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- Atlas Lathe Operations Manual | PDF | Woodworking | Industrial Processes
All books are in PDF format. For easy searching and printing If you have an old lathe. This Craftsman lathe was made by Atlas and is similar to the Atlas Lathe Practices Series. Lathe Operations. Level Lathe Bed. Mounting Lathe. Sears craftsman 6" metal lathe May 29, It turns up on eBay frequently and I believe it is finally being offered as a reprint. Late-model Craftsman inch Lathes A comprehensive manual and data pack is available for this. In the s the lathe carried a "Craftsman Commercial.
A complete Data Pack is available for the Atlas 6-inch lathe. Enormously popular in America - it was affordable and with a. Always position the tool rest above the centedine of the Lathe for spindle turning, Do not apply the turning tool to the workpiece below the level of the tool rest. Do not run the Lathe in the wrong direction, This could cause the turning tool to be thrown from your hands. The Lathe must run in a direction so.
The is the 12x36 craftsman delux lathe, not a This is the biggest home machinist lathe that they built for sears. It is supposed to have manuals and other info on Atlas lathes. Is it worth the money , AM Greg B. Thanks for the PDF Holescreek. Wayne , PM May 14, Craftsman Lathe 06 Sep 28, Earliest known copy, dated November, Manual and IPL for Craftsman metal lathe. Craftsman lathe manual pdf battletech logo.
Page 1 Sears Craftsman lathes were manufactured by Atlas Press Company and parts are interchangeable. Leave lathe bolted on skid, it is easier to move to final location.
Next, loosen the carriage lock screw located on.. Manuals and free owners instruction pdf guides. Find the user manual and the help you need for the products you own at ManualsOnline. Craftsman Air. Atlas Craftsman Lathe Restoration.
Old Iron Shops. This is a reproduction, not a photocopy, of an original Craftsman 12 Lathe Parts Manual for Models This manual contains explosive view parts diagrams and parts list for entire lathe.
Craftsman is a trademark for a line of tools covering hand tools, power tools, tool boxes, lawn and garden equipment, work wear and many other things that you can find in a garage or working area. Number of Pages 5. This is a reproduction, not a photocopy, of an original Craftsman Please Read The parts section of this manual contains pictures of the parts laid out with parts numbers. The quality is usable, but does not meet the..
Email to friends Share on Facebook - opens in a new window or tab. When you're looking to take your. This saw was also sold under the Craftsman name as a model The saw part is the same and similar to the bench model This manual contains information on lubrication, operating instructions, changing the blade, adjustments, maintenance, and controls as well as a complete parts list and exploded views diagrams.
Using that and the manual and the parts that he had, we came up with the exploded view drawing shown. A luminum guards provide a safety cove ring. The m echanism for changing from direct drive to back geared drive is quick and s imple in op erat ion. Adequate bearings and good gears are both vitally important in lathe cons ruction. The lat he back gearing mechanism is pict u red in F igure 11, a n d exp la ins the details of operat ion.
The "bull g ea r," D is k eyed soli dly to the spindl e. This small gear and pulley assembly is fr ee to rotate unl ess the pin, G, is pushed in, locking the pulley to the bull gear and sp indle. To divide the circumference of a piece of work into a giver. Perform operation, release pin and, after consulting indexing table below, rotate gear the proper number of indexing holes. Engage hole and repeat operations until circle has been completed.
NOTE: When using lathe dog be sure that tail of dog fits tightly in slot of face plate. In layout work it is advisable to use a pencil to mark all required divisions before beginning the actual operation. This type is "quick-change" with the belt tension lever within easy reach for speed changes. Sixteen speeds are available, ranging from 28 to RPM. This modern countershaft design does away with the irritating disadvantages of a cumbersome, space taking flat belt drive with its limited speed range and difficulties of adjustment.
It provides a smooth, even flow of power to the spindle at the exact speed most efficient for the work being done. The countershaft spindle revolves on bronze bearings, amply lub ricated through the hollow housing.
Rem ove cap S fr om headstock. Slide back g ea r shaft in righ t hand eccentric sleeve T - turning sleeve with a screw d river to line u p groove pin hole in sleeve and shaft. R eplac e groov e pin Q and slide collar R against headstock and tigh ten set s crew. A fter reassembling the headstock sp indle, run the lathe in back g ear d rive to check the mesh of the back gears.
If lathe runs noisy, or if there's t oo much play between the gears. L ight ly file all burrs caused by set screws from spindle and keys Nan d P. To reassemble, reverse the procedure in "Removing Headstock Spindl e", pa ge Be sure belt is in position.
When driving spindle into headstock, use the palm of your hand as much as possible to avoid dam aging the p recision surfaces of the spindle nose.
Use Figure 11 as a g uide, making sure all part s are installed in their proper positio ns. Read the fo ll owing instructions for spindle and back gear adjustments. Slide collar L against shoulder of spindle and lock in place. M ove pulley-gear assembly against collar and s lide large spindle gea r D ag ainst pu ll ey and tighten set screw in gear.
There should be a slight amount of clearance between the pulley and t h e large spin dle gear to permit pulley to turn freely. Ti ghten collar B unt il all lateral end and radial side play has b een r em oved fr om spindle. Check by tapping spindle back and forth w ith th e hand. V -belts of the type shown at the left have been scienti fically designed to give long, efficient service. The milling or planing prcclclon-ground The. The bed-way surfaces must then be eit her hand scraped or machine ground.
This unusually large bearing surface provides a sturdy base for the entire lathe and keeps vibration at a minimum. After the bed is cast, it is first rough-milled and allowed to season, or age, for a number of months. This permits internal strains in the metal to become normalized, so that warping and twisting will not occur in the finished bed. After seasoning, a finish milling cut is taken, and the ways are then finish-ground on esp ecially designed surface grinders.
This la r g e amount of bearing surface minimizes wear and results in mor e p ermanent accuracy. The front of the carriage, called the "apron," contains the power feed mechanisms. Pull ing the knob control on the carriage apron engages the power cross feed. The lever at the right engages longitudinal feed. Both may be reversed by shifting t h e feed reverse lever located on t h e left side of the lath e h eadstock.
The compound can be tu rned in a complete circl e, and it is graduated in degrees from 0 to , so that any angle can be cut wit h the comp ound rest.
Bearing plates on the carriage, which b ear on the under side of both t he front and the back bed ways, anchor the carriage firmly to the bed in a vertical direction.
These bearing plates have shims for adjustment of possible wear. T hese gears can be adjusted for play by loosening t he screws on the front of th e apron, moving the gear case toward t h e rack, and tightening the scr ews.
First remove the tailstock, then unbolt the bearing on the right end of the lead screw and remove the lead screw half-nut lever must be u p. With the lead screw out, it is a simple matter to loosen t h e gibs on the back of the carriage, and slide the carriage off t h e b ed. This lever is used to reverse or stop the rotation of the lead screw.
Three holes are drilled in the headstock providing three positions for the lever. D irt or chips will damage the half-nuts and the lead screw. Oil r egularly.
Work range includes practically eve r y f eed fro m. By varying the gear train with Atlas change gears, hundreds of additional threads and fe eds are available for such jobs as metric threadi ng, coil and wire winding and speci al toolin g.
Gear train arrangements and instructions for cutting metri c threads and freque n tly used odd threads are contained in Sectio n 7. The p recision of the gro und ways and the extra care t aken in the fitt ing of t he t ailstock assu r e accurate alignment at any posit ion. Any dirt or chips b et ween these tapers will score both and d estro y their a ccu racy. D o not oil t he tapers. E ven a sl ight fi lm of oil wi ll prevent a firm fit an d cause t r ouble in turning.
It is vitaily important to kee p all tapers v ery clean. Form threads including National Coarse U. Square and Whitworth. All standard metric threads from. Feeds a r e available for spring making. Multiple threads, machine screws, pipe-type threads and special screws can also be cut with the standard gears furnished. Complete set-ups and dir ections for the most common threads and feeds are given in the Threading Supplement.
A kn ife s lici ng a block of wo od wi th the gra in. Th e small s ections are ex a2"gerated in size. Absolute ri gidity is impossible to at tain, but every effort should be made to app roach it. Th e cut t ing edge of a lathe t ool for metal t u rning is ground t o an angle of between sixty an d ninety degrees. This wedge angle must be lar ge because the tool edge must stand up under enormous pressure - an actual downward pressure as hi gh as , pounds per squar e inch has been measured on a lathe tool in turning steel.
The dark portion is deposited on the tool when takin g heavy cuts. The wedging or cutting is done with t his I bit of metal, not the edg e of the t ool bit. A tool bit that has been used on rather heavy cuts has a small ridge of metal directly over the cutting edge.
This bit of metal i is much harder than the metal being cut and is a lmost welded to the edge of the tool, indicating that an immense amount of heat and pressure was developed at this point. It is a decided advantage in heavy turning because it relieves the edge of the tool bit from most of the work of cutting and I lengthens tool life. For conti n uous heavy cuts, the speed should be k ept low enough, and the rake of the tool small enough in order to build up this false edge.
However, in taking fine finishing cuts, this built-up edge should be avoided by tak ing finer cuts at higher speeds and with larger rake angles. It is generally agreed, however, that the cutting action, aided by the heat and pressure at the end of the tool bit, causes the metal particles to deform or flow which produces what is called II "work hardening" of the metal.
The important point to remember is that the false cutting edge is desirable for heavy cuts-on fine finish cuts I it should be avoided. When grinding tools for special work, simply keep in mind the shapes and angles recommended for general tu rning and a pply these principles to the special tool being groun d. See the examples on page E x cell ent R. Tool for genera l turning and s houldering l ow OiIrd headstock ; a lso faci n g.
P oint should be r ounded for fi ni shing w ork. A p rop erly ground tool will have cont inuous wheel marks on each face - that is, each face is one clean cu t all the way across. The beg inne r can grin d tools quit e a ccu r ately by comparing each side of the t ool w ith the angles given in t he drawings on pages 34, 36 a n d 37, while grindin g t he t ool.
T hree view s of the process of grin ding a R. Tool A Straight Tool Holder. Tool Holder. Inasmuch as the tool must cut to the center, larger clearances should be used than when turning cylindrical work.
Although ordinary R. Figure 52 shows a tool which will be found excellent for this type of cutt ing. It is designed to cut from the center of the work toward the outside. This rake angle should be the same as, or slightly greater than , the angles given for front rake for the various metals and plastics in the follow ing section of this Manual. Figure 53 shows how the tool should b e set into the work.
Some machinists make a practice of setting tools above the center line, but they must grind their tools especially for that type of setting. For the average operator, student or beginner, it is recommended that the tool bit be ground to the given angles and set exactly on the center line. Several methods can be used to set the tool on the center line.
Another excellent method is to scribe a line along the tailstock ram: set a sharp pointed tool sidewise in the tool holder and align it with the headstock center. 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. Because som e set-ups a re s im p le-g ea red an d some are compounded, the carriage tra vel w ill n ot ne cessarily b e to the right when the r everse lever is shi fted t o t h e right. Swing entire gear bracket upward an d ti ghten so t hat 64 tooth gear in Position A meshes with the 32 tooth compounrl tumbler gear. Gear set-up for 8 throu g h 16 threa d s per in c h.
Place on back position of screw stub the gear list ed in "Gear on Screw" column of threading chart. Place 64 tooth gear and 20 tooth gear on b ush ing in Posit ion B with 64 tooth gear in back position. Tight en s o th at 64 t oo th gear meshes with gear in screw posit ion. The 64 tooth gear is an idler; the 20 tooth gear is a spacer.
Swing entire gear bra cket upward and tig h t en s o that 64 tooth gear in Position B meshes w ith 32 tooth compound tumbler gear.
Place on front position of screw stub the gear listed in "Gear on Screw" column of threading chart. Place 20 tooth gear and 64 tooth gear on bushing and mount in Position C with 20 tooth gear in back position.
Tighten so that 64 tooth gear meshes with gear in screw position. Exception; When cutting 32 threads per inch, substitute a 56 t ooth gear for the 64 t ooth g ear.. Place 64 tooth gear and 32 t ooth gear on b ushing an d m ount in Position A with 64 tooth gear in back p osition.
Tighten so that 32 tooth gear meshes with 64 tooth gear in P osition C. P lace 32 t ooth gear and 64 too th gear on bushing and mount in Position B with 32 tooth gear in b ack position. Tighten so that 32 tooth gear meshes with 64 tooth gear in Position C. Exceptions: 1 When cutting 36 threads per inch substitute 24 tooth gear for 32 too th gear and 48 tooth gear for 64 tooth gear. S wing entire gear bracket upward so that the 64 tooth gear in P osition B meshes with the 16 tooth compound tumbler gear.
G ear set-up for '12 thre a ds per inch. Place 64 tooth gear in back position of screw stub. Place 54 tooth gear an d 24 tooth gear on bushing and mount in Positio n B with 24 tooth gear in back position. Tighten so that 24 tooth gear meshes with the 64 tooth gear in screw position. Place 56 tooth gear and 20 tooth gear on bushing and mount in Positi on A with 20 tooth gear in back position. Tighten so that 56 tooth gear meshes wi t h 54 tooth gear in Position B.
T h e 56 tooth gear is a n idler; the 20 tooth gear is a spacer. Swing entire gear bracket upwa r d and tighten so that the 56 tooth gear in Position A meshes with the 16 tooth compound tumbler gear. Place 48 t ooth gear on front position of screw stub. P lace 40 tooth gear and 24 tooth gear on bushing in Position D with 40 tooth gear in back position. Tighten so that 24 tooth gear meshes with 48 tooth gear on screw stub. Exception: Wh en cutting 96 th reads per inch substitute 20 to oth gear fo r 24 tooth gear.
Without the threading dial it would be necessary to reverse the motor at the end of each cut and "wind" the tool out FIG. A n y one of the fOUI dial markings may be used for following cuts. When cutting odd-numbered threads such as 7.
Either the "I" or "2" dial marking may be used for following cuts. Other lines m a y be marked in by t he same mark on the threading operator as needed. The setting of the compound rest feed is changed only after each of the four grooves has been cut to the depth of setting. The cutting operation is the same as in the preceding paragraph.
The sett ing of the compound rest feed is changed only after each of the four grooves has been cut to the depth of setting. To cut multiple threads by slipping teeth on the compound gear: cut the complete first groove to a minor diameter dependent upon pitch of the desi r ed th r ead.
The change gear train should be arranged for the desired lead. It is important to use the same o point of reference to cut each thread - be sure to remember this point during the cuttin g operations.
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