Course Title: Write and modify basic CNC programs

Part B: Course Detail

Teaching Period: Term1 2012

Course Code: MIET7504

Course Title: Write and modify basic CNC programs

School: 130T Vocational Engineering

Campus: City Campus

Program: C6069 - Advanced Diploma of Engineering Technology

Course Contact: Program Manager

Course Contact Phone: +61 3 9925 4468

Course Contact Email:

Name and Contact Details of All Other Relevant Staff

Teacher: Alan Wazir

Tel. No.: +61 3 99254153


Nominal Hours: 40

Regardless of the mode of delivery, represent a guide to the relative teaching time and student effort required to successfully achieve a particular competency/module. This may include not only scheduled classes or workplace visits but also the amount of effort required to undertake, evaluate and complete all assessment requirements, including any non-classroom activities.

Pre-requisites and Co-requisites


Course Description

This unit of competency sets out the knowledge and skills required
to create and modify basic CNC programs for linear and circular
turning and milling operations limited to 2D and 2.5D. This
excludes programming machines with multiple spindles and using
complex programming structures such as canned cycles and
No licensing, legislative, regulatory or certification requirements
apply to this unit at the time of publication.
Application of the Unit:

 The unit applies to manufacturing enterprises where metallic and
non-metallic components or parts are produced by CNC controlled
machine centres.
This unit of competency is intended for courses at diploma level or

National Codes, Titles, Elements and Performance Criteria

National Element Code & Title:

VBQU243 Write and modify basic CNC programs


1. Determine programming requirements

2. Write/modify CNC machine program and operation sheet

3. Verify CNC program

Performance Criteria:

1.1 OH&S and environmental requirements for a given work area are obtained and understood.
1.2 Established OH&S requirements and risk control measures and procedures in preparation for the work area are followed.
1.3 The programming requirements are determined from documentation, work requests or discussions with appropriate personnel.
1.4 Appropriate personnel are consulted to ensure the work is co-ordinated effectively with others involved at the work site.
1.6 Resources and equipment needed for the task are obtained in accordance with enterprise procedures and checked for correct operation and safety.

2.1 OH&S requirements for carrying out the work are followed.
2.2 Machine function and tool path is defined by referencing engineering drawings
2.3 Coordinates for tool path and machine function are calculated
2.4 CNC program is written and/or modified using EIA-274-D coding standard and according to enterprise procedures.
2.5 Operations sheets are produced in accordance with enterprise procedures.
2.6 Methods for dealing with unexpected situations are selected on the basis of safety and specified work outcomes.

3.1 OH&S requirements for completing the work are followed.
3.2 Program is tested and verified by operating machine in manual mode.
3.3 Corrective action is taken to eliminate any errors in the program and the program is manually revalidated.
3.4 The program is documented with comments and stored according to enterprise procedures.

Learning Outcomes


1. Determine programming requirements

2. Write/modify CNC machine program and operation sheet

3. Verify CNC program


Required skills:

Evidence that confirms skills in:
• interpreting and evaluating documentation, specifications and
• planning and scheduling required operations;
• calculating co-ordinates and references points for the
components being produced;
• visualising cutting tools movements;
• writing CNC code in using EIA-274-D standard;
• producing operations sheets;
• verifying CNC programs using manual mode;
• editing CNC programs;
• modifying CNC programs;
• programming for safety;
• ensuring that component will be produced to specifications;
• preparing and maintaining CNC programming records;
• working with others;
• communicating technical requirements to others; • adapting to changes in work.

Required knowledge:

Evidence that confirms knowledge of:
• motions of various machines centres;
• programmable functions;
• CNC process flow;
• point of reference;
• program structures;
• program codes and languages;
• program formatting;
• programming mistakes;
• linear and circular tool motion control;
• offsets and compensation techniques;
• tool length compensation.

Details of Learning Activities

The learning activities in this course are designed to equip students with knowledge and skills in writing and modifying CNC programs.

The course will be using a combination of lectures, reading tasks, practical work and mainly tutorials/assignments to achieve these objectives.

Tutorial work & Practical Assignments challenge the students and ensure that participants apply and deepen the theoretical knowledge covered in lectures.

Teaching Schedule

Please note: While your teacher will cover all the material in this schedule, the weekly teaching and assessment order is subject to change depending on class needs and availability of resources.

Teaching week 01:OH&S, Hazards and Risk control, Safety in the Workshop, Workshop Tour, risk control measures in place in the CNC workshop, Identification of machines and their movements (Travel Axes), Established RMIT OH&S requirements.. Read and sign Safety Sheet, Revision: Geometry and Trigonometry, set exercises.

Teaching week 02:Interpret customer requirements for the job in hand from drawings, discussions with teacher (client), etc. Draw up a list of materials types and sizes, machines and tools to be used in making the part(s) using technical lists, charts, and catalogues. (Resources and equipment needed for the task.) Process flow, Cutting tools, machines and their movements, basic program formatting- essentials of every program, Example of a basic program, programming codes and languages used in industry.

Teaching week 03:Operation sheets: Processes, Tool build-up, Calculating Speeds and feeds, Using available data from manufacturers of tools and inserts, etc. Identifying and avoiding common programming mistakes. Reference points: Machine home position vs Program zero point, Calculate co-ordinates: Absolute and incremental.

Teaching week 04: Manual programming: Generic start and finish lines, Work planes, Cancelling offsets, Calling up tools and tool change, Establishing the start position, order of commands, read a basic program using the ’G’ and ’M’ codes tables. Workshop demonstration of basic commands: Tool change, rapid moves vs controlled feed moves, spindle speeds and direction of rotation, etc.

Teaching week 05: Manual Programming: Create manual programs with rapid moves and linear interpolation only with the generic start and finish codes - no compensations, Tool length compensation - what it is and how it is used, examples. Test 1: 1hour

Teaching week 06: Circular interpolation: calculating the start and end points, relationship of "I", "J" and "K" values to the start and finish points, Exercises: Incorporating generic start lines, tool selection and change, rapid to position, feeding to depth, calling the tool tool length offset and feeding to depth, programming toolpaths for basic profiles.

Teaching week 07: Compensation Control: Diameter offset, lead in and lead out, Simple examples, Exercises using lead-in, lead-out, G40, G41 and G42, tool length compensation.
Roughing and finishing cuts, "race track" machining, pocketing.

Teaching week 08: Exercises using lead-in, lead-out, G40, G41 and G42, tool length compensation. Roughing and finishing cuts, "race track" machining, pocketing. Fill in setup sheet, Simulate toolpaths using in-house/freeware toolpath simulation software, correcting programming errors visually.

Teaching week 09: Exercises using lead-in, lead-out, G40, G41 and G42, tool length compensation. Roughing and finishing cuts, "race track" machining, pocketing using multiple tools Fill in setup sheet, Simulate toolpaths using in-house/freeware toolpath simulating software, correct errors

Teaching week 10: Prove final exercise on the CNC machine.

Teaching week 11: Revision/ tutorial, worked examples.

Teaching week 12: Revision, Test 1.5  hrs.

Learning Resources

Prescribed Texts


Other Resources

Engineering tooling catalogues,
Machinery’s Handbook,
Fitting and Machining Handbook,
Engineer’s Black book,
Zeus pocket book.

Overview of Assessment

Assessment may incorporate a variety of methods including written/oral activities and demonstration of practical skills to the relevant industry standards. Participants are advised that they are likely to be asked to personally demonstrate their assessment activities to their teacher/assessor. Feedback will be provided throughout the course.

Evidence of student’s competence can be gathered through a variety of ways including:
• observation of processes and procedures;
• oral and/or written questioning on required knowledge and skills;
• testimony from supervisors, colleagues, clients and/or other appropriate
• inspection of the final product or outcome;
• a portfolio of documentary evidence.

Graded Assessment out of 100 Marks will be based on the results obtained for Assignments & Practical Reports and/or Unit Tests.
Students must gain a pass in ALL forms of assessment in order to gain this competency.

Assessment Tasks

This subject has ongoing assessments for the set work. 

Two written assignments, two tests, set class work & practical exercises - 100%

Assessment Matrix

Other Information

Study and learning Support:

Study and Learning Centre (SLC) provides free learning and academic development advice to all RMIT students.
Services offered by SLC to support numeracy and literacy skills of the students are:

assignment writing, thesis writing and study skills advice
maths and science developmental support and advice
English language development

Please Refer to find more information about Study and learning Support

Disability Liaison Unit:

Students with disability or long-term medical condition should contact Disability Liaison Unit to seek advice and support to complete their studies.

Please Refer to find more information about services offered by Disability Liaison Unit

Late submission:

Students requiring extensions for 7 calendar days or less (from the original due date) must complete and lodge an Application for Extension of Submittable Work (7 Calendar Days or less) form and lodge it with the Senior Educator/ Program Manager. The application must be lodged no later than one working day before the official due date. The student will be notified within no more than 2 working days of the date of lodgement as to whether the extension has been granted.

Students seeking an extension of more than 7 calendar days (from the original due date) must lodge an Application for Special Consideration form under the provisions of the Special Consideration Policy, preferably prior to, but no later than 2 working days after the official due date.

Assignments submitted late without approval of an extension will not be accepted or marked.

Special consideration:

Please Refer;ID=riderwtscifm (unresolved) to find more information about special consideration


Plagiarism is a form of cheating and it is very serious academic offence that may lead to expulsion from the University.

Please Refer to: to find more information about plagiarism.

Other Information:

All email communications will be sent to your RMIT email address and you must regularly check your RMIT emails.

Course Overview: Access Course Overview