Building an narrow gauge locomotive on 5"gauge...2 1/2" scale by John G. Richardson
Part 3 Chapter 17 to end of book
Spray cabinet for small parts from scrap, computer fans and drier hose.
Painting. Workplace and equipment. Types of paint and preparation. The finishing coats.
It is quite pleasing to leave the locomotive unpainted as long as possible, the parts that won't rust that is. Unfortunately fingerprints on polished mild steel may rust overnight so that items such as the mild steel platework have to be painted on completion. Otherwise all the stainless, rustless, and gunmetal parts can be left unpainted so that one can enjoy the appearance of the raw metal. Some parts can be decorated, up to the time of painting, using the age-old technique of a split dowel in the lathe or the drill, with a piece of wet and dry paper set into the slotted end. this can be set to revolve at speed and the part then applied systematically to the ' tool ' This imparts a finish akin to that from milling, although on a much finer scale. It looks good in the raw and, according to the strength of paper used, provides a nice key for a priming coat later.
WORKPLACE AND EQUIPMENT
Whatever finish is selected, the results achieved will depend to some extent on the temperature of the workplace. An even temperature and a dust free environment are two key aspects to be considered when painting. Probably the worst place for the operation is the workshop as there is almost always a film of dust from machines and equipment which can easily be disturbed by the smallest draught. Good work can be carried out in in a greenhouse or in a spray booth set up temporarily using polythene dust sheets from the local D.I.Y store. Small parts have been sprayed in a sink in the utility room, the water set running over the back surface of the sink by a piece of card, simulating the wet back in some commercial spray booths. In the writer's early days of modelmaking, a good sized cardboard box for a booth, with a larger box placed overall whilst the paint dried, yielded quite satisfactory results. Latterly a simple ' spray booth ' for small parts has been fabricated from a steel box, using one of Messrs Proops brushless fans and a length of spin-drier hose to take away the overspray.
Regarding equipment, the range is enormous, from simple spray guns to sophisticated airbrushes. Expensive equipment does not guarantee good results, choice is likely to be based upon one's budget and, provided preparatory work has been carefully carried out, good work can be achieved with simple equipment. With sound preparation a combination of simple tools used skillfully and ongoing care taken in rubbing down and finishing, an excellent paint job will result.
Spray guns and airbrushes require a satisfactory air supply. Cans of propellant are expensive and are soon used up in the course of coating the many parts of a locomotive. For economy, a small electric tyre pump can be used to provide an air supply via an inner-tube as a reservoir, ( the writer once re-sprayed a motor cycle using only a car footpump ! ). Compressors provide a reliable, consistent source of supply and need not be expensive although a filter must be used to provide a clean supply. There have been several articles in the model engineering press on adapting compressors from refrigerators. One very clear description was that by Steve Ballinger entitled ' An Airbrush Compressor ' in ENGINEERING IN MINIATURE Vol 2, No.5 October 1980. It is important that some form of pressure regulator is used as varying paint consistency calls for a means of controlling the pressure. The simple ' external mix ' gun can, with care, provide a good finish although mix adjustment has to be carried out between actuations. The ' internal mix ' tool is probably more favoured by the professional and expert, providing as it does more immediate control of the air / paint mix at the touch of the trigger. For occasional use an electric, airless spraygun can provide an economic solution and again, excellent results can be achieved with care.
Other equipment includes lint-free cloth, wet and dry paper, rubbing compound, metal polish, masking tape and an endless supply of newspaper. Masking film and masking fluid will be useful to protect polished parts and to mask-off in the course of developing a livery. An out-of-date telephone directory will provide a good source of paper for masking purposes and on which to sit small parts for painting and some stiff wire hooks will be useful for handling and ' hanging out ' the parts to dry. A turntable such as those used in icing cakes will also prove useful. A good supply of thinners appropriate to the paint system to be used is essential. Where paint and thinners are concerned small tins are wasteful. Both materials will be cheaper if purchased in sensible quantities from a paint supplier. Your local dealer will advise on the type of solvent to be used according to the system selected. Paints will keep in the can for years provided it is properly sealed, the lid firmly replaced and a seal formed by inverting the can before storage.
Spaying small parts is simplified and can be carried out in the workshop if a suitable facility is provided. The simple cabinet illustrated at the top of this chapter has proved effective and useful. The ply box has two fans from defunct computers mounted high at the back. Extracted air and spray is blown into a cone-shaped funnel, which mounts on the ply back, into a length hose from a tumble drier and out of a window. At the front of the box a strip of perspex prevents overspray from escaping. The whole somewhat ' Sid Carnow ' cabinet can be packed together taking the minimum amount of space in a busy workshop.
TYPES OF PAINT
Firstly a decision is required regarding the type of paint to be used. The choices range from cellulose and acrylic car sprays, through enamels, to special heat resistant paints such as those intended for automotive use. The choice rests with the individual, but whatever system is selected it has to be remembered that sound preparation is critical to achieving a good finish. A colleague calls the painting stage ' the spoiling stage ' and this it may well prove to be if the preparatory work is hurried or not carried out systematically.
Contact with the suppliers of various types of paint systems reveals an interesting fact. On investigation, the majority of complaints regarding substandard finishes achieved across a wide range of materials result from failure on the part of the user to read, or comply with the manufacturers instructions. Whilst it might be argued that the manufacturer is bound to come up with this conclusion, it has been proved time and time again that similar products have produced differing results in the hands of different people. It seems that when all else fails, when the paint fails to dry, or to provide the required surface, the user turns to the instructions, or complains to the makers!
LBSC used to advise washing parts to be painted in petrol, this seems a risky business and today a thorough wash in detergent, a rinse and then drying in a warm spot is probably more effective. The aim here is to remove all traces of oil, grease and cutting fluid which will otherwise prevent the priming coats bonding to the metal. Failure to remove grease will be evidenced by wrinkling of the early coats of primer. Should this be observed then the best course will be to go back to the bare metal, thoroughly degrease and start again.
Whatever paint system is to be used, the same steps are required in preparation of the surfaces for paint. Paint will not mask irregularities of surface, it will not fill joints and it certainly won't fill holes in castings! Minor defects in castings can be filled with a polyester or epoxy filler and rubbed down to the required form, a rasp will cut away any overfill and a scraper can be used to take the repair to the stage where wet and dry paper will finish the job. Castings and any nonferrous surfaces should be coated with an etching primer, obtainable from any good automotive paint supplier. This should again be cut down using wet and dry paper, recoating and rubbing as necessary to produce a consistent matt surface to accept the selected paint. Filler is next, this fills any minor defects and can be carefully cut back using wet and dry paper until an allover, dead smooth surface results. The paper should always be supported, using small blocks of wood or a hard rubber block to ensure that the thickness of coating is left consistent throughout, and that corners are not exposed, or rounded out. The surface should now be dried. Wiping with a lint-free cloth helps, as does leaving the coated part on a radiator for an hour or two or spend some time using a hair dryer, the latter technique is good as it dries out all the little nooks and crannies in a complex part. Take time, attempt to speed things up and the painting stage will rapidly transform into my colleagues ' spoiling stage ' !
Next is the priming stage, here we are building the surface which will finally be apparent. The smoothness of finish achieved at this stage determines the appearance of the part after the application of the final coats of paint. This is true whatever paint system is adopted. Any small defect after this stage will be magnified by succeeding ' finishing ' coats. The use of materials of differing colours up to this stage assists by indicating depressions and local defect. After each succeeding coat is rubbed down, high spots will be shown up by the previous colour, ' grinning through ' and local depressions retain the colour of the last coat applied. The aim is consistency and a uniform colouration all over the part. Once this stage is reached all is ready for the application of the final finishing coat (s) according to the selected sytem.
Provided one is satisfied with the available colours, brushing enamel provides a good durable finish. It is always advisable to warm tins of enamel in a bowl of hot water prior to use. Don't shake the tin before use, open it and thoroughly stir the contents. Using enamel, applied by brushing, the finish will depend a great deal to the quality of the brushes used. Only brushes from a well known maker should be used, and they should be washed frequently using thinners and finishing with soap and water, as work on any large parts is carried out. This avoids problems and brush damage caused by enamel drying where the bristles are set into the handle. Carefully dry the brush after this cleaning operation, otherwise any moisture remaining in the brush will upset the paint consistency on restarting brushwork. Enamels can be spray applied although absolute cleanliness of the spray equipment is essential, and defects are not easily corrected.
Whilst ideally one coat of enamel should provide a good quality finish, it is sometimes necessary to recoat. Previously coated parts should be set aside for the paint to harden before re-coating. A warm, dust-free spot is desirable, a cardboard box on top of the central heating boiler has proved effective in the past. Before re-coating, the surface should be lightly cut back taking care not to remove paint from the corners and edges of the piece. Work painted using enamel generally benefits from rubbing and buffing using automotive rubbing compound prior to finishing with metal polish, these processes should be carried out over a few square inches at a time, first rubbing, then buffing. A soft brush will be needed when polishing rivetted surfaces, care being taken to avoid exposing the metal of the rivet heads by rubbing too hard.
HEAT RESISTANT PAINTS
Heat-curing paints can be used to advantage on the smokebox and chimney. These paints, applied from a spray can, are cured either by the heat of operation, by blowlamp or by baking in the oven. Heating parts coated with this material in a very hot oven ( Regulo No. 9 ) for half an hour proved satisfactory in the case of Pixie. The black finish obtained is midway between eggshell and gloss and can be maintained by a light rub with an oily rag. The black heat resisting paint in spray cans so beloved of motorcycle enthusiasts is great for chimneys, smokeboxes and similar items. Oven or gentle heat from a blowlamp will cure it to a satisfying matt finish.
SPRAY CANS, GUNS AND AIRBRUSHES
When painting using spray cans, the can must warmed gently before being shaken according to the makers instructions, generally for some minutes after the mixing ball is heard to rattle within the can. The spray should be tested to determine the spray pattern and the distance of the jet from the work by trials on a piece of scrap. With both cans and guns the spray should be started away to one side of the part being coated and carried across the part several times before moving away from the workpiece to stop the spray. In this way the finish will not be marred by blobs of paint which often occur when starting and stopping the paint flow. Before succeeding coats are applied, (some instructions say that the succeeding coats should be applied quite soon, whilst the previous coat is tacky even, others require a dry finish before recoating) the parts should be turned to ensure that all edges are coated. The temptation to build with one coat of spray has to be resisted. A series of thin coats always gives the best results. Building should be done in the course of a series of coats, rubbing down between each coat.
When using an airbrush much better control of the paint and thus regulation of the coating is possible, the most critical aspect here being the cleanliness of the equipment. Paint consistency is important and it is advisable to strain all but the freshest paints. Mix the paint by stirring, not by shaking the can. Always test the consistency of the paint on a piece of scrap before coating any model parts. Most paints also benefit from straining after mixing, strainer material can be obtained from model or automotive spares suppliers. When deciding on the correct mix of thinner and paint, start on a piece of scrap with a 30 - 50 percent thinner content, adding more until the flow is correct. A short blow of air alone will clear the brush if it clogs. Always clean the airbrush using thinners immediately on finishing painting, any minute flake of paint that dries on the tool could spoil the next job to be tackled.
During the coating process the air brush should be kept on the move, using a motion of the hand and arm which maintains the head at a constant distance from the surface and sweeps the piece with spray. Movement of the wrist varies this distance and prevents even coating. Spraying should be started and stopped away from the piece being coated. Runs and pools of paint result when the brush is stationary for even a second. When paint dries too quickly, before reaching the part being coated, a rough texture develops. Ideally the coat should appear to shine as it is applied, rapidly drying as the spray is moved on.
DEALING WITH DEFECTS
Whatever tools are being used in the painting process, should there be the slightest evidence of a run or ' orange peel ' surface developing no attempt being made to rectify things by wiping with a cloth. This action can result in the removal of the current coat of paint and parts of the previous coats which have become softened by the spray. The components should be set aside for the paint to harden completely then the surface can be cut back with successive strengths of wet and dry paper, care being taken not to expose primer at edges and corners. Once a uniform, matt finish is achieved overall, then priming, rubbing down then re-coating can commence.
Test track and a simple driving trolley. Driving position and access to controls. Braking.
Pixie with driving roof and back. The driving trolley footrest is stowed.
As this was the first 5 " gauge locomotive built by the author it became necessary to build a test track. This would later be extended to provide a running facility. Material costs were of course a major consideration and the search began for scrap material which could be recycled ! The track would prove expensive if an attempt were made to replicate narrow gauge practice, for example using 4' 6" Sleepers of 9" x 4" section at 3' 0" centres as described on the Ffestiniog Railway of yore. Some more simple trackage was envisaged, probably having randomly spaced sleepers as are sometimes encountered. The solution came in the form of discarded pallets which are fabricated from anonymous timbers and occasionally hardwoods. A kind friend, who is keen on woodworking, ripped down enough of the pallet staves to the appropriate section which were cut to length prior to slotting. The 1 " x 3 / 8" mild steel section used for rails was purchased from a commercial supplier in 6' 0"lengths. Joints at 6' centres have not proved to present a running problem provided that they are properly aligned at the time of tightening the fishplate bolts.
The three pieces of equipment on the side of the workshop allocated to drilling and milling operations provide a useful bed for supporting lengthy stock. The drilling machine tables can be set level with that of the milling machine and long stock thus supported at three points in its length. After being brought to a nett 6' length, the rails were drilled for fishplate bolts in a jig set on the table of the drilling machine. . The jig consisted of a pre-prepared fishplate of 1"x 1 / 4" material fitted with a stop to accurately position the rail end, holes were positioned to establish the location of a pilot hole drilled using a centre bitt. Clearances were kept to a minimum for 2 B.A. bolts, this resulted in a tight joint. With holes centrally positioned in the height of the rail the heads of the bolts do not interfere with the wheel flanges in service.
Initially a few trial sleepers were slotted on the milling machine to establish the correct depth of slot and to prove the rigidity of the simple sleepering arrangement. Araldite was employed to bond the sleepers and rail and it was found that sleepers spaced at a maximum of 8 inch centres provided a suitably rigid assembly. Latterly the sleepers have been secured in place by self-tapping screws from below a somwhat tedious job but aided by fences to position the drill in the press central in the rail. the sleeers being positioned laterally by eye.The remainder of the sleepers were slotted in a jig set up on a sawbench, the cut being made with a wobble saw. This was to be a simple straight track and eight 6' 0" lengths were fabricated and used in the early stages of testing. Subsequently a curved section of track has been built using the same techniques and has performed satisfactorily. For this the rail section was taken to a local works and put through their rolls. When not in use the track is stored on top of a cupboard in the utility room and causes no offence to the domestic authority . The track described can be laid onto a flat path, or onto gravel along a level patch or trench in the garden. Should the powers-that-be demand that the track be removed and stored between uses this can be simply accomplished by means of simple trestles, ladder type arrangements of 75 x 50mm timbers which form the supports for the sleepers. In their turn, short lengths of fence post set into the metal brackets supplied for fencing purposes can be cut and provided with cross members to support the ladder frames. When the track and ladder frames are stored, along the wall inside the garage, hung under the eaves of the garage or in a convenient shed the posts can be removed and, provided the tops of the sockets are set below ground level the grass can be mowed as if the railway line never existed. Such an arrangement would surely satisfy the most demanding indoor authority!
A SIMPLE DRIVING TROLLEY
Most of us, with the exception of the ride-on 7 1 / 4" brigade, will at some time have to build a driving truck. Clubmen have access to club vehicles, but the lone model engineer with a few yards of track in the garden has to have a vehicle from which to drive his pride and joy. Having completed Pixie and run it on air on a short length of track a few times the writer looked around for inspiration. Whilst it was intended that the chosen vehicle should convey the spirit of narrow gauge working, what was needed was something simple and relatively quick to build, ( this a major consideration in view of the length of Pixies gestation period )
The vehicle which became the final choice was found in one of two volumes of a book on the bookshelf, the excellent history, ' The Festiniog Railway ' by J. I. C. Boyd, published by The Oakwood Press. The open mineral wagon illustrated therein would be straightforward to build, the wheelbase being such as to permit, with a little licence, manufacture of a near scale vehicle which, whilst not looking out of place behind Pixie, would offer a comfortable driving position.
At the time of completing the locomotive, with driving in mind, a special driving back and roof were built with openings to improve the view of the gauges and allow access to the regulator and brake, Between steamings, when the loco is on show these are replaced by nearer scale components.
DRIVING POSITION AND ACCESS TO CONTROLS
On commencing design of the truck, a mock-up was built in Dexion angle, this was perched on wooden blocks representing the wheels. Set-up behind the locomotive this proved the projected sitting position to be comfortable. It established that the intended design would be stable axially, with drivers ' mass ' imposed upon the driving seat positioned relative to the proposed wheel centres. Transverse stability was also checked to avoid sideways rock on the proposed track. The mock-up also avoided what would have been a major blunder, production of a vehicle which, whilst looking right would, due to its height, have allowed only limited access for driving and firing the little locomotive. A reduction in the height of just the front of the wagon was found to be necessary to permit good access to the firehole door. The space in front of the drivers seat provides useful storage for spare coal, tools and so on.
Construction, apart from the wheel blanks bought at Kennions, Hertford, now defunct but who provided excellent service over the past 20 years, is from scrap materials gleaned from rubbish skips. The main frame materials were part of a discarded steel door form, the roller bearings came from worn-out washing machines, courtesy of the service engineer. Whilst these bearings are not in good enough condition for the high speed, arduous requirements of washing machine at ' full chat ' they are quite satisfactory at the speeds encountered in the model application. The footrest is from gas barrel. Plywood and framing timber are from kitchen cabinets which were replaced and dismantled 20 years ago! The timber is superb, clear pine, the likes of which one would be hard pressed to find even in specialist timber yards today, let alone todays ridiculously pricey Do-It-Yourself stores. A weather eye maintained on rubbish skips about the town, such a source, particularly where shopfitters are working is likely to yield just the stuff our hobby calls for ! Rexine and foam for the luxurious upholstered seat are from a dearly departed lounge suite.
BUILDING THE TRUCK
The frames which are over-scale and extremely robust are constructed as are frames for most locomotives. They are joined using mild steel angle and bolts, great care being taken to maintain the whole assembly in truth. Slots were provided in the frames for the substantial axle assemblies. This allows the complete assembly of bearings, bearing housings and wheels, whilst bonded up solid onto the axles, to be dropped out in the event of a need for maintenance at a later date. In service the absence of any form of springing has been found acceptable and the vehicle runs freely, reducing the work that the locomotive has to do to a minimum.
The wheel blanks were turned on the mandrel previously used in producing the locomotive wheels. Axles were turned between centres to ensure concentricity, a separate bearing being set into the back of one of each pair of wheels to overcome differential rates of rotation on tight curves. We are talking narrow gauge here! A variety of bushes were needed to allow for the assortment of sizes of available, ( inexpensive! ) bearings, four of which were built into simple, turned housings bolted into the slots in the frames. Bonding fluid is used throughout to secure axles, bushes and bearings.
The bodywork was mounted onto timber bearers bolted to the main frames, the edges of the 5 / 16" plywood being built-up to the scale thickness of the timbers of the prototype. The lines of individual planks were scribed into the ply in accordance with the drawings thoughtfully included in the history book.
1 1 / 4" and 1 / 2" x 1 / 8" strapping was applied to the sides and one end. Whilst these items are somewhat overscale, the extra thickness seems to add character. For the same reason dummy coach-screw heads turned from 3 / 16" square bar were Araldited to the strapping, square heads were chosen as looking ' more interesting ' than would the bolt heads of the original. A ' liberty ' perhaps, but one of those little bits of licence that the near-scale modeller can allow himself from time to time ! Rudimentary strapping is included at the back end to convey the ' atmosphere ' of the hinged parts of original vehicle.
Painting was carried out using automotive paint in ozone friendly dispensers, expensive in themselves but economic in view of the availability of appropriate colours in the small quantities required. An added bonus obtained by using spray-cans is the reduction in clean-up time after the painting operation.
Coupling to the locomotive is by rigid bar using the scale coupling block on the loco and a fabricated coupler on the trolley. A heavy duty spring slipped over the coupling bar prevents snatch due to take-up in the clearance holes in couplings and coupling bar as the locomotive moves away, reduces rattle and acts as a buffer when the amachine is brought to a halt.
Driving truck braking, should it prove necessary, will be achieved by disc braking, not the complex automotive type of disc brake but a simple lever operated vee-d block working upon a tapered disc or discs, clamped round and pinned to the axles, between the frames. These discs can be retrofitted using the technique employed in installing the axle pump onto Pixies front axle.
THE FINISHED TRUCK
The finished result is quite pleasing in appearance, comfortable to ride and economic to produce. Nett cost was in the region of about Fifteen Pounds thanks to the recovered and re-cycled materials employed! The 18 hours of construction time provided a pleasant change from the more exacting work of modelling the locomotive. The next project is the construction of ride-in wagons for passengers, these will be based upon other prototypes as illustrated in 'The Festiniog Railway'. The search for materials has begun !
Even a small, narrow gauge locomotive on 5 1 / 2" gauge track will prove to be quite weighty. Pixie weighs some 120 lbs dry, that is with the boiler empty and without coal in the bunkers. A model of this weight and proportions is literally ' quite a handful ' Thought has to be applied to handling the locomotive in the workshop and at the track. For the workshop where routine servicing is carried on, a hoist was built from standard box-section steel, the material came from...yes, a skip! A local builders merchants was discarding racking and enquiries of the manager brought forth permission to acquire the material. Whilst this was a stroke of luck, similar section can often be found at the local scrapyard or, as a last resort, at a steel stockists. The material has good mechanical properties and can be simply sawn and bolted or welded. Where bolting is employed care must be taken to sleeve bolts within the section using fitted lengths of thickwall tube to ensure that they can be properly tightened without the section becoming distorted.
The proportions of the hoist frame to the base were decided by the requirements of stability, also the fact that the equipment was to be used on ground which whilst paved was not level throughout.
The hoist for Pixie is of welded construction, gussets being placed to stiffen the whole assembly, although with a good fillet of weld the whole frame works up sufficiently rigidly to provide a safe lift. The lifting tackle is typical of that available from the local automotive parts stockist being intended for handling car parts, and is fitted with a positive ratchet control over the lifting and the lowering actions. Heavy duty castors were bolted to the bottom fork frame which is of such width that it can be rolled through a 2' 6" door opening. Where castors are used it has to be remembered that with the wheels swivelled towards each other, inwards, the true base width of the assembly can be very much reduced. In the case of large wheels on a narrow base this may reduce the actual base size to the point of instability
The hoist is used to transfer the loco from the bench to a trolley and vice versa, the trolley is constructed from Dexion angle and has two wheels on an axle placed centrally on the frame also a single fixed trailing wheel, actually a bearing from some long departed piece of machinery. The assembly is similar to that of the trolley used to move upright pianos. Pixie is immobilised upon the length of track secured to this trolley by some removable chocks sitting on the rails. The wheel configuration of the trolley provides absolute maneuverability through doorways and up and down some portable ramps constructed from plywood and the trolley can be turned in its own length.
As in full size practice the lifting connection between locomotive and hoist is by spreader bar. This is fabricated from box section with lifting points welded into position. These ensure that the locomotive is correctly balanced in the course of a lift. Where more that one locomotive is to be handled using the same equipment the lifting loop positions can be made adjustable as long as positive location is provided against longitudinal movement. Only good quality slings are used, these are made from climbing rope of guaranteed tensile strength, purchased from the local yacht chandlers. In the short lengths required this rope offers very good value. The knotted ends of the slings are prevented from unraveling by a touch of the blowlamp, not sufficient to burn, but sufficient to melt the rope and allow it to be rolled to a smooth finish.
TESTING THE EQUIPMENT
Although such equipment may be intended for the sole use of the owner, and probably will only be used in the workshop and on private ground away from the public, it is recommended that the equipment is tested. A test should be carried out by a full lift, throughout the range of the gear, of twice the maximum weight intended to be lifted in practice. Bags of cement or shingle provide suitable loads of known weight for the test. The safe working load ( SWL ) thus established should be indicated on the frame and the spreader bar. At no time should anyone be allowed under a suspended load, except where some trestle or benchwork is arranged in such a manner as to prevent the load from dropping in the event of failure. It is unwise and dangerous to attempt to move such a frame under load on bad or uneven ground.
Steaming the locomotive. Simple blowers. Raising steam and driving. Safety aspects.
Blast pipes on prototype
EQUIPMENT FOR FIRING THE LOCO
A supply of soft water heads the list of needs, water from a rainwater butt, filtered through an old stocking is ideal. Distilled water is also ideal for the job, although a costly item. Whichever is used, have plenty of water available. The plastic bottles that mineral water comes in are ideal storage containers / dispensers. Coal of the type favoured by your local club will be the best bet. It is not desirable to experiment at this stage ! A quantity of small paraffin soaked sticks will be used to light-up, these are best kept in a plastic box of the ice-cream container type.( LBSC favoured charcoal soaked in paraffin ) A cheap cigarette lighter will save matches. Impatient types may wish to use a gas torch although with care this may prove unnecessary.
For lubricating oil, light standard motor oil will suffice for oiling-round, a good pump type, oil can will ease the application of the lubricant to the motion, eccentrics and so on.
Shell 'Valvata' or similar, a sticky steam oil is required for lubrication. The lubricator being filled 3 / 4 full prior to a run.
A pricker / rake and a firing shovel complete the inventory, except perhaps for a pair of industrial gloves, the small wheels on valves can get quite warm after a time in steam. My pricker is of bent wire pointed at the end and with a loop handle, the rake similar but having a blade in place of the point. My firing shovel is fashioned from a serving spoon, part of the ' family silver' , with the end ground square and the sides turned up. It just enters the firehole door and the handle is just long enough to stay cool. One day it will be treated to a wooden handle !
TWO SIMPLE BLOWERS
When it comes to steaming the loco almost essential as the supply of coal and water, is a blower. Having a small compressor in the workshop it seemed sense to make up an air powered blower. The principal is described in LBSC's book on ' Tich '. A small tube blows air up a larger diameter tube which fits into the locomotive chimney causing the vacuum necessary to draw the fire. The outer tube in the assembly devised for Pixie comprises a length of large diameter copper water pipe and a parallel union. The union has a groove turned around the periphery into which is fitted an ' O ' ring to ensure a push fit in the chimney and importantly an airtight joint. The small angled tube, which is silver-soldered into the main body about 1 inch above the level of the chimney cap, is swaged to a point then drilled using a No 70 bitt. The supply end of the small tube is fitted with a Schraeder valve, acquired from a local tyre fitting shop ( collect a handful whilst you are there, they come in for lots of things about the workshop ). The valve permits coupling to the inflator accessory of the compressor.
In use the main tube is inserted into the chimney where it stands firmly fixed by the friction provided by the ' O ' ring. The tyre inflator is attached to the schraeder valve and the blower is ready for action. An advantage of the air powered blower is that the draught obtained is infinitely variable according to the amount of air allowed to flow through the inflator valve. In practice only a very small blast is required. Too strong a blast makes a hole in the fire and causes embers to clog the tubes. Once the correct draught has been established, a small block of wood wired to the handle of the inflator helps maintain the setting by limiting the trigger travel.
A novel blower for use whether or not a power source is available was illustrated in MODEL ENGINEER Vol 156, No. 3778. 6-19 June 1986. The blower built by Maurice Simmons was based upon a traditional bicycle lamp case. A disc of metal replaced the glass and provided support for a low voltage motor and three small diameter struts supporting a further plate which served as a bearing for the impeller fan. In use, a tube mounted on a further plate below the fan, fitted into the chimney of the locomotive. Mr Simmons replaced the battery in the body of the lamp with a pack containing two re-chargeable batteries for economy. Any model engineer worth his salt would be able to build a similar device quickly and cheaply.
OILING ROUND AND FILLING UP
Check that the mechanical lubricator is filled, work the manual wheel or lever a few times to free the clack, go right round the locomotive with the oil can, oiling bearings, rods, eccentrics and so on, plus fill all oil cups.
Check that the blowndown valve(s) are closed, then open the whistle valve or some other vent to allow air to escape as the boiler is filled with water. Water can be introduced either through the safety valve bush from an external supply, a bottle or can, or from the tank using the hand pump. The latter method will be quite a slow job although it will prove the efficiency of the pump, and the tightness of the unions in the feedwater system. Filling through the safety valve bush, or better still through a bush provided for the purpose on the steam dome, can be speeded-up using a plastic bottle fitted with a small diameter plastic tube, the plastic bottle being squeezed to introduce an element of force feeding! For the more ' laid back ' a can of water set on top of the cab can be used to feed water siphoned through a small bore tube.
The water level should be checked in the gauge glass. You are aiming for about 3 / 4 of a glass. It makes sense at this stage to open the water gauge drain valve. As the drain tube is of small diameter the water rises slowly in the glass despite the small quantity draining away. Once the correct level shows in the glass the valve can be closed, the safety valve or the filler plug inserted, and whatever is used as a vent, closed. The saddle tank can next be filled. With both the boiler and the water tank filled, refill the water containers, this will avoid a panic situation when the onboard water supply gets low after some time in steam !
Check that the regulator is closed and that the reversing lever is set in mid-gear ! With sufficient of the paraffin soaked sticks in the firebox to cover the grate area ' light the blue touch-paper ' With care, a breath of blower will fan the sticks into flame. After a while, when they settle to a red glow, put in a few shovel fulls of coal. Close the door and after a few minutes further blowing when the whole fire will be glowing red, add more coal. Soon the air blower can be removed and the locomotives own blower set to work. The pressure gauge will start to register and continued firing will bring the pressure to working level and the safety valves will start to lift. Watch the water level, pumping by hand as required, not too much however.
As the beginner soon finds out, firing and driving a locomotive, albeit a model locomotive does not come easy. One has to learn how to best use the controls to maintain a head of steam, and more importantly what to do if the pressure falls off. It is exciting, and even though the first few firings may prove disappointing as far as performance is concerned a lot will be learned and a great sympathy develops for the engine men of the steam era who drove through whatever weather and conditions prevailed, rain, snow, ice and sometimes even, flood. These men ( heros ) took great pride in their work and in their time keeping.
Spare a thought for the engine men of the Festiniog Railway of 1876. The Railway Regulations of the day set out a series of fines which were to be levied on unfortunate workers as follows:-
'Engine driver for having used greater quantity of Coal or Oil than the fixed lb. per mile Coal 2s 6d. Oil 1s 0d.
Fireman ditto. Coal 6d. Oil 3d.
If reported to have used more than the stipulated quantity, more than three times in six months is liable to dismissal.
THESE RULES to be strictly enforced: none but the most tangible excuse will be accepted in favor of not imposing the fine'
We shall have to watch our fuel consumption!
GETTING UNDER WAY
Having built the fire to an all-over incandescence, and topped up with a layer of fresh coal. it is time to start! With the reversing lever in full forward gear and with cylinder drain valves open, open the regulator slightly whilst easing the loco forward a few feet. Steam will drive out any water from the cylinders as well as beginning to heat the pistons and cylinders. During this process the locomotive will be blowing off and using steam so it is essential to watch the gauge glass and pump up as necessary.
There may be a shower of water from the chimney at this stage as the condensate is blown past the slide valve, this will soon cease however and the whole show will settle down ! Close the the drain valves soon as the cylinders are clear and steam alone is issuing from them.
The setting of the safety valves should be checked against the pressure gauge which will have been calibrated against a full size gauge in the workshop. Have the necessary tools to hand at firing-up time. In the case of there being two valves fitted, they both should be set to blow at the same pressure.
Now is the time to set the reversing lever to full forward gear, open the regulator gently, avoiding wheel slip, close the blower down and feel the locomotive surge forward, as surely it will.
Once under way adjust the gear back a notch or so, and enjoy!
Whilst driving there a lot of things to be remembered :-
Two of the driver / fireman's actions result in loss of boiler pressure, those of adding coal to the fire, and adding water to the boiler. These actions should be carried out when the safety valves are blowing . Always shut the blower down after opening the regulator. In motion the exhaust is sufficiently strong to draw the fire. Open the blower valve before closing the regulator in order to maintain the draught.
Adjust the by-pass valve to maintain the water level in the gauge glass, remember that the axle driven pump works flat-out all the time, and with both pumps working one can soon be in for a shower!
Fire little and often to maintain an incandescent fire whilst avoiding a drop in steam pressure.
A few droplets of oil around the chimney top are a good sign that oil is getting through the system
Make sure to add coal to the front of the fire, use a pricker if necessary to distribute the coal and avoid a choked grate.
On an ' out and back track ' add coal when the locomotive is stationary and when the safety valves blow, its too late when the fire blackens.
A layer of coal on an incandescent fire will light and burn, on a black or holey fire it will not.
It is not necessary to keep the fire up to the level of the firehole door, this is wasteful and leads to a choked fire.
If the fire does die down, avoid pumping cold water into the boiler, use the blower in short bursts or make the loco work harder, by putting the reversing lever into full forward gear, until the fire comes back.
In the event that the pressure continues to fall off it will be necessary to open the blower to increase the draught and draw the fire, this is also necessary at the stops and at the end of an out and back track. In the latter circumstances it is all too easy to forget to close the blower valve so be alert and avoid a holey fire!
Notching-up, shortening the cut-off by moving the reversing lever nearer to mid-gear, saves steam and thus coal and water.
If on any of the first few runs things appear to be ' getting ' out of hand, do not hesitate to pull the pins and drop the fire. Better safe than sorry is a good motto where the pressures encountered with model locomotives are concerned.
The sequence of shutting down after steaming is equally important as that of firing up the loco. The fire should be allowed to burn right down as far as possible whilst retaining sufficient pressure to a permit blowing down. The blowdown valve ( s ) should be fully opened to permit the sediment that collects about the foundation ring to be ejected.
The firegrate and ashpan can be dropped, and the firebox brushed out. With the smokebox door open and the ash cleared, a blowthrough with compressed air will clear away any debris from the tubes. Later tube brushes will finish of the task.
All valves should be left open and the warmth of the boiler will dry all out. It is best to leave the valves open whilst the locomotive is in store, particularly the regulator. Martin Evans, in ' Rob Roy, Building a Caledonian 0 - 6 - 0 Tank locomotive ' Argus Books Limited., passes on the helpful tip that ' should a regulator or blower valves stick in storage, rather than attempt to force them open, it is better to raise steam when they will almost certainly free themselves with very little persuasion '
At this stage the engine drivers friend, the oily rag passed over the paint work will promote that silky, satiny finish so beloved of the railway enthusiast. WD 40 or similar lubricant in suspension will protect the working parts and can be cleaned off using a rag dipped in methylated spirit prior to the next run.
This is a good time to check the locomotive over, tightening any loosened fastenings, replacing lost pins, caps or corks and generally putting things in order so that the next steam-up can be started without hold-ups.
SOME USEFUL TOOLS AND EQUIPMENT FROM SCRAP
These are illustrated elsewhere on my site to view click here workshoptoolsetc.htm
Although excellent models can be produced with the bare minimum of equipment there are certain tools and attachments that can be readily fabricated from scrap. The following have proved useful in general model engineering work in fact, without them some parts would have been difficult to produce. The attachments for the Myford noted here can be made from offcuts, or at least from relatively cheap materials found in the odds-and-ends bin at the material suppliers. Whilst the time expended in making them has to be set aside from model making the results will prove useful in constructing the present and many future models.
REAR TOOL HOLDER
The most useful attachment made to date is the rear toolpost used for parting-off. This was machined from two blocks of mild steel, fixed together using socket-head screws. This assembly was then drilled and bored for a clamping bolt passed from the top through into a length of tee nut which fits into any of the slots in the topslide. The clamping bolt is fitted with a lever terminating in a ball handle. The parting tool holder is located, upside down of course, within the toolpost using two further socket head screws. Use of the rear tool post removes the possibility of dig-ins and jamming. This attachment has transformed parting-off from a chore to a pleasure, and all for minimal cost. Used on the front of the top slide it can be used for holding the more substantial boring tools although due to the constant need for a parting-off tool in practice, a further similar tool holder has been produced for this purpose.
FLY CUTTING ATTACHMENTS
A very simple device for use in fly cutting can be made from a length of bar drilled to accept cutters, secured by grub screws. This can be set in the four-jaw chuck and adjusted as necessary by moving the bar within the jaws. Material to be machined is clamped on the saddle or mounted on the vertical slide. For the milling machine a tool holder has been fabricated from a billet of steel obtained from the local scrap yard. This is turned to register with the backplate on the quill of the milling machine and is secured by Allen cap head screws in counterbored holes. The cutters, from silver steel rod, are adjusted and secured by grubscrews. In service, in the light milling machine, the mass of the block provides a ' flywheel ' effect and also reduces vibration when intermittent cuts are made.
A BORING TOOL HOLDER AND ARBOUR
Boring small and deep holes can be carried out using a simple attachment based upon a design illustrated in MODEL ENGINEER. The body of the attachment is a block of mild steel, cleaned up all round and trued on top and bottom faces by turning in the four jaw chuck. The block is drilled and reamed to match the tool clamp stud on the topslide of the lathe. This completed the block is secured on the topslide in place of the tool clamp assembly ready for drilling and boring for a silver steel bar of 1 / 2 inch diameter which forms the tool holder. The hole for the tool arbour is drilled and reamed from the headstock drill chuck, feed being achieved by advancing the saddle. If required, the tailstock can be brought up to the back of the block to provide additional support during these operations. With the hole completed the block is drilled and tapped for two socket headed screws then slotted to form a clamp which secures the tool arbour in service. The arbour is turned down and threaded with a fine thread to accept the coned cap. The cap is cross drilled for the tool, coned, then tapped to suit the thread on the bar, it is provided with a knurled grip for first adjustment and two flats which permit the use of spanners in tightening the the thread to grip the tool. A small slug of phosphor bronze acts as a bearing between the thread end and the tool. Suitable cutters may be ground from circular tool steel (a broken centre bitt will suffice )
In use, with block set up on the topslide clamp stud and the arbour gripped in the block, the toolsteel is set into the coned head and a spanner used to tighten the grip. With the clamp eased, the arbour can then be rotated to bring the cutting tool to true centre height. The clamping screws are then tightened. The bar can now lined up in the hole to be bored and the lathe clamping stud tightened. Depth of cut within the bore is adjusted by the cross slide feed screw.
Several clamping bolts have been made up. These are from silver steel and match the threads in the Myford tee-slot nuts and also the closer disk for the crosslide anchor plate. Apart from normal duty retaining the various tool holders and the Verdict gauge stand, they can be used, in conjunction with suitable drilled and slotted plates to secure work in course of milling, fly-cutting and so on.
A SIMPLE DIVIDING ATTACHMENT
A lathe attachment which is very simple to construct is a dividing attachment to engage in the bull ring. This is in constant use, in preparation of bolts, nuts, in setting out holes on cylinder covers and operations such as filing carried out in the lathe. The attachment comprises a plate bracket which, attached to the headstock casing using a bolt through the existing hole, supports a spring-loaded plunger engaging in the bullwheel of the backgear assembly. Using the attachment the headstock spindle can be locked in any one of 60 positions and of course multiples of those positions, providing divisions of 60, 30, 20, 15, 10, 6, 4, 3, and 2.
A simple modification, cutting the detent tongue to match the profile of the bull ring teeth increases the divisions that can be achieved. In this role the detent tongue is rotated through 90 degrees to pick up a further 60 positions.
Over the years, whenever offcuts of steel have come to hand, these have been checked out for size, marked accordingly and set aside for use as gauge pieces. One straightforward use for such pieces is in setting the saddle from a saddle stop.
This comprises a length of 1/4 inch diameter bar sliding within two lugs. The lugs are secured to a backplate attached to the headstock of the lathe, using bolts into the tapped holes provided for gearbox fixing. Length of travel is limited using a bolt through a small collar sliding within the lugs. In use the tool is run to its intended eventual position relative to the headstock, a shoulder or thread end. the rod is brought up to contact the edge of the lathe carriage, the collar is slid to contact the rearmost lug, that furthest from the tailstock end, and locked into position. The projecting rod thus governs the travel of the saddle. To set a specific length of cut the cutting edge of the tool is brought to the end of the workpiece, one of the gauge pieces, or a drill shank matching the required length of cut is placed between the stop and the saddle and the bush secured against the backstop. Turning can then commence confident in the knowledge that the saddle stop will determine the correct length of cut. If auto feed is engaged the leadscrew nut should be disengaged a short distance from the stop and the cut completed manually. The little gadget is invaluable when turning to a shoulder and where putting a set length of thread onto a rod held in the chuck.
A FOUR-WAY TOOLPOST
A four-way toolpost was constructed completely from scrap. A piece of round mild steel was turned to replicate the Myford closer disk for the topslide anchor plate and provide the fixing to the lathe carriage. Three blanks of mild steel were cut to size and squared-up in the four jaw chuck to form the main body of the attachment. The height of the lower block of the three is sized, relative to the centre height of the lathe, to permit either square shank tools or tools set in the Myford tool boat to be used. The three pieces of the body were welded together ( socket headed cap screws could have been used ) and the whole assembly cleaned-up. The upper plate was drilled and tapped for the tool retaining bolts. The Myford closer disk and the circular base of the toolpost were joined using 1 / 4 inch B.S.F. Cap screws and the central hole tapped for the clamping bolt. The clamping bolt is a length of 3 / 8 inch silver steel threaded each end with a B.S.F thread, the bottom engaging in the base plate, the top terminating in a a length of 1 1 / 4 inch diameter mild steel into which the spindle for the ball handle is inserted. A simple detent comprising an externally threaded bush with a plunger actuated by a spring was fabricated, again from offcuts of mild steel rod ready for insertion into a 1 / 4 inch reamed hole in the body. With the body, the base and the clamping screw completed the blind holes in the base were drilled by spotting through the 1/4 inch hole in the body with the toolholder locked in the four required positions. The body was then removed from the base and the spotted holes were completed in the pillar drill with the stop set to avoid breaking-through the plate.
A KNURLING TOOL
A knurling tool was fabricated to details published in Ian Bradleys book 'The amateurs workshop'. This is a tool described as a straddle turning tool, comprising a body supporting a yoke retaining two arms, each fitted with a commercially obtainable knurling wheel. The advantage of straddle knurling is that, provided the wheels are adjusted to be diametrically opposite each other when forming the knurl, the forces are contained within the tool and not transmitted to the headstock bearings.
A TAPPING GUIDE
There are a large number of tapped holes in the parts of the average locomotive, many of which are of the smaller sizes, 7 BA, 8 BA and beyond. To ensure the accuracy of the threads and avoid tap breakage, time spent in making a small tapping tool will be amply rewarded. Any flat piece of plate can be used for the baseplate, careful filing will provide the necessary accuracy. The head can be arranged to slide on pillar, a stock length of silver steel of about 1 inch diameter, secured into the base with retaining fluid. The head, a block of mild steel has two holes which have been drilled and bored in the same set-up on the lathe cross slide. One hole is a nice slide fit on the pillar, a slot enables this to be locked into position by two cap screws. A length of 1 / 2inch diameter bar is set into the other hole, one end prepared to accept whatever chuck is available, the other a knurled head. In service it is helpful if the head is cross-drilled for a tommy-bar. It is advisable that if a thread is used for mounting the chuck it is screwcut on the lathe to ensure concentricity.
A UNIVERSAL CHUCK MOUNT
A chuck mount is a useful attachment which permits work to be set up away from the lathe. Some second operations can also be carried out on, for example, the milling or drilling machine. Either the four jaw, or the three jaw chuck can be accomodated and mounted on ancilliary equipment such as the vertical table or a rotary table. The basis of the attachment is a standard accessory, a Number 2 Morse taper spindle. this is mounted in the three jaw and the tapered spindle parted off just behind the register. for the chuck. The back of this piece should be lightly relieved to ensure that it beds down fully on the baseplate at the time of assembly. These operations are easy as the material used is extremely free cutting. ( The tapered spindle can be set aside and used for another purpose such as a screw support for use when working on slender discs in either type of chuck ) The threaded portion is then drilled and tapped for two 1/4 inch cap screws which will be used to secure it to a base plate.
The base plate can be from any piece of plate of reasonable thickness. Ideally it should be of sufficient size to permit of picking up the tee slots in the equipment to which it will be attached, yet small enough to be used on the available surface plate whilst leaving room for the base of a height gauge to be moved about whilst marking out. The plate should be squared-up and turned, or fly cut, to uniform thickness throughout before drilling for the tee bolts and the two cap screws for fixing the nose piece. The holes for the cap screws should be counterbored and the attachment can then be assembled.
Whilst lathe chucks can be mounted on the finished attachment for a variety of operations, heavy milling cuts should be avoided as they could loosen the chuck on the mounting with dire results! It is also essential to remember when using the mount to cut in such a direction that the tool attempts to ' climb '
A SIMPLE 'WOBBLER'
This device is based upon an article in MODEL ENGINEER Vol 159, No 3811 October 1987 by Mr Cruikshank. The wobbler comprises a length of 2mm diameter rod with pointed ends, floating in a rubber bearing (cut from a car tyre tread), projecting through a 1 / 8 inch hole at centre height within a short length of mild steel bar. Any small eccentricity at the pointed end in contact with the part to be set is reflected by a greater movement at the free end. The ratio of the lengths of the two arms of the rod about the bush determine the amount of movement of the indicator end and a ratio of 6 : 1 seems to be about right for most purposes. In use the pointed end of the rod is located into a centre pop mark on the piece to be set and the chuck jaws are adjusted until the movement of the free end is minimised. When this stage is reached the piece is properly centred.
To view illustrations of these inexpensive tools Click here workshoptoolsetc.htm
Last Updated 25th Feb 2011
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