AU INSY3800 Chapter 23-25

Chucks

A lathe ______ is a device on the driven spindle on the head (headstock) of the machine that holds the workpiece. It grips and spins it.

Machining Center

A milling machine whose motions are electronically controlled which has tool and pallet exchange capability.

Peripheral Milling

A milling operation in which the cutting edge of the mill is parallel to the axis of spindle rotation.

slab milling-

A milling process that rotates on an axis parallel to the workpiece. __________ produces flat surfaces.

Milling Machines

A variety of machines that perform different processes to generate progressive chip removal from a surface.

End Milling (614-15)

A very common operation performed on both vertical and horizontal spindle milling machines or machining centers.

Boring

Always involve the enlarging of an existing hole, which may have been made by a drill or may be the result of a core in a casting. Essentially, ______ is internal turning. _____ can use single-point cutting tools to produce internal cylindrical or conical surfaces.

Facing

An operation called _________ is when the tool is fed at 90 degrees to the axis of rotation, using a tool that is wider than the width of the cut producing a flat surface

Milling

Cutting and shaping materials into products with milling machines

Interrupted Cutting

Equally spaced peripheral teeth will intermittently engage and machine the workpiece.

Chisel End

If a plain conical point is ground on the drill, the intersection of the web and the cone produces a straight-line _______, which can be seen in the end view of figure 24-2. page 588

Climb Down Milling (617)

In ___ the cutter rotation is in the same direction as the feed rate.

Column-and-Knee Milling Machine (623)

Most milling machines are constructed using this method. The column, mounted on the base, is the main supporting frame for all the other parts and contains the spindle with its driving mechanism. This construction provides controlled motion of the worktable in three mutually perpendicular directions. 1) through the knee moving vertically on ways on the front of the column 2) through the saddle moving transversely on ways on the knee and 3) through the table moving longitudinally on ways on the saddle.

Trepanning

Removing a cylindrical sample from a metal section or structure to determine soundness of the section

Convential (Up) Milling (616)

The conventional way to mill, often called conventional milling. In ___ the cutter rotates against the direction of feed of the workpece.

Milling Cutters

The cutting tool used in milling.

Saddle

The mill _____ slides in and out (Y-axis) on the mill base. The mill table moves left and right (X-axis) on top of the ______

Milling

This can be done on a lathe but requires special attachments; it is the basic machining process by which a surface is generated by progressive chip removal. The act or process of grinding, cutting, pressing, or crushing

Metal Removal Plate

This controls the trimmings and shavings that are created in turning and boring processes

Quill

This is a hollow steel cylinder, usually about 2 to 3 inches in diameter that can be moved longitudinally in and out of the upper casting by means of a handwheel and screw.

Knurling

This produces a regularly shaped, roughened surface on a workpiece. In most cases this is done on external cylindrical surfaces using lathes; it is a chipless, cold forming process

Center Core Drill

This, aka slot point drill, is relatively new to the marketplace. This drill has twin carbide tips brazed on a steel shank and a hole (or slot) in the center. It has a self-centering action and greatly relieves the thrust force produced by the chisel edge of conventional twist drills. This drill operate at about 30 to 50% less thrust than that of conventional drills.

Cutting Time (541)

Time in minutes it takes to produce a piece.

Fixtures (or Vises)

Various workholding devices.

Metal Removal Rate (MRR)

Volume / Cutting Time. Rate of metal being removed. THE CUTTING SPEED.

Insert-tooth Milling Cutter

When the body is made of steel, with the teeth cutter made of high-speed steel, carbides, or TiN carbides, fastened to the body by various methods.

Cutoff

When the tool is fed all the way to the axis of the workpiece, it will be cut in two. Also known as parting.

Lathe center

Workpieces that are relatively long with respect to their diameters are usually machined between __________. Two of these are used, one in the spindle hole and one in the hole in the tailstock quill. Two types are used, called dead and live

Mandrels

Workpieces that must be machined on both ends or are disk-shaped are often mounted on ______________ for turning between centers. There are three common types: Gang, Solid, and Cone.

Face Milling (619)

____ have a center hole so that they can be arbor mounted. _____ cutters are widely used in both horizontal and vertical spindle machine tools and come in a wide variety of sizes and geometries.

Tang

a long and slender projecting strip, tongue, or prong forming part of an object, as a chisel, file, or knife, and serving as a means of attachment for another part, as a handle or stock

Turret Lathe

a longitudinally feedable, hexagon turret replaces the tailstock and the turret on which six tools can be mounted can be rotated about a vertical axis to bring each tool into operating position, and the entire unit can be translated parallel to ways.

Jig

a plate, box, or open frame for holding work and for guiding a machine tool to the work

Carriage

a relatively flat H-shaped casting, rides on the outer set of ways on the bed. It is on the carriage assembly which provides the mean for mounting and moving cutting tools.

Reaming,hand

a tool used for turning and fed by hand and to remove only a few thousandths of an inch of metal.

Screw Machine

are lathes designed for completely automatic operations

Multiple spindle drilling machine-

are mass production machines with as many as 50 spindles driven by a single power head and fed simultaneously into the work.

Turret Drilling Machine

are used when a series of holes of different sizes, or a series of operations (such as center drilling, drilling, reaming, and spot facing), must be done repeatedly in succession.

Spade Drill

are widely used for making holes 1 in. or larger in diameter at low speeds or with high feeds.

Tailstock

assembly containing three parts, a lower casting fits on the inner ways of the bed, an upper casting fits on the lower one, and the third major component of the assembly is the tailstock quill; support consisting of the movable part of a lathe that slides along the bed in alignment with the headstock and is locked into position to support the free end of the workpiece

Web

between the flutes, forms a metal column or backbone.

Indexable insert drill

can produce a hole four times faster than a spade drill because they run at high speeds/low feeds and are really more of a boring operation than a drilling process.

Drill Press

common name for the machine tool used for drilling. Consists of a base, a column, that supports a powerhead, a spindle,and a worktable.

Turning

constitutes the majority of the lathe work and is the process of machining external cylindrical and conical surfaces.

Lip

cutting edge of a drill

Workholding

devices for lathes that are commonly used for supporting work pieces.

Subland Drill

have a separate set of flutes on a single body for each diameter or operation; they provide better chip flow, and the cutting edges can be ground to give proper cutting conditions for each operation.

Chuck

hold straight-shank drills. __________ are adjustable over a considerable size range and have radial steel fingers. When the _______ is tightened by means of a _______ key, these fingers are forced inward against the drill.

Drilling

how majority of holes are made in manufacturing. Makes up about 25% of all manufacturing processes performed.

Thrust Force

increases with feed for all drill geometries, is influenced greatly by the web or chisel end design.

Collets

is a holding device, specifically, a subtype of a chuck that forms a collar around the object to be held and exerts a strong clamping force on the object when it is tightened via a tapered outer collar. It may be used to hold a workpiece or a tool.

Spot Facing

is done to provide a smooth bearing area on an otherwise rough surface at the opening of a hole and normal to its axis.

straddle milling-

is face milling of two parallel vertical surfaces of a workpiece simultaneously by using two side-milling cutters.

Bed

is the base and backbone of a lathe. Is usually made of well normalized or aged gray or nodular cast iron and provides a heavy, rigid frame on which all the other basic components are mounted.

Taper Turning

is when the tool is fed at an angle to axis of rotation and an external conical surface results.

staggered-tooth milling cutter-

milling cutter with successive teeth having alternating helix angles

Profiler

milling machines that can duplicate external or internal geometries in two dimensions are called profilers or tracer-controlled machines.

Woodruff keyseater-

mills the semi-cylindrical seats required in shafts for Woodruff Keys

Twist Drill

most common type of drills; A rotating cutting tool, used for cutting holes in metal, wood, or other materials, that consists of an essentially conical point, relieved and fluted to form cutting lips, and spiral flutes which direct the chips away from the lips and toward ejection from the hole

Shell Reamer

often are used for hole sizes over 3/4 in. in order to save cutting-tool material. The shell, is made of tool steel for smaller sizes and with carbide edges for larger sizes or for mass-production work, is held on an arbor that is made of ordinary steel.

Cutting Tools

p 572 Most lathe operations are done using single point ____, such as those illustrated in Figure 23-25. On right-hand (and left-hand turning) and facing tools, the ____ usually takes place on the side of the tool; therefore, the side rake angle is of primary importance, particularly when deep cuts are made.

Follow Rest

p 580 This is bolted to the lathe carriage. It has two contact fingers that are adjusted to bear against the workpiece, opposite the cutting tool, in order to prevent the work from being deflected away from the cutting tool by the cutting forces.

Feed

p 585 The ___, fr, is given in inches per revolution. The depth of cut in drilling is equal to half the ____ rate, or t = fr/2. The ___ rate in inches per minute fm, is frN. In dealing with drilling, because the ___ may be manually controlled, care must be exercised, particularly in drilling small holes.

Depth of cut

p550 Roughing cuts may be as heavy as proper chip thickness, cutting dynamics, tool life, lathe horsepower, and the workpiece permit. Large _______ and smaller feeds are preferred to the reverse procedure, because fewer cuts are required and less time is lost in reversing the carriage and resetting the tool for the following cut.

Drilling

p553 This can be done on lathes with the ____ mounted in the tailstock quill of engine lathes or the turret on turret lathes and fed against a rotating workpiece.

Engine Lathe

p556 The essential components of an _____ are the bed, headstock assembly, tailstock assembly, carriage assembly, quick-change gearbox, and the leadscrew feed rod.

Face Plates

p579 These are used to support irregularly shaped work that cannot be gripped easily in chuck or collets. The work can be bolted or clamped directly on the ____ or can be supported on an auxiliary fixture that is attached to the _____.

Steady Rest

provide means for supporting such work between the headstock and the tailstock. Can also be used in place of the tailstock as a means of supporting the end of long pieces, pieces having too large an internal hole to permit using a regular dead center, or work where the end must be open for boring.

Helix angle

relation formed by the principal rake angles behind the cutting edges, most drills angles are 24 degrees

Flute

spiral or helical grooves in the body of a twist drill.

Gundrill

the oldest deep-hole technique, are used when deep holes are to be drilled.

Headstock

this is mounted in a fixed position on the inner ways of a lathe and provides powered means to rotate the work at various rpm values.

Parting

this is the operation by which one section of a workpiece is severed from the remainder by means of a cutoff tool; If the tool is fed all the way to the axis of the workpiece, it will be cut in two. This is called ____________ or cuttoff and a simple, thin tool is used

Reaming

this on a lathe involves no special precaution; machining to make existing holes dimensionally more accurate by enlarging to desired size by means of a reamer.

Apron

together with the ____, provides the means for mounting and moving cutting tools. Is a part of the carriage assembly.

Gang-Drilling Machine

used in mass production when several related operations must be done on a single part. Consist essentially of several independent column, heads, and spindles mounted on a common base and having a single table. Work can be slid into position for the operation at each spindle.

Radial drilling machine

used on large workpieces that cannot easily be handled manually. The column supports a radial arm that can be raised and lowered by power and rotated over the base.

Deep Hole Drilling

used when deep holes are to be drilled. Most hole makers consider a depth-to-drill diameter ratio of 3 to 1 to be __________. AKA gun drills.

Reaming,machine

uses various machine tools at slow speeds to remove a small amount of material from the surface of holes.

Countersinking

usually follow drilling; makes a beveled section at the end of the drilled hole to provide a proper seat for flat-head screw or rivet.

Counterboring

usually follow drilling; provides an enlarged cylindrical hole with a flat bottom so that a bolt head or not will have a smooth bearing surface that is normal to the axis of the hole.