Setting CNC machining centres for production of aircraft components
Overview
This standard identifies the competences you need to prepare and set up Computer Numerical Control (CNC) machining centres, in accordance with approved procedures to produce aircraft components. It covers both fixed wing and rotary winged aircraft components. You will be expected to select the appropriate workholding devices to be used and to mount and position them to the machine in the correct location for the type of operation being carried out. You will also be required to select the appropriate tools and cutters, check them for defects and mount and secure them to the relevant tool holding devices and machine spindle.
You will need to ensure that all the tools have been allocated a relevant tool number and that the relevant data on their co-ordinates and datum positions are entered into the operating program and machine. This will involve loading and proving component programs, checking for errors/faults, editing and saving program changes. You must produce trial components and prove the machine is working satisfactorily before declaring the machine ready for production. Making adjustments to settings to achieve specification and solving machine-related problems during production, will also form part of your role.
Your responsibilities will require you to comply with organisational policy and procedures for the machine setting activities undertaken and to report any problems with the equipment, tooling, programs or setting up activities that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work and will provide an informed approach to the setting-up procedures used in an aeronautical manufacturing environment. You will understand the CNC machining centre used and its application and will know about the workholding devices, tooling, machine operating programs and setting-up procedures, in adequate depth to provide a sound basis for setting up the equipment, correcting faults and ensuring the work output is produced to the required aircraft specification.
You will understand the safety precautions required when working with the machine and its associated tools and equipment. You will be required to demonstrate safe working practices throughout and will understand the responsibility you owe to yourself and others in the workplace.
Performance criteria
You must be able to:
| 1. work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines 2. follow the correct specifications for the component to be produced 3. determine what has to be done and how the machine will be set to achieve this 4. mount, set and secure the required work-holding devices, work piece and cutting tools 5. set the machine tool operating parameters to achieve the component specification 6. check that all safety mechanisms are in place and that the equipment is set correctly for the required operations 7. complete the relevant documentation in accordance with organisational requirements 8. deal promptly and effectively with problems within your control and report those that cannot be solved 9. leave the work area and machine in a safe and appropriate condition on completion of the activities |
Knowledge and Understanding
You need to know and understand:
- the specific safety precautions to be taken when setting up workholding devices and tooling on CNC machining centres
- the requirements and importance of understanding and applying human factors as defined by the regulatory requirements and the potential impact if these are not adhered to
- how to start and stop the machine in normal and emergency situations
- the importance of ensuring that the machine is isolated from the power supply before mounting cutting tools and workholding devices
- the importance of wearing the appropriate protective clothing and equipment (PPE) and of keeping the work area clean and tidy
- the hazards associated with working on CNC machining centres (such as use of moving machinery, automatic machine operation, handling cutting tools, lifting and handling workholding devices, hot and airborne metal particles) and how to minimise them and reduce any risks
- how to handle and store cutting tools safely and correctly
- how to handle and store operating programs safely and correctly
- how to extract and use information from engineering drawings or data and related specifications (to include symbols and conventions to appropriate CAA, FAA, BS, ISO or BSEN standards) in relation to work undertaken
- how to interpret first and third angle drawings, imperial and metric systems of measurement, workpiece reference points and system of tolerancing
- the range of workholding methods and devices that are used on CNC machining centres
- why it is important to set the workholding device in relation to the machine datum's and reference points
- the methods of setting the workholding devices and the tools and equipment that can be used
- the range of cutting tools used on CNC machining centres and typical applications
- how to check that the cutting tools are in a safe and serviceable condition
- the use of tungsten carbide, ceramic and diamond indexible tips and the factors which will determine their selection and use (such as condition of material supplied, hardness of the material, cutting characteristics of the material, tolerances to be achieved, component surface finish and specifications)
- the various tool holding devices that are used and the methods of correctly mounting and securing the cutting tools to the tool holders
- the advantages of using pre-set tooling and how to set the tooling using setting jigs/fixtures
- the use of magazines and carousels and how to position and identify the tools in relation to the operating program
- how to place the machine into the correct operating mode and how to access the program edit facility in order to enter tooling data (such as tool datums, positions, lengths, offsets and radius compensation)
- how to conduct trial runs, using single block run, dry run and feed/speed override controls
- the methods of measuring and checking trail components against the specification and the tools and equipment that can be used
- the items that you need to check before allowing the machine to operate in full program run mode
- how the various types of materials will affect the feeds and speeds that can be used
- the application of cutting fluids with regard to a range of different materials and why some materials do not require the use of cutting fluids
- typical problems that can occur with the setting up of the tooling and workholding devices and what to do if they occur
- the extent of your own responsibility and to whom you should report if you have problems that you cannot resolve
Scope/range
Scope Performance
Carry out all of the following during the setting-up activities:
- obtain and use the appropriate documentation (such as job instructions, drawings, quality control documentation)
- adhere to procedures or systems in place for risk assessment, COSHH, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
- follow safe practice/approved setting up procedures at all times
- confirm that the correct operating program has been loaded
- check that the tooling is in a usable condition
- ensure that the workpiece is correctly positioned and secured without distortion
- update the program tool data as applicable
- ensure that correctly adjusted machine guards are in place
Position and secure workpieces using four of the following workholding methods and devices:
- clamping direct to machine table
- chucks with soft jaws
- indexing/rotating device
- magnetic or pneumatic tables
- vee blocks and clamps
- collet chucks
- machine vice
- jigs and fixtures
- chucks with hard jaws
- angle plate
- other specific work holding devices
Select and mount in the appropriate tool holding device, eight of the following types of cutting tool:
- turning tools
- twist/core drills
- slotting cutters
- slot drills
- boring tools
- reamers
- slitting saws
- grinding wheels
- facing tools
- recessing/undercutting tools
- end mills
- taps
- thread cutting tools
- face mills
- knurling tools
- U drills
- paring odd tools
- other specific types of tools
Prepare the tooling for operation by carrying out all of the following activities, as applicable to the machine type:
- positioning tools in the correct position in the turrets, magazine or carousel
- checking tools have a specific tool number in relationship to the operating program
- entering all relevant tool data to the operating program (such as tool lengths, tool offsets, radius compensation)
- setting tool datums
- pre-setting tooling using setting jigs/fixtures
- saving changes to program
Set up the machine to produce aircraft components combining several different operations and cover ten from:
- external diameters
- square and parallel faces
- grooves/undercuts
- reamed holes
- tapered diameters
- angular faces
- tapped holes
- shoulders and/or steps
- indexed or rotated forms
- drilled
- slots
- internal and external profiles
- holes
- tapered holes
- bored holes
- flat faces
Machine one of the following types of material:
- ferrous
- non-ferrous
- non-metallic
Set the machine to produce aircraft components within all of the following quality and accuracy standards, as applicable to the operations performed:
- dimensional tolerance equivalent to BS EN ISO 286-1 or BS 1916-1 Grade 7
- components to be free from false tool cuts, burrs and sharp edges
- flatness and squareness 0.001" per inch or 0.025mm per 25mm
- reamed/bored holes within H8
- angles within +/- 0.5 degree
- screw threads BS medium fit
- surface finish 63µin or 1.6µm
Set the machine to produce aircraft components which comply with one of the following standards:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- Ministry of Defence (MoD)
- Military Aviation Authority (MAA)
- Aerospace Quality Management Standards (AS)
- Federal Aviation Authority (FAA)
- Aerospace Quality Management Standards (AS)
- BS, ISO or BSEN standards and procedures
- customer standards and requirements
- company standards and procedures
- manufacturers standards and procedures
Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:
- build records
- job cards
- log cards
- aircraft log
- other specific recording method
Scope Knowledge
Values
Behaviours
You will be able to apply the appropriate behaviours required in the workplace to meet the job profile and overall company objectives, such as:
- strong work ethic
- positive attitude
- team player
- dependability
- responsibility
- honesty
- integrity
- motivation
- commitment