Engine Lathe Setup 231

4-position toolholder

A type of toolholder, also called a station toolholder, that allows the mounting of four different tools at once on a lathe. 4-position toolholders allow for quick tool changes and efficient machining operations.

alignment

The accurate positioning of machine components. Alignment on a lathe requires the workpiece and spindle to share a common centerline.

axes

A theoretical line that is used to measure the location, orientation, and movement of an object in three–dimensional space. Axes in the Cartesian coordinate system include the X, Y, and Z axes.

axial depth of cut

The measurement of how far the cutting tool cuts into the face of the workpiece. Axial depth of cut measure cutting along the Z axis.

axial runout

A type of misalignment describing a cylindrical workpiece when one end is concentric and the other is not. Axial runout on an engine lathe means the workpiece is not parallel with the machine spindle.

bar stock

Raw material purchased from metal manufacturers in the form of long bars. Bar stock may be round, square, or hexagonal.

bearings

A device that allows one moving part to glide past another moving part with reduced wear and friction. Bearings are located in a live center to make for easy rotation in the spindle.

boring bar

A cylindrical toolholder used to position a single-point tool for internal cutting operations. Boring bars are used for internal taper turning operations on a lathe.

burrs

A rough, sharp edge on a material, such as metal. Burrs on a chuck could cause axial runout.

camlock spindle nose

A type of spindle nose that holds the workholding device in place with camlocks around its perimeter. Camlock spindle noses are often used on high-powered machines.

camlocks

A type of fastener used to secure a chuck to a camlock spindle nose. A camlock contains a base that a chuck key can attach to and turn the cam, which latches the camlock in place.

carbide

A common cutting tool material developed by combining carbon with a hard metal, such as titanium or tungsten. Carbide cutting tools are the most commonly used in the metal cutting industry.

carriage

A component of the lathe that slides along the ways parallel to the spindle axis. The carriage houses the cross slide.

carriage handwheel

A hand-cranked wheel that moves the lathe carriage back and forth along the ways, parallel to the workpiece. The carriage handwheel positions the cutting tool for turning operations.

Cartesian coordinate system

A numerical system that describes the location of an object by expressing its distance from a fixed position along three linear axes. The Cartesian coordinate system is used to properly align machining positions on a lathe.

center-drill

Using a center drill to make a tapered hole in the end of a part. Once a part is center-drilled, the center can support it using the tapered hole.

centering

Aligning the axes of the cutting tool and workpiece on a lathe. Centering is an important step in setup.

centerline

An imaginary line that divides a shape into two equal halves or that runs through the center of a cylindrical object. A cylindrical workpiece rotates along a centerline.

centers

A cylindrical workholding device with a pointed tip. Centers require that the workpiece is center-drilled before using them.

chuck

A device that holds a workpiece in place as it rotates on a lathe or other machine. The chuck commonly has two, three, or four jaws that can be adjusted to fit various workpieces.

chuck key

A device used to loosen the bolts or camlocks on a chuck. A chuck cannot be removed from a camlock spindle nose without the use of a chuck key.

clevis pin

A cylindrical semi-permanent pin with a head at one end and one or more through holes at the other end. Clevis pins are used to secure a drawbar and collet or adapter in a lathe spindle.

closer lock ring

A device on a collet that adjusts the clamping pressure of the collet on the workpiece. Closer lock rings prevent rotation of the workpiece during machining.

collet

A slotted device that holds a workpiece or cutting tool in place as it rotates. A collet has a hole through which the workpiece or tool passes and is designed to hold specific dimensions.

combination set

A multi-faceted measuring device that allows operators to lay out any size angle. Combination sets consist of a protractor head, square head, and center head on a steel rule.

compound rest

The part of the lathe that holds the tool post. The compound rest makes smaller movements than the cross slide for making finer cuts.

concentric

A description of multiple round or circular shapes that have a common center or share the same axis. When the workpiece and lathe spindle share a common centerline, they are concentric.

concentricity

A geometric tolerance that creates a tolerance zone for the median points of a cylindrical feature. Concentricity is related to tolerance.

cross slide

The part of the carriage assembly on an engine lathe that holds the compound rest. The cross slide moves the cutting tool perpendicular to the workpiece.

cross slide feed dial

The graduated scale that indicates depth of cut. The cross slide feed dial setting determines how far the cross slide moves the cutting tool each pass.

cross slide handwheel

A hand-cranked wheel that moves the cross slide perpendicular to the workpiece. The cross slide handwheel moves the cutting tool toward or away from workpiece.

cutting fluid

A liquid used to cool or lubricate a metal cutting process. Cutting fluids are typically oil- or water-based liquids.

cutting tool

A device that is used to remove metal by creating chips. Cutting tools used for lathe operations are usually single-point tools such as carbide inserts.

cutting tool sleeve

A device that secures a cutting tool and may go inside another toolholder. Cutting tool sleeves prevent the cutting tool from slipping or moving during machining.

cutting zone

The area of contact between the cutting tool and the workpiece. The cutting zone is often lubricated and cooled through the use of cutting fluids.

dead center

A type of center designed that is solid in construction with no moving parts. Dead centers must be lubricated with cutting fluid during each use.

depth of cut

doc. The distance that a cutting tool penetrates the surface of a workpiece. Depth of cut determines the amount of material removed with each cutting pass.

dial indicator

A measuring instrument used to indicate linear movement, roundness, and runout. Using a dial indicator is the best way to determine runout in order to ensure the workpiece is properly aligned with the spindle.

diameter

A line that divides a circle into two equal halves. Diameter indicates the width or thickness of a round or cylindrical workpiece.

digital readout

DRO. A type of readout that uses an encoder attached to a machine that transfers information to a digital display. Digital readouts can display very precise measurements.

dimensions

A measurement of space, especially length, width, and height. Dimensions of a part are detailed in a blueprint.

display panel

The screen that displays information about a machine for the operator. Display panels indicate the position of the workpiece on a manual milling machine.

draw nut

A threaded device that inserts into the spindle shaft or toolholder to compress the workpiece against the collet. Draw nuts should be tightened when inserting a collet into the spindle to secure the cutting tool.

drift pin

A fastener that locks a tool into the taper of the tailstock sleeve of a lathe. The lathe drift pin also allows for easy tool removal.

drip method

A manual coolant-delivery method in which an operator uses a brush to apply fluid on the workpiece surface. The drip method is often used with oil-based cutting fluids.

drive plate

A plate that is mounted to the spindle to provide the turning force during machining a workpiece between centers. Drive plates have slots for attaching a lathe dog, which transmits rotation from the plate to the workpiece.

DRO

Digital readout. A type of readout that uses an encoder attached to a machine that transfers information to a digital display. Digital readouts can display very precise measurements.

ductile

Characterized by the ability to be drawn, stretched, or formed without breaking. Ductility is generally present in the absence of strength.

eccentric

A description of multiple round or circular shapes that have different centers. Eccentric rotating components have different centerlines, or axes.

engine lathe

The original and most basic type of manual lathe. Engine lathes are used to make cylindrical metal parts.

faceplate

A circular workholding device with holes, slots, or both to allow the placement of fixture components. A faceplate is the most basic means of mounting a workpiece on the spindle of a lathe.

fasteners

A device that holds objects together or locates them in relation to one another. Common fasteners include bolts, screws, and rivets.

feed

The rate at which the cutting tool moves along a workpiece during cutting. Feed is often measured in inches or millimeters per minute (ipm or mm/min), or in inches or millimeters per revolution (ipr or mm/rev).

feed direction lever

A lever on the carriage that controls the direction of the automatic feed on a lathe. The feed direction controls the direction of feed to move the carriage forward or backward.

feed ratio

An expression that compares the measurements on a lathe's feed dial with the amount of material the tool removes. Feed ratios for feed dials with diameter measurements are 1:1, which means the tool removes the same amount of material listed on the dial, while a 2:1 ratio means that the dial uses radius measurements, and the tool removes twice the diametric amount on the dial.

feeler gage

A device of known thickness used to measure small distances. Feeler gages come in a range of sizes.

finishing cuts

A final pass of the cutting tool that emphasizes accuracy, tolerance, and surface finish. Finishing cuts often require faster speeds and a lighter depth of cut.

flood cooling

A coolant-delivery method that covers the cutting zone with cutting fluid. Flood cooling is the least commonly used fluid delivery system for manual machining.

graduated dial

An analog device that measures linear movement. Graduated dials are numbered collars attached to handwheels on the lathe that record and measure movement and positioning.

hard

Able to resist scratching, indentation, or penetration. Hard workpiece materials are usually more difficult to machine, and they generate more heat during machining than soft materials.

headstock sleeve

An insert that goes into the drive plate on the headstock for particular workholding devices. Headstock sleeves may be adapted to fit centers, chucks, or live centers.

height gage

A measuring device with a column mounted on a base, a unit that slides up and down, an indicator, and an arm that extends out. Height gages precisely measure vertical distance.

hex key

A hexagonal wrench that is used to fasten socket head cap screws. Hex keys can be used to tighten an indexable insert into place.

ID operations

Inner diameter operations. Cutting operations that take place on the interior surface of a workpiece. Inner diameter operations, also known as internal diameter operations, on the lathe include drilling, reaming, and boring.

inches per revolution

ipr. A measurement of how many inches a cutting tool advances along a workpiece in one revolution of that workpiece. Inches per revolution measures feed.

independent chuck

A type of chuck with jaws that can each move separately. Independent chucks can grip irregularly shaped workpieces during lathe operations.

index

To rotate a cutting insert from one fixed position to another fixed position in order to reveal a fresh cutting edge. A cutting tool with multiple cutting edges should be indexed once the original edge as been worn or damaged.

indexable insert

A removable, replaceable cutting tool with multiple edges that can be rotated into place. Indexable cutting inserts must be replaced or repositioned when a cutting edge wears out.

inner diameter operations

ID operations. Cutting operations that take place on the interior surface of a workpiece. Internal diameter operations on the lathe include drilling, reaming, and boring.

knockout bar

A steel rod with a brass tip that is used to dislodge objects, like collets, centers, or sleeves from a lathe spindle or tailstock. Knockout bars are used to remove a cutting tool from the tailstock.

lathe dog

A workholding device that clamps onto the workpiece and transmits rotary motion from the spindle of a lathe to the workpiece. The lathe dog allows a workpiece to be mounted between centers.

lathe dog tail

The part of a lathe dog that fits into the drive plate and then rotates the spindle of a lathe. Lathe dogs may have multiple tails or straight or bent tails.

live center

A type of center designed with bearings so that the point of the center rotates with the workpiece. Live centers require only monthly lubrication.

locating

The establishing of a designated location. Locating a workpiece ensures it will be machined to the correct specifications and tolerances.

lock pins

A cylindrical device, sometimes with a shaped head, used on fixtures to restrict workpiece motion. Lock pins are the most commonly used fixture locating component.

locking handle

The lever on a quick-change tool post that locks the tool block into place. Locking handles prevent the tool block from sliding off of the quick-change tool post.

long taper spindle noses

A type of spindle nose with an extended taper that is designed for precise centering and locating. Long taper spindle noses are typically used on older lathes.

lubricant

A substance that reduces friction. Lubricants in metal cutting are generally a type of cutting fluid.

lubricates

Reduces friction between components. Lubricating a cutting tool typically reduces resistance, heat, and wear.

machinability

The relative ease with which a machining process, such as milling or turning, can remove workpiece material. Machinability depends on the properties of the workpiece material.

machinist's rule

A long, thin metal strip with markings used to measure length. Machinist's rules are used to align the cutting tool and spindle on a lathe.

meters per minute

m/min. The distance, in meters, that the cutting surface and workpiece move past one another at the point of contact in one minute. Meters per minute is also sometimes referred to as surface meters per minute, or smm.

micrometer stop

A mechanical device attached to the ways of a lathe and mounted in front of or behind the carriage. The micrometer stop limits the travel of the carriage assembly when in automatic mode.

millimeters per revolution

mm/rev. A measurement of how many millimeters a cutting tool advances along a workpiece in one revolution of that workpiece. Millimeters per revolution measures feed.

mist cooling

A coolant-delivery method that uses a high-velocity stream of air to disperse a small amount of cutting fluid over the cutting area. Mist cooling reduces the overall amount of cutting fluid needed in a cutting operation.

nuts

A fastener with a threaded hole that mates with a bolt. Nuts have internal threads.

OD operations

Outer diameter operations. Cutting that takes place on the outer surface of a cylindrical or round workpiece. Outside diameter operations on the lathe include turning, facing, and parting off.

offset axis

An axis that is different from the centerline or origin. Offset axes are used for turning eccentric workpieces.

offset turning

A turning operation on a lathe in which the workpiece centerline axis is not continuously aligned with the Z axis. Offset turning operations include taper turning.

outer diameter operations

OD operations. Cutting that takes place on the outer surface of a cylindrical or round workpiece. Outside diameter operations on the lathe include turning, facing, and parting off.

parallel

A set of lines, components, or axes that are equidistant from each other at all points along their length and thus never intersect. On an engine lathe, the Z axis is parallel to the spindle centerline.

perpendicular

A set of lines, components, or axes that meet or intersect at a 90° angle. The cross slide moves the cutting tool perpendicular to the workpiece.

personal protective equipment

PPE. An article of clothing or a device worn to minimize exposure to hazards and prevent injury. Personal protective equipment for engine lathe operators includes safety glasses.

planer gage

A measurement device consisting of two right-triangle metal blocks fastened together. Planer gages allow users to measure dimensions of parallel surfaces within a range by sliding one block onto another.

pocket

An opening in a toolholder that has tracks for a cutting tool to be inserted into. Pockets may be different shapes or sizes depending on the type of cutting being performed.

power feed lever

A lever located on the carriage that controls the movement of the Z and X axes for feeding. The power feed lever works in conjunction with the feed direction lever to control the feed rate on the lathe.

precision test bar

A tool that is placed in the spindle of a machine for aligning the workpiece and spindle. Precision test bars are used to check the spindle runout.

print

A document containing all instructions necessary to manufacture a part. A print includes a part drawing, dimensions, and notes.

quick change gearbox

The location of the gears that control the power being transferred from the lathe motor to the spindle. The quick change gearbox allows the spindle speed and rotation to be adjusted quickly.

quick change tooling

A set of toolholders that uses a master toolholder with a series of rapid, interchangeable toolholders. Quick-change tooling increases the speed of production, but operators must check alignment after changing tools.

quick-change toolholder

A set of toolholders that uses a master toolholder that holds rapidly releasing interchangeable toolholders. Quick-change toolholders increase production speed.

quill

Tubing that fits into the tailstock of a lathe and moves towards and away from the head stock. The quill functions as a toolholder.

radial alignment

The degree to which a cylindrical or round workpiece is concentric to the centerline of the lathe spindle. Radial alignment is accurate if the spindle and workpiece rotate around the same axis.

radial depth of cut

The measurement of how far the cutting tool cuts into the workpiece diameter. Radial depth of cut measures cutting along the X axis.

radial runout

A type of lathe misalignment where a cylindrical workpiece is parallel to the spindle axis but not concentric. Radial runout on an engine lathe occurs with the workpiece is above or below the spindle axis.

radius

A straight line extending from the center point to the periphery of a circle. The radius of a circle is always one-half of its diameter.

roughing cuts

An initial pass of the cutting tool that emphasizes heavy metal removal rates, high feed rates, and a heavy depth of cut. Roughing cuts are made prior to finishing operations.

rpm

revolutions per minute. A unit of measurement that indicates the number of revolutions a machine component makes in one minute. Rpm measures rotation from the center of a tool or spindle.

runout

When two rotating objects do not share the same axis of rotation on the centerline. Runout determines the accumulated position error and deviation of a workpiece exterior or interior from a center axis as the workpiece rotates.

safety glasses

A form of protective eyewear, usually made of thick plastic, that shields the eyes from flying debris and other potentially hazardous materials. Safety glasses protect eyes from chips during turning.

scrap

A nonconforming product that cannot be used or sold. Scrapped products are recycled or destroyed.

self-centering chuck

A chuck with jaws that open and close together. Self-centering chucks accurately position a workpiece along the centerline of the chuck.

set zero

To establish a starting point on a workpiece or machine by setting the coordinate values to zero. To set zero, or zero the tool, an operator positions the tool in a location and then resets the analog measuring devices or DRO display to zero.

setup

All tasks and preparation necessary to prepare a machine for an operation. Setup can include preparing machines, tools, and materials.

shank

A cylindrical part of a tool or device opposite the cutting edge. The shank is the part of the cutting tool that is held in the toolholder.

short taper spindle noses

A type of spindle nose that holds the workholding device in place with fasteners around its perimeter. Short taper spindle noses are often used on high-powered machines.

smearing

A condition that causes a tool to leave burrs on a workpiece when it is not properly lubricated during machining. Smearing causes a poor surface finish.

soft

Able to be easily scratched, indented or penetrated by another material. Soft materials are characterized by their lack of hardness.

spacer

A small device under a cutting tool insert that creates a gap between the screw and cutting tool. Spacers help prevent premature wear and should be cleaned when changing out the cutting tool.

spindle

A machine tool component that holds and rotates another component, tool, or workpiece. Spindles on lathes hold and rotate workholding devices and workpieces.

spindle nose

A component of the spindle onto which the workholding device is mounted. The type of spindle nose on the lathe determines the appropriate workholding device to use.

spindle speed selector

A device that controls spindle speed. The spindle speed selector is a dial located on the gearbox or headstock of an engine lathe that allows an operator to select and adjust the spindle’s revolutions per minute.

standard tool post

A type of toolholder that holds a single cutting tool. Standard tool posts are not as common as quick-change toolholders.

station toolholder

A type of toolholder, also called a 4-position toolholder, that allows the mounting of four different tools at once on a lathe. Station toolholders allow for quick tool changes and efficient machining operations.

surface feet per minute

sfm. The distance in feet that the workpiece surface travels in one minute. Surface feet per minute, which is an English measurement for speed, depends on workpiece diameter and rpm.

surface finish

The degree of roughness and variation on the surface of a manufactured part. Surface finish may be poorer as a result of improper machine setup.

tailstock

A engine lathe component located opposite the headstock that can hold a cutting tool or support the end of longer workpieces. Tailstocks have the same centerline as lathe spindles.

tailstock spindle

A metal sleeve or cylinder that fits into a manual lathe tailstock to hold cutting tools or centers. Tailstock spindles, unlike the machine spindle in the headstock, do not rotate.

tailstock spindle lock

A mechanism that prevents the tailstock from moving. Tailstock spindle locks are important to prevent the tailstock from sliding and ruining a workpiece.

taper

On a manual lathe, the section of the spindle nose that holds workholding in the machine spindle. Tapers on a spindle nose can be short or long.

taper sleeve

A tool used to provide a better fit for cutting tools in a tailstock. Taper sleeves are used to balance the cutting tool.

threaded spindle noses

A type of spindle nose with screw threads to secure workholding devices to the spindle. Threaded spindle noses are often used on small lathes.

threads

A long, spiraling groove that may appear on the interior or exterior of an object. Threads help fasteners, such as screws, grip material and hold components together.

three-dimensional

3D. Having a length, depth, and width. Solid shapes are three–dimensional.

tolerances

A specification indicating an unwanted but acceptable deviation from a given dimension. Parts outside of a required tolerance must be discarded or reworked.

tool block

A toolholder that is kept with the tool already mounted on it. Tool blocks are considered quick-change tooling because operators can easily change them in and out of a lathe's toolpost.

tool post

A lathe component that sits on the compound rest of the carriage assembly. The tool post contains a slot for positioning the toolholder and cutting tool.

tool wear

The erosion of tool material as a result of friction. Tool wear degrades the accuracy and precision of a tool.

toolholder

A mechanism used to rigidly hold a cutting tool in place during machining. Toolholders for the lathe are generally shanks that hold indexable inserts or chucks or collets that hold solid holemaking tools.

touch off

To determine the exact location of a tool tip by touching it against an object with a known measurement. Touching off establishes a starting point for the cutting tool on the workpiece.

turning

A cutting operation that rotates a cylindrical workpiece while gradually passing the cutting tool along the surface of the rotating part. Turning is performed on a lathe and is commonly used to create cylindrical parts.

ways

A set of parallel tracks along which a machine component moves. The ways allow the carriage and tailstock to move along the bed of a lathe.

workholding device

A device for locating and supporting a workpiece for cutting operations. Common workholding devices in turning are chucks, collets, and centers.

workpiece

A material being machined or undergoing another type of processing. Workpieces for the lathe are often metal bars.

X axis

An axis in the Cartesian system that measures movement towards or away from the Z axis. The cross slide of an engine lathe moves in the X axis.

Y axis

A linear axis in the Cartesian system that is perpendicular to Z and X axes. The Y axis is not utilized on a manual lathe.

Z axis

An axis in the Cartesian coordinate system that represents motions and positions perpendicular to the X and Y axes. On an engine lathe, the Z axis measures movement and locations parallel to the workpiece and spindle.

zero the tool

To establish a starting tool position on a workpiece or machine by setting the coordinate values to zero after positioning the tool. To zero the tool, or set zero, position the tool and then reset the analog measuring devices or DRO display to zero.