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Cylindrical Grinder Operation 250

Abrasives Training

Class Information

Tooling U classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and typically requires at least two hours of instruction time.

Class Name:	Cylindrical Grinder Operation 250
Description:	This class identifies the main components of common cylindrical grinders and describes the various types of operations that can be performed.
Prerequisites:	250110, 250120
Difficulty:	Intermediate
Number of Lessons:	15

Class Outline
Objectives What Is Cylindrical Grinding? Types of Cylindrical Grinders Components of a Cylindrical Grinder Cylindrical Grinding Accessories Traverse Grinding Plunge Grinding Grinding Wheel Selection Balancing and Dressing Adjusting the Wheelhead and Headstock External Grinding Setup External Grinding Grinding Shoulders Internal Grinding Summary

Class Objectives

Describe cylindrical grinding.
Identify types of cylindrical grinders.
Identify the components of a cylindrical grinder.
Describe cylindrical grinding accessories.
Describe traverse grinding.
Describe plunge grinding.
Describe grinding wheel selection.
Describe wheel balancing and dressing.
Describe how to adjust the wheelhead and headstock.
Describe how to setup for external grinding operations.
Describe the steps to perform external grinding operations.
Describe grinding shoulders.
Describe internal grinding operations.

Class Vocabulary
abrasive grain		A small, hard particle or crystal of abrasive material used to machine, grind, or finish a workpiece. The tensile strength of workpiece material determines the abrasive grain of the grinding wheel.
adjusting screw		A screw that gradually moves the table with each turn to provide precise and easy swiveling.
angular truing attachment		A cylindrical grinder accessory that is used for angle dressing.
automatic balancer		A precision device that uses one of several methods, including gasses and fluids, to detect vibration. Automatic balancers are used to balance grinding wheels where exact precision in grinding is required.
axis		The imaginary line around which a part rotates as it is turned.
base		The foundation of a grinding machine that supports all the other machine components.
bump		Undercutting the corner that joins the two surfaces of a workpiece. Bumping is done to maintain a square corner on the grinding wheel.
center		A hardened, pointed, cylindrical component used to hold the end of a workpiece by inserting its tip into a matching hole in the part.
center steady rest		A cylindrical grinder accessory that provides support for long, slender workpieces.
center-type cylindrical grinder		A type of grinder that mounts the workpiece on centers to finish it.
chatter		The occasional unwanted vibration between components. Chatter decreases productivity and can cause wear.
chuck		A device that holds a workpiece in place as it rotates. The chuck commonly has three or four jaws that can be adjusted to fit various sizes.
clamping screw		A screw that fixes one component of the grinder to another. If the table or headstock need to be swiveled, the clamping screws can be loosened.
collet		A slitted device that holds a workpiece in place as it rotates. A collet has a hole through which the workpiece passes, and it is designed to hold specific dimensions.
concave		Curving inward like the inside of a bowl.
convex		Curving outward like the exterior surface of a circle or sphere.
crossfeed handwheel		A grinding machine component that controls movement along the ways. The crossfeed handwheel is used for traverse grinding.
crowning		A change in wheel shape where the center of a grinding wheel becomes raised due to the edge material wearing down faster. Traverse grinding can lead to crowning because the edge of the wheel tends to contact the workpiece surface more than the center of the wheel.
crush roll		A hard grinding wheel used under pressure to improve the face of another grinding wheel and usually to add a special shape.
cylindrical grinding		A common grinding process that holds a cylindrical part on each end and rotates the part as a rotating grinding wheel is guided along its length.
diamond dresser		A tool containing one or more diamonds used to remove material from the surface of a grinding wheel.
dished		Having a concave shape, much like a dish or dinner plate. This shape prevents the entire wheel from contacting a workpiece.
dressing		To remove swarf, dull grains, and bonding material from a grinding wheel. Dressing sharpens the wheel.
fillet		A rounded internal corner. A fillet adds strength to the corner and is often easier to machine.
finish		The final grinding operation intended to obtain the desired tolerance and surface finish.
flange		A flat or raised metal disk that helps deflect mounting stresses from the hole in a grinding wheel. The grinding wheel is typically mounted to the spindle using flanges.
friability		The ability of abrasive grains to fracture and self-sharpen under stress. For cylindrical grinding, the workpiece diameter determines the necessary friability of the grinding wheel.
grinding wheel		A wheel made of a bonded abrasive used to remove material from a surface by rotating and shearing away microscopic chips of material. Grinding wheels can produce very fine surface finishes.
headstock		The end of a cylindrical grinder that holds the spindle and the drive that rotates the workpiece.
infeed grinding		A method of cylindrical grinding in which the workpiece is held stationary while the grinding wheel is fed into the workpiece at a specified location and depth.
plain cylindrical grinder		A basic type of cylindrical grinder that can perform a limited number of grinding operations.
plunge grinding		A type of cylindrical grinding in which the cylindrical wheel is fed directly into the workpiece. Plunge grinding is also called infeed grinding.
radius truing attachment		A cylindrical grinder accessory that is used to produce radii truing of the wheel.
shoulder		An angled surface similar to a chamfer, created by turning and finished by cylindrical grinding.
sliding table		The lower table on a cylindrical grinder that reciprocates during grinding passes along the workpiece length.
step		A type of part finish that resembles stairs, with progressively narrower levels meeting at right angles.
swarf		The gritty combination of chips, abrasive grains, and worn bonding material that is produced during grinding.
table		That part of the grinding machine which directly or indirectly supports the workpiece.
table reverse dogs		A control component of a grinding machine that reverses the direction of table movement at the end of a stroke.
table traverse rate knob		The control on a cylindrical grinder used to adjust the rate of table feed. Depending on the model of grinder, feed can be between 3 and 200 inches (76 and 5080 mm) per minute.
tapering		Grinding a workpiece to form a shape with a gradually decreasing diameter, similar to the shape of a cone.
tensile strength		A material's ability to resist forces that attempt to pull apart or stretch it. In cylindrical grinding, the tensile strength of the workpiece determines the abrasive grain of the grinding wheel.
traverse grinding		A type of cylindrical grinding in which the cylindrical wheel is fed perpendicular to the axis of the part.
universal back rest		A cylindrical grinder accessory that helps prevent workpieces from deflecting.
universal cylindrical grinder		The most common type of cylindrical grinder. The universal grinder can perform many external and internal grinding operations.
upper table		The fixed portion of the table that supports the workpiece. The upper table can be swiveled to grind tapers.
wheel balance		A wheel that has equal weight and shape throughout, making it completely concentric. A balanced wheel does not vibrate.
wheelhead		The part of the grinding machine on which the wheel is mounted. On a cylindrical grinder, the wheel head contains the grinding wheel and grinding wheel spindle.