Health & Safety. Maintenance of D&T Workshop Equipment

Transcription

1 G254 Health & Safety Maintenance of D&T Workshop Equipment March 2016 Maintenance of D&T Workshop Equipment G254 March 2016

2 CLEAPSS 2016 Strictly Confidential Circulate to members and associates only As with all CLEAPSS materials, members and associates are free to copy all or part of this guide for use in their own establishments. CLEAPSS Brunel Science Park Kingston Lane Uxbridge UB8 3PQ Tel: Fax: Web Site: 1

3 Contents 1 The scope of this guide Introduction Risk assessments Maintenance of the learning environment Maintenance of hand tools and equipment Maintenance of machines General principles of maintenance Cleaning Local exhaust ventilation (LEV) systems Electrical and gas installations Lubrication Detailed maintenance advice on workshop machines Disc and belt sanding machines Drilling machine Bench-mounted jig saw Band saw Circular saw Planing machines for wood:overhand planer, thicknesser, combined planer / thicknesser Radial arm saw Wood-turning lathe Metal-turning lathe Milling machine - horizontal/vertical Power hacksaw Mortising machine Double-ended, high-speed grinding machine Polishing/buffing machine Plastic forming machine (vacuum former, line bender, strip heater, injection moulder) Laser cutter/3d printer/cnc equipment Detailed maintenance advice on metal-heating equipment Gas safety system Brazing hearth and/or chip forge Crucible furnace Detailed advice on portable equipment Portable electrical equipment Portable pneumatic equipment Recording of checks Guide to cutting speeds Drilling Wood-turning lathe Metal-turning lathe Milling machine Appendix: EQUIPMENT REGISTER AND MAINTENANCE LOG

4 1 The scope of this guide Guide G254 Health & Safety Maintenance of D&T Workshop Equipment These notes have been prepared to give an overview of the way in which maintenance of equipment will contribute to healthy and safe working conditions in design & technology (D&T), particularly in school workshops. The main focus is on resistant materials, however, the principles can be carried over into any practical environment. It should be read in conjunction with other CLEAPSS publications, particularly the following. Model Risk Assessments for D&T in Secondary Schools and Colleges. Guide L225, Local Exhaust Ventilation in D&T. Leaflet PS62, LEV in D&T: Suppliers, Testers and Monitoring Equipment. These, and other CLEAPSS publications relevant to D&T, will be found on the members part of the CLEAPSS web site: If you are unsure of your user name and password, please phone CLEAPSS on or making it clear you want access to the D&T area of the members-only web site and giving details of your school s name and address. 1.1 Introduction All equipment used in design & technology will require some sort of maintenance programme. This will range from ensuring that hand tools are maintained with sharp cutting edges to ensuring that machine tools are correctly lubricated and are maintained in good order. It should be remembered that a blunt cutting tool is more dangerous than a sharp one, since more force is required to make it cut. This applies to both hand and machine tools. Cleaning of machines and equipment is an important part of a maintenance programme, since equipment that is clogged with dirt or dust is unlikely to work in an efficient manner. A regular maintenance programme should be established which should aim for preventative maintenance rather than emergencies. The frequency of maintenance will depend on the amount of use of the equipment and the nature of the hazards and risks. It is a good idea to have a check sheet for equipment and a planned programme of monitoring. A sample of a possible check sheet is given in Appendix 1 and it is available on the members part of the CLEAPSS web site in an easily-modified electronic file, DL254. The checklists in sections 3 and 4 are also included in this download file. Where technicians are available, they are the obvious people to do the maintenance checks but anyone who does such work should be trained to do it properly. CLEAPSS runs training for teachers and technicians to enable them to carry out the monitoring and maintenance of general workshop equipment. CLEAPSS sees this activity as being primarily something that a D&T technician should be doing as part of their role. It should be overseen and managed by the head of department. 1.2 Risk assessments Before maintenance of fixed equipment is begun, the hazards of doing it must have been identified and the risks assessed and controlled. A record of the risk assessment should be kept to help with developing safe practices and enabling future work to be carried out safely. The risk assessment can be reviewed after the maintenance has been carried out and amended to influence future work. Whilst a visual inspection of the condition of electrical cables and the supply to fixed equipment such as workshop machines can be done by anyone, on no account should unqualified people carry out electrical maintenance. Maintenance of gas equipment should also be carried out only by a qualified person. 3

5 If it is necessary to remove covers or guards from machines and other equipment, to permit maintenance or repair work, then the equipment should be isolated from the power supply through the use of isolating switches or by unplugging from the socket outlet. Where possible, isolators should be locked in the OFF position. Notices should be placed on equipment to state that it is under repair and must not be used. Where possible, cutting tools that have sharp edges should be removed before repairs or maintenance are carried out. Where maintenance is required, but cannot be done at once, equipment should be taken out of use until such time as the necessary work can be carried out and a notice fixed to the machine to state that it must not be used. 1.3 Maintenance of the learning environment The condition of the learning environment is an important aspect of maintenance. Teaching, preparation and store rooms should be kept clean and tidy. Where necessary, the daily cleaning schedule should be modified to allow sufficient time for proper cleaning to take place. Removal of wood dust is best done with a suitable industrial vacuum cleaner 1 rather than by brushing. All waste materials should be removed at the end of the school day. Consumable materials, such as timber, should be properly stored in suitable racks and should not obstruct doorways, fire exits, fire-fighting equipment, emergency-stop buttons or machines. The same is true about pupils work. Fire extinguishers will normally be checked by a competent person on a regular basis and the check should be recorded on the equipment itself. If this is not happening, the head of department should inform the employer 2. Eye protection should be cleaned regularly. It is best if eye protection is kept in a suitable holder located next to the machine with which it is to be used. 1.4 Maintenance of hand tools and equipment Cutting tools with sharp edges should be maintained in good condition. The frequency of sharpening will depend on the amount of use and the material being cut. This means that a planned programme of sharpening them every day, every week or every month may not be adequate. Paper for example, blunts scissors and craft knives very easily and it is better to use the type of craft knife with replaceable blades, rather than attempting to sharpen them. Woodworking with blunt tools causes a particular problem for pupils, who may be inexperienced and physically small. They will need to exert excessive effort to cut materials. This presents an additional hazard because they are unable to control the force needed. Chisels and the blades of planes may need sharpening every week, depending on the amount of use. Teachers who have a detailed knowledge of woodworking will know that some types of timber wear down sharp-edged tools very quickly and sharpening may be needed much more frequently than once each week. Depending on the amount of use, saws used to cut timber will typically need sharpening once a year. These days, it is often cheaper to buy new bench saws than to have the old ones sharpened, especially in parts of the country where it is difficult to find companies with the expertise to carry out sharpening. 1 2 A vacuum cleaner designed to collect wood dust must be used. General-purpose vacuum cleaners are unlikely to be suitable, as they will not trap the fine dust involved. See the CLEAPSS leaflet PS62, LEV in D&T: Suppliers, Testers and Monitoring Equipment for companies that supply suitable models. The employer for most maintained schools (community and voluntary-controlled schools) is the local authority. For foundation & voluntary-aided schools, academies, post-16 colleges and most independent schools, it is the governing body or Trust. 4

6 Proper storage of tools with sharp edges will help to maintain the sharp edge. Planes should be stored so that the blade is not touching a surface; they should be laid on their side on the work bench when not in use. Wood chisels should be stored in proper racks with the cutting edges protected, as should craft knives. Handles of files need to be checked for splits, and for tightness of fit onto the tang of the file. The hammered end of tools such as centre punches and cold chisels will occasionally need grinding to remove burrs. 1.5 Maintenance of machines The amount of machine maintenance will depend on the type of machine and the way in which it is designed. Many schools still use older machines of heavy cast-iron construction. These machines were often designed for industrial use and are normally very robust. Whilst sometimes dated in appearance, they will normally last a long time in school use. In contrast, modern machines are frequently constructed from pressed steel sheet and are not as robust as the older models. Some schools purchase machines designed for the d-i-y market. These types of machines are designed for infrequent d-i-y use, rather than the more-frequent use which would be the norm in schools, and are unlikely to give long service. Their purchase may prove to be a false economy. 2 General principles of maintenance 2.1 Cleaning All machines should be cleaned regularly, although the frequency of cleaning will depend on the amount of use. This will range from the normal cleaning to remove sawdust, chips or swarf after use, to a morethorough cleaning each week. Woodworking machines such as band saws, circular saws and planing machines should be checked to see that dust and chips are being removed by the dust-extraction system. Some types of band saw have the collection point for dust located in a poor position and dust is often not removed effectively from all crevices. In these cases, an industrial vacuum cleaner specifically designed to collect dust should be used to remove it during general maintenance. 2.2 Local exhaust ventilation (LEV) systems 3 The filters of dust-extraction systems should be cleaned at frequent intervals, at least weekly, to remove the dust, and the collection bags or trays emptied frequently. Note that appropriate dust masks, (type FFP3) should be worn during emptying. Wood dust should be disposed of in sealed bags and not tipped loosely into a dustbin. The ducting of LEV systems needs checking to ensure that slivers or chips of wood are not obstructing it, especially on bends. This can impede the airflow and reduce the efficiency of the system. Note that the COSHH Regulations require local exhaust systems to be examined at least every 14 months and a record maintained of the efficiency of the system. A notice should be fixed to each extraction unit to indicate that it has been checked on a particular date. 2.3 Electrical and gas installations The condition of electrical cables, fixed and flexible conduit should be visually checked. The operation of all switches (including isolating, no-volt release and overload switches) should be checked. The operation of emergency-stop buttons in workshops should be checked once every half term. Flexible conduit, in particular, needs checking to make sure that there are sound connections at each end. Isolators need to be checked by the operation of the lever to ensure that they do in fact cut off the power to the machine and that the lever moves easily. Checking that an isolator breaks all power connections to the machine (i.e. line and neutral or all three phases and neutral) is best left to a person competent to do it. (This is unlikely to be a member of the school staff). Care should be taken to ensure that access to isolators is not impeded by 3 For more details, see the CLEAPSS guide L225, Local Exhaust Ventilation in Design and Technology. 5

7 machines, furniture or materials. The operation of residual-current devices (earth-leakage circuit breakers) should be checked by the use of the test button on the device. Portable electrical equipment needs to be checked as required by the Electricity at Work Regulations. It is for the employer to decide who does the checking. Sometimes, a contractor may go round from school to school. Elsewhere the task may be delegated to the school which in turn may employ a contractor or use its own, suitably-trained, staff. The time interval for testing is not directly specified but most employers expect most equipment to be checked annually. However, equipment subject to arduous or heavy use, such as power tools and extension leads, should be inspected more frequently. Items that are rarely unplugged, e.g., refrigerators, may only need checking every 3 or 4 years. The operation of electrical interlocks on machine guards should be checked to ensure that they function correctly. Guidance from the HSE 4 on the Electricity at Work Regulations suggests that fixed electrical installations should be inspected at least every 5 years, although this is normally arranged by the employer. There is a similar requirement for the inspection of gas installations 5. However, heads of department should check that this is happening and, if not, should take steps to ensure that the employer is informed. The contractor carrying out such tests should apply labels to the equipment to indicate when testing has been done. There will also be records made but these may go to the employer or be held by the bursar. Hoses on gas equipment should be checked for damage before use and replaced where required. 2.4 Lubrication Moving parts of machines will require lubrication. Some machine bearings are sealed for life and will not require additional lubrication. For other machines, oil or greasing of bearings will be required. Lathes with geared headstocks, and some drilling machines that have a gearbox, will have an oil reservoir that will need checking and re-filling as required. The feed drives on planing machines for wood will require checking and cleaning. Excess dust should be removed and chain drives should be greased. Machines such as metalturning lathes, milling machines and power hacksaws will need the slideways lubricated as necessary. It is good practice to apply a coat of a thin lubrication oil (e.g., as used in motor cars) to bright metal parts of tools and machines at the start of holiday periods, especially where there is likely to be excessive moisture in the air. 4 5 Guidance Note GS23, Electrical safety in schools, HSE, Although this is now out of print, the HSE has informed CLEAPSS that it regards most of the advice as still valid. IM/25 Guidance Notes on Gas Safety in Educational Establishments, British Gas/DES, 1989, paragraph 2 stated that checking of the soundness of gas supply pipework should not normally be needed more often than once every five years. However, its replacement IGE/UP/11 Gas installations for educational establishments, IIGEM, 2004, offers more complicated advice. 6

8 3 Detailed maintenance advice on workshop machines 3.1 Disc and belt sanding machines Clean any dust not removed by the extraction system. Check condition of sanding belt/disc and replace if torn/worn. Check fit of sanding table to disc/belt (it should be as close as possible, normally no greater than 2 mm). Check that quadrant guard is in the correct position. Clean filters in dust-extraction system, if fitted. Empty dust-collection tray/bag if fitted. Check condition of motor, drive system and drive belts, if fitted. Replace if worn. Check operation of dust-extraction system. Check bearings for wear. 3.2 Drilling machine Check that the chuck guard is clean, functions correctly and is not cracked/broken. Make sure that the guard over the driving belt fits correctly and that the interlock or securing device is in place and working correctly. Make sure that the chuck key fits correctly and is not worn. Make sure that the drill head clamping bolts are tight and the head-locking ring is in place. Make sure that the table clamp functions correctly. Check condition of drill bits. Sharpen as required. Replace twist drills that have worn shanks. If wooden blocks are used under the work piece, replace those that are worn. Check condition of motor, drive system and drive belts. Replace if worn. Machines with gears running in an oil bath should have the oil level checked. Check bearings for wear. Check that machine vices and hand vices function correctly and are not worn or clogged with waste materials. 3.3 Bench-mounted jig saw Clean any dust not removed by the extraction system. Check condition of blade and replace if blunt. Check that blade guard is correctly set. Where fitted, check that machine foot functions correctly. 7

9 Clean filters in dust-extraction system, if fitted. Empty dust-collection tray/bag, if fitted. If fitted, check fit of table insert and replace if required. Check condition of motor, drive system and drive belts, if fitted. Replace if worn. Check operation of dust-extraction system. Check bearings for wear. 3.4 Band saw Clean any dust not removed by the extraction system. Check condition of blade; replace if blunt or if welded joint on blade is suspect. Check that blade guard is correctly set. Check that machine braking system functions correctly. Clean filters in dust-extraction system, if fitted. Empty dust-collection tray/bag, if fitted. If fitted, check fit of table insert to blade and replace if required; (the gap between the insert and the blade should be no greater than 4 mm). Check blade guides and thrust wheel for wear and adjust/replace as required. Check tracking setting and condition of rubber tyres on blade wheels, if fitted. Replace if required. Check condition of motor, drive system and drive belts, if fitted. Replace if worn. Check operation of dust-extraction system. Check bearings and blade guards for wear and replace if necessary. 3.5 Circular saw Clean any dust not removed by the extraction system. Check condition of blade and replace if blunt. Check that top or crown guard is correctly set and connected correctly to the extraction system, if the latter is fitted. Check that machine braking system functions correctly. Clean filters in dust-extraction system, if fitted. Empty dust-collection tray/bag, if fitted. 8

10 Check condition of motor, drive system and drive belts, if fitted. Replace if worn. Check operation of dust-extraction system. Clean the inside of the machine using an industrial vacuum cleaner. Check fit of table insert, if fitted, and replace if required. Check bearings and replace if necessary. Check condition of crown guard and replace if necessary. 3.6 Planing machines for wood: overhand planer, thicknesser, combined planer / thicknesser Clean any dust/shavings not removed by the extraction system. Check that all guards are correctly set. Check that machine braking system functions correctly. Clean filters in dust-extraction system, if fitted. Empty dust-collection tray/bag, if fitted. Check condition of blades and replace if blunt. Check condition of motor, drive system and drive belts. Replace if worn. Check condition of feed roller drive, clean, overhaul and lubricate as required. Check operation of dust-extraction system. Check bearings and blade guards for wear and replace if necessary. 3.7 Radial arm saw Clean any dust not removed by the extraction system. Check that blade guard and side-protection guards are correctly set and function as required. Check that machine braking system functions correctly. Clean filters in dust-extraction system, if fitted. Empty dust-collection tray/bag, if fitted. Check condition of rear timber support and replace if necessary. Check condition of blade and replace if blunt. Check condition of motor and drive system. Lubricate as necessary. Check bearings and blade guards for wear and replace if necessary. 9

11 3.8 Wood-turning lathe Clean any dust not removed by the extraction system, where fitted. Check functioning of electrical interlock for top guard on headstock, or mechanical fixing as appropriate. Check that foot switch or other emergency-stopping device functions correctly. Check that mandrel nose guard for unused spindle nose is in place. If fitted, check functioning of dust-extraction system. Check condition of motor, drive system and drive belts. Replace if worn. Lubricate as necessary. Check operation of dust-extraction system. Check bearings wear and replace if necessary. 3.9 Metal-turning lathe Clean chuck guard and any chip screens if fitted. Check functioning of electrical interlock on chuck guard. Check that cover plate on outer end of hollow mandrel is in place. Check functioning of electrical interlock on change wheel guard. Check condition of motor, drive system and drive belts. Replace if worn. Lubricate as necessary, including slideways. On machines with geared headstock, check oil level in gearbox. Check bearings for wear and replace if necessary. If fitted, check coolant pump and system; clean if required. Yearly check If a coolant pump is fitted, drain the coolant, flush out the system with clean water and replace the coolant every 12 months Milling machine - horizontal/vertical Clean all cutter guards. Check sharpness of milling cutters; take out of use any that are blunt or damaged. This should include any separate motors used for power feeds. 10

12 Check condition of motor, drive system and drive belts. Replace if worn. Lubricate as necessary, including slideways. Check bearings for wear and replace if necessary. If fitted, check coolant pump and system. Yearly check If a coolant pump is fitted, drain the coolant, flush out the system with clean water and replace the coolant every 12 months Power hacksaw Check condition of blade and replace if blunt, or damaged. Check that machine functions correctly. Clean machine of swarf/metal dust. Check condition of motor, drive system and drive belts, if fitted. Replace if worn. Lubricate as necessary, especially sliders of saw arm. Check bearings for wear and replace if necessary. Check functioning of dash pot and pressure-relief system. If fitted, check coolant pump and system. Yearly check If a coolant pump is fitted, drain the coolant, flush out the system with clean water and replace the coolant every 12 months Mortising machine In most schools this machine is used infrequently. Therefore, the checks below should be made before use, rather than on a regular basis. Before use Check condition of chisel and auger bit; replace or sharpen if blunt or damaged. Check that the vice functions correctly. Check that all guards are in place, including the guard around the auger chuck. Check condition of motor, drive system and drive belts, if fitted. Replace if worn. Lubricate as necessary, especially sliders of motor frame. Check bearings for wear and replace if necessary. 11

13 3.13 Double-ended, high-speed grinding machine Clean eye screens and check that they are in the correct position. Check position of tool rest and adjust if required; (the tool rest should be as close as possible to the grinding wheel, normally within 3 mm). Check condition of grinding wheels Polishing/buffing machine Check position of spindle guards and adjust if required. Check condition of polishing mops Plastic forming machine (vacuum former, line bender, strip heater, injection moulder) Check power supply cable. Check castors and brakes. Check seals/rubbers Check vacuum pump operation Check heating element(s) operation Clean debris from cavity and platen surface 3.16 Laser cutter/3d printer/cnc equipment Check power supply cable. Check work table and remove debris/waste material. Clean viewing panel(s) Check and clean laser focusing mirrors Check cooling/venting/extraction operation. Change water in cooling tank (this may need to be changed more regularly in warm weather) Check filters (if fitted) Check table bearings and drive mechanism operation and lubricate Yearly check Replace filters in laser cutter filter units 12

14 4 Detailed maintenance advice on metal-heating equipment 4.1 Gas safety system Most school workshops that have several items of heat-treatment equipment will have a gas safety system which will not allow gas to flow through the system if a leak or other fault is detected, and which will stop the flow of gas if the electrical power is stopped, for example, if an emergency-stop button is operated. Where there is only one item of equipment, then the safety system is often built into the equipment itself. The gas installation should be checked by a qualified gas engineer (ie, Gas Safe registered) every 5 years. A record of the check should be kept. The functioning of the gas safety system itself can be checked by normal operation. Normally a warning light will indicate the presence of a fault. Any faults should be rectified by a qualified, Gas Safe registered gas engineer. The system and equipment connected to it should not be used until any faults have been corrected. A gas shut-off valve should be installed in every room where there is a gas supply. This should be located in an accessible position and should be labelled. It should be standard practice to turn off the gas supply at the end of the school day, or earlier if the room is not used in the last period of the day. This leaves the room in a safe condition and serves as a check that the valve is working. A shut-off valve should be fitted in the supply pipe to each item of equipment. This should be turned off when the equipment is not in use, and at the end of the school day. In order to meet the requirements of the COSHH Regulations, the LEV system for heat-treatment equipment should be checked every 14 months. 4.2 Brazing hearth and/or chip forge Check condition of air and gas flexible hoses. If fitted, check functioning of spark igniter. Check function of gas shut-off valve. Visually check extraction system. 4.3 Crucible furnace Note, in most schools this equipment is used infrequently. Therefore the checks below should be made before use, rather than on a regular basis. Before use The crucible should be inspected for damage or cracks. Any crucible showing signs of damage should be immediately taken out of use. Check condition of all personal protective equipment. Eye protection/face shields should be free of scratches and fit the user properly. Gloves should be of an appropriate size, sufficiently flexible to use and free of holes. The buckles on aprons should fasten correctly. Spats should fasten correctly. If a tilting type of crucible furnace is used, check that the tilt mechanism functions correctly. If the crucible is lifted out of the furnace and placed in a pouring ring, check that the lifting tongs and pouring ring are a good fit on the crucible. If fitted, check functioning of spark igniter. Check function of gas shut-off valve. Visually check fume-extraction system. 13

15 5 Detailed advice on portable equipment 5.1 Portable electrical equipment Most school workshops have numerous pieces of portable electrical equipment. In general terms these will fall under the requirement for Portable Appliance Testing, which schools generally carry out annually (actually every 14 months, to allow some flexibility). However, for equipment that is used more often it may be appropriate to have it tested more often. Cables and plugs should be visually checked every time they are used. Equipment should be stored with due care taken over the safe keeping of the cable and plug. It is not good practice to wind the cable around the equipment in storage as this puts undue tension on the insulation and can cause cracking, making the insulation fail. Good practice is to hang cables, or for longer cables, loosely wind them over hooks. Many schools have started to use cordless electrical tools; this alleviates the concern over cables becoming trip hazards or being damaged when they are in use. However, the charge units should still be checked regularly to ensure that the plugs and cables are in good condition. The charging unit will still fall under PAT schedules. Batteries that no longer hold a charge should be disposed of according to manufacturer s instructions. 5.2 Portable pneumatic equipment Some schools use air operated tools. These use a compressed air line to supply energy to the tool. Compressed air must be supplied to the tool at the manufacturer s recommended pressure, this should be checked prior to use by observing the reading on the regulator and pressure gauge. All fittings must be checked regularly to ensure that they fit securely and do not leak. Most portable equipment is sealed and will not normally need any lubrication or maintenance, other than cleaning and checking. 14

16 6 Recording of checks Most schools use some form of paper-based recording system for their regularly monitoring, servicing and maintenance, such as that shown in the appendix. However, schools are starting to move to an electronic monitoring record. One example seen in a school, uses QR codes to help record checks as well as being embedded as part of the teaching in the department: QR codes have been generated and attached to every piece of fixed equipment and to some portable devices. They are also affixed to cupboards and other storage facilities. The technician or other members of staff can scan the code to get information related to the resource. This is integrated with a shared calendar which identifies when a maintenance check should be carried out. The calendar can be updated and checked remotely by the head of department. The technician receives a reminder on their ipad which tells them that a particular piece of equipment is due to be checked or serviced. They then go to the item and scan the QR code, this brings up a checklist or maintenance schedule for the item which can be completed by the technician as they carry out the work. The head of department can then check that it has been completed. The technician can sign off that the check has been done and the head of department can sign off that he is happy with it. If, at any other time, somebody has to carry out any remedial work, such as changing a blade on the band saw, the person doing so can scan the QR code and indicate on the records what has been done, when and by whom. The pupils can also scan the QR codes, but they access a different resource which is a teaching aid and gives information about the use of the item. 7 Guide to cutting speeds Whilst this section is not directly about maintenance, using the most appropriate speed will prolong the life of cutting tools and machines, and will therefore reduce the amount of maintenance and repairs needed. It is possible to do quite complicated calculations in order to find the optimum speeds for machines such as drilling machines, milling machines, metal-turning lathes and wood-turning lathes. However, in a busy workshop it may be difficult for a teacher to find time constantly to change the speed of a machine; often a machine will be set at an average speed which will cope with most situations. It is possible to apply some general guidelines for speeds. As a general rule, the speed should decrease as the size of the cutting tool or work becomes larger. Harder materials should be drilled at a slower speed than softer materials. One exception is acrylic, for which a slower speed minimises the risk of swarf melting, re-solidifying and jamming the tool. 7.1 Drilling Drill speeds are given in revolutions per minute (rpm). An approximate guide to speeds that will apply to most materials is given below. Drill size Speed 3 mm 3000 rpm 6 mm 1500 rpm 8 mm 1000 rpm 12 mm 800 rpm 15

17 7.2 Wood-turning lathe Large-diameter pieces of work should be turned at a slower speed than smaller items. The speed can be increased as the workpiece becomes more cylindrical. Often a fairly heavy cut at a slow speed is more effective at removing materials than a light cut which will only remove dust and will blunt the tool more quickly. A fairly average speed for starting most work is 1000 rpm. When glass papering, the speed can be increased. 7.3 Metal-turning lathe The general rule is that softer materials are turned at faster speeds than harder materials but the diameter of the material is important, with larger sizes being turned at slower speeds than smaller sizes. As a guide, 20 mm diameter mild steel should be turned at about 1440 rpm. 20 mm diameter aluminium should be turned at about rpm. If the tailstock chuck is being used for drilling, then the speeds for drilling machines should be used as a guide. 7.4 Milling machine Assuming a 12 mm diameter end mill is being used to cut mild steel, the end mill should rotate at about 1450 rpm. On aluminium, the end mill should rotate at about rpm. 16

18 Appendix: EQUIPMENT REGISTER AND MAINTENANCE LOG Note: This sheet is an example. A blank sheet, which can be copied, is on the next page. An electronic version can be downloaded from the members-only part of our web site, as part of file DL254. Type of equipment Wood turning lathe. Serial No AB. Location Workshop 2. Make Union Graduate If electrical, details of phase/ power, etc. 3 phase 440 volts. DATE OF SERVICE AND INSPECTION REPAIR/SERVICING WORK REQUIRED/CARRIED OUT AND REMARKS SIGNATURE OF PERSON CARRYING OUT SERVICE/ INSPECTION DATE WORK WAS DONE SIGNATURE OF PERSON CARRYING OUT WORK REQUIRED 4 April 2016 Burrs removed from short tool rest. Rotating centre Fred Bloggs 4 April Fred Bloggs checked. Driving centre sharpened /4/16 LEV cleaned and adjusted FB 4/4/16 FB 11/4/16 LEV inspected FB 11/4/16 FB 18/4/16 Machine cleaned and bare metal surfaces oiled and machine locked off (not to be used again this term) 6/6/16 Machine given full check ready to brought back into use; bearings, belt drive, switch gear, tool posts, LEV, guards in place. FB 18/4/16 FB FB 6/6/16 FB 17

19 School D&T Department EQUIPMENT REGISTER AND MAINTENANCE LOG Type of equipment. Serial No.. Location Make. If electrical, details of phase/ power, etc. DATE OF SERVICE AND INSPECTION REPAIR/SERVICING WORK REQUIRED/CARRIED OUT AND REMARKS SIGNATURE OF PERSON CARRYING OUT SERVICE/ INSPECTION DATE WORK WAS DONE SIGNATURE OF PERSON CARRYING OUT WORK REQUIRED 18