Grinding Workpiece (Complex)

DLM 03 Developing print-based Learner’s Guide
Notes Learner’s Guide

Sector:

METALS AND ENGINEERING

Qualification:

MACHINING NC III

Unit of Competency: GRIND WORKPIECE (COMPLEX)
Module Title: GRIND WORKPIECE (COMPLEX)

Technical Education and Skills Development Authority
Regional Training Center VII – Cebu

Corner Salinas Drive and A. Reyes Avenue, Cebu City 6000

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Introduction:
Welcome to the module “Grind Workpiece (Complex)”. This module contains learning materials and
activities for you to complete.

The unit of competency “Grind Workpiece (Complex” contains the knowledge, skills and attitudes
required for Machining. It is one of the specialized modules at National Certificate level III (NC III).

You are required to go through a series of learning activities in order to complete each learning
outcomes of the module. In each learning outcome there are instructions given to help you better
understand the required activities. Follow these activities on your own and answer the self-check at
the end of each learning outcome. You may remove a blank answer sheet at the end of each module
(or get one from your facilitator/trainer) to write your answers for each self-check. If you have
questions, don’t hesitate to ask your facilitator for assistance.

The content of this learner’s guide include:

 Information Sheet - This is the compilation of the technical knowledge and
information (concepts, principles and other relevant information
performing certain activities.

 Operation Sheet - The operation sheet guides you to perform single task, process
object in a job. Example how to operate the machine and
equipment needed in all the experiments.

 Job Sheet - This is to guide you to complete a job that will contribute to the
attainment of the learning outcome.

 Worksheet - This consists of exercises that will help reinforce your learning
and to check your understanding on the technical knowledge
need in this whole task.

For each learning activity, there are instructions provided to guide you through the activity. At the end
of each learning activity, you have to complete the worksheet given to ensure that you have
understood the technical knowledge and when you have completed the task given to you in the job
sheet, inform your facilitator.

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Recognition of Prior Learning (RPL)

You may already have some or most of the knowledge and skills covered in this learner’s guide
because you have:

 Been working for some time
 Already completed training in this area

If you can demonstrate to your trainer that you are competent in a particular outcome, you don’t have
to do the same training again.

Talk to your trainer about having them formally recognized. If you have a qualification or Certificate of
Competence from previous training, show it to your trainer. If the skills you acquired are still current
and relevant to the unit/s of competency they may become part of the evidence you can present for
RPL. If you are not sure about the currency of your skills, discuss this with your trainer.

After completing this module ask your trainer to assess your competency. Result of your assessment
will be recorded in your competency profile. All the learning activities are designed for you to complete
at your own pace.

Inside this learner’s guide you will find the activities for you to complete and at the back are the
relevant information sheets for each learning outcome. Each learning outcome may have more than
one learning activities.

At the back of this learner’s guide is a Learner’s Diary. Use this diary to record important dates, jobs
undertaken and other workplace events that will assist you in providing further details to your trainer
or an assessor. A Record of Achievement is also provided for your trainer to compete once you
complete the module.

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Course: MACHINING NC II
Unit of competency: MACHINING NC II
Grind Work piece (Complex)
Module: At the end of the session, learners should be able to:
Learning outcomes:

Duration: 1. Determine Job Requirements.
2. Select wheels and accessories.
3. Perform Grinding Operations.
4. Check/Measure Work piece.
40 hrs

Situating Learning: You are an apprentice machinist/DTS trainee of a metalworking industry in
an Export Processing Zone in Cebu. You are assigned as a Cylindrical
Grinding Machine Operator. You are given a drawing to rough cut a piece of
tapered shaft (SAE 4140 hardened carbon steel, 60HRc) to be used as a
core pin for an Aluminum Die Casting Mould. Before doing the task, you
are asked by your supervisor to:

1. Choose the most appropriate machine to complete the task
2. Select, prepare and set up attachments and accessories needed for

the operation(s).
3. Produce the component to the required specifications
4. Check/measure the workpiece in conformance to the requirements

of the drawing

You need to finish the task within 4 hrs so that it will be submitted to the
Finishing section for final cutting. The die casting section has stopped their
operation due to the breakdown of the part required.

Assessment Criteria: The candidate must satisfactorily show and be assessed in the following
criteria:
1. Determined job requirements
2. Selected wheels and accessories.
3. Performed grinding operations
4. Checked/measured the workpiece

Learning chunk Performance Criteria Learning Activities Learning documents
(Brief description of (Documents
1 strategies, sequence
Determine Job of lesson, evaluation) referenced by each
Requirements learning activity)

 Drawings are 1.1 Interpret drawings 1.1.1. Answer review
interpreted to to produce worksheet in
produce component components to drawing
to specifications. specifications interpretation

 Sequence of 1.2 Determine 1.2.1 Read
operation is sequence of Information
determined to operations to Sheets on
produce component produce Cylindrical
components to

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Learning chunk Performance Criteria Learning Activities Learning documents
to specifications. (Brief description of (Documents
strategies, sequence
of lesson, evaluation) referenced by each
learning activity)
specifications
grinding terms
and operations
1.2.2 Answer
Worksheet
Grinding terms
and definitions
1.2.3 Answer
Worksheet
Terms used for
cylindrical
grinding

 Workholding devices 1.3 Select workholding 1.3.1 Read
devices according 1.3.2 Information
are selected to the requirements 1.3.3 sheet on
according to the of the operation 1.3.4 Cylindrical
requirements of the grinding
operation. operations
Answer
Worksheet on
Cylindrical
grinding
operations
Read
Information
sheets on Types
and functions of
accessories for
Cylindrical
grinder
Answer
worksheet on
Accessories
used for
Cylindrical
grinder

2  Grinding wheels are 2.1 Select, balance and 2.1.1 Perform Job
Select wheels and selected, balanced dress grinding wheels 2.1.2 sheet on
accessories and dressed to the to the required form removing and
required form and and size as required. replacing a
size as required. grinding wheel
Read and
perform
Operation
sheet on

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Learning chunk Performance Criteria Learning Activities Learning documents
(Brief description of (Documents
strategies, sequence
of lesson, evaluation) referenced by each
learning activity)

Selecting and
mounting
workholding
devices

 Accessories 2.2 Accessories 2.2.1 Read
selected are selected are 2.2.2 Information
appropriate to the appropriate to the 2.2.3 sheet on
requirements of the requirements of the Cylindrical
operation. operation. grinding
Machine
accessories
Read and
perform Job
Sheet on use a
table mounted
holder to dress
a wheel
Read and
perform Job
sheet on
removing and
replacing a
grinding wheel

 Machine guards, 2.3 Machine guards, 2.3.1 Read
coolant and dust coolant and dust Information
extraction devices extraction devices are sheet on Safety
are checked checked according to precautions in
according to worksite procedure. Operating
worksite procedure. Grinding
Machines

3  Grinding machine is 3.1 Set up and adjust 3.1.1 Read
Perform grinding setup and adjusted grinding machine 3.1.2 information
operations in accordance with according to worksite sheet on Types
worksite procedures. procedures of grinding
machines
Answer
worksheet on
types of
cylindrical
grinding
machines

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Learning chunk Performance Criteria Learning Activities Learning documents
(Brief description of (Documents
strategies, sequence
of lesson, evaluation) referenced by each
learning activity)

 Workpiece is set up 3.2 Set up and clamp 3.2.1 Read and
and held or clamped workpiece according to perform
to required level of the required accuracy Operation Sheet
accuracy as per as per specifications on Select and
specifications. mount
workholding
devices and
accessories

 Grinding operations 3.3 Perform grinding 3.3.1 Refer to
are performed operations utilizing Information
safely, utilizing guards, safety sheet 2.3.1
guards, safety procedures and Safety
procedures and personal protective precautions in
personal protective clothing and devices operating
clothing and grinding
devices. machines

 Grinding operations Perform grinding 3.4.1 Perform Job
are performed to operations to produce sheet on Grind
produce component component to A workpiece to
to specifications in specifications in the dimension
the drawing. drawing

4  Workpiece is Check and measure 4.1.1 Read Information
Check and measure checked and workpiece for sheet on Selecting
workpiece measured for conformance to appropriate measuring
conformance to specification using device
specification using appropriate techniques,
appropriate measuring tools and
techniques, equipment
measuring tools and
equipment.

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Information Sheet 1.2.1. : Terms and definitions used in Grinding

Learning Outcomes :

1 Determine job requirements

Learning Activity :

1 Identify and describe terms used in Grinding.

I. Terms and definition used in cylindrical grinding:

A. Work rotation – Rotation of workpiece at desired rate in opposite direction of
grinding wheel

B. Work speed – Number of revolutions per minute (rpm) that workpiece should turn
to give correct surface speed and to obtain maximum wheel life, chip removal,
and desired finish.

C. Work feed – Rate at which wheel is fed into workpiece each time table reverses.

(NOTE: Machines with automatic feeds can be set to feed right, left, or both right
and left)

D. Wheel speed (rpm) – Number of revolutions per minute (rpm) that grinding wheel
turns

(CAUTION: The wheel speed should not exceed that of the manufacturer’s
marking.)

(NOTE: Wheel should turn as close as possible to recommended maximum
speed. As wheel wears, speed should be increased if possible.)

E. Automatic feed – Movement of table or workhead by hydraulic and/or mechanic
feed

F. Live Center – Center that revolves with workpiece

G. Dead Center – Center that does not revolve

H. OD (outside diameter) grinding – Grinding on outside circumstances of round
workpiece

I. ID (inside diameter) grinding – Grinding on inside of workpiece to enlarge a bore
or hole

J. Plain cylindrical grinder – Cylindrical grinder with headstock and work-head are
fixed; used to perform OD, straight, and taper grinding

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 1.2.1. : Terms and definitions used in Grinding

K. Universal cylindrical grinder – Cylindrical grinder with headstock and workhead
that can be swiveled; used to perform OD, ID, and free grinding

L. Internal cylindrical grinder – Cylindrical grinder assigned designed especially for
ID grinding

M. Dwell or tarry time – Pause at one or both ends of table travel to permit grinding
wheel to grind workpiece to size and to provide for completion of feed before
table reverse direction

N. Feed index – Mechanical feed device that allows for adjustments of feed

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Worksheet 1.2.2 : Grinding terms and definitions

Learning Outcomes :

1 Determine Job Requirements

Learning Activity :

1 Match terms associated with cylindrical grinding to their correct definitions

Write the correct numbers in the blanks.

____a. Number of revolutions 1. ID (inside diameter)
per minute (rpm) that grinding
grinding wheel turns
2. Feed index
____b. Movement of table or 3. Work speed
workhead by hydraulic 4. Wheel speed (rpm)
and/or mechanical feed 5. OD (outside

____c. Grinding on outside diameter) grinding
circumference of a round 6. Automatic feed
workpiece 7. Plain cylindrical

____d. Cylindrical grinder with grinder
headstock and workhead 8. Work feed
that can be swiveled; 9. Work rotation
used to perform OD, ID, 10. Internal cylindrical
and face grinding
grinder
____e. Rotation of workpiece at 11. Live center
desired rate in opposite 12. Dwell or tarry time
direction of grinding 13. Universal cylindrical
wheel
grinder
____f. Center that does not 14. Dead center
revolve
Date Revised Page # 1
____g. Grinding on inside of
workpiece to enlarge a
bore or hole

____h. Rate at which wheel is
fed into workpiece each
time table reverses

____i. Cylindrical grinder with
headstock and workhead
that are fixed; used to
perform OD, straight,
and taper grinding

Code No. Grind Workpiece (Complex) Date Developed :

MEE722308

Worksheet 1.2.3 : Terms used for cylindrical grinding

Learning Outcomes :

1 Determine Job Requirements

Learning Activity :

1 Match terms associated with cylindrical grinding to their correct definitions.

Write the correct numbers in the blanks.

____a. Holding and driving 1. Faceplate
workpieces for external 2. Driving dogs
grinding operations of small 3. Chucks
workpieces that do not vary 4. Collet chuck
in size; allows quick 5. Center rest
clamping 6. Universal backrest with adjustable

____b. Supporting long workpieces shoe
so that accuracy can be 7. Headstock and footstock centers
maintained and chatter can 8. Magnetic chuck
be eliminated during
grinding operation

____c. Holding and driving
workpieces for external or
internal grinding operation

____d. Supporting workpiece at
each end for external
grinding operations

____e. Driving workpiece held
between centers

____f. Supporting long workpieces
for external or internal
grinding operations that
cannot be chucked; allows
mounting of fixtures

____g. Holding and driving thin
workpieces that cannot be
chucked in a conventional
chuck for face grinding

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

Learning Outcomes :

1 Determine Job Requirements

Learning Activity :

1 Identify and describe the different cylindrical grinding operations

I. Cylindrical grinding operations

A. Straight grinding – Grinding a cylindrical surface to an accurate size and
finish, with sides parallel to center axis throughout its length (Figure 1)

EXAMPLE :

FIGURE 1

Grinding
wheel

C C

Workpiece

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

B. Taper grinding – Grinding a conical surface that changes in diameter at a
constant rate along its axis (Figure 2)

FIGURE 2

Workpiece Grinding d
wheel
D
L

C. Shoulder grinding – Grinding a surface 90 degrees to axis of workpiece
(Figure 3 and 4)

(NOTE : Shoulders can be ground with the side of the wheel or by turning
wheel head and dressing at 90-degree angle on the wheel. Shoulders
that are deeper than one-half the width of the wheel can be ground by
cross feeding.)

FIGURE 3

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

FIGURE 4

D. Contour (form) grinding – Grinding a surface to a particular shape by
means of a grinding wheel dressed to produce the desired shape (Figure
5 and 6)

FIGURE 5

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 3

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

FIGURE 6

E. Internal grinding – Grinding a hole or bore to an accurate size, taper, or finish
(Figure 7 and 8)

(NOTE : Internal grinding is performed on an internal grinding machine,
universal grinding machine with internal grinding spindle, or a tool-post
grinder mounted to the compound of an engine lathe.)

FIGURE 7

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 4

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

FIGURE 8

F. Face grinding – Grinding end of workpiece by rotating surface to be
ground at a 90-degree angle to grinding wheel (Figure9)

(NOTE : Slight angles for purpose of relief can be face ground by setting
the headstock at angles slightly less than 90 degrees.)

FIGURE 9

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 5

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

G. Angular grinding – Grinding an angle by rotating workhead at desired
angle to grinding wheel (Figure 10)

(NOTE : This operation is usually done on a universal-type grinding
machine.)

FIGURE 10

Grinding
wheel

Workpiece

Chuck jaws of workhead

H. Plunger or infeed grinding – Grinding a surface or shape by feeding wheel
into workpiece with cross feed; can be performed on external or internal
surfaces (Figure 11)

(NOTE : Contour grinding is done by plunge or infeed grinding.)

FIGURE 11

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 6

MEE722308

Information Sheet 1.3.1 : Cylindrical grinding operations

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 7

MEE722308

Worksheet 1.3.2 : Cylindrical Grinding Operations

Learning Outcomes :

1 Determine Job Requirements

Learning Activity :

1 Identify cylindrical grinding operations

Write the correct names in the blanks.

Taper grinding Plunge or infeed grinding
Shoulder grinding Contour (form) grinding
Internal grinding Straight grinding
Angular grinding Face grinding

________________________a. Grinding end of workpiece by rotating
________________________b. surface to be ground at a 90-degree angle
________________________c. to grinding wheel
________________________d.
________________________e. Grinding a conical surface that changes in
________________________f. diameter at a constant rate along its axis

________________________g. Grinding a surface to a particular shape by
________________________h. means of a grinding wheel dressed to
produce the desired shape

Grinding a cylindrical surface to an accurate
size and finish, with sides parallel to center
axis throughout its length

Grinding a surface 90 degrees to axis of
workpiece

Grinding a surface or shape by feeding
wheel into workpiece with cross feed; can
be performed on external or internal
surfaces

Grinding an angle by rotating workhead at
desired angle to grinding wheel

Grinding a hole or bore to an accurate size,
taper, or finish

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 1.3.3 : Types and functions of accessories

Learning Outcomes :

1 Select wheels and accessories

Learning Activity :

1 Identify and select accessories needed to perform the required
operations

I. Types and functions of accessories

A. Chucks – Holding and driving workpieces for external or internal
grinding operations

B. Faceplate – Holding and driving workpieces for external or internal
grinding operations that cannot be chucked; allows mounting of
fixtures

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 1.3.3 : Types and functions of accessories

C. ollet chuck – Holding and driving workpieces for external grinding
operations of small workpieces that do not vary in size; allows quick
clamping

D. Magnetic chuck – Holding and driving thin workpieces that cannot be
chucked in a conventional chuck for face grinding

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Information Sheet 1.3.3 : Types and functions of accessories

E. Center rest – Supporting long workpieces for external or internal
grinding operations

F. Universal backrest with adjustable shoe – Supporting workpieces so
that accuracy can be maintained and chatter can be
eliminated duing grinding operation

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 3

MEE722308

Information Sheet 1.3.3 : Types and functions of accessories

G. Headstock and footstock centers – Supporting workpiece at each
end for external grinding operations

H. Driving dogs – Driving workpiece held between centers

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 4

MEE722308

Worksheet 1.3.4 : Dressing wheel for cylindrical grinding

Learning Outcomes :

1 Determine Job Requirements

Learning Activity :

1 Identify accessories used with cylindrical grinders

1. Write the correct names of the accessories in the blanks.

Driving dogs Center rest
Three-jaw chuck Magnetic chuck
Universal backrest with Headstock and footstock centers

adjustable shoe Faceplate
Four-jaw chuck
Collet chuck

a.

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Worksheet 1.3.4 : Dressing wheel for cylindrical grinding

b.

c.

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Worksheet 1.3.4 : Dressing wheel for cylindrical grinding

d.

e.

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 3

MEE722308

Worksheet 1.3.4 : Dressing wheel for cylindrical grinding

f.

g.

h.

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 4

MEE722308

Worksheet 1.3.4 : Dressing wheel for cylindrical grinding

i.

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 5

MEE722308

Job Sheet 2.1.1: Remove and replace a grinding wheel

Learning Outcomes :

1 Select wheels and accessories

Learning Activity :

1 Removing and replacing a grinding wheel

I. Equipment and materials
A. Wrench to remove wheel guard
B. Wrench to remove spindle nut
C. Wheel-sleeve puller
D. Wrench to remove outer
E. Grinding wheel (correct size to fit machine)
F. Plastic-handled screwdriver
G. Wooden dowel, 1-inch diameter, 4 to 5 inches long
H. Shop towels
I. Cylindrical grinding machine

II. Procedures to remove wheel
A. Remove outer portion of wheel guard
B. Remove spindle nut
(NOTE: Spindle has left-hand threads.)
C. Screw wheel-sleeve puller into spindle, and tighten puller screw until
taper of wheel sleeve is loosened from spindle
(CAUTION: Never try to loosen the wheel sleeve from the spindle
by pulling or tapping on the wheel; the wheel can be cracked.)
D. Remove wheel sleeve and wheel as one unit, and place it with bolts up
on a bench
E. Remove screws from wheel
F. Remove outer flange from sleeve
G. Remove sleeve from grinding wheel
H. Store or discard grinding wheel

III. Procedure to mount wheel

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Job Sheet 2.1.1: Remove and replace a grinding wheel

A. Clean spindle and surfaces of fixed flange and/or wheel sleeve
B. Ring test grinding wheel
C. Slide wheel and blotters onto wheel sleeve

(CAUTION: Never force the wheel onto the sleeve or alter the hole
size.)
D. Place outer flange on sleeve
E. Start and finger-tighten all screws
F. Use wrench provide by manufacturer to tighten all screws snugly in
alternating sequence (Figure 16)
(CAUTION: Do not over tighten screws; too much pressure from
bolts can crack wheel.)
G. Check balance of wheel; balance if necessary
H. Place sleeve on spindle, and tighten spindle nut
I. Replace wheel guard
J. Stand to one side and jog start grinder; allow wheel to reach operating
speed and run for one minute
K. Dress wheel
(NOTE: After eight to twelve hours of grinding, the flange screws
should be retightened to allow for compression on the blotters.)
L. Have instructor check your work
M. Clean machine, and put away tools

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

Learning Outcomes : Select Wheels and accessories
Learning Activity : Select and mount workholding devices and accessories

I. Selecting the holding device

The correct method of holding the workpiece is determined by the type of grinding
operation, the nature of the workpiece and the machine to be used.

Check:
 The shape.
 Whether it is hollow or solid.
 Whether it includes centers.
 The position of the surface to be ground.
 The strength of the workpiece.
 The accuracy required.
 The type of material.

The results of this check will determine whether the work should be held in:
 A jaw-type chuck;
 A magnetic chuck;
 A collet;
 A vice;
 A steady rest;
 Centers;
 A mandrel.

Selection of an unsuitable method may cause damage to the work or the machine. It may
also cause injury.

II. MOUNTING IN A CHUCK

There are two types of chucks:
 The three jaw chuck.
 The four jaw chuck.

Each type is designed to screw onto the headstock of the grinding with the chuck key. The
jaws are reversible of the grinding machine or to be mounted in the tapered spindle and
held with a draw bar.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 1
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

In the four jaw chuck, each jaw is moved independently with the chuck key. The jaws are
reversible and stepped to engage different sizes of work. A workpiece may be centered with
superior accuracy in a four jaw chuck but the operation is time consuming.

NOTE:
The headstock is also referred to as the workhead.

The jaws of three jaw chuck are moved in unison with the chuck key. Centering may be
carried out quickly, but is not always as accurate as with the four jaw chuck. The centering
accuracy of the three jaw chuck is dependent on the wear of its jaw surfaces, but should be
within 0.05 mm to 0.80 mm.

Some three jaw chucks are able to be moved on their backing plate. This enables a
workpieces to be held in the chuck and adjusted to run true using a dial indicator.

The three jaw chuck is used to support.
 Short cylindrical workpieces for internal or external cylindrical grinding operations;
 One end of a long cylindrical workpiece not provided with centers.
o In case the other end of the workpiece must also be supported in a rest or a
center.

CAUTION:
 Use soft metal packing pieces to prevent scoring of the workpiece
surface.
 Do not tighten the jaws excessively on the workpiece as the jaws
may mark or deform the surface.

The three jaw chuck may also be used to hold hollow workpieces for external or internal
grinding operations:

In this case, select the appropriate jaw set and adjust the jaws to bear against the interior
surface of the workpiece.

NOTE:
It is essential that the end face of the workpiece bearing against the chuck is true and fitted
carefully to prevent eccentric movement of the workpiece during rotation of the chuck.

8.1.1 Use of the four jaw independent chuck

A four jaw chuck will hold work more accurately that the three jaw chuck. As the jaws move
independently, it may also be used for holding workpieces that are not perfectly round.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 2
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

To use the chuck
 Open each jaw with the key.
 Place the work between the open jaws and locate as centrally as possible against
the chuck.
 Use the guide rings to held center the workpiece.
 Tighten the jaws against the workpiece.
 Rotate the chuck and mount a dial indicator to rest against the workpiece so that it
touches only the high spots during rotation. The dial indicator will show any
eccentricity of the workpiece.
 Position the workpiece so that the dial indicator is in contract with the high point on
the workpiece circumference.

NOTE:
If the high point is at near one of the chuck jaw it is advisable to loosen one of the jaws 90º
away from the high spot before adjusting the jaws aligned with the high and low spot. If this
is not done, the workpiece surface may be scored. This jaw must be re-tightened after the
correction is made.

 Carefully retract the jaw or jaws of the chuck opposite the high point by an amount
approximately equal to half the run-out of the high spot.

 Tighten the opposite jaw or jaws as necessary to move the workpiece into contact
with the retracted jaw or jaws.

 Rotate the chuck again and note the dial indicator reading.
 If eccentricity is still present read just the jaws until true running of the workpiece is

obtained.

NOTE:
The precautions taken with three jaw chucks to prevent workpiece damage should also be
taken with four jaw chucks.

III. Holding in a magnetic chuck

A magnetic chuck may be used to hold ferrous workpieces during cylindrical grinding
operations. Some magnetic chucks are designed to screw onto the headstock spindle and
some to be clamped to a face plate or held with a draw bar.

The field generated by permanent magnets in the body of the chuck holds the work firmly
on the chuck face.

This force is sufficient to make centering of the work difficult. A soft faced hammer may be
used to carefully tap the workpiece and adjust its position as the chuck is rotated.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 3
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and

Accessories for grinding

Holding the workpiece in a magnetic chuck is also useful where the workpiece has an

unusual shape not suited to other mounting methods.

NOTE:
The face of the chuck will attract metal particles. These must be cleaned off to prevent
damage to the face of the chuck and faulty centering of the workpiece.

CAUTION:
Turn the field off before locating the workpiece. The magnetic field action is quite
strong and may snatch the workpiece from your hand as you approach the chuck. Do
not forget the field on again before releasing the workpiece.

IV. Mounting in a collet

Collets are designed to hold work which is close to its required final diameter. A collet
should only be used for holding work which is within about 0.13 mm of size.

The type of collet selected will depend on the shape and size of the workpiece. The
following example is one of a spring collet to hold a solid cylindrical workpiece of small
diameter for an external cylindrical operation.

To mount the workpiece
 Select a round collet with an internal diameter suitable for holding the workpiece.
 Fit the collet to the headstock spindle and secure it in position with the collet hood.
o Use the hood tool provided to screw the hood to the spindle and lock it in
position.
 Insert the collet by passing it into the hood and along the interior of the spindle
towards the end of the pull rod.
 When the collet meets the pull rod, rotate the hand wheel carefully to engage the
collet loosely with the pull rod thread.
o Do not tighten by turning the wheel further.
 Pass the end of the workpiece into the collet and towards the pull rod. If necessary,
the extremity of the workpiece may pass into the bore of the pull rod.
 Rotate the hand wheel to clamp the collet firmly against the workpiece.

CAUTION:
Do not tighten the hand wheel excessively as this may damage the collet
threads.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 4
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

V. Mounting with a vice

When the shape of a workpiece is irregular it may be necessary to use a machine vice to
hold it during grinding.

The steps to follow are
 Mount a face plate of suitable size on the machine headstock.
 Loosely bolt the vice to the faceplate.
 Secure the workpiece in the vice, taking any precautions necessary to protect the
workpiece and vice jaws from damage.
 Center the workpiece as accurately as possible by sight, moving the vice and
workpiece as required.
 Firmly fix the vice to the face plate and mount the workpiece in the vice.
 Remove the handle from the vice.
 Disengage the headstock drive to allow the face plate to rotate freely.
 When the faceplate comes to rest, mark the uppermost parts of its edge with chalk.
This point is diametrically opposite the heavy point.
 Balance the face plate by bolting or clamping counterweight on or near an imaginary
radius from the faceplate center to the chalk mark. Position the weights as close as
possible to the vice.
 Adjust the size and, if absolutely necessary, the position of counterweights until the
faceplate is statically balanced
 Re-engage the headstock drive.

WARNING:

Make sure the clamps are correctly fitted and firmly secure the
counterweights.

 Rotate the face plate at a slow speed and check centering of the workpiece. Adjust
position of work and vice until the grind centering accuracy is obtained.

 Check that the work is still balanced.
 When grinding, use a suitable slow speed to eliminate chatter and vibration.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 5
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

VI. Using a steady rest

To main accuracy during internal grinding it may be necessary to use a steady rest to
support the end of the work remote from the chuck.

The steps to follow are
 Mount the workpiece in a four jaw chuck.
 Center the workpiece accurately in the chuck and if possible, in the tailstock.
o Fitting the workpiece in the tailstock is not possible for internal grinding as
illustrated.
 Retract the adjustable fingers of the rest, open the rest and pass it over the
workpiece to be supported.

 Fix the rest to the worktable, making sure that it is correctly aligned with the axis of
the workpiece.

 Advance each finger until it just touches the surface of the workpiece.

 Check that centering of the workpiece is still correct.

 Run a dial indicator along the top and the side of the workpiece (while it is stationary)
to ensure that the steady is not bending the component.

The outer surface of the workpiece may be scored by:
 The jaw of the chuck;
 The fingers of the rest.

To prevent, fit soft metal spacers between the surface and the chuck jaws and between the
surface and the rest fingers.

Bend the spacers around the rest fingers to prevent them from slipping out of position.

Position the rest accurately in alignment with the headstock center to prevent tapering of
the workpiece.

NOTE:
The fingers of rests are often provided with fiber pads, making the use of soft metal spacers
unnecessary.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 6
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

VII. Mounting between centers

Centers are normally used when grinding cylindrical workpieces.

The steps to follow are

 Set the headstock and tailstock of the machine in correct alignment
 Fit a center to the headstock and the tailstock.
 Check that the centers are clean.

 Use a center gauge to check that the centers are ground at the correct angle of 60º

 Fit a face plate to the headstock.

 Check that the workpiece centers are clean.

 Use the center gauge to check that the workpiece centers are of the correct size.

 Oil both workpiece centers.

 Fit a carrier to one end of the workpiece.

 Fir the workpiece between the machine centers by moving the tailstock towards the
headstock as required.

 Check that the carrier engages the face plate.

 Adjust the pressure of the tailstock center on the workpiece so that it will move freely
between the centers but without axial movement.

 Clamp the tailstock in position.

To avoid irregular wear of the worktable it is good practice always to center the workpiece
to the grinding wheel center.

 This means setting the position of both the headstock and the tailstock for a
particular workpiece when using centers.

 In this way, the wear caused by movement of the headstock and tailstock will be
distributed over the length of the worktable during the life of the machine.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 7
MEE722308

Operation Sheet 2.1.2. : Select and mount workholding devices and
Accessories for grinding

VIII. Mounting on a Mandrel

To grind the exterior surface of a cylindrical workpiece with accurate central bore, a
mandrel to mount the workpiece between the centers of the grinding machine may have to
be used.

Procedure
 Select a mandrel with a diameter appropriate for the bore in the workpiece.
 Clean the surface and centers of the surface,
o Distribute the oil evenly.
 Check that the mandrel runs true between the machine centers.
 Remove the mandrel from the machine and slide the workpiece onto the narrow end
of the mandrel.
 Tap the thick end of the mandrel gently with a soft faced hammer to firmly locate the
workpiece on the mandrel.
 Fir a carrier to the larger end of the mandrel and a face plate to the headstock of the
grinding machine.
o The headstock must be fitted with a dead center.

 Mount the mandrel between the machine centers.

Failure to clean and oil the mandrel before fitting the workpiece may result in the
workpiece binding to the mandrel. This will make it difficult to remove the workpiece
without damage to the mandrel and the workpiece.

To remove the workpiece from the mandrel, clean the mandrel surface and then tap the
narrow end of the mandrel with a soft faced hammer.

When using the soft faced hammer to tap the workpiece onto or off the workpiece onto
or off the mandrel, support the workpiece to prevent it from falling to the floor.

NOTE:
A good for fitting the workpiece to a mandrel is by using an arbor press to press the
mandrel in, where the illustration shows the use of a soft faced hammer.

Code No. Grind workpiece (Complex) Date Developed : Date Revised Page # 8
MEE722308

Information Sheet 2.2.1. : Types and functions of accessories

Learning Outcomes :

1 Select wheels and accessories

Learning Activity :

1 Identify and select accessories needed to perform the required
operations

I. Types and functions of accessories

A. Chucks – Holding and driving workpieces for external or internal
grinding operations

B. Faceplate – Holding and driving workpieces for external or internal
grinding operations that cannot be chucked; allows mounting of
fixtures

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 2.2.1. : Types and functions of accessories

C. ollet chuck – Holding and driving workpieces for external grinding
operations of small workpieces that do not vary in size; allows quick
clamping

D. Magnetic chuck – Holding and driving thin workpieces that cannot be
chucked in a conventional chuck for face grinding

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Information Sheet 2.2.1. : Types and functions of accessories

E. Center rest – Supporting long workpieces for external or internal
grinding operations

F. Universal backrest with adjustable shoe – Supporting workpieces so
that accuracy can be maintained and chatter can be
eliminated duing grinding operation

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 3

MEE722308

Information Sheet 2.2.1. : Types and functions of accessories

G. Headstock and footstock centers – Supporting workpiece at each
end for external grinding operations

H. Driving dogs – Driving workpiece held between centers

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 4

MEE722308

Job Sheet 2.2.2 : Use table-mounted holder to dress a
Grinding wheel
Learning Outcomes :

1 Select wheels and accessories

Learning Activity :

1 Use table-mounted holder to dress a grinding wheel

I. Equipment and materials
A. Cylindrical grinder with wheel mounted
B. Single-point diamond dresser
C. Table-mount diamond holder
D. Wrenches
E. Shop towels

II. Procedure
A. Place diamond in table-mount holder so that its point is as close to
holder as possible; tighten until diamond is sung
B. Mount holder at center of table, and secure lock bolt (Figure 1)

FIGURE 1

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Job Sheet 2.2.2 : Use table-mounted holder to dress a
Grinding wheel

C. If holder is adjustable, position diamond slightly downward to prevent
gouging (Figure 2)

(NOTE: Some table-mount holders have a built-in downward angle.)

FIGURE 2

D. Adjust diamond to center height; tighten adjustment bolt and diamond
lock screw

E. Adjust stops so that point of diamond clears each side of wheel width
about 1 inch

F. Put table in truing position, or set table feed for 5 to 10 inches per
minute

G. Start grinding wheel, and allow it to run until bearings have warmed up
(about five minutes)

H. Position diamond near center of wheel

I. Using cross feed, move wheel to diamond until diamond cuts high point

J. Move diamond to right side of wheel

K. Start coolant

L. Advance wheel 0.0005 inch, and engage power feed

(NOTE : Dressing the wheel with the coolant running will keep the
diamond cooler, clean the wheel, and keep the dust out of the air.)

M. Continue to advance wheel 0.0005 inch per pass until face of wheels
has been dressed smooth and flat

N. Stop table travel with diamond at one side of wheel

O. Turn off coolant; allow wheel to run for about one minute

P. Stop spindle and examine wheel

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Job Sheet 2.2.2 : Use table-mounted holder to dress a
Grinding wheel

Q. Have instructor inspect your work

R. Clean machine, and put away all tools

(NOTE: the wheel may need to be dressed during grinding operations.
To dress wheel, remove the workpiece or use a footstock-type holder.
If the wheel is dressed when it first starts to load or dull, material can
be removed at a faster rate and the quality of the finish can be
maintained.)

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 3

MEE722308

Job Sheet 2.2.3: Remove and replace a grinding wheel

Learning Outcomes :

1 Select wheels and accessories

Learning Activity :

1 Removing and replacing a grinding wheel

I. Equipment and materials
A. Wrench to remove wheel guard
B. Wrench to remove spindle nut
C. Wheel-sleeve puller
D. Wrench to remove outer
E. Grinding wheel (correct size to fit machine)
F. Plastic-handled screwdriver
G. Wooden dowel, 1-inch diameter, 4 to 5 inches long
H. Shop towels
I. Cylindrical grinding machine

II. Procedures to remove wheel
A. Remove outer portion of wheel guard
B. Remove spindle nut
(NOTE: Spindle has left-hand threads.)
C. Screw wheel-sleeve puller into spindle, and tighten puller screw until
taper of wheel sleeve is loosened from spindle
(CAUTION: Never try to loosen the wheel sleeve from the spindle
by pulling or tapping on the wheel; the wheel can be cracked.)
D. Remove wheel sleeve and wheel as one unit, and place it with bolts up
on a bench
E. Remove screws from wheel
F. Remove outer flange from sleeve
G. Remove sleeve from grinding wheel
H. Store or discard grinding wheel

III. Procedure to mount wheel

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 1

MEE722308

Job Sheet 2.2.3: Remove and replace a grinding wheel

A. Clean spindle and surfaces of fixed flange and/or wheel sleeve
B. Ring test grinding wheel
C. Slide wheel and blotters onto wheel sleeve

(CAUTION: Never force the wheel onto the sleeve or alter the hole
size.)
D. Place outer flange on sleeve
E. Start and finger-tighten all screws
F. Use wrench provide by manufacturer to tighten all screws snugly in
alternating sequence (Figure 16)
(CAUTION: Do not over tighten screws; too much pressure from
bolts can crack wheel.)
G. Check balance of wheel; balance if necessary
H. Place sleeve on spindle, and tighten spindle nut
I. Replace wheel guard
J. Stand to one side and jog start grinder; allow wheel to reach operating
speed and run for one minute
K. Dress wheel
(NOTE: After eight to twelve hours of grinding, the flange screws
should be retightened to allow for compression on the blotters.)
L. Have instructor check your work
M. Clean machine, and put away tools

Code No. Grind Workpiece (Complex) Date Developed : Date Revised Page # 2

MEE722308

Information Sheet 2.3.1: Safety precautions in operating Grinding
Machines

Learning Outcomes :

1 Perform Grinding Operations

Learning Activity :

1 Check machine guards, coolant and dust extraction devices
2 Perform grinding operations safely

I. CYLINDRICAL AND UNIVERSAL GRINDING SAFETY

Grinders can cause serious injury when they are used incorrectly or when hands or
fingers come into contact with moving grinding wheels.

The machines are fitted with guards to protect the operator from injury and to make the
operation of the machine as safe as possible. Despite this, accidents still happen.

These accidents are usually caused by:

 Ignorance
 Thoughtlessness
 Carelessness
 Lack of consideration for safety of others

Internal grinding requires special precautions because, in contrast to the cylindrical
grinder, there is no fixed guard over the grinding wheel.

 The safety glasses used for all grinding operations are particularly important,
because the wheel usually rotates in such a direction that it will throw off any grit
towards the operator.
o This is especially when dressing the wheel.

Take care and ensure that the spindle is strong enough for its length.

 This is particularly important when it rotates at the high speeds, common in
grinding in small wheels. If it is not strong enough it may whip around.

Do not check parallel bores with a plug gauge while grinding wheel is rotating.

 The bore may grip the cold plug gauge, throwing the operator’s hand back
against the grinding wheel.
o This could cause a serious hand injury and also damage the bore.

 When fitting or mounting grinding wheels:
 Fasten the screw so that it is tight enough to hold the wheel securely but not too

tight to crush it.

Code No. Grind Workpiec (Complex) Date Developed : Date Revised Page # 1

MEE722308

Information Sheet 2.3.1: Safety precautions in operating Grinding
Machines

o This is particularly important on small wheels.
 Take care that the standard paper washers are fitted on each end of the wheel.

o This will help to prevent crushing.

Dress the wheel frequently

 The relatively small circumference makes the wheel wear more quickly than the
wheel on an external grinder.

II. GENERAL SAFETY PRECAUTIONS

 Keep the work area around machines free of obstacles and waste material.
 Immediately clean up any oil, grease or coolant on the floor.
 Place cleaning cloths and waste materials in proper containers after use.
 Store hand tools and accessories away from machines after use.
 Do not touch workpieces which may be hot as a result of grinding operations.
 Use the correct hand tools for the job in hand.
 Seek assistance when handling heavy machine accessories, grinding wheels of

workpieces.

III. DO’S AND DON’TS IN CYLINDRICAL GRINDING

 Don’t use any cylindrical grinder until you are familiar with the controls and
authorized to use it.

 Don’t use any machines without appropriate guards.
 Wind the wheel well out of the way before measuring work.
 Make sure the work is firmly held in the holding device before grinding.
 Do not touch a surface being ground while the machine is in operation.
 Be careful of burrs on newly ground workpieces and remove them as soon as

possible.
 Keep the machine table clear of hand tools while it is in operation.
 When setting table traverse, allow the wheel to over travel the workpieces in bot

directions.
 Whenever possible, use coolant in grinding operations.
 If a grit exhaust system is fitted to the machine, use it at all times.
 Stop the machine before cleaning or oiling, or before making any adjustments to

the accessories or to the workpiece.
 Do not leave the machine while it is still running.
 Do not lean or touch on a machine while someone else is using it.
 Do not divert the attention of someone else using a machine.
 Never step backwards while in the vicinity of a machine.

Code No. Grind Workpiec (Complex) Date Developed : Date Revised Page # 2

MEE722308

Information Sheet 2.3.1: Safety precautions in operating Grinding
Machines

IV. PERSONAL SAFETY PRECAUTIONS

 Wear a goggles at all times when using a grinding machine.
 Report any injuries, however slight, to your instructor or supervisor.
 Wear close-fitting clothes
 Avoid wearing a tie and long sleeves.

o If necessary, tuck your tie carefully inside your shirt or keep it inside of outer
clothing, buttoned or zipped up high and roll up your sleeves.

 If your hair is long, wear a protective head covering, and make sure your hair is
completely enclosed inside it.

 Do not wear a watch, rings or other loose ornaments.
 Do not wear gloves.
 Wipe your hands clean before operating a machine, adjusting accessories or

handling a workpiece.
 Wear safety shoes or safety boots at all times in the workshop.

V. GRINDING WHEEL SAFETY PRECAUTIONS

 Select And use the correct wheel for the job.
 Make sure the machine is rigid to prevent wheel vibration.
 Before fitting a wheel to a grinding machine, test the wheel for cracks.
 Do not use a cracked or chipped wheel.
 Do not use glazed of loaded wheels.
 Check that the wheel is balanced before fitting it to a machine.

o Check the wheel for faults and correct type.
 Stand clear of the wheel when switching the machine on for the first time.

VI. CYLINDRICAL GRINDING SAFETY RULES

Many safety principles are common to all grinding processes due to the nature of grinding
wheels and the high speeds used, but there are a number of hazards that exst which only
apply on cylindrical grinding.

 When starting the wheel, switch on and off a number of times to allow coolant to be

thrown out of the wheel, so that the wheel will resume proper balance.

 Before starting the machine, ensure that you know how the machine operates.
o Many modern machines have automatic wheel retract.
o When the table traverse of these machines is turned off, the wheel retracts to

allow measurement of the work and when it is turned on again, the wheel

returns to the grinding position.
o If the operator has not allowed for the wheel coming in to the work position the

wheel could crash into the work.

Code No. Grind Workpiec (Complex) Date Developed : Date Revised Page # 3

MEE722308