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CNC Operator

Competency-Based Apprenticeship
Sponsoring Company:
Workforce Intelligence Network (WIN)
O*Net Code
Rapids Code
Req. Hours
Jul 16, 2021
Jul 16, 2021

Competency-Based Skills

26 skill sets | 155 total skills
Safety - Safety Procedures
Demonstrate ability to safely enter a work cell including performing proper Energy Control Power Lockout (ECPL) procedures
Describe how an ECPL Control Gravity procedure as it relates to robotic manipulator prior to performing any inspection or maintenance work
Describe the proper PPE (Personal Protective Equipment) that should be worn while operating a CNC machine as well as other OSHA safety precautions and practices you should take in regards to material handling, lifting, chemicals, inhalation, etc.
Describe the proper personal grooming and work clothes worn while operating machinery and the safety requirements including lengths, jewelry, hair, shoes, gloves, protective sleeves, etc.
Describe the Emergency Stop Activation procedure and when it should be used Then describe the Emergency Stop Reset procedure to recover
Describe the possible hazardous areas inside and outside of a CNC machine area including pinch points, sharp edges, confined space, etc., as well as locating guarding and other safety features which must be in place and operational before starting the machine
Describe the safety checks to perform before starting a CNC operation or maintenance
Describe the functions of the Set-up /Run mode switch if so equipped, and the safety hazards involved
Safety - Safety Features
Locate and describe the safety features of a CNC machine
Locate the emergency stop pushbutton(s) and explain when and when not to activate its function
Locate the teach pendant Hold-to-Run button(s), a.k.a.: live man switch, and explain its function
Locate and identify the following safety components as applicable: ECPL signage, all Emergency Stop pushbuttons, gate interlocks, floor markings, area scanners, light curtains, vision sensors, pressure mats, warning/indicator lights
Components - CNC Machine Components
Describe the basic types of CNC machines and the operations they perform
Describe the basic axes of 2, 3, 4, 5,and 6 axis CNC machines and the direction of travel or rotation
Describe the basic parts of CNC mill machines and the function they perform
Describe the basic types of CNC turning machines and the operations they perform
Identify the areas of operation for a given CNC machine Operator Control Panel
Identify the areas of operation for a tool changer panel if equipped
Describe the type of spindle the unit uses and the components which control it
Describe the tool attachment setup for a given CNC machine
Describe the work fixture setup for a given CNC machine
Identify the following components of a CNC Lathe: Headstock, Chuck, Tailstock, Carriage, Turret and describe their function
Identify the following components on a CNC Turning Center: Spindle, Collet, Work Platform or Fixture, Chip Removal system, Tool Changer and describe their function
Identify the following components on a CNC Mill: Spindle, Collet, Work Platform or Fixture, Chip Removal system, Tool Changer and describe their function
Locate and describe the following services: Electrical (main control panel), Pneumatic, Hydraulic, Coolant, Feedback Sensors
Describe the type of drive system and controls used on a given machine (i.e., ballscrew, leadscrew, stepper motor, servo motor)
Describe the types of measuring systems used in CNC machines and the benefits of the type used (linear, rotary, encoder)
Identify the types of coolants used and explain their function for the types of cutting operation. Describe the delivery system typically used (manual, through tool, flush, etc.)
Identify the types of lubrication systems used and explain their function for the types of CNC machine. Describe the delivery system typically used such as MQL (Minimum Quantity Lubrication), centralized lubrication, pump, etc.
List the different ways workpieces may be loaded into CNC machines
Describe chip removal systems both internal (machine integrated) and external (chip conveyor)
Locate and explain the function of the foot pedal(s) for a given CNC machine if so equipped
Components - CNC Tooling
Describe the basic tool types used on a lathe CNC machine and the functions they perform
Describe the basic tool types used on a mill CNC machine and the functions they perform
Describe the basic tool types used on a grinding/finishing CNC machine and the functions they perform
Identify tool holder types, style, size, and rigidness for various tooling operations including turning, milling, lathe, drilling, etc.
Explain the purpose of the drawbar and what types of tooling requires it use
Describe how broken tool detection positive contact (wand or probe), and non-contact (laser, camera, vibration, proximity sensors) works and the advantages/disadvantages of each Discuss wired vs non-wired systems
Planning/Setup - Math Skills
Demonstrate converting fractions to decimal, and decimal to fractions
Demonstrate converting U.S. standard (Imperial) to metric, and metric to U.S. standard (Imperial)
Describe various geometric principles/formulas relating to triangles, quadrilaterals, and circles that are applied to obtain needed data for setting up projects and calculating tool locations
Demonstrate ability to calculate feeds and speeds using SFPM (Surface Feet per Minute), RPM (Rotations Per Minute), Chip Loads Per Tooth or Inches Per Tooth (IPT), Chip Load Per Tool in Inches Per Revolution (IPR), and the feed rate in IPM (inches per minute)
Demonstrate ability to interpret tool manufacturer provided information, chip load, feeds and speeds charts to setup tooling parameters
Planning/Setup - Metrology
Demonstrate the proper selection and use of fractional and decimal scales as it applies to measuring parts to the accuracy of a part print
Demonstrate the ability to properly use the following precision measuring instruments: I.D. and O.D. Micrometers (Vernier, Dial, and Digital), Height Gage, Vernier and Digital Calipers, Dial, and Digital Indicators with Magnetic Stand, Bore Gauges, Depth Gauges, Digital Protractors
Demonstrate the proper use of Gauge Blocks, Gauge Pins, 1-2-3 & 2-4-6 Blocks, Angle Blocks, Go/No Go Gauges, Feeler Gauges, Precision Levels, Sine Bar & Plate, Thread Gauges, and Surface Plates
Explain the care, inspection, and calibration techniques for Micrometers, Height Gages, Calipers, Indicators, Depth Gages, Bore Gauges, and Surface Plates
Describe the uses of a CMM (Coordinate Measuring Machine) and Optical Comparator in a CNC machining environment
Planning/Setup - Blueprint Reading
Demonstrate the ability to read and interpret a blueprint including the title block, revision block, line types, symbols, dimensions, scale, tolerances, orthographic and isometric views
Discuss Geometric Dimensioning and Tolerancing (GD&T) in terms of symbols used, tolerancing, modifiers, datums. Feature Control Frames, Datum Features, Maximum Material Condition (MMC) and Least Material Condition (LMC), etc.
Explain how to read and interpret ISO and ANSI surface finish symbols (a.k.a. surface texture or surface roughness symbols)
Planning/Setup - Metallurgy
Demonstrate basic knowledge of material types used in metal forming operations and the characteristics they process for determining tool selection, feeds and speeds, tool wear, etc.
Describe the various material hardness scales (Rockwell, Brinell, Vickers) and how they influence tool selection to achieve best results
Describe surface finish characteristics, ways to measure, (Ra vs RMS) and machine process choices to achieve the specified finish
Planning/Setup - Layout
Demonstrate proper use of machine cutting tools for preforming material stock for a semi-finish work
Demonstrate the proper handling of hand tools and how to use them safely to perform manual operations such as honing, tapping, shaping, deburring, etc., including but not limited to; electrical, pneumatic, and standard tools such as drills, grinders, saws, presses, hammers, chisels, files, punches, pliers, screwdrivers
Demonstrate ability to fill out and/or read setup sheets. Include information such as the part number, fixture location, tooling list, the X, Y and Z zero points, etc.
Demonstrate job planning and sequencing to effectively and safely produce qualified parts to specifications in a timely manner
Demonstrate accurately transferring part detail information to part such as hole centers, surface features, etc., using appropriate tools
Demonstrate setup and installation of workholding fixtures, setting datum points, work offset values (a.k.a. Work Zero Offset), and verify clamping pressures. Include process planning for workpiece turning for multiple operations on different faces and how to maintain squareness, perpendicularity, or parallelism within acceptable TIR (Total Indicator Reading) measurements
Demonstrate setup and installation of tools including parameters and tool offset values (a.k.a. Touching Off Tools) for a Mill, Turning, and Lathe operation. Discuss the different methods commonly used to set tool offset values (jogging, precision block, probes, etc.)
Demonstrate Homing a machine to set reference points
Demonstrate setting part zero reference points
Demonstrate setting up a tool changer such as a turret, magazine, or carousel, and inputting tool information to tool management program
Calculate Feeds and Speeds values for a given CNC operation
Demonstrate loading programs into CNC memory
Demonstrate running a warm-up program prior to production
Demonstrate running a test (air) program without parts prior to production
Demonstrate running a first run part and checking dimensions to specifications on part print
Operation - Operator Control Panel and Screens
Explain the Operator panel screen elements: Menu, status bar, buttons, task bar, message bar, quick select, etc. (varies per screen, manufacturer, mode) of a program and how to navigate between various operating and monitoring screens
Identify the basic areas of the teach pendant and their functions
Explain the color coded functions of a stacklight for a given system if so equipped
Operation - Operation
Demonstrate the pre-checks required before starting a CNC machine
Demonstrate the CNC machine Start-up sequences in Manual and Automatic modes
Demonstrate the Shut-down sequence for a short term shut-down (i.e., shift change, tool change)
Demonstrate the Shut-down sequence for a long term shut-down (i.e., maintenance, weekend)
Demonstrate changing from Automatic mode to Manual mode and vice-versa
Demonstrate operating in Automatic Step (block or single mode) and Continuous modes
Demonstrate stopping machine in cycle and recovering
Demonstrate the Access Door opening procedure
Demonstrate a Tool Change procedure for a manual and automatic (tool changer) operation
Explain a fault recovery and restart procedure
Demonstrate ability to perform mill, lathe, and turning machining operations using various tooling setups including between centers, chucks, work support, material feeder, etc.
Demonstrate ability to machine on multiple work planes during an operation including changing part orientation, fixtures, tool setups, while maintaining final specification
Operation - Jogging
Demonstrate manually jogging the machine in all available axis transitionals (linear and rotary if applicable) using the control panel and teach pendant including changing the direction, and jog rate
Demonstrate the procedure for jogging with the work door in the open position
Demonstrate varying jog speed (override) while manually jogging an axis
Operation - Coordinate Systems
Explain the concept of the Cartesian Coordinate System, Work (Workpiece) Coordinate System, Polar Coordinates, Coordinate Planes, and Quadrant Coordinates
Demonstrate the "Right Hand Rule" in relationship to the available axes
Explain the concepts of Relative (Incremental) vs. Absolute Coordinates
Operation - Error/Alarm Messages
Explain how warning and error messages are displayed at the CNC Operator panel and how to access the History screen
Locate where error messages and warnings are located on the teach pendant and how to view alarm history
Demonstrate the procedure for fault reset, clearing the alarms, and reset teach pendant if necessary
Programming - Basic Program Functions
Explain accessing the programming environment and simulation software
Demonstrate loading production programs from teach pendant if applicable
Demonstrate the procedure for backing up the CNC program
Demonstrate the process for switching between programs and changing the program uploaded to the machine
Explain the differences (advantages and disadvantages) between manual coding and CAM coding
Explain the concept of "Conversational" coding and how it is used
Demonstrate using a CAD software to model a simple part for conversion to CAM
Demonstrate how to write a basic G-Code programs for a given part print for Lathe, Turning, and Milling operations
Programming - Data Types
Explain the three basic operations/essential functions of a CNC machine regarding tool paths
Explain what the G Code is and it's basic functions List examples of G Code functions (G codes vary by machine)
Explain the purpose of M Codes and how they correlate to the machine List examples of M Codes functions (M codes vary by machine)
Explain the functions of the remaining letters of the G Code/CNC program (N, X/Y/Z, F, S, T, I/J, R, A, B, C, D, L, P)
Explain modal G Codes and how they function within groups
Programming - Editing Programs
Demonstrate editing a CNC program G Codes to adjust tool offsets
Demonstrate editing a CNC program G Codes to adjust work offsets
Demonstrate the ability to create a basic CNC program using G Code (as appropriate for available machine), incorporating both linear and circular interpolation. Show how to adjust speed, force, and to run in step, cycle, and continuous modes.
Demonstrate creating a peck drilling tool path program including dwell time
Explain the uses of "canned" cycles in CNC G Code programming
Demonstrate adjusting programs based on inspection of parts to shop prints to maintain specifications (such as work piece holding fluctuation, tool wear, etc.)
Demonstrate adjusting programs based on chip formation, cut conditions, tool wear, and cutter rake angle
Quality - Quality Control and Finishing
Describe quality control management systems and practices such as ISO 9001, Six Sigma, and how to utilize statistical information gathering techniques and develop capability studies
Describe setting up and utilizing a part inspection plan including sampling rates, data collection, charting or graphing test results, mean deviation, and actionable steps.
Demonstrate measuring workpieces (first run, production) to ensure compliance to shop print specifications.
Demonstrate utilizing work sheets, program notes, etc., to convey production changes for continual improvement.
Describe typical benchwork required for finishing parts including cleaning, deburring, honing, tapping, lapping, polishing, coating, engraving, stamping, etc.
Demonstrate proper finished part handling and storage.
Maintenance - Maintenance Safety
Demonstrate how to place the machine into safe maintenance position and locking it out.
Explain SDS (Safety Data Sheet) information, where to locate and how to read them.
Demonstrate knowledge of OSHA safety standards as well as plant or shop specific safety protocols.
Explain choosing proper PPE (Personal Protective Equipment) for the specific maintenance task to be performed.
Explain the proper use of air gun and handling of chips when cleaning the machine.
Maintenance - Basic Maintenance
Demonstrate the necessary procedures for cleaning and maintaining the CNC machine, work area, fixturing, and tools. Include the proper use of approved cleaning solvents, their handling, and storage.
Explain what it means to use the five senses to inspect the CNC machine and related equipment.
List examples of potential mechanical problems to look for during an inspection of the CNC machine and related equipment.
List examples of potential electrical problems to look for during an inspection of the CNC machine and related equipment.
List examples of potential pneumatic problems to look for during an inspection of the CNC machine and related equipment.
List examples of potential hydraulic problems to look for during an inspection of the CNC machine and related equipment.
List examples of potential lubrication problems to look for during an inspection of the CNC machine and related equipment.
Demonstrate how to identify tool wear (inserts, drills, etc.), and tool holder issues.
Maintenance - Maintenance Procedures
Demonstrate the process for lubricating the tooling/machine. For automated lubrication systems, inspect the lubrication system and show how to refill the reservoir. Understand the different kinds of lubricant and their purposes in the machine.
Demonstrate replacing pneumatic and hydraulic filters used on the machine.
Demonstrate Probe (tool setting and work offset) battery replacement (as applicable).
Demonstrate drive belt replacement/tensioning procedure.
Demonstrate how to check/adjust spindle drawbar or tool clamping force.
Demonstrate proper chip bin removal and replacement procedure.
Maintenance - CNC Machine Calibration
Demonstrate how to put the machine into calibration position and the steps required for calibrating the machine per preventive maintenance schedule or suspected mechanical alignment error.
Demonstrate calibrating the work setting probe and tool setting probe.
Demonstrate calibrating sensors used such as surface gage, thermo probes, etc.
Maintenance - Tooling Maintenance
Demonstrate the procedure for tool sharpening.
Demonstrate tool replacement procedures for a given type, such as: insert, drill, cutter, etc., utilizing heat shrink, hydro collet, standard collet, end mill.
Explain the inspection of various tool holders for symptoms such as pull stud condition, taper fretting, chattering, etc.
Troubleshooting - Safety Considerations
Demonstrate how to determine the proper PPE (Personal Protective Equipment) required for troubleshooting live equipment.
Explain the considerations to ensure the safety of personnel and equipment when performing troubleshooting on live robotic systems.
Troubleshooting - Troubleshooting Process
Explain the troubleshooting process when diagnosing systems including the specific steps to be taken to ensure the problem is verified, identified, and corrected. Include the follow-up process to ensure the equipment problem has been properly corrected, verified, and documented.
List the various ways systems may be monitored (electronically and physically) and how feedback systems can be utilized to identify, diagnose, and correct the root cause(es) of the problem.
Demonstrate where and how to view event messages, error codes, fault messages, alarm messages, warning messages, etc.
Demonstrate troubleshooting and repairing a system based on error code analysis, probable causes, and recommended actions from program diagnostics and manufacturer documentation.
Troubleshooting - Troubleshooting Systems
Demonstrate troubleshooting an electronic fault and electrical system.
Demonstrate troubleshooting a PLC generated fault or message.
Demonstrate troubleshooting a pneumatic system fault.
Demonstrate troubleshooting a hydraulic system fault.
Demonstrate troubleshooting a coolant system fault.

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