D.M.L. Exam 2 - Lathes

A 1/2 in pitch single-lead thread will move .125 in in one revolution of the nut. How far will a 1/8 in. pitch, three-start thread move in one revolution.

.375 in...

Calculate the rpm for roughing a 1 1/2 diameter shaft of machine steel.

240...

What is the included angle of the Acme threads?

29 degrees...

On what percent of thread are tap drill charts usually based?

75 percent...

How is the tool aligned with the whorl?

A center gage is used to align the tool to the work...

How can a steady rest be set up when there is no center hole in the shaft?

A center punch mark is placed in the center of the end of the shaft. The lower two jaws on the steady rest are adjusted until the center punch mark aligns with the point of the dead center...

Workpieces mounted between centers are driven with lathe dogs. Which type of plate is used on the spindle nose to turn the lathe dog?

A drive plate...

When a long, slender shaft needs to be turned or threaded for its entire length, which lathe attachment could be used?

A follower rest...

What tool is used facing shaft ends when they are mounted between centers? In what way is this tool different from a turning tool?

A right had facing tool is used for shaft ends. It is different from a turning tool in the tits point is only a 58 degree included angle to fit in the narrow space between the shaft face and the center...

After a scratch cut is made, what would be the most convenient method to measure the pitch of the internal thread?

A screw pitch gage should be used...

By what method are threads cut or chased with a single-point tool in a lathe? how can a given helix or lead be produced?

A series of cuts are made in the same groove with a single point tool by keeping the same ratio and relative position of the tool on each pass. The quick change gearbox allows choices of various pitches or leads...

Give two advantages and two disadvantages of turning between centers.

A shaft between centers can be turned end for end without loss of concentricity, and it can be removed from the lathe and returned without loss of synchronization between thread and tool. Cutting off between centers is not done, as it would break the parting tool and ruin the work. Steady rest work is not done with work mounted in a center in the headstock spindle.

Standard plug or bottoming taps can be used when hand tapping in the lathe. If power is used, what kind of tap works best?

A spiral-point tap works best for power tapping...

Name four methods of indexing the lathe for multiple threads.

Accurately slotted faceplate Indexing a gear on the drive train Using the thread-chasing dial The compound rest method...

Describe the procedure in turning to size predictably.

After roughing is completed, .015 to .030 in. is left for finishing. The diameter of the workpiece is checked with a micrometer, and the remaining amount is dialed on the cross feed micrometer collar. A short trial cut is taken and the lathe is stopped. This diameter is again checked. If the diameter is within tolerance, the finish cut is taken...

Name two similarities and two differences between American National and Unified threads.

American National Standard and Unified Standard threads both have the 60 degree included angle and are both based on the inch measure with similar pitch series. The depth of the thread and the classes of thread fits are different in the two systems...

What can you use to check internal threads for fit?

An Acme thread plug gage...

Nicks and scratches are damaging to lathe ways. What can be employed to prevent them?

Because most nicks come from dropping chucks and heavy workpieces on the lathe, a lathe board used every time a chuck is changed or heavy work is installed will prevent much of this damage. A tool board will help keep tools such as files from being laid across the ways.

What does deflection or spring of the boring bar cause cutting internal threads?

Boring bar and tool deflection cause the threads to be undersize from the calculations and settings on the micrometer collars...

What are Buttress threads mostly used for?

Buttress threads are used where great forces or pressures are exerted in one direction...

Name three methods of aligning the centers.

By the witness mark on the tailstock, by using a test bar, and by taking a light cut on a workpiece and measuring...

What are two advantages in turning a single-point threading tool 180 degrees opposite the operator?

By using a 1/16 in. undersized drill and boring to the minor diameter...

How can a steady rest be used on an irregular surface shush as a square or hex stock?

By using a cat head...

In what way is percent of thread obtained? Why is this done?

By varying the bore size, usually larger than the minor diameter. This is done to make tapping easier...

Describe the kinds of tapers that may be made by using a form tool or the side of a tool.

Chamfers, V-grooves, and short tapers may be made by the form tool method...

Why are drilled holes not used for bores in machine parts such as pulleys, gears, and bearing fits?

Drilled holes are not sufficiently accurate for bores in machine parts, as they would be loose on the shaft and would not run true...

Why should you avoid excess overhang with the tool and toolholder when roughing?

Excess overhang promotes lack of rigidity. This causes chatter and tool breakage..

By what means are grooves and thread relief made in a bore?

Grooves and thread relief are made in bores by means of specially shaped or ground tools in a boring bar...

Other than hardness and toughness, what is the most important aspect of a lathe tool?

Its geometric form: the side and back rake, front and side relief angles and chip breakers...

Ordinary knurls do not cut. In what way do they make the diamond or straight pattern on the workpiece?

Knurling is used to improve the appearance of a part, to provide a good gripping surface, and to increase the diameter of a part for press fits. Ordinary knurls make a straight or diamond pattern impression by displacing the metal with high pressures.....

Why are lighter cuts taken when using the compound slide method of indexing?

Lighter cuts should be taken to keep from tearing the threads...

Why should chips be broken up?

Long stringy chips or those that become snarled on workpieces, tool post, chuk, or lathe dog are hazardous to the operator. Chip breakers and correct feeds can produce an ideal chip that does not fly off but will simply drop to the chip pane and is easily handled....

Should a steady rest be used on a rough surface? Explain.

No. When the surface is rough, a bearing spot must be turned for the steady rest jaws...

How is a standard left-hand toolholder identified?

On a left had toolholder when viewed from above the cutting tool end is bet to the right...

How often should a lathe be lubricated?

Once daily.

Determine the bore size to make a 3/4-6 general purpose internal Acme thread.

P = .1666 in; minor diameter = .750 - .1666 in = .58e in...

What is the depth of thread for a 3/4 -6 general purpose internal Acme thread?

P = 1/6 = .1666 in.; depth = .5P + .010 in = .93 in...

If cutting field is not used on parting tools, or chips do not clear out of the the groove because of a heavy feed, what is general the immediate result?

Parting tools tend to seize in the work, especially with deep cuts or heavy feeds. Without cutting fluids seizing is almost sure to follow, with the possibility of a broken parting tool and misaligned or damaged work....

If for some reason it becomes necessary for you to temporarily remove the tool or the entire threading setup before a thread is completed, what procedure should you follow when you are ready to finish the thread?

Picking up the thread or resetting the tool is a procedure used to position a tool to existing threads...

How are tool height adjustments made on a quick - change toolholder?

Quick-change toolholders are adjusted for height with a micrometer collar.

List five ways to eliminate chatter in a boring bar.

Shorten the bar overhang Reduce the spindle speed Make sure the tool is on center Use as large a diameter bar as possible without binding in the bore Reduce the nose radius on the tool Apply cutting fluid to the bore Use tuned or solid carbide boring bars

Name five thread forms used as translating screws.

Square, modified square, Acme, stub Acme, and Buttress are five basic translating thread forms...

Explain the difference between the fit of threads and the percent of threads.

The fit of the thread refers to classes of fits and tolerances, while percent of thread refers to the actual minor diameter of an internal thread, a 100 percent thread being full-depth internal threads...

The root truncation for unified threads and for American National threads is found by .125P. What should the flat on the end of the threading tools be for both systems on a 1/2-20 thread?

The flat on the end of the toll for 20 threads per inch should be P = .050 x .125 = .006 in. for American National threads and for Unified threads...

What is an independent chuck, and what is it used for?

The independent chuck is a four jaw chuck in which each jaw can move separately and independently of the others. It is used to hold odd-shaped workpieces....

What precaution can be take to prevent scoring of a finished shaft?

The jaws should be readjusted when the shaft heats up from friction, to avoid scoring. Also, soft materials are sometimes used on the jaws to protect finishes...

When internal threads are made with a tool, what should the bore size be?

The minor diameter of the thread...

Give one disadvantage of the sharp V thread.

The sharp V-thread can be easily damage during handling if it is dropped or allowed to strike against a hard surface...

What is the function of the side and back rakes?

The side rake directs the chip flow away from the cut and also provides for a keen cutting edge. The back rack also promotes smooth chip flow and good finishes....

Explain the purpose of the side and end relief angles.

The side relief allows the tool to feed into the work material. The end relief angle keeps the tool end from rubbing on the work....

What would the spacing or distance between tool marks on the workpiece be with a .01 in feed?

The spacing would be .010 in. as the tool moves that amount for each revolution of the spindle...

How is the steady rest set up on a straight finished shaft when it has centers in the ends?

The steady rest is placed near the tailstock end of the shaft, which is supported in a dead center. The steady rest is clamped to the lathe bed, and the lower jaws are adjusted to the shaft finger tight. The upper half of the frame is closed, and the top jaw is adjusted with some clearance. The jaws are locked and lubricant is applied...

What is the major difference between V-form threads and Acme threads?

The thread angle...

How is the tool aligned with the workpiece?

The tool is aligned by using the Acme tool gage...

Should the point of the tool be set above, below, or at the center of the spindle axis when taking a facing cut?

The tool should be on the center of the lathe axis

Why would threads cut with a hand die in a lathe not be acceptable for using on a feed screw with a micrometer collar?

The variations in pitch of the hand-cut threads would cause the micrometer collar to give erroneous readings. A screw used for this purpose and for most machine parts must be threaded with a tool guided by the leads crew on the lathe...

Explain the speed shifting procedure on the variable-speed drive.

The varidrive is changed while the motor is running, but the back gear lever is shifted only with the motor off....

Name three advantages offered by multiple-lead threads.

They provide rapid traverse, are more efficient, have a large minor diameter, are stronger, and furnish more bearing surface area than a single thread...

Explain the differences between through boring, counterboring, and boring blind holes.

Through boring is making a bore the same diameter all the way through the part. Counter boring is making two or more diameters in the same bore, usually with 90 degree or square internal shoulders. Blind holes are bores that do not go all the way through...

What is a major reason for thread allowances and classes of fits?

To allow for tolerancing of external and internal threads to promote standardization and interchangeability of parts....

How does the toolholder overhang affect the turning operation?

Toolholder overhang affects the rigidity of a setup; too much overhang may cause chatter...

For what two major purposes are translating-type screw thread used?

Translating-type screws are mostly used for imparting motion or power and to position mechanical parts...

Which standard toolholder would be best used for turning close to the chuck?

Turning close to the check is usually yes accomplished with a left hand toolholder...

How do form tools work?

Unlike single point tools, form tools produce their shape by plunging directly into the work...

A tool that has been reground too many times on the same place can form a chip trap. Describe the problems that result from this.

When a "chip trap" is formed by improper grinding on a tool, the chip is not able to clear the tool; this prevents a smooth flow across the face of the tool. The result is tearing of the surface on the workpiece and possible a broken tool....

How can you avoid producing a knurled surface on which the metal is flaking off?

You can avoid producing a flaking knurled surface by stopping the knurling process when the diamond points are almost sharp. Also, use a lubricant while knurling.

How can you determine the number of leads?

You can determine the number of leads by counting the number of starting grooves at the end of a bolt or screw...

How can you know if the lathe you are using is calibrated for single or double depth?

You can test with a rule and a given slide movement such as .125 or .25 in. if the slide moves half that distance, the lathe is calibrated for double depth and reads the same amount as that take for double depth and reads the same amount as that take off the diameter...

Why should the gears, ways, leads crew, and carriage be lubricated before cutting coarse threads?

Coarse threading on a lathe imposes heavy loads on these parts. Lubrication prior to threading helps reduce excess wear...

What factors tend to promote or increase chip curl so that safer chips are formed?

Coarser feeds, deeper cuts, and smaller rake angles all tend to increase chip curl. Chip breakers also make the chip curl....

Name one advantage of using steel spring collets. Name one disadvantage.

Collet chucks are accurate work-holding devices. Spring collets are limited to smaller material and to specific sizes...

What chuck types make possible the frequent adjusting of chucks so that they will hold stock with minim runout?

Combination chuck and Adjust-Tru three-jaw chucks...

Machine reamers produce a better finish than is obtained by boring. How can you get an even better finish with a reamer?

Hand reamers produce a better finish than machine reaming....

Reamers will follow an eccentric drilled hold, thus producing a bell mouth bore with runout. What device can be used to help eliminate bell mouth? Does it help remove the runout?

A floating reamer holder will help eliminate the bell mouth, but it does not remove the runout...

How can you avoid drilling oversize with a tap drill?

A tap drill can be sued as a reamer by first drilling with a drill that is 1/32 to 1/16 in. undersized. This procedure ensures a more accurate hole size by drilling...

Give two methods of checking an internal thread for size.

A thread plug gage, a shop-made plug gage, or the mating part...

When should a zero or negative rake be used?

A zero rake should be used for threading tools. A zero to slightly negative back rake should be used for plastics and brass, because the tend to 'dig in'...

Why should the dead center be frequently adjusted when turning between centers?

Because of expansion of the workpiece from the heat of machining, it tightens on the center, thus causing more friction and more heat. This could ruin the center...

Why will you not achieve the same surface finish (tool marks per inch) on the face of a workpiece as you will on the outside diameter when on the same power feed?

Because the cross feed is geared differently (about 1/3 of the longitudinal feed), the outside diameter would have a coarser finish than the face...

What will the depth of thread be for a General Purpose Acme thread that is 4 tpi?

Because the pitch for 4 TPI would be .250 in., the depth of the Acme thread would be .5P + .010 in., or .5x.250+.010 = .125 in....

What will the depth of thread be for a square thread that is 4 tpi?

Because the pitch for 4 TRI would be .250 in., the depth of thread would be P/2 = .250/2 = .125 in

In what ways can a steady rest be useful?

Because they are useful for supporting long workpieces, heavier cuts can be taken, or operations such as turning, threading, and grooving may be performed without chattering. Internal operations such as boring may be done on long workpieces.

Are boring bar holders that are used in standard tool posts more or less rigid than those held in quick-change tool holders?

Boring bars are less rigidly held in the older style starboard tool posts...

How are Unified and metric thread forms similar?

Both are 60 degree forms...

In what ways can chips be broken?

Chips can be broken up by using coarse feeds and maximum depth of cuts for roughing cuts and by using tools with chip breakers on them...

Cutting speeds for reaming are (twice, half) that used for drilling; feeds used for reaming are (twice, half) that used for drilling

Cutting speeds for reaming are half that used for drilling; feeds used for reaming are twice that used for drilling...

Using Px.541 as a constant for Unified single-depth internal threads, calculate the minor diameter of a UNC 1-8 thread.

D = P x .521 x 2 P = 1/8 in. = .125 in. D = 1 - (.125x.541x2) = .8648 in...

Name three kinds of centers used in the tailstock and explain their uses.

Dead centers are hardened 60 degree centers that do not rotate with the work but require high-pressure lubricant. Ball bearing centers turn with the work and do not require lubricant. Pipe centers turn with the work and are used to support tubular material....

What kind of tools are used in the lathe tailstocks?

Drilling machine tools are used in a lathe tailstock...

Explain which positions on the threading dial are used for engaging the half-nuts for even, todd and fractional numbered threads.

Even numbered threads may be engaged on the half-nuts at any line, and odd-numbered threads at any numbered line. It would be best to use the same line every time for fractional numbered threads...

Describe a face driver.

Face drivers use multiple driving pins that dig into the work and are hydraulically compensated for irregularities

Why should fine chips, filings, and grindings be cleaned form the ways and slides frequently?

Fine chips, filings, and grinding form an abrasive sludge that wears and scores the sliding surfaces. Frequent cleaning will help prevent damage to the machine.

What is the difference between a standard toolholder for high-speel steel tools and for carbide tools?

For high speed tools the square tool bit hole is angled upward in relation to the base of the toolholder, whereas it is parallel to the base for carbide tools...

How much should be left for finishing?

For most purposes where liberal tolerances are allowed, .015 to .030 in. can be left for finishing. When closer tolerances are required, two finish cuts are taken, with .005 to .010 in. left for the last finish cut..

Name four method of measuring tapers.

Four methods of measuring tapers are using the plug and ring gages, using a micrometer on layout lines, using a micrometer with precision parallels and drill rod on a surface plate, and using a sine bar, gage block, and dial indicator...

What is the main difference between General Purpose Acme threads and centralizing Acme threads?

General-Purpose Acme threads bear on the flanks, and centralizing Acme threads bear at the major diameter...

How should the ways and slides be cleaned?

Heavier chips should be removed with a brush; never use an air jet. The ways should then be wiped clean with a cloth and lightly oiled.

List the advantages to using high-speed steel for tools.

High speed steel is easily shaped into the desired shape of cutting tool. It produces better finishes on low speed machines and on soft metals....

Which would be best for making a 6 in. diameter internal thread using an engine lathe: a tap or a single point threading tool? Explain.

Large internal threads are produced with a boring tool Heavy forces are needed to turn large hand taps, so it is not advisable to use large taps in a lathe....

Give two advantages of making internal threads with a single-point tool on the lathe,

Large internal threads of various forms can be made, and the threads are concentric to the axis of the work...

In what way can speed changes be made on geared head lathes?

Levers located on the headstock can be shifted in various arrangements to select speeds....

Explain how a good tool finish may be obtained on an Acme thread.

Light finishing cuts with a hone tool and a good grade of sulfured cutting oil will help make good thread finishes. A rigid setup and low speeds will also help...

How can the shift to the low-speed range be made on the belt-drive lathe that have the step cone pulley?

Low speeds are made possible by disengaging the spindle by pulling out the lock pin and engaging the back gear...

What kinds of threads can be made multiple lead?

Most kinds. Sharp-V, American National, Unified, metric, Buttress, square, and Acme can be made multiple lead, in either right- or left-hand threads

When a taper is produced by the compound slide method, is the reading in degrees on the compound slide method, is the reading in degrees on the compound swivel base the same as the angle on the finished workpiece? Explain.

No. The angle on the workpiece would be the included angle, which is twice that on the compound setting. The angle on the compound swivel base is the angle with the work centerline...

Is the carriage moved along the ways by means of hears when the half-nut lever is engaged? Explain.

No. The carriage is moved by the thread on the leads crew when the half-nuts are engaging it...

Should you being work immediately on a lathe that looks perfectly clean? Explain.

No. The oil on the ways may have collected dirt or grit from the air to form an abrasive mixture. The ways should first be cleaned and oiled.

If you set the quick-change gearbox to .012 in, is that considered a roughing feed for facing?

No. The resultant facing feed would be approximately .003 to .005 in. which would be a finishing feed....

Is is possible to correctly sett up a steady rest by using a dial indicator on the rotating shaft to watch for runout?

No...

A high-speed tool bit can easily be overheated by using a glazed wheel that needs dressing or by exerting too much pressure. What does this cause in the tool?

Overheating a tool causes small cracks to form on the edge. When a stress is applied, as in a roughing cut, the tool end may break off...

Why should both leads be roughed out before taking the finish cut on coarse threads?

Roughing of coarse threads may move the tool slightly. If one thread has already been finished, there is no more allowance for adjustment. Finishing both threads consecutively, however, gives a much greater assurance that the setup will not move...

Which thread has more force or holding power for fasteners, a single or a multiple lead?

Single lead...

Why is it not always necessary to grind a back rake into the tool?

Some tool holders provide a built-in back rake of about 16 degrees; to this is added any back rake on the tool to make a total back rake that is excessive...

State the difference in use between steep tapers and slight tapers.

Steep tapers are quick-release tapers and slight tapers are self-holding tapers...

Name two types of gibs used on lathes.

Straight gibs and tapered gibs.

In what three ways are tapers expressed (measured?)?

Tapers are expressed in taper per foot, taper per inch, and by angles...

Briefly describe the six methods of turning a taper in the lathe.

Tapers are turned by hand feeding the compound slide, by offsetting the tailstock and turning between centers, or by using a taper attachment. A fourth method is to use a tool that is set to the desired angle and form cut the taper.

By what means should a threading tool be checked for a 60 degree angle?

The 60 degree angle on the tool is checked with a center gage or optical comparator...

Of the translating thread forms, which type is most used and is easiest to machine?

The Acme thread form...

Name two metric thread standard systems.

The SI thread and the British Standard ISO Metric Screw Threads are two metric thread systems in use...

If a tool turns into the workpiece and gouges it, what is usually the cause?

The T-bolt holding the tool post to the the compound rest was not sufficiently tightened.

How can these angles be checked while grinding?

The angle can be checked with a tool grinding gage, a protractor or an optical comparator....

Micrometer collars are attached on the cross feed handle and compound handle. In what ways are they graduated?

The are graduated in English units. Some metric conversion collars are being made and used that read in both English and metric units at the same time...

What is the chief advantage of boring over reaming in the lathe?

The chief advantage of boring in the lathe is that the bore runs true with the centerline of the lathe and the outside of the workpiece, if the workpiece has been set up to run true (with no runout). This is not always possible when reaming bores that have been drilled, because the reamer follows the eccentricity or runout of the bore....

The better practice is to feed the tool in with the compound set at 29 degrees rather than with the cross slide when cutting threads. Why is this so?

The chips are less likely to bind and tear off when feeding with the compound set at 29 degrees, and the tool is less likely to break...

What should you do when you are finished using the lathe?

The chips should be cleaned from the lathe and swept up on the surrounding floor area. The lathe ways and slides should be wiped and oiled.

Who far should the compound set at 30 degrees move to cut a 1/2-20 Unified thread? (The formula is .701/n)

The compound at 30 degrees will move in .708/20 = .0354 in. for Unified threads. The compound will move in .75/20 = .0375 in. for American National threads...

Where is the compound most frequently set when cutting Acme threads? What setup is preferred by some machinists?

The compound is usually set at 14 1/2 degrees. Some machinists prefer to set the compound at 90 degrees...

An alignment step must be machined on a cover plate .125 in, .003 in, in depth. What procedure should be taken to face to this depth? How can you check your final finish cut?

The compound must be swung to either 30 or 90 degrees so that the tool can be fed into the face of the work by a measured amount. A depth micrometer or a micrometer caliper can be used to check the trail finish cut....

Which measuring instrument is used when using a test bar?

The dial indicator...

What is the difference between a standard toolholder and a quick-change toolholder?

The difference between a standard type toolholder and a quick change toolholder is the speed with which tools can be interchanged. The tools are usually fastened more securely in a quick change toolholder and height adjustments on a quick change toolholder do not change the effective back rake angle of the cutting tool...

Define pitch

The distance from a point on one thread to a corresponding point on the next...

Define lead

The distance the nut travels in one revolution...

What should the feed rate be for roughing?

The feed rate for roughing should be one fifth to one tenth as much as the depth of cut. This should be limited to what the tool, workpiece, or machine can stand without undue stress....

What lever is shifted to reverse the lead screw?

The feed reverse lever...

Explain the general use of the stub Acme threads.

The general use for stub Acme threads is where a coarse pitch thread with a shallow depth is required...

How tightly should the gibs be adjusted on the cross slide and on the compound?

The gib on the cross slide should be adjusted so it will have a slight drag, but the compound should be set up fairly tight when it is not being used.

The half-nut lever is not used to move the carriage for turning. Name its only use.

The half-nut lever is used only for threading....

When grinding an Acme threading tool, what three important parts should be carefully measured?

The included angle, the relief angle, and the flat on the end of the tool...

Briefly describe the lathe spindle. How does the spindle support chucks and collets?

The lathe spindle is a hollow shaft that can have one of three mounting devices machined on the spindle nose. It has an internal Morse taper that will accommodate centers or collets....

How are tools fastened in the tailstock?

The lathe tailstock is bored with a Mores taper hole to hold Morse taper shank tools...

What is the procedure for cutting left-hand threads?

The lead screw rotation is reversed, which causes the cut to be made from the left to the right. The compound is set at 29 degrees to the left. The threading tool and lathe settings are set up in the same way as for cutting right-hand threads...

What is a live center made of? How does it fit in the spindle nose?

The live center is made of soft steel, so it can be turned to true it up if necessary. It is made with a Morse taper to fit the spindle taper or special sleeve if needed....

Which thread form has a 10 degree included angle?

The modified square thread...

How can the number of threads per inch be checked?

The number of threads per inch can be checked with a screw pitch gage or by using a rule and counting the threads in one inch...

What other method besides turning between centers is extensively used for turning shafts and long workpieces supported by the tailstock center?

The other method is one whereby the workpiece is held in a chuck on one end and in the tailstock center on the other end.

Explain the difference between the threads per inch and the pitch of the thread.

The pitch is the distance between a point on a screw thread to a corresponding point on the next thread measured parallel to the axis. "Threads per inch" is the number of threads in one inch...

When is the proper time to use the carriage hand wheel?

The quick approach and return of the tool; this is used for delicate work and when approaching a shoulder or chuck jaw....

If the swivel base is set to a 35-degree angle at the cross-slide centerline index, what will the reading be at the lathe centerline index?

The reading at the lathe centerline index would be 55 degrees, which is the complementary angle...

The jaws of the follower rest are usually 1 or 2 in. to the right of the tool on a set up. If the workpiece happens to be smaller than the dead center or tailstock spindle, how will it be possible to bring the tool to the end of the work to start a cut without interference by the follower rest jaws?

The shaft is purposely made 1 or 2 in. longer, and an under cut is machined on the end to clear the follower rest jaws...

Name the spindle nose types.

The spindle nose types are the threaded, long taper key drive, and the camlock...

How fast should the spindle be turning for threading?

The spindle should be turning slowly enough for the operator to maintain control of the threading operation, usually about one fourth of turning speeds...

What is the most practical and convenient way to check internal and external tapers when they are in the lathe?

The taper plug gage and the taper gage are the simplest and most practical means to check a taper...

What are the two types of taper attachments, and what are their advantages over other means of making a taper?

The two types of taper attachments are the plain and the telescopic. Internal external and slight to fairly steep tapers can be made. Centers remain in line, and power feed is used for good finishes....

What is a universal chuck and what is it used for?

The universal chuck is most often a three-jaw chuck, although these chucks are made with more or fewer jaws. Each jaw moves in or out by the same amount when the chuck wrench is turned. They are used to hold and quickly center round stock...

What happens to the workpiece when the centers are out of line?

The workpiece becomes tapered...

Describe the procedure used to produce drilled holes on workpieces in the lathe with minim oversize and runout.

The workpiece is center spotted with a center drill at the correct rpm and if the hole is to be more than 3/8 in. in diameter, a pilot drill is put through. Cutting fluid is used. The final size drill is put through at a slower speed....

What happens to the workpiece when the tailstock is offset toward the operator?

The workpiece is tapered with the small end at the tailstock...

The sliding gar shifter levers on the quick-change gearbox are used for just two purposes. What are they?

These levers are used for selecting feeds or threads per inch per threading...

What does 1/2-20 UNC-2A describe?

This describes a diameter of 1/2 in., 20 threads per inch and Unified coarse series external thread with a class 2 thread tolerance...

By what means is thread relief on external grooves produced?

Thread relief and external grooving tools except that they have less end relief. Parting tools are often used for making external grooves...

Why were quick-changes tool holders developed?

To increase rigidity and hence greater production...

When making internal right-hand threads, in which direction should the compound be swiveled?

To the left of the operator...

How are tool height adjustments made on a standard toolholder?

Tool height adjustments on a standard type tool holder are made by swiveling the rocker in the tool post ring...

How are tool height adjustments made on a turret-type toolholder?

Tool height on turret tool holders is adjusted by placing shims under the tool.

When is a tailstock turret used?

When a series of repeat tailstock operations is to be performed on several different workpieces, a tailstock turret should be used....

If a knurl is producing a double impression, what can you do to make it develop a diamond pattern?

When knurls produce a double impression, they can be readjusted up or down and moved to a new position. Angling the toolholder 5 degrees may help...

When should a steady rest be used?

When workpieces extend from the chuck more than four or five workpiece diameters and are unsupported by a dead center; when workpieces are long and slender...

By what means is the measuring done when checking taper by taking a cut?

With a micrometer. The tailstock is set over with a dial indicator...

Which is the best way to make small internal Acme threads?

With an Acme tap set...

How is the dead center correctly adjusted?

With no end play in the workpiece and the bent tail of the lathe dog free to move in the slot...

On which type of plate are workpieces and fixtures mounted? How is it identified?

Workpieces and fixtures are mounted on faceplates. These are identified by their heavy construction and the T-slots. Drive plates have only slots...

How can you avoid chatter when cutting off stock with a parting tool?State three reasons for knurling.

You can avoid chatter when cutting off with a parting tool by maintaining a rigid setup and keeping enough feed to produce a conintuous chip if possible...