning and other machining operations, diagrams, photographs and much useful general lathe-work advice.
The workpiece is rotating between the two centres i. Here the tool is moved longitudinally to obtain the required type of the thread. When the tool is moved from right to the left we get the left-hand thread. Similarly, when the tool is moved from left to the right we get the right-hand thread.
Here the motion of the carriage is provided by the lead screw. A pair of change gears drives the lead screw and by rotating the handle the depth of cut can be controlled. It is the finishing operation performed after turning. This is done on a lathe to remove burrs, sharp corners, and feed marks on a workpiece and also to bring it to the size by removing the very small amount of metal.
The operation consists of passing a flat single-cut file over the workpiece which revolves at a high speed. The speed is usually twice that of turning. This operation is performed after filing to improve the surface quality of the workpiece. Polishing with successively finer grades of emery cloth after filing results in a very smooth, bright surface.
The lathe is run at high speeds from to m per min, and oil is used on the emery cloth. It is the process of reducing the diameter of a workpiece over a very narrow surface. It is done by a groove tool. A grooving tool is similar to the parting-off tool. It is often done at the end of a thread or adjacent to a shoulder to leave a small margin.
Support is also given from the tailstock end. Spring winding is the process of making a coiled spring by passing a wire around a mandrel which is revolved on a chuck or between centers. A small hole is provided on the steel bar, which is supported by Tool Post and the wire is allowed to pass through it.
It is the process of turning a convex, concave, or of any irregular shape. Form-turning may be accomplished by the following method:. Forming tools are not supposed to remove much of the material and is used mainly for finishing formed surfaces. Generally, two types of forming tools are used straight and circular.
The straight type is used for wider surface and the circular type for narrow surfaces. Lathe machine operations performed by holding the work by a chuck or a faceplate or an angle plate are:.
Drilling is the operation of producing a cylindrical hole in a workpiece. It is done by a rotating tool, the rotating side of the cutter, known as a drilling drill. In this operation, The workpiece is revolving in a chuck or a faceplate and the drill is held in the tailstock drill holder or drill chuck. The feeding is adopted is affected by the movement of the tailstock spindle. This method is adopted for the drilling of regular-shaped workpiece.
Reaming is the operation of finishing and sizing a hole which has been already drilled or bored. The tool is used is called the reamer, which has multi-plate cutting edges. The reamer is held on the tailstock spindle, either directly or through a drill chuck, and is held stationary while the work is revolved at a very slow speed.
Boring is the operation of enlarging the hole which is already drilled, punched or forged. It cannot produce a hole. Boring is similar to the external turning operation and can be performed in a lathe. In this operation, the workpiece is revolved in a chuck or a faceplate and the tools which are fitted to the tool post is fed into the work. It consists of a boring bar having a single-point cutting tool that enlarges the hole.
It also corrects out of the roundness of a hole. This method adopted for boring small-sized works only. The speed of this process is slow.
Counterboring is the operation of enlarging the end of the hole through a certain distance. It is similar to shoulder work in external turning. The operation is similar to boring and plain boring tools or a counterbore may be used.
The tool is used called a counterbore. The speed is slightly less than drilling. The principle of turning a tapered hole is similar to the external taper turning operation and is completed by rotating the work on a chuck or a faceplate. The feeding tool is at an angle to the axis of rotation of the workpiece. A boring tool is mounted on the tool post and by swivelling the compound slide to the desired angle, a short taper hole is machined by hand feeding.
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