SEMET19 Producing toolroom components using NC/CNC turning machines

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1 Producing toolroom components using NC/CNC turning machines Overview This unit identifies the competences you need to prepare, set up and run numerically controlled (NC) turning machines, computer numerically controlled (CNC) turning machines or CNC machining centres, in accordance with approved procedures, to produce toolroom components used in moulds, press tools, dies, jigs and fixtures, test rigs and other experimental or developmental activities. You will be expected to select the appropriate workholding devices, and to mount and secure them to the machine spindle. You will also be required to select the appropriate cutting tools, mount and secure them to the appropriate tool holding devices, and to place the cutting tools in the relevant positions within the tool posts, turrets, slides or tool change magazine/carousel, where this is applicable. 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. In operating the machine, you will be expected to follow the correct procedures for running the operating program, dealing with any error messages, and executing the program activities safely and correctly. The components produced will have a number of different features, including turned plain diameters, eccentric diameters, internal/external threads, stepped diameters, flat faces and shoulders, chamfers and radii, special forms and profiles, tapered diameters and faces, internal and external profiles, grooves/undercuts, steps, drilled holes, reamed and tapped holes, and plain and tapered bored holes. You will be required to continuously monitor the machining operations, making any necessary adjustments to machine parameters, in order to produce components which meet the required specification. Your responsibilities will require you to comply with organisational policy and procedures for the machine setting and operating activities undertaken, and to report any problems with the equipment, tooling, programs, setting-up or operating 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 setting up and running NC/CNC turning machines. You will understand the NC/CNC turning machine used, and its application, and will know about the workholding devices, tooling, machine operating programs, setting-up and running procedures, in adequate depth to SEMET19 1

2 provide a sound basis for setting up and running the equipment, correcting faults, and ensuring that the work output is produced to the required specification. You will understand the safety precautions required when working with the machine, and with 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. SEMET19 2

3 Performance criteria You must be able to: P1 work safely at all times, complying with health and safety and other relevant regulations and guidelines P2 determine what has to be done and how the machine will be set to achieve this P3 mount and set the required workholding devices, workpiece and cutting tools P4 set the machine tool operating parameters to achieve the component specification P5 check that all safety mechanisms are in place and that the equipment is set correctly for the required operations P6 follow the defined procedures for starting and running the operating system P7 deal promptly and effectively with error messages, equipment faults or other problems that are within your control, and report those that cannot be solved P8 monitor the computer process and ensure that the machine output is to the required specification P9 shut down the equipment to a safe condition on conclusion of the activities SEMET19 3

4 Knowledge and understanding You need to know and understand: K1 the specific safety precautions to be taken when setting up workholding devices and tooling on NC/CNC turning machines, and the importance of ensuring that the machine is isolated from the power supply before mounting cutting tools and workholding devices K2 the safety mechanisms on the machine, and the procedures for checking that they are operating correctly K3 how to start and stop the machine, in normal and emergency situations K4 the importance of wearing the appropriate protective clothing and equipment, and of keeping the work area clean and tidy K5 the hazards associated with working on NC/CNC turning machines (such as use of power operated chucks, moving machinery, automatic machine operation, handling cutting tools, lifting and handling workholding devices, hot and airborne metal particles), and how to minimise them K6 how to handle and store cutting tools, and verified tapes and programs, safely and correctly K7 how to use and extract information from engineering drawings and related specifications (to include symbols and conventions to appropriate BS or ISO standards) in relation to work undertaken K8 how to interpret first and third angle drawings, imperial and metric systems of measurement, workpiece reference points and system of tolerancing K9 the range of workholding methods and devices that are used on NC/CNC turning machines K10 why it is important to set the workholding device in relationship to the machine datums and reference points K11 the methods of setting the workholding devices, and the tools and equipment that can be used for this K12 the range of cutting tools that are used on NC/CNC turning machines, and their typical applications K13 how to check that the cutting tools are in a safe and serviceable condition K14 the use of tungsten carbide, ceramic and diamond indexable tips, and the factors which will determine their selection and use (the condition of material supplied, hardness of the material, the cutting characteristics of the material, tolerances to be achieved, component surface finish and specifications) K15 the various tool holding devices that are used, and the methods of correctly mounting and securing the cutting tools to the tool holders K16 the advantages of using pre-set tooling, and how to set the tooling by using setting jigs/fixtures K17 the use of tool posts, magazines and carousels, and how to position and SEMET19 4

5 identify the tools in relationship to the operating program K18 how to interpret the visual display and understand the various messages displayed K19 the function of error messages, and what to do when an error message is displayed K20 the operation of the various hand and automatic modes of machine control (such as hand wheels, joysticks, program operating and control buttons) K21 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) K22 how to operate the machine using single block run, full program run and feed/speed override controls K23 the things that you need to check before allowing the machine to operate in full program run mode K24 how to set and secure the workpiece to the machine spindle/workholding device; the effects of clamping the workpiece; and how material removal can cause warping/distortion of the finished workpiece K25 how the various types of materials used will affect the feeds and speeds that can be used K26 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 K27 typical problems that can occur with the setting up of the tooling, workholding devices, and turning activities, and what to do if they occur K28 the quality control procedures used, inspection checks to be carried out, and the equipment that is used for these K29 the extent of your own responsibility and whom you should report to if you have problems that you cannot resolve SEMET19 5

6 Additional Information Scope/range related to performance criteria You must be able to: 1. prepare the machine for operation, by carrying out all of the following: 1.1 confirm that the correct operating program has been loaded and is at the correct start point 1.2 check that the tooling is in a usable condition 1.3 ensure that the workpiece is correctly positioned and secured without distortion 1.4 check that the workpiece is clear of the machine spindle 1.5 update program tool data, as applicable 1.6 position and adjust machine guards 1.7 safe working practices and start-up procedures are observed 1.8 machine settings are adjusted, as required, to maintain accuracy 2. prepare one of the following NC/CNC turning machines in readiness for producing toolroom components: 2.1 NC lathe 2.2 CNC lathe 2.3 CNC machining centre 3. position and secure the workpieces using three of the following workholding methods and devices: 3.1 chucks with hard jaws 3.2 fixtures 3.3 collet chucks 3.4 magnetic/pneumatic devices 3.5 chucks with soft jaws 3.6 drive centres 3.7 faceplates 3.8 other workholding devices 4. select and mount the appropriate tool holding device, and six of the following types of cutting tool: 4.1 roughing tool 4.2 screw-thread tool 4.3 centre drills 4.4 reamers 4.5 finishing tool SEMET19 6

7 4.6 profiling tools 4.7 twist/core drills 4.8 maxi-tipped drills 4.9 parting-off tool 4.10 form tools 4.11 boring tools 5. prepare the tooling for operation, by carrying out all the following activities, as applicable to the machine type: 5.1 positioning tools in the correct position in the tool posts, turrets, magazine or carousel 5.2 checking that tools have a specific tool number in relation to the operating program 5.3 entering all relevant tool data to the operating program (such as tool lengths, tool offsets, radius compensation) 5.4 pre-setting tooling by using setting jigs/fixtures 5.5 setting tool datum(s) 5.6 saving changes to the program 6. set up the machine, and produce components combining several different operations, covering twelve from: 6.1 parallel diameters 6.2 internal profiles 6.3 eccentric diameters 6.4 stepped diameters 6.5 external profiles 6.6 external screw threads 6.7 tapered diameters 6.8 reamed holes 6.9 internal screw threads 6.10 flat faces 6.11 tapped holes 6.12 chamfers and radii 6.13 internal undercuts 6.14 drilled holes 6.15 bored holes 6.16 external undercuts 6.17 parting-off 6.18 grooves 7. machine two of the following types of material: 7.1 ferrous 7.2 stainless 7.3 non-ferrous 7.4 non-metallic SEMET19 7

8 8. carry out the necessary checks during manufacture, for accuracy of eight of the following: 8.1 external diameters 8.2 lengths/depths 8.3 internal diameters 8.4 thread profile and fit 8.5 hole size/fit 8.6 profile/contour 8.7 angle/taper 8.8 concentricity 8.9 surface finish 8.10 slot/recess position and width 9. produce toolroom components within all of the following quality and accuracy standards: 9.1 dimensional tolerance equivalent to BS4500 or BS 1916 Grade surface finish 63µin or 1.6µm 9.3 reamed and bored holes within H8 9.4 angles/tapers within +/- 0.5 degree 9.5 screw threads BS medium fit SEMET19 8

9 Developed by SEMTA Version number 1 Date approved January 2005 Indicative review date Validity Status Originating organisation Original URN Relevant occupations December 2013 Current Original SEMTA O45NET19 Metal Machining, Fitting and instrument making trades Suite Engineering Toolmaking Suite Key words Engineering, toolmaking, toolroom, components, NC, CNC, turning, machine, cutting tools, operating program SEMET19 9