Setting centre lathes for production
Overview
This standard identifies the competences you need to prepare and set up centre lathes, in accordance with approved procedures. This will involve selecting the appropriate workholding devices, securing them to the machine spindle, selecting and setting suitable chuck jaws or collets, boring out soft jaws, setting workpieces mounted between centres, mounting workpieces in jigs/fixtures or setting workpieces on face plates in the correct relationship to the machine spindle. You will be expected to select the appropriate turning tools, check that they are in a usable condition and mount and secure them to the relevant tool holding devices.
You will need to set the machine operating parameters to produce the workpiece to the required specification. This will involve setting feeds and speeds, setting roughing and finishing cuts and using accessories such as taper turning attachments, profiling attachments, offsetting the tailstock, angular setting of compound slide, and the setting and adjusting of change gears for screw cutting. You must produce trial cuts 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 machine, tooling, equipment 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 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. You will understand the machine used, and its application, and will know about the workholding devices, turning tools, relevant materials, consumables and setting up procedures, in adequate depth to provide a sound basis for carrying out the activities, correcting faults and ensuring the work output is to the required specification.
You will understand the safety precautions required when working with the machines and their 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.
This standard does not cover CNC turning activities, for which other standards apply.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- follow the correct specifications for the component to be produced
- determine what has to be done and how the machine will be set to achieve this
- mount, set and secure the required workholding devices, workpiece and cutting tools
- set the machine tool operating parameters to achieve the component specification
- check that all safety mechanisms are in place and that the equipment is set correctly for the required operations
- complete the required production documentation
- deal promptly and effectively with problems within your control and report those that cannot be solved
Knowledge and Understanding
You need to know and understand:
- how to work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- the hazards associated with setting lathes and how to minimise them and reduce any risks
- how to stop the machine in both normal and emergency situations, and the procedure for restarting after an emergency
- the importance of ensuring the machine is isolated from the power supply before mounting turning tools and workholding devices
- the importance of wearing the appropriate protective clothing (PPE) and equipment, and of keeping the work area clean and tidy
- the basic principles of operation of the centre lathe and its accessories, and typical operations that they can perform
- how to handle and store turning tools safely and correctly
- how to extract and use information from engineering drawings and related specifications (to include symbols and conventions to appropriate 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
- terminology used in turning in relation to the activities undertaken
- the range of workholding methods and devices that are used on centre lathes
- the methods of mounting and setting the workpiece in/on the workholding devices, and the tools and equipment that can be used
- the different types of turning tools that are used, and how they are selected, prepared and mounted to the machine tool holding devices
- factors which determine speeds and feeds to be used
- how the various types of material will affect the feeds and speeds that can be used
- the types of cutting fluids that are used, and precautions to be taken when handling and using them
- how to set up the centre lathe and its accessories for the particular operations being performed
- the need to conduct trial runs and check that the machine is set up and producing the components correctly
- problems that can occur with setting up the workholding devices, tooling and machine operating parameters, and what to do if problems occur
- the extent of your own authority and to whom you should report if you have problems that you cannot resolve
Scope/range
Scope Performance
- Carry out all of the following activities during setting up:
- obtain and use the appropriate documentation
- adhere to procedures or systems in place for risk assessment, 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
- ensure that correctly adjusted machine guards are in place
- check that cutting tools are in a suitable condition
- hold components securely without distortion
- leave the work area and machine in a safe and appropriate condition on completion of the activities
- Mount, set and secure the workpiece using four of the following workholding devices:
- 3 jaw chuck with hard jaws
- drive plate and centres
- magnetic or pneumatic devices
- chucks with soft jaws
- fixtures
- fixed steadies or travelling steadies
- collet chucks
- faceplates
- four jaw chucks
- Use two of the following groups of turning tools:
- solid high speed steel
- brazed tungsten carbide
- indexible tips (carbide, ceramic or diamond)
- Select and mount the following types of lathe tools to include eight of:
- turning
- knurling
- recessing
- twist/core drills
- thread chaser
- facing
- parting off
- chamfering
- reamers
- single point threading
- boring
- forming
- centre drills
- taps
- other specific tool types
- Use two of the following taper turning or profiling methods:
- taper turning attachment
- profiling attachment
- offset tailstock
- compound slide
- form tools
- Set the machine parameters in accordance with instructions/specifications to include all of the following:
- position of workpiece
- linear feed rate
- position of turning tools in relationship to workpiece
- depth of cut for roughing and finishing
- mechanisms (threading, profiles, taper)
- cutting fluid flow rate
- workpiece revolutions per minute
- machine guards and safety mechanisms
- Set up the machine to produce internal and external profiles that includes ten of the following:
- flat faces
- drilled holes
- internal threads
- chamfers
- parallel diameters
- bored holes
- external threads
- knurls or special finishes
- stepped diameters
- reamed holes
- eccentric features
- grooves
- tapered diameters
- profile forms
- parting off
- undercuts
- Machine components made from one of the following types of material:
- ferrous
- non-metallic
- non-ferrous
- Set the machine to produce components within all of the following quality and accuracy standards, as applicable to the operations performed:
- components to be free from false tool cuts, burrs and sharp edges
- general dimensional tolerance +/- 0.15mm or +/- 0.0006"
- one or more specific dimensional tolerances within +/- 0.05 or +/- 0.0002"
- surface finish 32µin or 0.8µm
- reamed and bored holes within H8
- screw threads BS medium fit
- angles within +/- 0.5 degree