Lathe Metal Next ILLUSTRATION LATHE METAL Copyright © 2004. Lathe Metal Back Next ILLUSTRATION (B) Copyright © 2004. Lathe Metal Back ILLUSTRATION (C) Copyright © 2004. Lathe Metal Next POSITIONING REQUIREMENTS It should be noted that the measurements displayed in FIGURE 1, are the minimum requirements. Planning Considerations To minimize the risk of injury, it is important to ensure that machinery and work areas are laid out in a safe and usable manner. This includes allowing enough space for: • Student circulation • Instruction by teachers • Machine maintenance • Occasional larger projects Space Requirements a. Operator Positions • Is considered an integral part of the machine. • Minimum 600mm (mandatory) safe space for operating zone. b. Operator Zone Copyright © 2004. • Minimum clearance required to another operator zone or trafficway ie. no overlapping (see specific diagrams). • Operating zones are indicated by yellow floor lines. Lathe Metal Back Next c. Trafficway Zones • These zones are frequently used and provide safe access between and to all operators. • 600mm mandatory minimum safe space for trafficways although 900mm is preferred. d. Machine Zones Minimum clearance (see specific diagrams) to: • Wall or screen (without trafficway) • Another machine (non operating side) • Fixture at ‘work-plane’ level e. Minor Adjustment Positions • Copyright © 2004. Indicates machine parts requiring space during adjustment or maintenance Lathe Metal Back PREVIOUS AND CURRENT SAFE WORK AREA FIGURE1 Lathes-Metal typically have a mass ranging from > 100kgs though some examples may weigh as much as 700kgs. This suggests that the machine must be located on a bench or a stand which is very sturdy. The floor must be in good condition and capable of bearing the weight, not only of the lathe itself, but also the lathe stand and any lathe accessories positioned on the stand. When positioned the machine should be level and plumb and securely fixed via the stand to the floor. Additional bracing may be required if the lathe stand lacks rigidity. Copyright © 2004. Lathe Metal POWER SUPPLY This machine can, on request, be ordered with a 240 volt single phase motor or a 415 three phase motor. It is not recommended that a ceiling drop supply be used but that the machine be hard wired by a licensed electrician or, preferably, that the machine be supplied by a 240 volt wall power point. LIGHTING Machining and turning operations require a lighting of 400 lux, or better. The light should be uniform around the workspace, free from glare and shadows. Where fluorescent tubes light the workshop it is important that all of the tubes function properly. Flickering or intermittent lights must be repaired or replaced immediately. Spent fluorescent tubes should be replaced promptly. Improper lighting may create a strobe effect. A condition may be generated in which a rotating chuck or work-piece would appear to be still. This is a dangerous situation, particularly if the noise of the motor is masked by other general workshop noises. Lighting circuits in workrooms are recommended to be connected over three phases to minimise stroboscopic effects. Supplementary lighting should be low voltage specifically = < 32 volts. Copyright © 2004. Lathe Metal GUARDING Because of the operating characteristics of this machine the lathe is a difficult machine to fully guard. Lathes should have guards fitted covering all drive systems and where the guards need to be opened for adjustments the guard may be electrically interlocked so that the machine can not be started while the guards are open. A guard should also be fitted covering the rotating lead screw. A hinged chuck guard is recommended and this may also be interlocked to the lathes electrical control to prevent operation while the guard is open. This machine requires the operator to have constant access to all areas of the lathe especially the chuck and work-piece zones making the lathe a difficult machine to guard. It is therefore essential to put in place thorough and complete induction and training of machine operators. Copyright © 2004. Lathe Metal SWITCHING This machine must be equipped with a start/stop switch, a mechanical isolation switch and an emergency stop switch that conform to Australian Standard AS 1202 Part 1. In particular the start switch must be green in colour and shrouded to prevent inadvertent operation. The off switch must be red in colour and stand proud. The preferred off-switch has a mushroom shaped button. Switching controls shall be positioned and spaced to provide safe and easy operation. Where necessary switching should be duplicated so as to ensure that an operator can access the controls at all times. MECHANICAL ISOLATION SWITCH The keyed isolation switch is used to isolate the machine from the power supply. This is commonly used to exclude the machine from operation when not required for class activities, during maintenance or when adjusting or fitting guards. When the workshop is unattended all machines must be keyed OFF. Copyright © 2004. STOP/START SWITCH EMERGENCY STOP SWITCH Lathe Metal Next COMMISSIONING INFORMATION The Lathe-Metal must not be used by staff or students until the following checks are completed and any adjustments made: Copyright © 2004. • The Lathe-Metal must be securely fixed to its base. • All nuts, bolts and grub screws must be in place and tight and the machine must be in a clean condition. • Any guarding must be in place and in good condition. • The mains cable and plug (if any) should be visually checked for flaws and then electrically tested. The machine’s details should be entered on the appropriate database/maintenance schedule. • Belt drives must be checked for pulley alignment, serviceability and proper tensioning of the drive belts. The belt profiles must suit the pulley type. • Lubrication points should be serviced and all moving parts should move freely. • Gibs should be adjusted to give smooth operation with no slop. • Operating instructions pertinent to the machine and its location should be placed in a suitable position. • Ancillary equipment e.g. faceplates, chucks, turning tools, spanners etc must be located in a suitable nearby location. • Appropriate swarf collection system must be put in place. • Appropriate Personal Protective Equipment should be positioned in a suitable nearby location. • Associated housekeeping equipment should be installed in a suitable nearby location. • Warranties should be processed and forwarded to the appropriate destinations. Lathe Metal Back Copyright © 2004. • Copies of the machine documentation should be made and the original documentation secured in a safe place. • A DET Risk Assessment should be made to identify any hazards associated with the equipment. The Risk Assessment is an important document and must be retained on file. • The school’s Asset Register should be updated. Lathe Metal DECOMMISSIONING INFORMATION Copyright © 2004. • The machine should be tagged barring use. • The machine should be in a clean condition. • The machine must be lubricated and a protective grease coating applied to the ways of the lathe. • The tail-stock ram should be retracted into the tailstock. • Any belt drives should be freed from tension. • A licensed electrician should disconnect hard-wired equipment. • The mains cable and plug (if any) should be securely taped to the bed with duct tape or similar. • Spare parts i.e. faceplates, chucks, centres etc together with the plant documentation should be parceled together and securely attached to the main unit. • The school’s asset register should be amended. • The electrical testing database/ maintenance register should be amended. Lathe Metal Next SAFE WORK PRACTICES Fundamental to the safe operation of the Lathe-Metal is the employment of the necessary complementary work processes. Self Centering chucks should have a spring loaded key, which eliminates the possibility of the key being left in the chuck. The work-piece should be suitably prepared so that the lathe operations will be minimised. Where possible long thin work-pieces should be supported with steadies. Work should only be performed on materials, which have a known characteristic. Unknown ‘scrap’ materials may require special processes to be safely worked e.g. annealing, lubricating etc. Should coolant be used then it is important that the condition of this lubricant be monitored. Operators must not, as far as is possible, be exposed to unnecessary contact with these fluids. Setup – Preparation phase Copyright © 2004. • Eye protection must be worn around the lathe workspace. • The work-piece must be gripped in the chuck. • The appropriate lathe tool should be selected and inspected for wear/damage and correct clearance angles. • The correct turning revolutions (speed) should be determined and the appropriate machine adjustments made. • All settings, adjustments and work-holding arrangements are rechecked. Lathe Metal Back Next • If coolant is to be employed, the delivery system is checked and adjusted to provide sufficient flow to the point of operation. • Ensure that provision is made for the proper and safe removal of swarf from the machine. Operation phase • Feed and cutting rates must comply with accepted practice. • Swarf accumulations must only be cleared from the machine after it has been stopped. • Attention must be paid to unusual noises and visual indicators of improper operation. Faulty or inadequate work-piece clamping must be corrected. • On removal of the work-piece any burrs or sharp edges should be dressed with a file or de-burring tool before the work is released for general handling. Shut down phase Copyright © 2004. • Using a brush, never compressed air, all swarf is removed from the machine and disposed of properly. • The work-piece should not be removed until it is ascertained that it is safe to do so. The machining of metal generates substantial amounts of heat! Lathe Metal Back Processes Students and staff must be properly inducted in the safe operation and the characteristics of the machine and the materials involved. Operators must wear the appropriate Personal Protective Equipment. Eye protection is mandatory. Operators must wear appropriate clothing. In particular overalls or aprons should be worn over the standard school uniform. Ties, shirt sleeves and other loose items of clothing and other tangle hazards must be properly addressed. Similarly it is important that the wearing of long hair, jewellery, rings etc do not constitute a safety hazard. Students should be encouraged to purchase approved safety shoes. Housekeeping operations are part of the lesson. Time must be allocated for cleaning up operations. Copyright © 2004. Lathe Metal PERSONAL PROTECTIVE EQUIPMENT All operators must wear eye protection in the form of approved safety glasses or face shields. Enclosed leather shoes is the minimum safety requirement. Gloves are not to be worn while using this machine, however they should be readily available to the operator to enable safe removal of swarf accumulations. Note that when this process is undertaken the lathe must be stationery. Hair and clothing protection is to be worn by the user if required. SIGNING REQUIREMENTS Signing should be employed which clearly describes the Personal Protective Equipment (P.P.E.) requirements for this particular machine. Where more than one lathe is positioned then each lathe should be identified e.g L-M 1, L-M 2 etc. Signing should state ‘For Authorised Use Only’ in the immediate vicinity of the machine. Copyright © 2004. Lathe Metal TESTING OF FIXED PLANT Detailed procedures for the Safety Testing Of Equipment are yet to be finalised. Reference should be made to the department’s Occupational Health, Safety and Injury Prevention Guide for the Principal or Manager manual - sections on Machinery and Electrical. It is suggested that the following processes as part of good practice, are undertaken on a ‘programmed’ basis for each individual item of fixed plant: 1. Visual checking of the physical integrity of: • Electrical cables • Switch boxes • Switch buttons Evidence of overheating (eg discolouration, odours etc) should be investigated. Machinery locations should be dry and clean. 2. Operational Checking. All switches must operate properly. Under no circumstance should a switch e.g. emergency stop button be mounted but not connected. Particular attention should be paid to the proper function of any machinery guard switches. Qualified electricians must be employed to make repairs and written confirmation of this work must be supplied by them for your records. Copyright © 2004. Lathe Metal RECOMMENDED MAINTENANCE SCHEDULE The Metal Lathe is a moderately high maintenance machine, and it is strongly suggested that a programmed maintenance schedule is developed for this machine and that time be allocated specifically for maintenance purposes. Table 1 is offered as a guideline. Metal Lathe Recommended Maintenance Schedule Maintenance Operation Week Check Drive belts for correct tension. * (odd) Check Drive belts for condition. * (odd) Check Switch gear and examine for observable defects. * (odd & even) Check Electrical wiring for visual damage. * (odd & even) Lubricate machine according to manufacturers specifications. Check condition of coolant (if used). * (odd & even) TABLE 1 Copyright © 2004. Daily or before use Monthly Check floorspace for oil contamination. Term Suds should be totally replaced at the beginning of the new term. Lathe Metal WARNINGS WARNINGS The Lathe-Metal is an engineering tool which presents significant hazards to untrained or unsupervised operators. Serious injury can be caused by lacerations from shavings, eye injury, entanglement with rotating parts, entrapment and impact from thrown work pieces or the chuck if not tightened securely. These injuries can be prevented by wearing the appropriate eye and face shielding together with the correct hair and clothing protection where required. Gloves are not to be worn while operating the machine. Copyright © 2004. Lathe Metal GLOSSARY Copyright © 2004. Belt profile The shape of the cross-section of a power transmission belt. Common examples are v-belts, flat and round belts. The belt profile must suit the pulley type. Cutters Specialised tools used in turning operations, usually made of high-speed steel or employing carbide inserts. Coolant A liquid which is used to facilitate machining operations sometimes referred to as suds. Feed rate The rate of movement of the tool into the work. Gibs Strips of metal which allow engineers to compensate for wear in slide-ways. Hard-wired. A method of electrical connection which is permanent as against the normal plug/socket method of supplying electrical power. Hard wired equipment must be connected and disconnected by a licensed electrician. Head-stock The driven end of the lathe. Usually equipped with a chuck or faceplate. Micro-switch Generally a miniature electrical switch commonly used in guarding applications in which guards must be in place to allow machine operation. Saddle That part of the lathe which traverses in a horizontal path. Commonly carries the cutting tool. Swarf Waste material generated by the machining of metal. Tail-Stock Usually position at the right-hand end of the lathe the tail stock supports that end of the work-piece not held by the lathe chuck. Typically non-driven and equipped with a centre or drill chuck. Three phase power A system of electrical generation and distribution which enables significant economies in industrial applications. Most commonly used in heavy duty equipment. Ways The ground surfaces of the lathe bed upon which the saddle bears. Lathe Metal SOURCES Government of New South Wales, SECONDARY SCHOOL CODE HS 580.29. TECHNOLOGY AND APPLIED STUDIES EDUCATIONAL SPECIFICATION,1994 Stanford University, TOOL AND MACHINERY SAFETY,1995 Standards Association of Australia, AUSTRALIAN STANDARD 1485 – 1983 SAFETY AND HEALTH IN WORKROOMS OF EDUCATIONAL ESTABLISHMENTS. Department of Education and Training, EQUIPMENT SAFETY IN SCHOOLS, 2003 South Australian Government Schools Website SOUTH AUSTRALIAN DEPARTMENT OF EDUCATION AND CHILDREN’S SERVICES (www.desc.sa.gov.au) Copyright © 2004.