What Does a Fitter & Turner Do ?
A frequently asked question is just what does a Fitter and Turner (F&T) do? This trade training, also known as Fitter and Machinist, provides the initial skills, and some of the knowledge base, so necessary for a great variety of careers in manufacturing and maintenance work in any modern economy anywhere in the modern world.
The real diversity of demand for these skills is evident from their use in the installation of diesel electric back-up power generators in our major city banks, large hospitals, and other large buildings. These units are the back-up systems for fire and power when a disaster occurs. On a larger scale, the F&T install similar, but larger, diesel-powered generators, main engines, and gearboxes in our ship building yards. In fact, where any industrial plant is installed, and then subsequently maintained, heavy machinery and processing plant requires the skills and knowledge of the specialist F&T trades. These skill sets split off into many sub-trades: Toolmaking; Gear Cutting; Milling Machinist; Cylindrical Grinder; Maintenance Fitter; CNC Machine operator/Setter/Programmer; Automotive Machinist; Engine Assembler; and often these trades people cross over into Hydraulic Engineering; Diesel Mechanics and Fitters. These trades service the road transport fleets of interstate trucking companies and industrial plant such as excavators, bull dozers, road graders, skid-mounted diesel driven power generators, and numerous other nitch sectors of the economy including small engines that drive industrial warehouse sweepers and concrete cutting machines.
The railway network uses the F&T trades in track maintenance and train recovery following accidents such as derailments. Heavy lifting equipment has to be supervised on site, often hundreds of kilometres from their normal storage yard, to lift the damaged carriages and main engine/s to one side, rebuild the damaged rail lines, effect whatever repairs are needed, and then get the train back into service. The under-carriage of these trains have maintenance requirements through their entire life cycle which involves fitters to dismantle, machinists/fitters to effect repairs, and fitters again to refit the repaired assemblies.
The manufacturing and repair needs of engineering industries use the F&T from first-line supervision through to production management and beyond. Given extra training and experience, the F&T trades lead to many different careers in management all the way to General Manager level and very often as owners of engineering businesses.
In past years, many private and public companies, had their own apprentice training schools to send selected applicants to. Here they received the initial training in the trade and personal discipline skills in preparation for roles in management for the better students. Such companies as Repco Limited took in students from family-owned private businesses and from all of their own manufacturing and remanufacturing subsidiaries. After their first year at the training centre, these apprentices were then transferred to their separate companies to continue their training. The public businesses such as the railway and tramway workshops had their own apprentice training schools. Likewise, public utilities such as the Board Of Works trained their own apprentices.
This training system collapsed as manufacturing was sent off shore and public utilities were privatised during the restructuring of the Australian economy.
In the broad sense, the F&T trades person moves around in plant maintenance in the dairy and food processing, hospitals, passenger car and interstate truck maintenance, ship building and maintenance, tram and railway plant manufacture and maintenance, and specialised sections such as gear cutting and precision machining. Some of the even more specialised sections involves temperature controlled laboratory conditions assisting scientists at our universities.
Going back to the transport industry for a moment, this huge industry of on-road (semi-trailer) and off-road (farming, mining and earth moving) is maintained using the machine shops of the remanufacturing industry. This sector of the economy has been decimated by the improved technology in modern oils, oil and air filtration, engine management systems, and better fuel, better engine designs, which all together extended the operating life of all petrol, gas, and diesel engines by a multiple factor of three in the last thirty years. Nonetheless, Germany has identified this remanufacturing industry as one for job opportunities in their economy and have funded a specialist university for the purpose of developing these opportunities.
The remanufacturing industry still exists here in Australia. For examples, follow the links from www.engineactioninternational.com.
In summary, the F&T trade fits into the economy as the support and hands-on staff that actually do the repair work. Someone has to wind the handles and turn the spanners so to speak.
All of these sections of manufacturing, remanufacturing, and maintenance, use trades staff that start out as an apprentice Fitter & Turner and then develop and change according to demand and certainly towards personal interests of the individual. In-house training is usually in the hands of very skilled foremen but is now moving into in-house E-Learning programs. These are being structured to assist the in-house trainer and to function as a faster method of keeping up to date with what is specific to today’s business model for each business.
It evolves as an option, perhaps as a competitor, to the traditional apprenticeship system.
Our workshop is involved in the maintenance of internal combustion engines. This covers passenger car, petrol and diesel, through to light and heavy diesel commercial vehicles and some industrial plant engines. We have even redesigned and converted a 13 litre, six cylinder diesel engine for Natural Gas fuel. This engine was then used for many years as a duel-purpose power generator and waste heat generator to run a large community swimming pool complex.
The exercise that follows shows just some of the knowledge and skills used by the trade in repairing a plant failure problem in our crankshaft grinding machine. Yes, we even have to maintain our own machinery due to the high replacement cost, and often inferior, options. Besides, who would buy a new $60,000.00 machine, wait some months for delivery, and go through the costly installation process, when the original machine can be repaired for a fraction of the cost and be up and running within a week? Industry maintenance requirements will continue as a high demand for skilled trades people whilst current technology exists.
The machine below was manufactured in England in 1964 and was purchased in a worn condition from New Zealand in 1990. On arrival, the whole machine was reconditioned with the help of a very skilled tradesman who had escaped from Europe during the Hungarian crisis. That part of Europe was well known for their toolmaking skills (an off-shoot of the Fitter and Turner) and Australia benefited as many migrants arrived in our country after the 2nd world war. But after twenty years of grinding crankshafts, the one-directional dog clutch had failed again.
Just what is a one-directional dog clutch? Refer photograph…..
Pinion shaft assembly showing worn and replacement dog clutch.
Pinion shaft assembly showing worn and replacement dog clutch.
The above shaft assembly, shows the original pinion drive shaft with the bronze worm wheel at the right hand end, attached to it by cap-head screws (not shown) is the new steel clutch we made, then at the centre of the assembly is the worn clutch trying to engage with the mating clutch that is keyed to the pinion shaft. The rotation motion is transferred from the pinion shaft to the worm gear when the toothed clutch is engaged. When not engaged, the worm gear rotates freely on the pinion shaft in a bath of oil.
The above photo shows the pinion shaft, clutch, and worm gear, after repairs and during the assembly process. Note the gear selector that slides the clutch in and out of drive for fast or slow speed.
The pinion shaft, dog clutch, and worm gear assembly sits deep in the head stock below the main spindle shown above. Shown in the above is the fitting of the cover with the external oil filter for the oil pump system that protects this assembly.
The grinding process in this particular machine requires both a slow and a fast speed, and variable speed controls within that, to rotate the crankshaft during grinding. The variable part of the design is achieved through a variable speed electric motor.
The method of repair in 1990 was to machine off the worn bronze dog clutch from the worm drive shown here as a two piece assembly of bronze worm wheel and steel dog clutch secured together by cap-head screws.
The repair solution was to analyse why it failed, try to improve the design or material, and to repeat the repair done in 1990. But this time, we would give the experience to our apprentice (under supervision) to do the whole job.
Step 1: Sketches had to be made by the apprentice as the head stock was pulled apart so that the assembly would be less of a problem. (Manufacturers rarely supply detailed maintenance drawings for major repairs. This is right across the industry. Intellectual property being protected?)
Notes were also made as the assembly came apart. This process serves two things: in drawing up what the apprentice sees as it comes apart, he has to work out in his mind how the thing works; and if he gets this wrong he just won’t be able to get it all back together after the repair is done. He also learns to use our camera to record as he goes. (He will use this same process as he strips engines down and rebuilds them after repairs.) Further, he learns that many mechanical systems, involving gearing, and precision components, follow similar designs. Also that machines use metric when designed in Europe, and imperial, when designed in U.S.A., and both when designed in Australia because Australia went “metric” after manufacturing, in imperial, items that last in service for decades and in need of maintenance before being replaced. Of course, the replacement may still be imperial if manufactured in the U.S.A. Maintenance trades employees will always use both systems.
Two points are made here: Free-hand engineering sketches are not part of the apprentice training at our institutes; they expect computer literacy using a lap top and that trades employees “don’t do drawings”. Their thinking appears to be “large-manufacturing oriented”. Total rubbish. Imperial measurement is also not part of their training. Yet in the maintenance industry, which is moving to a dominant position as manufacturing moves off-shore, trades people will use both the metric and the imperial systems for the rest of their working lives in maintenance work.
Back to the dog clutch exercise: Because our business had been a manufacturing machine shop back in 1990, we had a universal milling machine and its accessories with which to make the first dog clutch. Having sold this plant in the mid-nineties, we now had to devise another way to machine this dog clutch on a simple “Bridgeport” mill and without a dividing head to index the teeth.
Step 2: The dog clutch engineering data can be found in most copies of the Machinery’s Hand Book. We have issue 29. This is the most common reference book for the F&T tradesperson when facing an engineering problem. From this data we established the tooth form and, with the unworn mating half of the dog clutch, we proceeded to make improvisations with which to machine this dog clutch as a mating part.
Step 3: A suitable piece of off-cut from our steel rack was selected to machine the blank from. The steel selected had to be a type that would be a “sacrificial” component designed to fail before the more costly case hardened pinion gear and drive dog clutch could be damaged. This worked in the 1990 repair. The softer steel dog clutch failed before the expensive case-hardened drive dog clutch could be damaged. Material was left on this new blank with enough to hold the blank in a small chuck as the dog teeth were cut on our milling machine.
Step 4: To machine the tooth form, we started with a conventional woodruff cutter, (shown at the left), and hand ground the tooth form, (shown at the right), to achieve what we needed. Refer photograph. The F&T trade learns to apply skills and to adapt to what equipment is available.
Step 5: The dog clutch has 12 teeth and to machine those teeth accurately, at equal pitch, required a method of indexing. Refer Photographs. This small four jaw chuck had 8 drillings positioned around the circumference on the same line as the four chuck key screws. That gave the twelve index points, accurately spaced around its circumference, using a pair of engineer’s dividers, a centre punch, a drilling machine, and patience. Using simple clamping, two fixed stops, and a stationary peg to index from, we proceeded to set up the correct angles by trial and error, by tilting the chuck, and to then machine the dog clutch. On completion, the dog clutch was cut off to length, drilled and tapped with the threads for the securing screws, and then fitted to the original worm gear. These three cap-head screws are shown in the photo. No heat treatment was done to the new dog clutch.
Step 6: Reassembly involved some adjustments by relocating the worm drive shaft laterally to correctly mesh with the repaired worm gear and dog clutch unit. The unit also has a clutch over- load device that needed adjustment during the setting up and test stage.
Photos indicate the fine tolerances of the components involved in this speed reduction gear box unit. Note that it has an oil pump and oil filter incorporated in the design to protect these precision components. The photo shows the finely serrated main shaft taper bearing pre-load nut and re-tension clip. The adjustment being made is to the over-load clutch pressure.
The end result was put to the test by grinding a crankshaft to achieve the tolerance required by the industry. Shown here is a restoration project grinding an old 1960’s Triumph crankshaft nose to correct the loose clearance found when the engine was pulled down.
The other end result of all this work was a good practical engineering lesson for our apprentice which leads to more self-confidence and good habits for more complex work later on in our shop when he has to strip a diesel engine, for example, and then re-assemble it after machining so that it starts up first time and runs to specification. Now that is a skilled trade.
The point is also made that manufacturers do actually train employees (apprentices or not). All knowledge does not come from training institutes despite what the universities may state or imply. Their course content is fed by industry committee work to build modules from which the T.A.F.E. or universities teach a few of the engineering fundamentals to apprentices. It is worth noting that metallurgy has all but been removed from apprentice training at schools. That explained why our apprentice had trouble plug welding a steel pipe when he “selected” a piece of 4140 alloy steel from which to make the plug. (More internal training fixed that). Business owners are well advised to have recognition of this limited school input and to have their own internal training program for their employees / apprentices. Such programs must be supplementary to what the schools teach and be specific to what each business needs. Do not expect other parties to do that for you.
This point was also made above in reference to the thinking towards E-Learning by at least one engineering group. Possibly, this could replace the slow, and increasingly expensive, business model of the traditional apprenticeship system. Just ask yourself: Does my business need accredited trades people, or skilled people trained in the skill set needed by my current business model? Will the traditional apprenticeship system have staff ready for when my business model needs them? Is the skill set going to remain steady in content or is my business model likely to change as technology affects me? If so, just how much training are my staff going to need and just where will they be trained?
Have a look at what internal training your staff are doing now and you may be surprised. If lucky, you may find a well-structured approach. From my experience, I doubt it.
From what is seen at year 2015, the rate of change in technology, federal and state government policy in Australia, together with the destruction of T.A.F.E. (by university interests as I see it) this all mandates that engineering businesses undertake more internal training to keep their business more agile and up-to-date for their business model.
Of course it also pays dividends with employees being challenged to better themselves. But of itself, satisfied employees will not save your business if technology and government policy overtakes your business model. To move with these times, look at how suitable your training is for what may be just around the corner about to make you, along with your employees, redundant.
Remember what our various governments have done over the years:
- 1970’s Clean Air Act. Legislation that cleaned up the foundry industry….and caused most to close shop.
- The Button Plan that rode over the automotive industry…ultimately driving manufacturers off shore as their industry struck “critical mass” problems.
- The various environment legislation that cleaned up industry practices of processing and disposing of liquid and solid wastes. (Aren’t universities now looking for projects to get their teeth into?)
- The 38 hour week.
- The four weeks annual leave.
- The Unfair Dismissal laws.
- The floating of the Australian Dollar.
- Selling off our ports to fund infrastructure. (Rail over-passes do not off-set increased port charges that flow on into costs for our importers and exporters that have to be passed on to product prices. Increases export costs and increases import costs. Politicians are proving to be poor custodians of the public purse.)
- Just to mention a few in case you get asked about local manufacturing.
- And: take history into account as you develop your business plan.
In hindsight, as our youth leave universities in numbers that are not synchronised with work opportunities, with many of the starting level jobs having moved off-shore with manufacturing, I hope our politicians think that possibly there may have been a better way.
No apologies for the “political” message; it is just as I see it. The Fitter & Turner, with the variations mentioned in the above, has a place in a modern economy, are not there just for manufacturing, but are essential to the maintenance of the many engineering features in our society.
It is certainly a place to check out for a career but make sure that the employer has a pro-active approach to training.