THIS PRESENTATION ON CENTRELESS GRINDING REGARDING THE MANUFACTURING SUBJECT, THIS PPT PRESENTED AT B&B INSTITUTE OF TECHNOLOGY. HOPE IT WILL HELPED THE ENGINEERING STUDENT.

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2. OBJECTIVE
 Definition of Centerless grinding.
 Describe the relationship between the
three main components used in
cenerless grinding.
 Describe advantages of centerless
grinding.
 Describe the component of the
centerless grinding.
 Describe how the regulating wheel
determines workpiece rotational speed.
 Indentify Grinding wheel Imbalance
FIGURE 2.The regulating wheel is anglead slightly to
enable workpiece through feed.
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3. DEFINITION OF CENTERLESS GRINDING
Centerless grinding is a machining
process that uses abrasive cutting
to removal material from a
workpiece.
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4. CENTERLESS GRINDING.
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 Common type of
Cylindrical grinding.
 Three main parts are used.
i) Grinding wheel
ii) Regulating wheel
iii)Work Rest Blade
 This component hold the work piece horizontally.
 Rotate it & Grain its Surface.
 Each component plays the roll in the grinding
process.
FIGURE: A Typical centerless grinding configuration

5. HOW THE CENTERLESS GRINDING WORKS.
 The work rest blade supports
the part slightly.
 It is made of wear-resistant
material.
 The regulating wheel rotates the
Cylindrical parts.
 It is commonly made of plastic
or rubber bond.
 The actual grinding is performed
by Grinding wheel.
 Both the wheel must be
periodically dressed and trued
to maintain precise roundness
of the workpiece
 FIG. Shows a typical machine
built for Centerless Grinding. 5

6.  The parts they Grind always must be round.
 However, Setup is fast
 And the process Can be automated.
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7. ADVANTAGES OF CENTERLESS GRINDING
 It Enables Fast, accurate
production of complicated
hand-held parts or workpiece that
require Tight Tolerances.
 Decrease grinding time.
 Automatic Feeding method.
 Reduce grinding wheel wear.
 Grinding of longer parts.
 Low Maintenance.
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FIGURE: center less grinding is often used to produse small Parts
such as bearings.
Centerless grinding is often used to mass production small parts
such as bolts , shafts, bearings, hubs or valves.

8. MAIN CATEGORIES OF CENTERLESS GRINDING.
 Generally, all centerless grinder fall under two main
categories.
i) Angular-bed-grinders
ii)Horizontal-bed-grinders
 On an angular-bed-grinder, the rotating regulating
wheel rotates the part @ specific rate .
 Angular-bed-grinders are usually used to grind
heavier workpieces or workpieces that require a
fine surface finish.
 The horizontal-bed centerless grinder is the most
common design.
 The parts being to rotate only after it touches the
rotating grinding wheel.
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9. MAIN COMPONENT OF MACHINE.
 A cast iron bed supports the
grinder and contains the
grinding and regulating wheel
head assembly and hydraulic
reservoir.
 A wheel head contains the
grinding wheel and grinding
wheel spindle.
 A swivel plate is mounted to
the bed and tilts or aling the
regulating wheel parallel to
the grinding wheel.
 A lower slide is attached to
the swivel plate and moves
the regulating wheel and
workrest blade towards or
away from the workrest blade.
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FIG. The main component of centerless grinder

10.  An upper slide is attached to the lower slide and
moves the regulating wheel towards or away from
the workrest blade.
 A regulating wheel housing is mounted to the
upper slide and houses the regulating wheel
houses the regulating wheel and regulating wheel
spindle.
 A work rest is mounted to the lower slide and
supports the work rest blade.
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11. THE REGULATING WHEEL & WORKPIECE
ROTATIONAL SPEED.
o During centerless grinding, the
Regulating wheel plays a key
role in the grinding of workpiece.
o Two key factors that the regulating
wheel controls are rotational
speed of the workpiece and the
feed rate of the workpiece.
o The surface speed of the
regulating wheel controls the
rotational speed, or work speed,
of the workpiece.
o During a centerless grinding
operation, the regulating wheel
rotates the workpiece by rotating
against it, as shown in fig.
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FIG: The regulating wheel rotates the workpiese
by revolving against it a uniform rate.

12.  Surface speed is the uniform rate at which the
regulating wheel revolves against the workpiece.
 Surface speed rate is measured in revolutions per
minute (RPM).
 Most regulating wheel revolves between 30 and 40
rpm.
 The work speed of the workpiece is approximately
equal to the regulating wheel surface speed.
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13. DETECTING GRINDING WHEEL IMBALANCE
 A simple method for detecting
wheel imbalance is to take a wheel
that has been mounted on a
mandrel.
 It is set between two equal points,
such as the balancing stand
shown in fig.
 If the wheel stays at rest, even if it
rotated to a new position, it is said
to be static balance.
 If the wheel is then pushed along
the stand, and it rotates smoothly,
stopping only when it loses
momentum, the wheel is said to be
in dynamic balance.
 If the wheel is out of balance , it will
rock back and forth before coming
to rest with its heaviest side down. 13
FIG: Placing a grinding wheel on a balancing
stand will determine if one side is heavier than
another.

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