Operating optical cylinder and dome process machines
Overview
This standard identifies the competences you need to carry out machining and finishing operations on optical cylinders and/or domes, in accordance with approved procedures, using optical process machines. You will confirm with the machine setter that the machine is ready for the operations to be performed and that all the required components/materials and consumables are available.
For domes, you will be required to machine components that combine a mixture of processes identified for optical domes, using a selection of specified optical dome materials. You will be expected to produce a range of components that combine a number of different features, such as centre thickness, diameters, generated blanks, optical form, and optical power (radius of curvature).
For cylinders, you need to carry out optical cylinder processing, in accordance with optical approved procedures, including hand preparation, smoothing and polishing, using a selection of specified optical cylinder materials. You will be expected to produce a range of cylinder components that combine different features, such as centre thickness, angles, axis, blocking, parallelism, and optical power and form error.
You will be required to operate the machines in line with safe working practices and approved procedures, to continuously monitor the machining operations and, where necessary, make minor adjustments or seek the help of the machine setter to make the adjustments, in order to ensure that the work output is to the required quality and accuracy. Meeting production targets will be an important issue, and your production records must show consistent and satisfactory performance.
Your responsibilities will require you to comply with organisational policy and procedures for the optical machining activities undertaken, and to report any problems with the machining activities, materials or equipment used that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work to instructions, 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 be sufficient to provide a good understanding of your work, and will enable you to adopt an informed approach to applying optical machining procedures. You will have an understanding of the optical cylinder and dome materials, the processes used and their application, and will know about the equipment, materials and consumables, in adequate depth to provide a sound background for carrying out the activities to the required specification.
You will understand the safety precautions required when working with the machines, 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.
Setting up of the machine, its tooling and associated workholding devices, is the subject of another standard and is the responsibility of the machine-tool setter.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- confirm that the machine is set up and ready for the machining activities to be carried out
- operate the machine tool controls safely and correctly in line with operational procedures
- produce components to the required quality and within the specified dimensional accuracy
- carry out quality sampling checks at suitable intervals
- deal promptly and effectively with problems within your control and report those that cannot be solved
- complete the required production documentation
- shut down the equipment to a safe condition on conclusion of the machining activities
Knowledge and Understanding
You need to know and understand:
- the safe working practices and procedures to be followed while operating optical cylinder/dome generating, hand lapping, smoothing and polishing equipment
- the safety mechanisms on the machine, and the procedure for checking that they function correctly
- the operation of the machine controls in both set-up and run modes, and how to stop the machine in an emergency
- the personal protective equipment (PPE) to be worn, and where this can be obtained
- the hazards associated with carrying out optical cylinder/dome process operations, and how to minimise them and reduce any risks
- the importance of keeping the work area clean and tidy
- where to obtain the component drawing, specifications and/or job instructions required for the components to be machined
- how to extract and use information from optical engineering drawings and related specifications (to include symbols and conventions to appropriate BS, ISO or BSEN standards) in relation to work undertaken
- how to use imperial and metric systems of measurement
- the various optical cylinder/dome operations that can be performed
- how to handle and store all cutting tools and kit required, safely and correctly
- the application of roughing and finishing cuts, cylinder/dome pressures used, and the effects on tool life, surface finish and dimensional accuracy
- how tool wear affects surface finish and dimensional accuracy
- how the various types of material will affect the way the operation is performed
- the application of cutting fluids and polishing mediums with regard to the range of material being produced
- the effect of clamping the workpiece, and how this can cause distortion in the finished component
- how to recognise machine faults, and how to identify when tooling needs refurbishment
- the problems that can occur with optical cylinder/dome machining activities, and how they can be overcome
- the quality control procedures used, inspection checks to be carried out, and the equipment used
- the extent of your own responsibility and to whom you should report if you have problems that you cannot resolve
Scope/range
Scope Performance
Apply all of the following during the machining 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
- confirm with the machine setter that the machine is ready for production
- where appropriate, seek any necessary instruction/training on the operation of the machine
- ensure that machine guards are in place and are correctly adjusted
- hold components securely, without damage or distortion
- follow the defined operating procedures and apply safe working practices and procedures at all times
- ensure that machine settings are adjusted as and when required (either by yourself or the setter) to maintain the required accuracy
- ensure that the components produced meet the required specification for quality and accuracy
- leave the work area and machine in a safe and appropriate condition on completion of the activities
Either - Operate two of the following types of optical cylinder processes:
- cylinder preparation process
- cylinder pitch polishing process
- cylinder hand lapping to axis/angle process
- cylinder silk polishing process
Or - Operate two of the following types of optical dome processes:
5. dome preparation process
6. dome silk polishing process
7. dome surface generation process
8. dome pitch polishing process
9. dome polyurethane process
Produce machined optical components that combine different operations and cover four of the following:
- cylinder/dome centre thickness
- cylinder/dome surface generation
- cylinder/dome concentricity
- cylinder/dome power analysis (radius)
- cylinder/dome cosmetic defects
- cylinder/dome form error analysis
- cylinder/dome diameter
- cylinder parallelism
- cylinder/dome truncation
- cylinder hand lapping process
- dome preparation/smoothing process
- dome transmitted wave-front analysis
- dome transmission analysis
Either - Machine three different types of cylinder material from the following:
- germanium
- anomalous dispersion flour crowns
- barium crowns
- optical orange filter glass
- dense flints
- optical blue filter glass
- flints/light flints
- borosilicate crowns
- lanthanum crowns
- magnesium fluoride
- barium dense flints
- optical neutral density cut glass
- other appropriate cylinder material
Or - Machine two different types of dome material from the following:
14. germanium
15. magnesium fluoride
16. zinc selenide
17. zinc sulphide
18. other appropriate dome material
Carry out the necessary checks for accuracy during production of four of the following:
- dome diameter
- cylinder/dome bevels
- cylinder parallelism
- cylinder/dome chamfers
- cylinder/dome truncation
- cylinder/dome cap height
- cylinder/dome centre thickness
- cylinder/dome surface power error
- cylinder/dome cosmetic surface finishes
- cylinder/dome surface form error
Produce components with dimensional accuracy, form and surface quality, which comply to one of the following
- BS, ISO or BSEN standards and procedures
- customer (contractual) standards and requirements
- company standards and procedures
- other accepted international standards