ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II COURSE

TESDA TRAINING REGULATIONS FOR ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II

The TESDA Course in Electric Discharge Machine (EDM)-Sinking Operation NC II consists of competencies that a person must achieve to set-up EDM, electrode and workpiece, perform EDM-sinking operations and perform post EDM -sinking operations.

A student who has achieved this TESDA Course in ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II is competent to be:

• Electric Discharge Machine-Sinking Operator

TRAINEE ENTRY REQUIREMENTS

Trainees or students who wish to enter this training should possess the following requirements:

• Holder of any Certificate of Competency in Machining NC I or 1-year industry experience in machining
• Must have completed the 10-year basic education or an Alternative Learning System (ALS) Certificate of Completion with grade 10 equivalent holder
• Can communicate orally or in writing
• Can perform basic mathematical computation

ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II COURSE MODULE

Course Title: ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION
Level: NC II
Nominal Training Duration :

(Basic Competency) 37 hours
(Common Competency) 104 hours
(Core Competency) 160 hours

TOTAL DURATION: 301 Hours

This course is designed to enhance the knowledge, skill and attitudes of ELECTRIC DISCHARGE MACHINE(EDM)-SINKING OPERATION NC II in accordance with industry standards. This covers competencies that a person must achieve in performing set-up of EDM, electrode and workpiece, perform operation procedures, and post-EDM operations.

Upon completion of the course, the learners are expected to demonstrate the above-mentioned competencies to be employed. To obtain this, all units prescribed for this qualification must be achieve.

COMPETENCIES REQUIRED IN ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II

This units of competency comprising this qualification include Basic, Common and Core Competencies.

To obtain this TESDA Course in ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II, all units prescribed below for this qualification must be achieved.

These units of competency comprising this qualification include the following:

UNIT CODE	CORE COMPETENCIES (160  hours)
MEE821314	Set-up Electric Discharge Machine, electrode and workpiece
MEE821315	Perform Electric Discharge Machine-sinking operations
MEE821316	Perform post Electric Discharge Machine-sinking operations
UNIT CODE	COMMON COMPETENCIES (104  hours)
MEE722201	Apply safety practices
MEE722202	Interpret working drawings and sketches
MEE722203	Select/ cut workshop materials
MEE722204	Perform shop computations (Basic)
MEE722205	Measure workpiece (Basic)
MEE722206	Perform routine housekeeping
MEE722207	Perform shop computations (Intermediate)
MEE722208	Measure workpiece using angular measuring instruments
MEE722210	Measure workpiece using gages and surface texture comparator
MEE722211	Perform preventive and corrective maintenance
UNIT CODE	BASIC COMPETENCIES (37 hours)
400311210	Participate in workplace communication
400311211	Work in a team environment
400311212	Solve/address general workplace problems
400311213	Develop career and life decisions
400311214	Contribute to workplace innovation
400311215	Present relevant information
400311216	Practice occupational safety and health policies and procedures
400311217	Exercise efficient and effective sustainable practices in the workplace
400311218	Practice entrepreneurial skills in the workplace

These guidelines are set to provide the Technical Vocational Education and Training (TVET) providers with information and other important requirements to consider when designing training programs for ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION NC II.

CORE COMPETENCIES

UNIT OF COMPETENCY : SET-UP ELECTRIC DISCHARGE MACHINE (EDM), ELECTRODE AND WORKPIECE
UNIT CODE : MEE821314

This unit covers the knowledge, skills and attitudes required to set-up electric discharge machine (sinking), electrode and workpiece.

1. Prepare EDM-Sinking
   • EDM sinking type and capacity is selected according to job requirement
   • Oil, grease and dielectric fluid is checked according to manufacturer’s specification.
   • Electrical settings and parameters are set according to manufacturer’s specification.
   • Work holding and clamping devices are mounted according to standard operating procedures.
   • Operate dielectric fluid pump and set working pressure according to manufacturer’s specification
   • Safety procedures are applied following OSHS
2. Prepare electrode
   • Electrode is selected according to job requirement
   • Electrode is mounted on EDM platen and holder according to manufacturer’s specification.
   • Electrode is aligned perpendicularly to the magnetic table according to standard operating procedures.
   • Safety procedures are applied following OSHS
3. Prepare workpiece
   • Clamping device is selected based on workpiece material
   • Workpiece is mounted on clamping device according to standard industry procedures
   • Workpiece is centered to required level of accuracy using tools and instruments in accordance with workplace procedures.
   • Zero reference point of X, Y. Z axes is set according to standard operating procedures.
   • Front wall of tank is clamped to enclose and seal working tank according to industry standard procedures.
   • Safety procedures are applied following OSHS

UNIT OF COMPETENCY : PERFORM ELECTRIC DISCHARGE MACHINE (EDM)- SINKING OPERATION
UNIT CODE : MEE821315

This unit involves the knowledge, skills and attitudes required in performing electric discharge machine (sinking) operations.

1. Operate EDM -Sinking
   • Dry run is conducted and adjustments are made if required according to EDM operating manual Workpiece is pressure flushed /submerged with dielectric fluid according to EDM operating manual
   • EDM is operated to meet dimensions, tolerances, limits ,fits and surface texture according to job requirements
   • EDM accessories are used according to job requirements
   • Worn out electrode is replaced according to job requirements
   • Safety procedures are applied following OSHS
2. Monitor performance of machine and electrode
   • Machine and electrode performance is monitored and adjusted with the aid of power control unit based on the accepted industry standards
   • Dielectric fluid level is maintained according to machine operating manual
   • Flushing pressure is progressively increased based on job requirements
   • Depth of cut is thoroughly maintained according to standard work procedures
   • Safety procedures are applied following OSHS
3. Visual inspection of workpiece and electrode
   • Working table is emptied of dielectric fluid according to operating manual
   • Surface of workpiece is cleaned according to job requirement
   • Surface texture of workpiece is visually inspected while on its holder according to job requirements
   • Electrode is inspected for wear according to job requirements
   • Safety procedures are applied following OSHS

UNIT OF COMPETENCY : PERFORM POST-ELECTRIC DISCHARGE MACHINE (EDM)-SINKING OPERATION
UNIT CODE : MEE821316

This unit involves the knowledge, skills and attitudes
to perform post-electric discharge machine-sinking operations.

1. Conduct post-EDM-Sinking operation
   • EDM flushing is shut off or gate valve is opened in accordance to operation manual
   • EDM tank front wall is opened according to the operating manual
   • Workpiece is removed from work holding and clamping devices according to job requirement
   • Workpiece is cleaned and dried according to job requirement
   • Safety procedures are applied following OSHS
2. Final check of workpiece
   • Workpiece is checked and measured using measuring tools following standard operating procedures
   • Inspected workpiece is applied with anti-corrosion agents
   • Inspected workpiece and accomplishment report are submitted to immediate supervisor following workplace procedures
   • Safety procedures are applied following OSHS
3. EDM-Sinking shutdown and housekeeping
   • Electrical, pneumatic and hydraulic switches are turned off according to manufacturers’ operating manual
   • Tools are maintained and stored based on established procedures
   • Defective tools are tagged and reported according to workplace procedures
   • Good housekeeping is performed following 5S
   • Wastes are disposed according to waste management procedures and environmental regulations
   • Safety procedures are applied following OSHS

COMMON COMPETENCIES

UNIT OF COMPETENCY : APPLY SAFETY PRACTICES
UNIT CODE : MEE722201

This unit covers the competencies required to apply safety practices in the workplace.

1. Identify hazards
   • Hazards are identified correctly in accordance with OHS principles.
   • Safety signs and symbols are identified and adhered to.
2. Use protective clothing and devices
   • Appropriate protective clothing and devices correctly selected and used in accordance with OHS requirements or industry/ company policy.
3. Perform safe handling of tools, equipment and materials
   • Safety procedures for pre-use check and operation of tools and equipment followed in accordance with industry/ company policies.
   • Tools, equipment and materials handled safely in accordance with OHS requirements and industry/ company policies.
4. Perform first aid
   • First aid treatment of injuries are carried out according to recommended procedures.
5. Use fire extinguisher
   • Fire extinguisher selected and operated correctly according to the type of fire.

UNIT OF COMPETENCY : INTERPRET WORKING DRAWINGS And SKETCHES
UNIT CODE : MEE722202

This unit covers the competencies required to read and interpret drawings and sketches.

1. Interpret technical drawing
   • Components, assemblies or objects recognized as required.
   • Dimensions identified as appropriate.
   • Instructions identified and followed as required.
   • Material requirements identified as required.
   • Symbols recognized as appropriate in the drawing.
   • Tolerance, limits and fits identified in the drawing.
2. Prepare freehand sketch of parts
   • Sketch drawn correctly and appropriately.
   • Sketch depicted objects or part appropriately.
   • Dimensions indicated in sketch are clear and correct.
   • Instructions included in sketch are clear and correct.
   • Base line or datum points indicated as required.
3. Interpret details from freehand sketch
   • Components, assemblies or objects recognized as required.
   • Dimensions identified as appropriate.
   • Instructions identified and followed as required.
   • Material requirements identified as required.
   • Symbols recognized as appropriate in the drawing.

UNIT OF COMPETENCY : SELECT AND CUT WORKSHOP MATERIALS
UNIT CODE : MEE722203

This unit covers the skills and knowledge required to select and cut workshop materials.

1. Determine job requirement
   • Plans/ drawings are interpreted to produce component to specification.
   • Sequence of operation is determined to produce component to specification.
2. Select and measure materials
   • Materials are selected according to the requirement of the operation.
   • Materials are measured to required level of accuracy using measuring tools.
   • Measuring tools are used according to manufacturer’s specification.
3. Cut materials
   • Materials are cut according to plans/drawing instruction.
   • Cutting tools/ equipment are used based on manufacturers specification, appropriate techniques or the safety procedure.

UNIT OF COMPETENCY : PERFORM SHOP COMPUTATIONS (BASIC)
UNIT CODE : MEE722204

This unit covers the competencies required to perform
basic calculations using the four fundamental operation.

1. Perform four fundamental operations
   • Simple calculations are performed using four fundamental operations.
2. Perform basic calculations involving fractions and decimals
   • Simple calculations are performed involving fractions and decimals using the four fundamental operations.
   • Decimal are converted into fraction (and vice versa) accurately.
3. Perform basic calculations involving percentages
   • Simple calculations are performed to obtain percentages from information expressed in either fractional or decimal format.
4. Perform basic calculation involving ratio and proportion
   • Simple calculations are performed involving ratio and proportion using whole numbers, fractions and decimals.
5. Perform calculations on algebraic expressions
   • Simple calculations are performed on algebraic expressions using the four fundamental operations.
   • Simple transposition of formulae is carried out to isolate the variable required, involving the four fundamental operations.

UNIT OF COMPETENCY : MEASURE WORKPIECE (BASIC)
UNIT CODE : MEE722205

This unit covers the competencies required to measure workpieces using measuring instruments such as steel rule, Vernier caliper, micrometer, etc.

1. Select and use measuring tools
   • Measuring tools are selected and used according to the level of accuracy required.
   • Measurements taken are accurate to the finest graduation of the selected measuring instrument.
   • Measuring technique used is correct and appropriate to the device used.
2. Clean and store measuring tools
   • Care and storage of devices undertaken to manufacturer’s specifications or standard operating procedures.

UNIT OF COMPETENCY : PERFORM ROUTINE HOUSEKEEPING
UNIT CODE : MEE722206

This unit covers the competencies required to maintain an organized and clean work area.

1. Organize work area
   • Work area maintained in a safe, uncluttered and organized manner according to workshop policy.
   • All tasks carried out safely, effectively and efficiently with minimum inconvenience according to workshop policy.
   • Workshop policies and procedures for tidying work areas and placing items in designated areas applied.
2. Clean work area
   • Shop policies and procedures applied for cleaning work area.
   • Wastes promptly removed and disposed of according to shop policies and environmental requirements.
   • Spills, wastes and other potential hazards reported to appropriate personnel and removed according to shop policies and environmental requirements.
   • Signage promptly displayed in regard to unsafe areas.
   • Consumable

UNIT OF COMPETENCY : PERFORM SHOP COMPUTATIONS (INTERMEDIATE)
UNIT CODE : MEE722207

This unit covers the competencies required to perform calculation involving triangles and tapers.

1. Perform calculations involving triangles
   • Problems involving right triangles are performed using the trigonometric functions.
   • Problems involving non-right triangles are performed using sine and cosine rules.

UNIT OF COMPETENCY : MEASURE WORKPIECE USING ANGULAR MEASURING INSTRUMENTS
UNIT CODE : MEE722208

This unit covers the competencies required to measure workpieces using angular measuring instruments.

1. Select and use angular measuring tools
   • Angular measuring tools are selected and used according to the level of accuracy required.
   • Measurements taken are accurate to the finest graduation of the selected measuring instrument.
   • Measuring technique used is correct and appropriate to the device used.
2. Maintain angular measuring tools
   • Measuring tools are adjusted and maintained to the required accuracy utilizing manufacturer’s or worksite procedures.
3. Clean and store measuring tools
   • Care and storage of devices undertaken to manufacturer’s specifications or standard operating procedures.

UNIT OF COMPETENCY: MEASURE WORKPIECE USING GAGES AND SURFACE TEXTURE COMPARATOR
UNIT CODE: MEE722210

This unit covers the competencies required to measure workpieces using fixed and adjustable gages.

1. Select and use fixed and adjustable gages
   • Appropriate gages are selected and used to undertake the required comparison or measurement using standard operating procedures.
   • Consistent and accurate measurements obtained conforms to drawing specification
   • Measuring technique used is correct and appropriate to the device used.
2. Perform surface texture measurements
   • Surface texture are measured according worksite procedures.
   • Measurements taken are within the level of accuracy required.
3. Clean and store measuring tools
   • Care and storage of devices undertaken to manufacturer’s specifications or standard operating procedures

UNIT OF COMPETENCY : PERFORM PREVENTIVE AND CORRECTIVE MAINTENANCE
UNIT CODE : MEE722211

This unit covers the knowledge and skills required in performing preventive and corrective maintenance such as inspection and repair of hand tools, cleaning and lubrication of machine parts and changing drive pulley and belts.

1. Perform inspection of machine
   • Machine inspected according to worksite procedures.
   • Status/Report recorded on pro-forma or reported orally according to worksite procedure.
2. Perform cleaning and lubricating of machine
   • Machines lubricated as per manufacturer’s recommendation using appropriate tools and materials
   • Fluids and lubricants replaced and/or topped up according to prescribed schedule.
3. Perform minor machine repair and adjustments
   • Minor machine repairs performed according to manufacturer’s instruction or worksite procedures.
   • Machine moving parts adjusted to manufacturer’s specifications.
4. Maintain hand tools
   • Tool cutting ground to recommended specifications
   • Hand tools lubricated and stored according to prescribed procedure

BASIC COMPETENCIES

UNIT OF COMPETENCY : PARTICIPATE IN WORKPLACE COMMUNICATION
UNIT CODE : 400311210

This unit covers the knowledge, skills and attitudes required to gather, interpret and convey information in response to workplace requirements.

1. Obtain and convey workplace information
   • Specific and relevant information is accessed from appropriate sources
   • Effective questioning , active listening and speaking skills are used to gather and convey information
   • Appropriate medium is used to transfer information and ideas
   • Appropriate non- verbal communication is used
   • Appropriate lines of communication with supervisors and colleagues are identified and followed
   • Defined workplace procedures for the location and storage of information are used
   • Personal interaction is carried out clearly and concisely
2. Perform duties following workplace instructions
   • Written notices and instructions are read and interpreted in accordance with organizational guidelines
   • Routine written instruction are followed based on established procedures
   • Feedback is given to workplace supervisor based instructions/ information received
   • Workplace interactions are conducted in a courteous manner
   • Where necessary, clarifications about routine workplace procedures and matters concerning conditions of employment are sought and asked from appropriate sources
   • Meetings outcomes are interpreted and implemented
3. Complete relevant work related documents
   • Range of forms relating to conditions of employment are completed accurately and legibly
   • Workplace data is recorded on standard workplace forms and documents
   • Basic mathematical processes are used for routine calculations
   • Errors in recording information on forms/ documents are identified and properly acted upon
   • Reporting requirements to supervisor are completed according to organizational guidelines

UNIT OF COMPETENCY: WORK IN TEAM ENVIRONMENT
UNIT CODE : 400311211

This unit covers the skills, knowledge and attitudes to identify role and responsibility as a member of a team.

1. Describe team role and scope
   • The role and objective of the team is identified from available sources of information
   • Team parameters, reporting relationships and responsibilities are identified from team discussions and appropriate external sources
2. Identify own role and responsibility within team
   • Individual role and responsibilities within the team environment are identified
   • Roles and responsibility of other team members are identified and recognized
   • Reporting relationships within team and external to team are identified
3. Work as a team member
   • Effective and appropriate forms of communications used and interactions undertaken with team members who contribute to known team activities and objectives
   • Effective and appropriate contributions made to complement team activities and objectives, based on individual skills and competencies and workplace context
   • Observed protocols in reporting using standard operating procedures
   • Contribute to the development of team work plans based on an understanding of team’s role and objectives and individual competencies of the members.

UNIT OF COMPETENCY : SOLVE/ADDRESS GENERAL WORKPLACE PROBLEMS
UNIT CODE : 400311212

This unit covers the knowledge, skills and attitudes required to apply problem-solving techniques to determine the origin of problems and plan for their resolution. It also includes addressing procedural problems through documentation, and referral.

1. Identify routine problems
   • Routine problems or procedural problem areas are identified
   • Problems to be investigated are defined and determined
   • Current conditions of the problem are identified and documented
2. Look for solutions to routine problems
   • Potential solutions to problem are identified
   • Recommendations about possible solutions are developed, documented, ranked and presented to appropriate person for decision
3. Recommend solutions to problems
   • Implementation of solutions are planned
   • Evaluation of implemented solutions are planned
   • Recommended solutions are documented and submit to appropriate person for confirmation

UNIT OF COMPETENCY : DEVELOP CAREER AND LIFE DECISIONS
UNIT CODE : 400311213

This unit covers the knowledge, skills, and attitudes in managing one’s emotions, developing reflective practice, and boosting self-confidence and developing self-regulation.

1. Manage one’s emotion
   • Self-management strategies are identified
   • Skills to work independently and to show initiative, to be conscientious, and persevering in the face of setbacks and frustrations are developed
   • Techniques for effectively handling negative emotions and unpleasant situation in the workplace are examined
2. Develop reflective practice
   • Personal strengths and achievements, based on self-assessment strategies and teacher feedback are contemplated
   • Progress when seeking and responding to feedback from teachers to assist them in consolidating strengths, addressing weaknesses and fulfilling their potential are monitored
   • Outcomes of personal and academic challenges by reflecting on previous problem solving and decision making strategies and feedback from peers and teachers are predicted
3. Boost self-confidence and develop self-regulation
   • Efforts for continuous self-improvement are demonstrated
   • Counter-productive tendencies at work are eliminated
   • Positive outlook in life are maintained.

UNIT OF COMPETENCY : CONTRIBUTE TO WORKPLACE INNOVATION
UNIT CODE : 400311214

This unit covers the knowledge, skills and Attitudes required to make a pro-active and positive contribution to workplace innovation.

1. Identify opportunities to do things better
   • Opportunities for improvement are identified proactively in own area of work.
   • Information are gathered and reviewed which may be relevant to ideas and which might assist in gaining support for idea.
2. Discuss and develop ideas with others
   • People who could provide input to ideas for improvements are identified.
   • Ways of approaching people to begin sharing ideas are selected.
   • Meeting is set with relevant people.
   • Ideas for follow up are review and selected based on feedback.
   • Critical inquiry method is used to discuss and develop ideas with others.
3. Integrate ideas for change in the workplace
   • Critical inquiry method is used to integrate different ideas for change of key people.
   • Summarizing, analyzing and generalizing skills are used to extract salient points in the pool of ideas.
   • Reporting skills are likewise used to communicate results.
   • Current Issues and concerns on the systems, processes and procedures, as well as the need for simple innovative practices are identified.

UNIT OF COMPETENCY : PRESENT RELEVANT INFORMATION
UNIT CODE : 400311215

This unit of covers the knowledge, skills and attitudes required to present data/information appropriately.

1. Gather data/ information
   • Evidence, facts and information are collected
   • Evaluation, terms of reference and conditions are reviewed to determine whether data/information falls within project scope
2. Assess gathered data/ information
   • Validity of data/ information is assessed
   • Analysis techniques are applied to assess data/ information.
   • Trends and anomalies are identified
   • Data analysis techniques and procedures are documented
   • Recommendations are made on areas of possible improvement.
3. Record and present information
   • Studied data/information are recorded.
   • Recommendations are analysed for action to ensure they are compatible with the project’s scope and terms of reference.
   • Interim and final reports are analysed and outcomes are compared to the criteria established at the outset.
   • Findings are presented to stakeholders.

UNIT OF COMPETENCY : PRACTICE OCCUPATIONAL SAFETY AND HEALTH POLICIES AND PROCEDURES
UNIT CODE : 400311216

This unit covers the knowledge, skills and attitudes required to identify OSH compliance requirements, prepare OSH requirements for compliance, perform tasks in accordance with relevant OSH policies and procedures

1. Identify OSH compliance requirements
   • Relevant OSH requirements, regulations, policies and procedures are identified in accordance with workplace policies and procedures
   • OSH activity non-conformities are conveyed to appropriate personnel
   • OSH preventive and control requirements are identified in accordance with OSH work policies and procedures
2. Prepare OSH requirements for compliance
   • OSH work activity material, tools and equipment requirements are identified in accordance with workplace policies and procedures
   • Required OSH materials, tools and equipment are acquired in accordance with workplace policies and procedures
   • Required OSH materials, tools and equipment are arranged/ placed in accordance with OSH work standards
3. Perform tasks in accordance with relevant OSH policies and procedures
   • Relevant OSH work procedures are identified in accordance with workplace policies and procedures
   • Work Activities are executed in accordance with OSH work standards
   • Non-compliance work activities are reported to appropriate personnel

UNIT OF COMPETENCY : EXERCISE EFFICIENT AND EFFECTIVE SUSTAINABLE PRACTICES IN THE WORKPLACE
UNIT CODE : 400311217

This unit covers knowledge, skills and attitude to identify the efficiency and effectiveness of resource utilization, determine causes of inefficiency and/or ineffectiveness of resource utilization and Convey inefficient and ineffective environmental practices

1. Identify the efficiency and effectiveness of resource utilization
   • Required resource utilization in the workplace is measured using appropriate techniques
   • Data are recorded in accordance with workplace protocol
   • Recorded data are compared to determine the efficiency and effectiveness of resource utilization according to established environmental work procedures
2. Determine causes of inefficiency and/or ineffectiveness of resource utilization
   • Potential causes of inefficiency and/or ineffectiveness are listed
   • Causes of inefficiency and/or ineffectiveness are identified through deductive reasoning
   • Identified causes of inefficiency and/or ineffectiveness are validated thru established environmental procedures
3. Convey inefficient and ineffective environmental practices
   • Efficiency and effectiveness of resource utilization are reported to appropriate personnel
   • Concerns related resource utilization are discussed with appropriate personnel
   • Feedback on information/ concerns raised are clarified with appropriate personnel

UNIT OF COMPETENCY : PRACTICE ENTREPRENEURIAL SKILLS IN THE WORKPLACE
UNIT CODE : 400311218

This unit covers the outcomes required to apply entrepreneurial workplace best practices and implement cost-effective operations

1. Apply entrepreneurial workplace best practices
   • Good practices relating to workplace operations are observed and selected following workplace policy.
   • Quality procedures and practices are complied with according to workplace requirements.
   • Cost-conscious habits in resource utilization are applied based on industry standards.
2. Communicate entrepreneurial workplace best practices
   • Observed Good practices relating to workplace operations are communicated to appropriate person.
   • Observed quality procedures and practices are communicated to appropriate person
   • Cost-conscious habits in resource utilization are communicated based on industry standards.
3. Implement cost-effective operations
   • Preservation and optimization of workplace resources is implemented in accordance with enterprise policy
   • Judicious use of workplace tools, equipment and materials are observed according to manual and work requirements.
   • Constructive contributions to office operations are made according to enterprise requirements.
   • Ability to work within one’s allotted time and finances is sustained.

DEFINITION OF TERMS

• Electric discharge machine (EDM) operation is the operation of removing metal thru electric discharge of short duration and high current density between the tool and workpiece
• Electrode a formed cutting tool usually made of electrically conductive material usually carbon (graphite)
• Dielectric fluid mostly of light lubricating oil of low viscosity and a non-conductor of electricity, able to rapidly ionize(vaporize) and deionize metal by removing it by flushing
• Flushing process of removing eroded particles from the spark gap thru the rapid passage of dielectric fluid on a pipe or nozzle or thru electrode
• Surface texture Is the surface finish on workpiece resulting from the spark duration, ie. Longer spark duration, rougher surface finish
• Wear refers to the tool or electrode’s microscopic particles being carried on every spark, ie. More spark, more wear
• Spark gap The distance between the face and sides of the workpiece and the electrode during machining operation
• Duty cycle Is the measure of efficiency from the relationship between the on-time to the off-time of machine operation
• Relaxation type circuit Depends upon the capacitor and resistance to provide the spark discharge. It gives higher electrode wear rate and lower metal removal
• Pulse type circuit – A valve or transistorized circuit to switch power into the working gap under accurate control, enabling precise amounts of energy to be measured in each spark discharge
• Dither/Audio – Attachments designed to give visual or audible signal if proximity of electrode and workpiece is less than the spark gap
• Gap Monitor Meter – It indicates deviation of spark gap; arching will cause a voltage increase and poor ionization of fluid will decrease the voltage
• Servo head It controls the advancement of the electrode into the workpiece. Correct spark gap is maintained when voltages at the working gap and the reference on the servo head are balance