Guidebook to Trade Tests For CNC Machining Centre (Vertical/Horizontal) Operators and CNC Lathe Operators

Vocational Training Council Trade Testing Committee of the Plastics Training Board

Guidebook to Trade Tests For CNC Machining Centre (Vertical/Horizontal) Operators and CNC Lathe Operators

Vocational Training Council Trade Testing Committee of the Plastics Training Board

CONTENTS Page

Part I Introduction 1

Part II Trade Test Details 2-4

Part III Application Procedures 5-6

Appendix 1 Trade Test Syllabuses 7-9

Appendix 2 Examples of Trade Knowledge Test Questions

10-11

Appendix 3 Examples of Practical Assignments 12

Appendix 4 Some Terms Commonly Used in CNC Programming and Machining Operation

13-15

16

17-18

19-20

1 21-23

2 24-25

3 26

4

27-29

1

PART I INTRODUCTION

The Trade Testing and Certification System The Trade Testing Committee of the Plastics Training Board has been entrusted by the Vocational Training Council with the task of implementing a voluntary trade testing and certification system for the industry. The system is operated on a voluntary basis and its objectives are:

(a) to help industry in the selection of workers for skilled jobs, (b) to facilitate the acquisition of a recognized qualification, in particular for

those who have not gone through any formal training, and enhance the status of skilled workers,

(c) to set the specifications related to standards for skilled workers, and

(d) to facilitate the establishment of skill hierarchy for career advancement of

skilled work. This guidebook sets out the trade test details and application procedures. For more information please contact: Trade Test Registry Vocational Training Council 10/F, VTC Tower 27 Wood Road, Wanchai Hong Kong Enquiry : 2919 1599 Web : http://ttr.vtc.edu.hk

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PART II TRADE TEST DETAILS

Trade Test Format Each trade test will consist of a trade knowledge test and a practical test. For the trade knowledge test, each candidate is required to take a written test normally of the multiple-choice type questions, the duration of which is about one hour. For the practical test, each candidate will be given practical assignments to complete. The duration of the practical test is approximately 6 hours. Venue Trade tests will be conducted at the Plastics and Tooling Technology Development Centre of the Vocational Training Council. Test Fee A non-refundable fee will be charged for each candidate. The amount will be notified in advertisements and the Trade Test Registry. Trade Test Syllabus Trade Test syllabuses for CNC Machining Centre (Vertical/Horizontal) Operators and CNC Lathe Operators are given in Appendix 1.

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Test Results Candidates will be informed of the results by post about two months after the test. Award of Certificate Candidates who have passed the trade knowledge test and the practical test, either at the same sitting or at different sittings within a time span of three years will be awarded a trade test certificate. Candidates who have passed either the trade knowledge test or the practical test will be issued a statement of result. Complaints/Review of Test Results Any complaints related to the conduct of the trade test should be addressed to the Chairman of the Trade Testing Committee of the Plastics Training Board. The Committees decision will be conveyed in writing to the complainants. If a candidate is dissatisfied with the test results, he may apply to the Chairman of the Committee for a review within 28 days of issue of the test result. Such application must be made in writing to the Chairman of the Trade Testing Committee of the Plastics Training Board at the following address: The Chairman Trade Testing Committee Plastics Training Board Vocational Training Council 10/F, VTC Tower 27 Wood Road, Wanchai Hong Kong Application for review of test results must be accompanied by a fee in cheque or bank draft made payable to the Vocational Training Council. The fee will be refunded if the application is successful.

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The Committees decision on the review of the application shall be final, and will

be conveyed in writing to the candidate. Others The Committee reserves the right to cancel the trade tests or make alterations regarding the application procedures, test regulations and the time and place of the tests. The affected applicants will be notified of the changes.

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PART III APPLICATION PROCEDURES

Eligibility Applicants for trade tests should have a minimum of five years relevant working/training experience including a minimum of 6 months in CNC machine operation. To be eligible for the tests, they may also be required, if necessary, to pass an interview to be conducted by the Plastics and Tooling Technology Development Centre. Submission of Application Prior to the start of the trade tests, advertisement will be placed in major newspaper to invite applications for tests. A closing date will be set for returning applications. Late applications will not be considered. Application forms and test regulations will be available free of charge at: Trade Test Registry Vocational Training Council 10/F, VTC Tower 27 Wood Road, Wanchai Hong Kong Enquiry : 2919 1599

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Application forms must be submitted by hand or by mail to the Trade Test

Registry. Photocopies of supporting documents such as craft certificates, employers testimonials, etc. should be attached to the application forms. Each submitted form will be acknowledged and assigned a serial number according to the sequence of submission.

Eligible applicants will be invited to call at the Trade Test Registry for

registration and vertification of the original copies of supporting documents. Qualified applicants will be notified to pay test fee by cheque or bank draft, made payable to the Vocational Training Council.

After payment of the test fee, each candidate will be informed of the test

procedures and given an admission ticket to the test centre. Test fees will not be refunded unless the test is cancelled by the Trade Testing Committee of the Plastics Training Board.

Ineligible applicants will also be informed in writing.

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Appendix 1 Trade Test Syllabuses

(A) CNC Machining Centre (Vertical/Horizontal) Operator

(a) Trade Knowledge Test

Candidates are expected to have knowledge on/of:

(1) Commonly used machining centers and controllers (such as Heidenhain and Fanuc).

(2) The economics of CNC machine tools. (3) The functions of codes and addresses used in part programming. (4) Preparation of process sheet, Part programme writing, editing and

loading using MasterCam. (5) Familiarize with advanced CAM drafting and programming. (6) Selection of cutting tools and determination of cutting conditions

and their application. (7) Multi-tool change setup, workpiece setup and initial machine

start-up procedure. (8) Safety procedures in the operation of a CNC machining center. (9) Industrial hazards and safety precautions such as wearing of proper

clothing, goggles; machine guards and lifting posture. (10) Interpretation of engineering drawings relating to precision part

construction, tolerances, surface finish, limits and fits, dimensioning etc.

(11) Properties and application of common trade materials. (12) Common measuring and checking instruments such as blade,

flange, internal and external micrometers, vernier calipers, dial test indicators, gauges.

(13) General workshop calculations such as areas, angles, and basic trigonometric functions.

(b) Practical Test

Candidates should be able to:

(1) Prepare process sheet, produce machining programmes using MasterCam, edit and load on controllers (such as Heidenhain and Fanuc).

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(2) Select correct cutting tools for their application. (3) Identify common trade materials and their properties. (4) Determine correct cutting conditions such as cutting speed, fedrate. (5) Set-up multi-tool change and workpiece. (6) Preparation of toolpath programming and post processing. (7) Perform machining operation using machining central. Perform

machining operation such as linear and circular interpolation, rounding and chamfer, tool approaches and departure, slotting and pocketing, boring, pecking, tapping, reaming, surface machining.

(8) Observe all necessary safety procedures at all times. (9) Interpret engineering drawings including common precision part

constructions, tolerances, surface finish, limits and fits, dimensioning etc.

(10) Use common hand tools, measuring and checking instruments such as blade, flange, internal and external micrometers, vernier calipers, dial test indicators, gauges, profile projectors.

(B) CNC Lathe Operator

(a) Trade Knowledge Test

Candidates are expected to have knowledge on/of:

(1) Commonly used CNC lathes and controllers (such as FANUC 10TE-F).

(2) The economics of CNC machine tools. (3) The functions of MasterCam used in part programming. (4) Preparation of process sheet, NC programme processing, editing and

loading. (5) The selection of cutting tools and determination of cutting conditions

and their application. (6) Turret multi-tooling setup, workpiece setup and initial machine

start-up procedure. (7) Safety procedure in the operation of CNC lathe. (8) Industrial hazards and safety precautions such as wearing of proper

clothing, goggles; machine guards and lifting posture.

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(9) Interpretation of engineering drawing relating to precision part

construction, surface finish, tolerances, limits and fits, dimensioning etc.

(10) Properties and application of common trade materials. (11) Common measuring and checking instruments such as internal and

external micrometers, vernier calipers, dial test indicators, gauges. (12) General workshop calculations such as areas, angles and basic

trigonometric functions. (b) Practical Test

Candidates should be able to:

(1) Create program, edit and load on controllers using MasterCam (such

as Fanuc 10TE-F). (2) Select correct CNC lathe cutting tools for application. (3) Identify common trade materials and their properties. (4) Determine correct cutting conditions such as cutting speed, feedrate. (5) Set up turret multi-tooling and workpiece. (6) Perform machining operation using CNC lathe. Perform machining

operation such as linear and circular interpolation, rounding and chamfer, tool approaches and departure, boring, grooving, internal and external threading, pecking, tapping, reaming.

(7) Observe all necessary safety procedures at all times. (8) Interpret engineering drawings including common precision parts

constructions, tolerances, surface finish, limits and fits, dimensioning etc.

(9) Use common hand tools, measuring and checking instruments such as internal and external micrometers, vernier callipers, dial test indicators, gauges, overhead projects.

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Appendix 2 Example of Trade Knowledge Test Questions (A) CNC Machining Centre (Vertical/Horizontal) Operator

Sample multiple choice questions are given below for reference: 1. Which one of the following is not a function of Drag command?

a) Translate

b) Rotate

c) Stretch

d) Scale

e) Copy and translate (Answer : (d))

2. Which one of the following is not a function of 2D Toolpath?

a) Contour

b) Drill

c) Flowline

d) Face

e) Pocket (Answer : (c))

3. Which operation selection button allows for the execution of a single CNC command?

a) Dry run

b) Single block

c) Block delete

d) Optional stop

e) None of the above (Answer : (b))

4. Which of the following factor influencing the feed during machining?

a) Workpiece material

b) Cutting Tools

c) Coolant

d) a & b

e) a, b & c (Answer : (d))

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(B) CNC LatheOperator Sample multiple choice questions (Fanuc) are given below for reference: 1. The code for tool nose radius compensation from the right is:?

a) G41

b) G42

c) G43

d) M41

e) M42 (Answer : (b))

2. AB is the diameter of a circle whose centre is C. If the coordinates of A are (4, 6) and the coordinates of B are (8, 0), find the coordinates of C.

a) (3, 6)

b) (6, -4)

c) (6, 3)

d) (6, -6)

e) (3, -3) (Answer : (c))

3. To perform Program Check for trial runs, an operator should:

a) Mode to tape check and ensure with safe working area

b) Mode to dry run and shift the workpiece datums to safe checking point

c) Mode to off and take off the workpiece

d) Mode to MDI and shift all axes to zero

e) Mode to jog and set axes to desire value (Answer : (a))

4. Which of the below are not the effects of incorrect cutting angles of a tool?

a) Tools does not cut the material efficiently

b) Tool life is reduced

c) Surface finish is impaired

d) Cutting time is longer

e) Power consumed is less (Answer : (e))

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Appendix 3 Examples of Practical Assignments (A) CNC Machining Centre (Vertical/Horizontal) Operator Time Allowed: 6 Hours

13

Appendix 4 Some Terms Commonly Used in CNC Programming and Machining Operation

(A) CNC Machining Centre (Vertical/Horizontal) (with Heideuhain Controller)

OPERATION

Dry run Test run Electronic hand wheel Graphics display Datum setting Touch probe Feedrate override Spindle speed override Home positioning Coolant

MATERIAL

Pre-harden steel (P20) Hot work tool steel (H13) Oil quenching tool steel (01) High wear resistance tool steel (D6) Medium carbon steel Mild steel Copper Aluminium Wax

PROGRAMMING

PGM editing PGM run in single block PGM run in full sequence Manual Data Input (MDI) Absolute/incremental Working spindle axis Working plane Tool length compensation Tool radius offset Arc approach & departure Up/down loading Direct Numerical Control (DNC) Pocket milling Slot milling Pecking Datum shift

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Mirror image Scaling Rotation Variable function Canned cycle International Standard Organization (ISO) Dialogue 2D machining 2.5D machining 3D machining

(B) CNC Lathe (with Fanuc Controller)

OPERATION

Hydraulic Chuck Hydraulic Tail Stock Turret Tool Post Tool Holder Vernier Calipers Micrometer Spindle Speed Override Feedrate Override Tool Setting Clamping Pressure Machine Lock Graphics/Symbolic Hand Wheel Manual Operation

PROGRAMMING

Tool Change Tool Offset Tool Nose Radius Compensation Work Zero Offset Zero Return Dry Run Tape Check Single Block Optional Stop Coolant Taper Edit MDI

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MATERIAL

Mild Steel Carbon Steel High Carbon Steel Pre-harden Steel DF-2 Copper Aluminium Wax

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1

(A)

(a)

(1) ( Heidenhain Fanuc)

(2)

(3)

(4) MasterCam

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(12)

(13)

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(b)

(1) MasterCam( Heidenhain Fanuc)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(B)

(a)

(1) ( Fanuc)

(2)

(3) MasterCam

(4)

(5)

(6)

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(7)

(8)

(9)

(10)

(11)

(12)

(b)

(1) MasterCam( Fanuc 10TE-F)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

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2

(A)

1. (Drag)

(a) Translate (b) Rotate (c) Stretch (d) Scale (e) Copy and Move (d)

2. (2DToolpaths)

(a) Contour (b) Drill (c) Flowline (d) Face (e) Pocket (c)

3. CNC

(a) (b) (c) (d) (e) (b)

4.

(a) (b) (c) (d) a&b (e) a,b&c (d)

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(B)

( Fanuc )

1.

(a) G41 (b) G42 (c) G43 (d) M41 (e) M42 (b)

2. AB C A B 4,68,0 C

(a) (3,6) (b) (6,-4) (c) (6,3) (d) (6,-6) (e) (3,-3) (c)

3. ProgramCheck

(a) Tapecheck (b) Dryrun (c) off (d) MDI (e) jog (a)

4.

(a) (b) (c) (d) (e) (e)

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3

(A) : 6

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4

(A) / ( Heidenhain )

(P20) (H13) (01) (D6)

/

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/ 2 2.5 3

(B) ( Fanuc )

/

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DF2