Model Engineer 12.08.2022_downmagaz.net

THE ORIGINAL MAGAZINE FOR MODEL ENGINEERS Vol. 229 No. 4697 • 12 - 25 August 2022 Join our online community www.model-engineer.co.uk COVER FEATURE IMLEC Efficiency drive at Guildford Grasshopper A half beam engine for beginners PEA RALLY We report from Fareham



272 Published by Mortons Media Group Ltd, 288 Media Centre, Morton Way, Horncastle, Lincs LN9 6JR Vol.229 No.4697 12 -25 August 2022 Tel: 01507 529589 Fax: 01507 371066 © 2022 Mortons Media ISSN 0026-7325 SUBSCRIBE & SAVE UP TO 52% 268 THE LITTLE DEMON SUPERCHARGED V8 www.model-engineer.co.uk See page 246 for details. Mick Knights builds a V8 internal EDITORIAL 248 SMOKE RINGS combustion engine. Editor: Martin R. Evans Deputy editor: Diane Carney News, views and comment on the 272 REWINDING A Designer: Yvette Green world of model engineering. TWO SPEED MOTOR Club News: Geoff Theasby Illustrator: Grahame Chambers 249 IMLEC 2022 Graham Astbury converts a single speed Retouching manager: Brian Vickers induction motor to a two speed motor. Publisher: Steve O’Hara Dave Tompkins reports on the first two days of the International Model Locomotive 276 THE STATIONARY CUSTOMER SERVICES Efficiency Competition at Guildford. STEAM ENGINE General Queries and Back Issues 01507 529529 Monday-Friday: 8.30am-5pm 254 GRASSHOPPER Ron Fitzgerald tells the story of the BEAM ENGINE development of the stationary steam engine. Answerphone 24hr [email protected] Martin Gearing describes a half 282 ROGER’S RAMBLINGS www.classicmagazines.co.uk beam engine suitable for a beginner. ON MEASUREMENT ADVERTISING 257 5 INCH GAUGE TIMBER Roger Curtis sings the praises of Group advertising manager: Sue Keily FRAME DRIVER’S TRUCK perches, rods and chains Advertising: Angela Price David Allen puts 3D CAD and laser cutting 284 BRITANNIA CLASS 7 [email protected] Tel: 01507 529537 to work to construct his riding trolley. LOCOMOTIVE IN 5 INCH GAUGE Ad production: Andy Tompkins 260 BALLAARAT Norm Norton resumes his rebuild of a By post: Model Engineer advertising, Mortons Media Modelworks 5 inch gauge Britannia locomotive. Luker builds a simple but authentic narrow Group, Media Centre, Morton Way, gauge 0-4-0 Australian locomotive. 288 THE 2022 SWEET PEA RALLY Horncastle, Lincs LN9 6JR 265 CLUB DIARY John Arrowsmith discovers a plethora PUBLISHING of Sweet Peas in Fareham. Sales and distribution manager: Carl Smith Future events. 292 CLUB NEWS Marketing manager: Charlotte Park 266 ENGINEERING’S Commercial director: Nigel Hole LOCAL HEROES Geoff Theasby compiles the latest from Publishing director: Dan Savage model engineering clubs around the world. Roger Backhouse tells the story of Dorothée SUBSCRIPTION Pullinger, a pioneering lady engineer. 295 EPILOGUE Full subscription rates (but see page 246 for offer): Mikhail Chernyshev offers an appreciation (12 months, 26 issues, inc post and packing) – of the steam locomotive. UK £128.70. Export rates are also available, UK subscriptions are zero-rated for the purposes of Value Added Tax. Enquiries: [email protected] PRINT AND DISTRIBUTIONS Printed by: William Gibbons & Son, Wolverhampton Distribution by: Marketforce (UK) Ltd, 3rd Floor, 161 Marsh Wall, London, E14 9AP 0203 787 9001 EDITORIAL CONTRIBUTION Accepted photographs and articles will be paid for upon publication. Items we cannot use will be returned if accompanied by a stamped addressed envelope and recorded delivery must clearly state so and enclose sufficient postage. In common with practice on other periodicals, all material is sent or returned at the contributor’s own risk and neither Model Engineer, the editor, the staff nor Mortons Media Ltd can be held responsible for loss or damage, howsoever caused. The opinions expressed in Model Engineer are not necessarily those of the editor or staff. This periodical must not, without the written consent of the publishers first being given, be lent, sold, hired out or otherwise disposed of in a mutilated condition or in other unauthorised cover by way of trade or annexed to or as part of any publication or advertising, literary or pictorial manner whatsoever. http://www.facebook.com/modelengineersworkshop THE ORIGINAL MAGAZINE FOR MODEL ENGINEERS ON THE COVER... http://twitter.com/ modelengineers Vol. 229 No. 4697 • 12 - 25 August 2022 Billy Stock sets out on his run at Guildford to win IMLEC for the second year running www.model-engineer.co.uk Join our online community www.model-engineer.co.uk (photo: Andrew Neish). COVER FEATURE This issue was published on August 12, 2022. IMLEC The next will be on sale on August 26, 2022. Efficiency drive at Guildford Grasshopper A half beam engine for beginners PEA RALLY We report from Fareham 243

SMOOTH, QUIET, HIGH PERFORMANCE VARIABLE SPEED CONTROL FOR LATHES AND MILLING MACHINES Managing director George Newton, originally from the British Steel industry where he worked with 20,000 HP rolling mill drives is also a skilled machinist and uses his own lathes to design and refine speed controllers especially for the Myford ML7 & Super 7 For the Myford ML7, George and his team produce the AV400, a complete ‘Plug & go’ solution including a new variable speed motor that meets the original Myford motor specification, has the correct 5/8ths shaft diameter and is a direct fit The ‘AV’ range is extended with the AV550 & AV750 for the Super 7 lathe giving a choice of 3/4HP & 1HP motor power Full Torque is available from motor speed 90 - 1,750 RPM. Advanced Vector control for maximum machining performance. Prewired and programmed ready to go. The AV400/550/750 speed controllers have an impressive 10 year warranty for the inverter and 3 years for the motor (Terms and conditions apply). Over 5,000 units supplied to Myford owners. Speed control solutions also available for other lathes including Boxford, Southbend, Colchester, Raglan etc call or email for details. Technical support available by telephone and email 7 days a week. Newton Tesla (Electric Drives) Ltd. Warrington Business Park, Long Lane, Warrington, Cheshire WA2 8TX, Tel: 01925 444773 Email: [email protected] Visit https://www.newton-tesla.com for more information. Follow us on Facebook: www.facebook.com/NewtonTeslaLtd Si (Systèm international d’unités) Newton, unit of mechanical force, Tesla, unit of magnetic field strength



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MARTIN ESSMEE Rally The Martin Evans (MkI) trophy is handed to Billy Stock by your editor, EVANS Martin Evans (MkII). (Photo: Andrew Neish) Editor The East Somerset Society DIANE of Model & Experimental Billy Does It Again! CARNEY Assistant Engineers (ESSMEE) will be This year’s IMLEC (International Model Locomotive Editor holding a Model Engineers’ Efficiency Competition) took place at the Guildford MES YVETTE Open Weekend at the track at Stoke Park on the weekend of July 22-24. Our GREEN Bath & West Showground reporter for the event is Guildford’s Dave Tompkins, the first Designer near Shepton Mallet on part of whose report may be found on the next page. The September 24/25 this rest will follow next time. Martin Evans can be year. Visitors are invited contacted on the mobile to share our passion for I had the pleasure of attending on the Sunday and enjoying number or email below our hobby in congenial the glorious weather. The track was rather tricky, for various and would be delighted to surroundings on our ½ reasons, and provided a real test of skill for the competitors. receive your contributions, mile 5 and 7¼ inch gauge The winner, by a clear margin, with an efficiency of 1.8%, was in the form of items of Billy Stock from Urmston, driving his 5 inch gauge ‘Britannia’ correspondence, comment track, shunting yards for William Wordsworth. Billy also won last year’s IMLEC at or articles. the smaller gauge, and the Maidstone, driving the same locomotive. Congratulations, 07710-192953 extensive tarmac network Billy, on your double win! [email protected] for steam road vehicles. 248 This event will be for booked Second place was taken by Steve Eaton, driving his 5 inch visitors only, with no public gauge German DB 2-8-0 and in third place was Ben Pavier with running. his 5 inch gauge LNER Q5. The 3½ inch gauge class was won by Les Pritchard, driving his LBSC ‘Mona’ locomotive. This There is ample space for locomotive, which is almost half a century old, has previously campers and caravaners who been a frequent competitor in LittleLEC. want to stay for the whole event, with all essential A full list of results will be included in the second part of facilities including electricity Dave’s report. hook-up. Refreshments will be available throughout the day, and a barbecue on the Saturday evening. For further details and booking forms, contact Michael Malleson on 01747 860719 or openweekend@ essmee.org.uk Oddity I have had an avalanche of replies to my challenge to identify the latest ‘oddity’! It looked like it may be some kind of tool but, in fact, it is a padlock, of the type found on carved camphorwood chests imported from the Far East. I feel slightly foolish as I should have recognised this device, being in possession of one of these chests. To be fair to myself, though, mine is missing its padlock. I have had so many replies to this query that it is not possible to list you all. My apologies, gentlemen – fame will have to wait! Another Oddity but why does it only read up to 60 degrees on the port side but Something completely all the way up to 180 degrees different… And something else for starboard? This asymmetry to ponder while you bask in the must surely provide some kind sun. I am rather intrigued by of clue. this instrument. I suppose it is either nautical or aeronautical Model Engineer 12 August 2022

David Tompkins reports from this year’s International Miniature Locomotive Efficiency Competition at the Guildford society’s track in Stoke Park. Nick Jackson - 5 inch gauge ‘Speedy’. IMLEC 2022 PART1 IMLEC came to the Guildford cleaned its 1450 feet of raised water level that he said was >> club this year and with 25 track to give the competitors often low! Moving off with a entries was held over the the best rail surface for their load of six the locomotive was weekend of July 22-24, just runs and we even closed the soon slipping and only just missing the heat wave. This track to our club members getting round at a slow pace was a relief to most of us at so the track could be kept and that with the safety valves our club and in fact for a while squeaky clean for the event. lifting. This was followed by it looked like it might even rain. the train coming to a stop on It did however stay dry and it It was rather disappointing a gradient. He managed to get was ideal weather for playing that the track soon became on the move again but had trains. In the previous two greasy again and on Friday to retire after 28 minutes, not weeks the club had completely just about every locomotive making it to the finishing line. was slipping with most having Tom Parham - 5 inch gauge Peppercorn A1 Tornado. to set back and offload some Tom Parham was run passengers in order to get at number 2 and afterwards least the first lap complete and when asked how his run went give the locomotive enough he said “Fiddlesticks”. This momentum to carry on. locomotive was really lovely - a 5 inch gauge Tornado built by Friday Edgar Playfoot. Tom said it runs regularly at his Maidstone The first run, which was at club, which was surprising midday was by Bracknell club given its immaculate condition member Nick Jackson driving - it looked almost new. Driven a 5 inch gauge ‘Speedy’. by Tom just a few times before He said he had bought the IMLEC, the locomotive got off locomotive which had been to a slippery slow start - a sign in his club for years, having of things to come for the rest been built in 1979. He also of the day. During his run Tom mentioned that he was really had a phone call from DHL a 7¼ inch gauge man but felt saying they had a parcel for IMLEC could be fun to enter, at him - can they deliver? Well least for the first time, and he yes, they could have come to said his spirits were high. The IMLEC with it! The locomotive same could not be said for the www.model-engineer.co.uk 249

continued on a steady pace runs well at his home track at see the LBSC influences and the locomotive set back and finished top of the table at in the design, particularly the end of play for the day. Bracknell and I have no reason to some level track. Now time with the Baker valve gear. Next was Dave Shepheard to doubt it - the track seemed was lost as the dynamometer Finished in maroon and with with a Polly kit he had put to be getting greasier. car derailed again - perhaps it together. It ran quite well at Next up was the first 3½ nameplates Mustang and Maidstone last year but this doesn’t like going backwards. inch gauge locomotive, driven with its eight driving wheels year - oh dear! From the start it looked an impressive 3½ Once on the run, and with a by Les Pritchard, a ‘Mona’ to inch gauge locomotive. It had it was slipping badly, setting lighter load to cope with low the LBSC design. With a load been recently bought and backwards, still slipping and of just three, which included I’m told it had five test runs, track adhesion, Matt had the grandson Archie, Les had three of which were ‘brilliant’. locomotive running fine, well then being stopped as the But again, it was another notched up. Injectors were a steady run and, like a lot track had not been set and he of IMLEC drivers, Les was run plagued by slipping and working well and there was not convinced that he put too was wrong routed to go back much coal on. It’s the first needed just a light load to get much need to use the shovel locomotive to compete at into the steaming bay. Let’s round the track. but a light load meant a low both LittleLEC, which it has Next up was the Guildford figure of efficiency. start again! At this point it was won, and IMLEC itself so that can go in the record books! It club entry, a 5 inch gauge B1 to So now it was the turn of decided to move the start line the last run of the day, a Nigel a few yards further on so that was built by Alan Hall ‘years the Martin Evans design driven Gresley design by Martin one of the passenger trolleys wasn’t actually on a down ago‘ and still runs well, only by Matt Butler. Its construction Evans. This was a heavy gradient at the start. Still the stopping once on the run and was started by Paul locomotive with eight driving that was for a dynamometer Wheatcroft who unfortunately wheels were going round at a car derailment. had a stroke and couldn’t wheels and was expecting good pace but unfortunately finish the locomotive, which he the locomotive was hardly The next locomotive, driven had taken to a well-advanced to do well but again poor moving. Offloading passengers by Danny Hayward, was quite chassis. The Tompkins family helped to get the wheels to an interesting freelance design took on the project with Paul adhesion due to the condition by a chap by the name R. C. of the track required a really grip the track but only one making the boiler. Again, light load for what is a lap was managed before a Marshall and built in 1944. It powerful design of locomotive. retirement. Everyone in Dave’s was freelance but you could slipping was a problem. Driver John Williams was soon Passengers were offloaded having to offload passengers party said the locomotive and set back. And set back he did, way, way back until he David Shepheard - 5 inch gauge Polly 5. Les Pritchard – 3½ inch gauge ‘Mona’. Danny Hayward - 3½ inch gauge 2-8-2 Mustang. MattButler - 5 inch gauge LNER B1. 250 Model Engineer 12 August 2022

IMLEC John Williams - 5 inch gauge Gresley 2-8-0. Glen Davies - 5 inch gauge ‘Simplex’ Janine. Robert Hurst - 5 inch gauge S&D 7F. Simon Batten - 5 inch gauge 0-6-0ST Jack. came to a falling gradient and by club members rather than Glen Davies was the first to run with his ‘Simplex’. he set off at top speed until the heavier duty trolleys used It was his first run at an IMLEC with the first he came to the rising gradient for public days - a smart move - and again more slipping. but it has to be considered locomotive he has made and was a joy to watch. John continued his run with that the heavier trolleys do The locomotive spent most of the time flying around spasmodic bouts of slipping require more work done by and a light load. the draw bar. The locomotive the track with its load of five in total. ran entirely on the axle pump That was the end of the managing to overfill the boiler Martin Evans design known as We now had the turn of >> runs for Friday and the start of once. Back in the steaming the S&D 7F. It ran very well at a smaller locomotive and a some head scratching about bay it was noticed there were last year’s IMLEC at Maidstone rare one at that - a design by what to do about the track with quite a few extra holes in the and Robert’s dad Ivan was Don Young known as ‘Jack‘. all the slipping. ash pan. The late Don Young was an hoping for better things this excellent designer so it was Saturday Seeing that the first no surprise that this particular locomotive of the day had a time round. The run had a bit model, driven by Simon Batten, Saturday was a much earlier good run was some relief to the had a good run. At the starting start, at 9.30am. host club as on the previous of a slow start with the slide line Simon wasn’t going to day a lot of runs were affected move off until he had full Glen Davies was the first to by the greasy track. A little valves lifting to allow water to pressure with the safety valves run with his ‘Simplex’. It was track cleaning had been done lifting. That was a wise move his first run at an IMLEC with but it was thought it would escape up the chimney. The as it got the run off to a good the first locomotive he has be a bit unfair to the ones start and with a light load made and was a joy to watch. who had run on the Friday if load was seven in total and the the locomotive was happily The locomotive spent most of we completely degreased the going round the track. I was the time flying around the track entire circuit and, besides, it train came to a stop after one with its load of five in total. would have taken too long, Half way into the run there was delaying the event. and a half laps. The train set a loss of about five minutes back down the track offloading caused by a passenger trolley It was Robert Hurst’s turn one passenger - a quick blow derailment. Glen opted to have next, with a fine example of the the lighter trolleys used only up and then the locomotive got on its way to have a very good run. www.model-engineer.co.uk 251

wondering if there was any the needle started to go south It seemed that f teen minutes the driver weight added as on every lap falling to about 20psi. Time Simon was taking on another was lost having a blow up just sat back and watched his well notched up bottle of water to fill his saddle before setting well back. For tank. For one of the smaller about the next ten minutes locomotive going round as if it was its own master. locomotives in the competition the locomotive was trying it performed very well. to get up the curved incline hook lifted the little truck off fire grate design. It had hooks before setting further back and the track several times causing and pins to hold it in place for So we now came to a ‘Star dropping a passenger. A rather delays to a little locomotive shovelling the coal and, on Turn‘, if I may call it that, a disappointing end to a rather that was running well. I one particular shovelling, the Nigel Gresley A4 built and run good start. understand there are plans to driver managed to accidentally by Roger Holland who, as an make a bigger stronger wagon hook the grate sideways with apprentice, was familiar with Lilla, a Hunslet 3½ inch for it to enter a future IMLEC. the shovel, dropping the coal the full-size article. I have to gauge locomotive, entered into the ash pan. Ah well, these say that if you can make one of the ring for the next round. The next locomotive was things happen but best not these things you are not doing The driver was George Winsall something interesting, as it when running at IMLEC. too badly! The programme - and what would IMLEC be had actually been driven by notes said the driver can be without the Winsall family? Nigel Gresley, the real flesh And now another interesting a bit of a problem but not the The locomotive means a lot and blood full size one, in runner, a 3½ inch gauge locomotive. With a load of nine to them as it was built by 1937. That makes the model – Southern Q1. I do believe that in total, the run got off to a George’s grandfather Fred but Spitfire, a 5 inch gauge Gresley no locomotive can be called smooth start. It seemed that got sold off. Recently it came A1 driven by Andy Nash, quite ugly, particularly if they’re for the first fifteen minutes back on offer to his family and the oldest one at this year’s Southern - ‘graceful’ seems a the driver just sat back and it was quickly snapped up. It IMLEC, or any other IMLEC for better word to describe them. watched his well notched up can’t be said that the run was that matter. As for the run – If anyone fancies building one locomotive going round as if trouble free. Quite a small and well, it wasn’t exactly trouble the designer and its driver Nick it was its own master. That lightweight truck was used free. The problem was with the Feast had the plans published might have been overdoing to act as a tender. The heavy things as a few minutes later dynamometer with its curling Roger Holland - 5 inch gauge Gresley A4 Wild Swan. George Winsall - 3½ inch gauge Hunslet Lilla. Andy Nash - 3½ inch gauge Gresley A1 Spitfire. Nick Feast - 3½ inch gauge Southern Q1. 252 Model Engineer 12 August 2022

IMLEC Tom Taylor - 3½ inch gauge Derby 4F. Andy Healey - 5 inch gauge ‘Britannia’ Apollo. Alan Crossfield - 5 inch gauge Ex LMS ‘Patriot’. Ben Pavier - 5 inch gauge LNER Q5. in the Model Engineer in 2009. had much driving experience And so it was now the turn of IMLECs and who knows how The run itself, and it was but he seemed a little what I can only describe as a to play them. I have to say quite a short one, did have a apprehensive while raising first class model of the highest his observer made my day. few problems. Several stops steam. Worse was to come - I standard - a locomotive built He thought it was my ‘Netta’! with setting backs - wait for started giving him advice! I by Alan Crossfield - the LMS The run was nothing other blow ups - have another go at suspect the thought he took class of locomotive known than was expected, superb getting up the incline with a away from the experience was as the ‘Patriots’. It’s won this and trouble free with his very light load and probably ‘right, next time I enter it will be cup, that cup, every cup. Just mates as his load. Except, thinking to enter another IMLEC a lot better’. for a laugh I asked Alan if the that is, for the last lap when somewhere else in future with tender had the exact number Ben took a gamble with a low a more level track. But it was a So it’s now late afternoon of rivets as its full-size sister. fire - pressure dropping and great looking engine. with just three more Alan looked puzzled and just the water going down in its locomotives to run, the first said ‘well, yes‘. The run itself, gauge. But the locomotive While Nick Feast was being a 5 inch gauge ‘Britannia’, well forget it. Matters were not managed one last lap and its having his run I noticed a very well known now as the work helped by a water pipe being performance got it top of the well cleaned up locomotive of Karl Midgley, who died wrongly connected tender to leader board. preparing for the next run. suddenly on the morning locomotive. Slipping on an oily It was Tom Taylor’s 3½ inch of his scheduled run at the track, setting back a few times We are not youngsters at gauge Derby 4F. I think this Maidstone IMLEC last year. until the locomotive found its the Guildford club so we went is a brilliant design that I Driven by his uncle Andy Healey feet better - it wasn’t the best home now to put our feet up would recommend to anyone, with the locomotive painted of runs. But still, a lot of people and look forward to the final particularly those with a in blue, because that’s what looking on were probably day tomorrow. modest workshop and not Karl wanted, the run was fast thinking how long did it take much experience in model without much fuss really. I can to make that one? and gosh! I All photographs were taken engineering. And don’t let only say it was a very good wish I had one. by Andrew Neish. anyone say the Joy valve run and one that Karl would gear isn’t that good because approve of, even if he thought So it’s time for the final ●To be continued. I’ve seen too many that run he could have done just a little run of the day by Ben Pavier, well. I’m not sure if Tom has bit better himself! a seasoned campaigner at www.model-engineer.co.uk 253

Martin Grasshopper Gearing Beam Engine presents an ideal beginner’s project with great potential for the more experienced builder. Introduction The version of my engine making the adjustments that described here is primarily will result. I created and made a larger intended as a training version of this engine some project for beginners - to Upon completion the 20 years ago as a training give experience - and constructor will experience the course final test piece and assumes access to basic pleasure of making something must confess to having only facilities. I have chosen that has visually one of the recently discovered that its metric dimensions because most interesting motions and true description is not that of I refuse to pay the premium enjoy experiencing the pride of a ‘Grasshopper Beam Engine’ now demanded for Imperial having created a conversation (which perfectly describes its tools and fixings and think a piece by their own application action) by which I've always beginner starting out would and handiwork, enough I known the design but should appreciate this. People who hope to want to make more. be referred to as a ‘Half Beam still have an aversion to the It is not based on any known Engine’ invented in about metric system can change prototype and is powered from 1795 and built commercially everything to Imperial by a readily available if slightly from 1801 by Oliver Evans, an using a calculator, dividing unconventional source! American engineer (see Model everything by 25.4, going to Engineer vol. 187 No. 4156 the nearest size available and The materials chosen p.324 for full details). are intentionally a little unconventional and a mixture 254 Model Engineer 12 August 2022

GRASSHOPPER of sizes but had to be easily material supplier a ‘One Stop because of the choice of Aimed at and written available stock sizes at the Shop’, which makes the whole valve gear, which I’ve taken unashamedly for a beginner, lowest cost. Certain parts may fag of getting all the materials from the type originally used I felt that it would be more be machined with alternative required very much easier - and on Mississippi stern wheel attractive if there was a readily options (given in the text) to with a discount. paddle steamers, it is able available form of motive force. enhance the appearance but to run reliably very slowly on The engine as designed will adding time to the engine’s When running, because all low pressure air in the form run on the vacuum provided construction. It has also been the motion work is visible, of a vacuum from a domestic by a domestic cleaner (or - if possible to negotiate with a the design makes for a very vacuum cleaner. a compressor and suitable interesting display and, regulator are available – low pressure compressed air). This Table 1. Materials required No Off Material choice means there’s no need 1 10mm x 12 inch square 5038 Ali Plate to produce a boiler with its Part # Description 2 10mm 5038 Ali Plate – From 1 attendant cost, annual testing 1 Base 2 10mm 5038 Ali Plate – From 1 and requirement for being 2 Main Bearing Carrier 1 10mm 5038 Ali Plate – From 1 operated in a well-ventilated 3 Cam Follower Bearing 1 10 x 30mm Mild Steel/Brass space. 4 End Link Pivot Block 2 Ø19mm/¾ inch LG2 5 Cam Follower Key 1 Ø8mm x 13 inch Silver Steel Getting an engine of this size 6 Main Bearing Bush 1 Ø8mm Silver Steel – From 7 to run on the low pressure that 7 Cam Follower Shaft - Short 1 10mm 5038 Ali Plate – From 1 a vacuum cleaner provides 8 Cam Follower Shaft - Long 1 Ø6mm x 13 inch Silver Steel has demanded a large cylinder 9 Cam Follower Frame 1 Ø8mm Silver Steel – From 7 diameter and this has been 10 Crank Pin 1 Ø60mm x ½ inch EN1A limited by the maximum 11 Crank Shaft 1 Ø50mm x 1 inch Cast Iron diameter the average beginner 12 Crank Web 1 Ø120mm x 1¼ inch Cast Iron is able to machine. This 13 Valve Cam 1 Ø40mm x 2 inch EN1A however produces a major 14 Flywheel 1 3 x 3 x 3 inch 6082 Ali benefit in that the tolerances 15 Flywheel Collet 1 3 x 3 x 1 inch 6082 Ali required to guarantee a running 16 Cylinder Block 1 Ø6mm Silver Steel – From 6 engine can be greater than 17 Cylinder Cover 1 Ø70mm x 1 inch Acetal for an engine that requires a 18 Piston Rod 1 16 x 16mm / ⅝ x ⅝ x 12 inch 6082 Ali magnifying glass to see! 19 Piston 1 10mm 5038 Ali Plate – From 1 20 Piston Rod Clevis 1 8mm x 6 inch square 5038 Ali Plate Whilst the buzzwords for 21 Link Anchor Mount 1 30 x 6mm / 1¼ x ¼ x 12 inch 6082 Ali Flat the moment are CNC, laser 22 Link Anchor 2 8mm 5038 Ali Plate – From 22 cutting and 3D printing the 23 Beam 1 8mm 5038 Ali Plate – From 22 tools required for this project 24 Control Link 1 12 x 12mm / ½ x ½ x 6 inch 6082 Ali are conventional and, more 25 End Link 1 Ø4mm x 13 inch Silver Steel importantly, readily available. 26 Connecting Rod 1 Ø4mm Silver Steel – From 27 To complete this project you 27 End Link/Pivot Block Pin 1 Ø4mm Silver Steel - From 27 will need basic hand tools 28 End Link/Beam Pin 2 Ø8mm Silver Steel – From 7 including a means of marking 29 Control Link/Beam Pin 1 Ø4mm Silver Steel - From 27 out. A 150mm digital caliper 30 Control Link/Anchor Pin 1 Ø4mm Silver Steel - From 27 would be essential and nice 31 Connecting Rod/Beam Pin 1 Ø6mm Silver Steel – From 10 to have or be able to borrow 32 Piston Clevis/Beam Pin 1 16 x 16mm / ⅝ x ⅝ inch 6082 Ali - From 20 would be: 33 Valve Gear Cross Shaft 1 Ø6mm Silver Steel - From 10 34 Valve Lever – Cam 1 16 x 16mm / ⅝ x ⅝ inch 6082 Ali - From 20 * A 0 – 25mm (and 25 – 50mm >> 35 Valve Lever Drive Pin 1 2 x 2 x 3 inch 6082 Ali if possible!) micrometer. 36 Valve Lever – Spool 1 Ø30mm x 4 inch Acetal 37 Valve Block 1 10 x 3mm Mild Steel Flat * Optical centre punch. 38 Valve Spool 2 Ø4mm Silver Steel – From 27 * Set of telescope gauges. 39 Valve Link 1 2 x 2 x 2 inch 6082 Ali * Lathe of at least 90mm (3½ 40 Valve Spool Link Pins 1 Ø40mm x 3½ inch Acetal 41 Control Valve Body 1 2 x 2 x ½ inch 6082 Ali inch) swing, with a basic 42 Control Valve Spool 1 Ø6mm x 6 inch Brass range of HS tooling. 43 Control Valve Spool Retainer 2 Ø3mm Brass - From 44 * Small vertical mill with (if 44 Control Valve Handle 1 Ø50mm x 2 inch Nylon 6/PVC possible) X and Y axis DRO, 45 Control Valve Stop Pins 1 2 x 2 x ½ inch 6082 Ali and a bed stop on the X axis, 46 Vacuum Hose Adapter 4 Ø25mm x 12mm Nylon 6/PVC with clamp kit. 47 Vacuum Hose Adapter Retainer * Small boring head. 48 Feet * H/V rotary table, or rotary table and horizontal indexing device. * Drilling machine Ø13mm preferred (Ø10mm capacity min.). * Drills - Ø1 to 6mm in 0.1mm steps and Ø6 to Ø13mm in 0.5mm steps. www.model-engineer.co.uk 255

Whilst the buzzwords Table 2. Sundry items No Off Material for the moment are 4 M5 x 20 SHCS CNC, laser cutting Description 4 M5 x 15 SHCS Link Anchor Mount 4 M4 x 20 SHCS and 3D printing Cylinder Cover 4 M4 x 15 SHCS the tools required Valve Levers 8 M5 x 12 CS Hd for this project are Adaptor Retainer 8 M4 x 16 CS Hd conventional and, more Cylinder (Bottom) & Feet 2 M4 x 13 CS Hd importantly, readily Main & Cam Bearings 4 M4 x 15 Round or Button Hd available. To complete End Link Pivot Block 4 M5 x 10 Grubscrew this project you will Control Valve Retainer 1 M4 x 10 Grubscrew need basic hand tools Crank & Cam Frame 1 M3 x 10 Grubscrew including a means of Valve Cam 1 M5 Nylock Nut Link Pivot Block 1 M5 Plain Nut marking out. Piston Rod Securing Nut 2 Ø5mm Plain Washer Piston Rod Securing Nut 4 M4 Plain Nut Piston Rod Securing Plain Washer 4 Ø4mm Plain Washer Valve Block Securing Nut 4 Ø4mm x 95mm Studding Valve Block Securing Washer 1 BS211 ‘O’ Ring (1.074 x 0.796 x 0.139 inch) Control & Engine Valve Blocks 14 3.2mm x 0.69mm Spring ‘E’ Clips Control valve Spool Valve Rotation Damper ‘E’ Clips * Taps and dies, covering the understood, and were familiar which I recommend are always mentioned earlier has been range M3 to M6. with, and created most of the intended as a guide to the un- brought about because I've terms we use today! initiated, rather than an attempt tried to obtain the lowest Access to a band saw to convert those with sufficient cost from a single source. (jigsaw as a second choice) In an effort to assist experience to be able to tackle I'm sure there are few that would be a great help but an beginners who are unfamiliar these problems in their own find pleasure in going to 60 alternative method for cutting with the process of working way’. That having been said, the different suppliers for 60 the thicker plate work is given. to information contained in design was always primarily different items, which would two dimensional drawings, I intended to provide experience be extremely dispiriting for Although it would be admit to having taken a large and lends itself to being made a beginner starting out with possible to use a lathe only, degree of ‘poetic licence’ as a project with a youngster/s, little or no stock materials. the setting up would make when the drawings provided or - with additional details it extremely hard/tedious are compared to the accepted added - limited only by the Just a reminder, that before for anyone other than a industry standards. My maker’s desires! starting this project, where VERY dedicated/motivated defence is simply that the the use of a vertical milling constructor (and most drawings are merely a form I am able to provide a machine is required, the head/ likely destroy a beginner’s of communication, and I have suggested metal cutting list spindle and vice should be motivation). found that the ‘quirks’ used with the item description, checked for correct alignment have helped to make the material type and size (table to the machine table, You or the person helping information less daunting for 1) in addition to a list of the something often forgotten and you will also need to absolute beginners when I sundry items required (table a frequent source of errors, have knowledge of basic was teaching at the secondary 2). By way of trying to assist and the spindle at standstill mechanical engineering level and was found to be those starting out, Noggin when any measurement or terminology and be able usefully productive again End Metals – 01782-865428 adjustment is being made. to make sense of two- when instructing adults. If (ask for the Grasshopper dimensional drawings. I you know enough to comment Metal Pack) - have agreed to lTo be continued. have included pictures that then you definitely should make a metal pack available show all of the setups and be able to work it out, whilst to cover the bulk of materials NEXT TIME drawings - breaking down explaining your thinking to required, which will be found the more complicated parts the person you should be a great help if you are starting We make a start by cutting into ‘bite sized chunks’! By mentoring! out and don't have ‘preferred out the plate material. relating the text with the suppliers’ or dad’s workshop drawings and pictures most Please understand that, for (to raid when he's not about) of the unfamiliar terms will be the more experienced, I can do and gives value for money self-explanatory. The original no better than quote Edgar T. with the convenience of a ‘one founding engineers described Westbury’s words from page 89 stop shop’. The mix of metric what they were creating of the July 23 1942 edition of and Imperial dimensions as using simple words they Model Engineer: ‘The methods 256 Model Engineer 12 August 2022

DRIVING TRUCK 5 Inch Gauge TimberPART2 Frame Driver’s Truck Fig 11 Side frame (25 x 50mm planed hardwood Idigbo, 2 off). David Allen makes extensive use of 3D CAD and laser cutting to make a timber framed driving truck. Continued from p.223 M.E. 4696, 29 July 2022 Fig 12 Building the frames >> View of basic framing with buffer The frames were cut from an plates and footrest brackets mounted. African hardwood known as Idigbo and finished to 25 x Fig 13 50mm (figs 11 and 12). My local timber merchant was Headstock (25 x 50mm hardwood, 2 off). very co-operative, supplying all www.model-engineer.co.uk hardwood cut to size including a Birch plywood base board for a very reasonable £38. It’s best to get the timber cut slightly longer than the drawings and then square up in the mill with a very sharp cutter. Add an off-cut of the same material as packing so the cut does not lift the fibres of the wood at the edge/end of the cut. Note that Idigbo is slightly acidic to ferrous metals so best not to leave the shavings on the mill table overnight. The headstock for the wagon (fig 13) comprises a similar cross section piece of hardwood together with a steel buffer plate designed to hold a footrest bracket and coupler. These are bolted onto the end of the side frames and held in place by dowel nuts. A middle stretcher is used to keep everything square. Dowel nuts used throughout this project are M6 at 10mm diameter x 25mm long, and six 257

Fig 14 Headstock buffer plate (5mm S275JRP0 steel plate, 2 off). Note that Idigbo Fig 15 is slightly acidic to ferrous metals so Footrest bracket (20 x 20 x 3mm mild steel angle). best not to leave the shavings on the mill table overnight. are required. They are listed on the centreline of the dowel Fig 16 nut each time. This part is eBay and other online retailers. shown with two 8mm dowel Middle stretcher (25 x 50mm holes cut in the top. These planed hardwood Idigbo). The headstock buffer plate should be transferred from the is shown in fig 14. This was baseboard. and front of the buffer plates. and the frame but a word of designed to support the This space is for the front and caution here; it’s a good idea footrest bracket (fig 15) and With the basic framing now rear side planking. to try your dowel plugs in a a coupler to hitch it up to the cut to size and drilled it’s time piece of scrap material before to mount on the baseboard, 8mm dowels were used you drill the parts. I found locomotive. Two holes on first as a dry run to transfer between the base board the dowel pins and then finally 55mm centres are provided for to glue and clamp the whole assembly together. mounting a coupler. The two 18mm Birch ply was chosen 8mm diameter holes are to for the baseboard (fig 17) so the sides are thick enough locate 8mm eyebolts as safety to support dowel plugs to secure side planking. With features as there are no brakes the headstock and buffer plates in place there should in this design. be a 12.5mm gap between the leading edge of the baseboard The middle stretcher shown in fig 16 is from 25 x 50mm hardwood. The dowel nut bolt- hole can be seen at the end of the timber. It’s advisable to jig these holes and try it out on a piece of scrap to ensure the hole is perfectly in line with 258 Model Engineer 12 August 2022

Fig 17 DRIVING TRUCK Birch plywood base. that dowel plugs including 11 Please reserve/deliver my copy of Model Engineer wood drill bits vary between on a regular basis, starting with issue suppliers. Some gave a good, Side frames and mid stretcher dowelled and glued. Title First name snug fit that tapped in with a If you can’t always find a copy of this Surname light blow from a hammer, but magazine, help is at hand! Complete this Address I found that some suppliers’ form and hand in at your local store, they’ll dowels were loose. Use fluted arrange for a copy of Postcode dowels as these allow the air each issue to be reserved Telephone number and excess glue to be expelled for you. Some stores may when tapped into a blind hole. even be able to arrange for it to be delivered to Once you’re satisfied that a your home. Just ask! test piece is okay, transfer the holes from the baseboard to Subject to availability the frame and then dowel and glue the baseboard in position. Alternatively, you could use woodscrews. The position of the dowels was chosen so as not to clash with the axle W frames. The dowel holes shown for the side planking are for 6 x 30mm dowels, drilled 15mm deep. Photograph 11 shows the mid stretcher and one side all clamped up with bits of scrap material to protect the surface. Idigbo might be classed as a hardwood but can be easily damaged if care isn’t taken. Next time we will complete the driving truck by adding the side panels and seat. ●To be continued. If you don’t want to miss an issue... ✃ www.model-engineer.co.uk 259

Luker describes a simple but authentic small locomotive. Continued from p.149 M.E. 4695, 15 July 2022 Ballaarat PART15 A 5 Inch Gauge 0-4-0 Aussie Locomotive Safety valve assembly The valve spindle is and threading operations. machined from solid stainless Flip the safety valve body The prototype safety valve bar (fig 29). Starting with the around and screw it into a configuration was closely thinner part of the spindle, this tapped mandrel clamped in followed in the model (photo is machined in the three-jaw the three-jaw chuck. The valve 123). It looks incredibly simple chuck the usual way. The spindle clearance can be bored but that’s where the simplicity taper or point is machined out using a small boring bar. ends. Any friction in the by flipping the part round Remove the valve seat and system will adversely affect and clamping it in the handy clean up any burr with a little the repeatability which needs home-made collet described steel wool. Finally, the body is to be avoided. Having said previously, cutting the angle screwed back into the tapped that, it pays to make sure the using the taper slide. This mandrel and the valve spindle spring assembly is properly operation needs to be done is held in a tailstock chuck aligned and moves with no carefully so the TLC (take with a little Brasso™ rubbed resistance, allowing the spring light cuts) principle applies. I on the sealing surface. At a to do its work unhindered. generally machine tapers like low speed, the valve seat is this with the lathe spindle in burnished using light pressure. The other stumbling block reverse, cutting the back end. with safety valves is the This way the taper slide handle Hold the valve onto the seat sealing surface for the actual is in the front so you don’t and use the tongue testing valve, which is as good a place need to lean over the lathe. method to check for a good as any to start. seal. If you get a tongue leak The safety valve body is, for check under a magnifying 123 the most part, a simple turning glass for the offending operation with the exception problem. Normally, it’s a burr Steam dome showing safety valve. of the sealing surface. This that needs to be removed; 260 needs to be machined using when the Brasso burnishing is the same methodology as redone you should get a good with all my clacks and valves tongue seal. (machining for a perfectly round hole). Just a reminder; The safety valve lever is a when reaming the seating simple marking, drilling and hole from the threaded side, filing exercise. Make sure to make sure the full shank check the centre distances of the reamer is cleanly in on the boiler to make sure the hole before the seating everything aligns. In all surface is reached. The outer likelihood the centre distances periphery is simple machining would have shifted a little. The cylinder at the end of the Model Engineer 12 August 2022

www.model-engineer.co.uk Fig 29 40 14 Ø14 Ø11 r2.2 14 40 M2 6.5 6 3 13 8.8 6 10 3 46 Ø2 5.5 13 3 6 20.6 15 Ø2.5 Ø6 20 21 Ø2 6 3/8 x 32 ME Ø5.8 2 Safety Valve Lever Ø2.5 reamed Safety Valve Body Mat’l: Stainless steel Mat’l: Gunmetal Ø5.8 Ø5 Ø818.5 5 Ø2 5 Ø2.5 M2.5 Ø1 2.5 2 drain hole 2 5 Ø8 40 M6 3.8 5.5 M2.5 M2.5 90° 7.85 5 Safety Valve Spindle 3.8 5.5 Mat’l: Stainless steel Front Coupling Middle Coupling 82.5 Lever spring 0.024” s/s M3 Free length = 12.5mm Ø10 6 Active coils = 10 Ground ends Ø6 6 86 5 Ø3 1/4 x 40 ME Ø11 8.5 92 Ø5 4.5 3 2.5 15 4.5 71 5 4 8AF File taper to underside Ø5 26 8 M2 to 5/16 x 32 ME reamed 1/4 x 40 ME 64 Ø6 Grate 13.8 12.28 lock gland M3 Ø8 Ø4 r6 9.8 8.3 Ø3 Mat’l: LC stainless steel 12 4 7.2 reamed 13.9 1 5 Safety valve. Mark off motion plate M2 2.5 8 0.5 Ø4mm stainless steel balls 3 8.8 Ram - stainless steel r3 Pump Body - brass or gunmetal 12 58 1/4 x 40 ME B A L LA A R AT 1/4 x 40 ME >> Crosshead Pump Ø3 261 reamed

Fig 30    Shaping the coupling in the vice. lever is machined with a slit the ball bearing requires a little clamp it in one of my trusty machine with a fast spindle, filed into the side for location metallurgical gymnastics. The clamping collets that have an end mill will do the job during brazing. ball I used was a standard but very fast speeds with carbon steel ball from a made an appearance here and light cuts need to be taken to The spring, rod and ball at discarded ball bearing. It’s hard there through the series. prevent breakage. Failing any the end are all designed to - a little tricky to drill and even of these tools the slot can be allow for easy movement and more tricky to tap an M2 hole The manufacturing of the filed using a modified file with low friction, allowing the spring through. The hack is to soften couplings requires some the coupling clamped length to do its job unhindered. Any the material by heating it red elaboration. There are a ways in a vice and the vice jamming due to misalignment hot in a little dry sand, cover it number of ways to tackle this jaws used as a filing guide (fig of the sliding surface is bad, in the sand and allow it to cool job with the one described 30). The modified file is any and will result in the safety slowly. This process softens my humble method. I file really with the thickness valve blowing off at a higher it enough for easy drilling typically make a few of these ground to size and cleaned up boiler pressure. and tapping in the lathe. I components because they with a flapper disk. I normally personally wouldn’t dent the tend to be useful for all sorts only thin the one side and The ball shaft is just a piece of applications in model leave two adjacent cutting of TIG welding rod tapped on ball in a chuck, but rather edges, one for deepening both ends. Drilling and tapping engineering. The square bar the groove and the other for is held in a square bar collet opening it up later. Make sure 124 described in Part 8 (M.E.4683, you use the clean side against January 28). The end round the precious vice jaws! Crosshead pump fitted. and hole are machined and drilled in the lathe - I normally Crosshead pump flip the bar around and do the same to the other end while The crosshead pump (photo I’m busy. The whole bar is 124) on the original prototype moved to the drill where the was removed at some point, shaft holes are drilled plumb from the pictures relatively centre. The couplings can early on in its working life. then be parted off in the lathe After completing the piping or cut from the main stock and running the locomotive using a hack saw. Generally, I I can understand why. For make the slots with a slitting a locomotive that ran on a saw but it seems they are timber line with stumps lying becoming more difficult to get around and a driver that’s hold of here in South Africa, less than vigilant that pump especially the thinner sizes. If you have a small milling 262 Model Engineer 12 August 2022

Fig 31 Ø2 www.model-engineer.co.uk Ø2 r2 Lever 4 2.5 6 Lever 4 36.5 r2 3.8 Top bracket M2.5 M2 6 Top bracket 10 4 1.5 Drain Cock Pull Lever 37.1 11.9 7 7 r3 Ø2 Closed Lever 3 2.5 Open 6 12 4 Lever 1 Lever 2 Slot for Top Bracket r2 57 - check on job wider movement Lever 3 0.8 11 11 Ø3 M2 Solder 11.33 6 7.3 7 Ø2 Lever 1 10 2.5 Lever 2 Ø3 r3 Ø2 Bottom Bracket Drain cock system. B A L LA A R AT3 Ø2 0.8 Ø6 r2 >> 263 Note: Plate thickness for levers = 0.8mm spring steel 21.5 Adjust for equal swing

would have been knocked very the bearing from phosphor 125 easily. For hobby steamers bronze. Liberal clearance can who generally have a clean be machined to the crosshead Drain cock push rod as viewed on footplate. track this is no problem; even spindle to take up any a derailment on a ground track tolerance issues when fitting and the grate is kept on the movement of the lever will be should leave the pump intact. the pump. locomotive - so no chance of adversely affected. getting left at the club. I machined the main body All the ball seats should be The coupling at the end of of the pump from a piece of tapped with a brass rod and Drain cock levers the rod was made in a similar brass riser which was big hammer for a decent seal fashion as the safety valve enough to make the flange but this is a water pump and A drain cock lever with a push- couplings but, again, I used profile (fig 31). The outside doesn’t require a steam seal pull system was used for the a slitting saw where builders was machined to drawing so I wouldn’t be too pedantic model (fig 31). The push rod with limited tooling can use and then parted off. The if you don’t get it perfect. The runs under the running boards a hacksaw with two blades gland flange is machined in efficiency of the pump will be to the footplate where the rod fitted to get the correct gap. a similar fashion with all the compromised but it’s not the is simply bent over to make a Modifying a file to this size holes marked out and drilled end of the world for our little simple neat handle (photo 125). as with the safety valve on the drill press. The flange models. couplings might be a bit of a and body are then bolted All the levers were made stretch. Brass as a material together with a neat profile The small screw by the using the high tensile for this coupling will be more filed using good old fashion flange is to lock the gland nut strapping which the leaf than adequate and is easier to radius guides. The assembly when set. These tend to work springs were made from. The work with. is marked and clamped in the themselves loose on the track holes are centre punched and three-jaw chuck to drill the and I have seen many efforts drilled on a piece of plastic or The pull rod bearing block is ram hole which, of course, to stop it from coming undone hard wood, properly clamped a simple square piece from the should be drilled undersize but the locking screw seems to the table to prevent the drill leftovers of the running board and finally reamed. to be the most reliable and from biting into the job and square edging and shouldn’t unobtrusive solution. taking a finger off! All edges give any issues. The block is The remaining bits for the are rounded using a file and fitted as close as possible to body are simple machined Fire grate radius guides. Lever 3 has a the slot in the running board components soldered to the centre cylinder soldered to with two countersunk screws main body with Tipp-ex’d The fire grate is a laser cut the plate to lock to the lever holding it in place. The rod screws holding the lot in place. component, which requires shaft that runs under the itself was just a piece of TIG Machining a convex on the little description. On my model locomotive. The same lever welding filler wire, actually fittings will give a neat joint I didn’t even bother filing a is used on the right-hand side measuring 2.4mm but close that is easy to solder. When taper to the underside of the of the locomotive, but the top enough and works just fine. soldering the lot together keep grate (with no ill effect) but to part is left off. With the whole assembly fitted a steel rod down the reamed be thorough I decided to put it check the travel of the drain bore to manage any heat into the drawings. My personal Two brackets at the top and cocks and make sure the drain distortion and oxidation. feeling is the grate isn’t thick bottom of the crosshead slide cock taper swings to both enough for the anthracite to bar make the pivot points for sides of the drain cock body. The end of pump ram was clog up the works. The bottom the lever mechanism. The If it doesn’t, you’ll need to slot drilled and tapped with the of the boiler was designed bottom bracket can be made the bottom hole of lever 4 to crosshead bearing given the to have the grate rest on two from some angle iron with increase the travel. Don’t slot same treatment; the two 4mm rods that can be pulled the top bracket a soldered the link too much or the drain components were screwed out to drop the fire. A simple assembly using the same cock levers will go past the together and brazed. One of ash pan can also be fitted if strapping as the links. centre line and lock up. the advantages of joining so desired. On my locomotive using silver solder is that I welded a piece of stainless The push pull rod and lever To finish off the handle dissimilar materials can pipe to the underside making fit nicely under the running neatly above the footplate a be joined. In this case, the the grate fixed on the one boards (photo 126) with a little shrink wrap will give it a pump ram is made from free side. The pin on the other end notch filed at the top of the softer look. The lever should be machining stainless and is pulled out to drop the fire motion plate when the final bent towards the side panels position of the footplate to avoid any tripping hazards! 126 handle has been fixed. The rod needs to be kept straight; lTo be continued. Drain cock levers behind cylinder end cap. if it’s bent at any point the 264 Model Engineer 12 August 2022

Club Diary 13 August - 25 September 2022 August 21 North Wilts MES 4 North Wilts MES 17 Bromsgrove SME Public Running, Coate Public Running, Coate Rob Roy Rally, Avoncroft 13/14 West Riding Small Water Country Park, Swindon Water Country Park, Museum. Contact: Rex Hanman, 11:00 – 17:00. Contact: Swindon 11:00 – 17:00. 01980 846815 Locomotiv y Ken Parker, 07710 515507 Contact: Ken Parker, Rally/Open Weekend. 07710 515507 Contact: Stuart Merton 18 Bradford MES on 01132 523258 or 25 Guildford MES Running Day, Northcliff [email protected] Open Day, Stoke Park, 7 Bradford MES Railway 13:30 – 16:00. Contact: Guildford 10:00 – 13:00. September Meeting, Saltaire Russ Coppin, 07815 048999 See www.gmes.org.uk Methodist Church 19:30. 14 Guildford MES Contact: Russ Coppin, 18 Bristol SMEE Open Day, Stoke Park, 25-29 Great Dorset Steam Fair 07815 048999 Public Running, Ashton Court Guildford 14:00 – 17:00. Tarrant Hinton, Blandford Railway, BS8 3PX, noon – See www.gmes.org.uk Forum. See www.gdsf.co.uk 7 Bristol SMEE 17:00. Contact : secretary@ Wilton windmill bristolmodelengineers.co.uk 14 North Wilts MES 28/29 Bristol SMEE restoration, Begbrook 18 Cardiff Model Public Running, Coate Public Running, Ashton Court Social Club BS16 1HY. Water Country Park, Railway, BS8 3PX, noon – Contact : secretary@ Engine y Swindon 11:00 – 17:00. 17:00. Contact : secretary@ bristolmodelengineers.co.uk Public running, Heath Park, Contact: Ken Parker, bristolmodelengineers.co.uk 8 Cardiff Model Cardiff 13:00 - 17:00. 07710 515507 28/29 Cardiff Model See www.cardiffmes.co.uk 17 Bristol SMEE Engine y Engine y 18 Guildford MES ZOOM Meeting – Talk: Medieval Cardiff, Open Day, Stoke Park, BRIMLEC/IMLEC Review. Public running, Heath Park, Heath Park, Cardiff. Guildford 14:00 – 17:00. Contact : secretary@ Cardiff 13:00 - 17:00. See www.gmes.org.uk bristolmodelengineers.co.uk See www.cardiffmes.co.uk See www.cardiffmes.co.uk 20 Cardiff Model 28/29 North Wilts MES 10 Cardiff Model 18 North Wilts MES Public Running, Coate Public Running, Coate Water Water Country Park, Swindon Engine y Country Park, Swindon 11:00 11:00 – 17:00. Contact: Steam-up and Family Day, – 17:00. Contact: Ken Parker, Engine y Ken Parker, 07710 515507 Heath Park, Cardiff. 07710 515507 Steam-up and Family Day, Heath Park, Cardiff. See www.cardiffmes.co.uk See www.cardiffmes.co.uk 28 York Model Engineers 10 York Model Engineers 21 Bristol SMEE Open Day. Contact: Evening Talk – 19:00. ZOOM Meeting – 20/21 Model Tram Bob Polley, 01653 618324 Contact: Bob Polley, ‘World’s Crane Makers’. 01653 618324 Contact : secretary@ and Railway Exhibition bristolmodelengineers.co.uk National Tramway Museum, September 11 Ayesha Centenary Rally Crich Tramway Village. Rugby MES 10:00 – 17:00. 23-25 East Somerset SMEE See www.tramway.co.uk 3 Southport MEC See www.n25ga.org Open Weekend at the Bath Small Gauges Day, Victoria and West Railway near Shepton 21 Bradford MES Park 10:00 – 16:00. 11 Bristol SMEE Mallett. See openweekend@ Running Day, Northcliff R Contact: Gwen Baguley, Public Running, Ashton Court essmee.org.uk or contact: ailway 13:30 – 16:00. [email protected] Railway, BS8 3PX, noon – Michael Malleson, Contact: Russ Coppin, 3/4 Sutton Coldfield MES 17:00. Contact : secretary@ 01747 860719 07815 048999 Federation of Model bristolmodelengineers.co.uk 23-25 Llanelli and Engineering Societies Rally, 21 Bristol SMEE Little Hay, Lichfield. See www. 11 North Wilts MES District Rally Public Running, Ashton scmes.co.uk/rally or contact: Public Running,cCoate Pembrey Country Park, Llanelli. Court Railway, BS8 3PX, Martyn Cozens, scmessec@ Water Country Park, Swindon See llanellianddistrictmodel noon – 17:00. gmail.com 11:00 – 17:00. Contact: engineers.wordpress.com Contact : secretary@ Ken Parker, 07710 515507 bristolmodelengineers.co.uk Notice for Subscribers to Model Engineer We’d like to let you know about a payment change that will be Please use the link below, or scan the required following our recent move from My Time Media to QR code, to continue your subscription Mortons Media Group Limited. after your current continuous credit card ends. We have so much planned for If you currently pay with a continuous credit card, this will the coming year and want to ensure all need to be renewed directly with Mortons as the current our loyal subscribers are with us as we operator can’t transfer your payment details due to data move the title forward. protection regulations. If you pay by direct debit, no action is www.classicmagazines.co.uk/renew/me1 required. www.model-engineer.co.uk 265

Engineering’s Local Heroes Dorothée Pullinger of Scotland and Guernsey For whatever reason, 1 engineering remains Roger a largely masculine Dorothée Pullinger with her creation, a Galloway car. Backhouse occupation but go back a (Image courtesy of the family of Yvette Le Couvey.) tells the hundred years and it was even story of Dorothée more male dominated. Women Her father worked for eventually admitted to full Aurélia Marianne engineers of the 1920s and various car companies before membership in 1921, the Pullinger, creator of later had to fight against becoming managing director first female member of the the Galloway car. real discrimination in order of the Paisley works of the Institution. to make their way in their Arrol-Johnston Company, a 2 chosen profession. Those that pioneering Scottish car maker. At just twenty years old, succeeded were often brilliant The firm had a modern and Dorothée was put in charge at their work – they simply largely integrated factory where of women munitions workers had to be exceptionally good most components were made at Vickers, Barrow in Furness. to survive. on site. As Managing Director She spoke French well and he introduced a new range of this could well have been a One such success story cars in 1909 (photo 2). reason for her appointment is that of the remarkable as, apparently, a significant Dorothée Aurélia Marianne Dorothée started working number of Belgian and French Pullinger (photo 1), creator of there as her father’s apprentice refugees worked there. (My the Galloway car. Dorothée in the drawing office. As a grandmother was a munitions was born in France in 1894, girl she was an accomplished worker in Barrow and may have the oldest of twelve children. watercolour painter and been one of her charges.) As a Her father was Thomas her sketchbook from 1908 manager, Dorothée introduced Pullinger, a car designer who survives. Perhaps those a canteen for the workforce had worked for Darracq. He artistic skills helped her in the which eventually supplied brought his family to Britain in drawing office. In 1914 she 7000 meals a day; no mean 1902 and Dorothée attended applied to join the Institution feat in itself, but Dorothée Loughborough Girls Grammar of Automotive Engineers but always had remarkable energy School. her application was rejected and was, in 1920, awarded the on the incredible grounds MBE for her wartime efforts. An Arrol-Johnston 15.9hp car built at Paisley in 1912. that ‘the word person means (Roger Backhouse 2021. Courtesy of Glasgow Museums.) a man and not a woman.’ Post war, Dorothée returned Although she had been offered to Scotland and to automotive Associate Membership - which engineering, restarting her she refused - Dorothée was engineering training. Arrol- Johnston had a subsidiary, 266 Model Engineer 12 August 2022

LOCAL HEROES the Galloway Engineering 3 Company, with a factory at Tongland near Kirkcudbright. The 1924 10.9hp Galloway coupé in Glasgow’s Riverside Museum. It has a much lighter style than the Here Dorothée helped the Arrol-Johnston built just 12 years before. (Roger Backhouse 2021. Courtesy of Glasgow Museums.) early design, development and production of the Galloway manufacturers like Morris and When they sold the laundry Motor Museum, Aberlady, East car playing a leading part in Austin. firm in 1946 they then moved Lothian. Only four examples making it a success. to Guernsey, this time setting remain in Scotland of a car Beside engineering, that once promised so much, The factory was, to a great Dorothée had other up Normandy Laundries which but Dorothée Pullinger’s extent, staffed by women distinctions. She was an inspirational legacy lives on. and offered them a three year early member – indeed, some operated successfully for apprenticeship - rather than sources say a founder - of Thanks to Suzanne Rough, the five year apprenticeships the Women’s Engineering many years. Glasgow Museums, for normally given to men as, of Society set up by Katherine considerable help with this course, women were expected and Rachel Parsons in 1920. Dorothée died in 1986 article and to the family of to be quicker learners. The A keen driver as well as an Yvette Le Couvey for images. women typically lived at a engineer she was awarded aged 92. Fittingly, she was Thanks also to Wikipedia and hostel on site. a silver medal for racing in Herstoria websites. 1922 and in 1924 became the inducted into the Scottish Described by Light Car first woman competitor in ME and Cycle magazine as a car the annual Scottish Six Days Engineering Hall of Fame ‘made by ladies for others of Trials, winning a silver cup. in 2012. A Galloway car their sex’, the Galloway was is displayed in Glasgow’s smaller, lighter and cheaper Dorothée married ship’s than Arrol-Johnston’s 15.9hp purser, Edward Marshall Riverside Museum, believed to model and most others of in 1924 and they had be one of just fifteen surviving. the period. It had innovations two children. A staunch Another is in the Myreton like a rear view mirror and a Conservative, she served hand brake more conveniently as the only woman on the 4 located near the driver’s seat Industrial Panel of the (a change to the previous Ministry of Production during Dorothée’s daughter, Yvette Le Couvey at the wheel of the car her mother helped practice of placing it beneath the Second World War, also design and engineer. (Image courtesy of the family of Yvette Le Couvey.) the dashboard). The gear contributing to a 1944 report change was placed in the on the future of British middle of the car rather than industry. Some sources say outside the body. The steering she was also employed to wheel was smaller, the seat recruit women for munitions higher and the dashboard factory work. was lowered. These were all welcome innovations for all After Arrol-Johnston’s drivers, not only the women closure Dorothée and her they were intended for. husband established White Service Laundries in Croydon. Unfortunately, the Tongland They used modern American factory lasted only three years machinery and the business before production was moved was a success, eventually to the Arrol-Johnston factory running seventeen shops. at Heathhall outside Dumfries. The first model, the 10/20, was based on a Fiat 501 design and had a 1460cc side valve engine. In 1925 it was replaced by the 1669cc 12/20 and 12/30 models. Early cars had rear wheel brakes only but by 1925 all wheel braking had become normal practice. Many independent car makers faced difficulties in the 1920s. Even though four thousand Galloway cars had been made, production ended by 1928 when Arrol- Johnston closed. With Galloway cars priced at £325 to £360 depending on chosen body style, it was hard to compete with mass market www.model-engineer.co.uk 267

The Little Demon Supercharged V8PART11 Mick Back now to the cylinder can then be used as a visual The hub on the crankshaft Knights block. The timing gear timing gear needs to be describes indicator for the position of shortened to 0.062 inch before the construction of a pockets need to be bonding to the crankshaft. To supercharged V8 internal this cam when setting the ensure no bonding fluid came combustion engine. produced in the front face and valve timing on final assembly. into contact with the front bearing, a paper gasket to sit Continued from p.215 the CNC is the obvious choice between the two was produced M.E. 4696, 29 July 2022 (photo 109). A modification using ½ inch and ¼ inch is required to the camshaft diameter gasket punches. 109 timing gear; two M3 holes are Now would be a good time for a quick word about produced at right angles to the choice of gear supplier. I asked for a quote for all accept grub screws (photo the gears required from the recommended supplier in 110) and two corresponding the USA, but when I received flats are produced on the end it I was a bit surprised as of the camshaft to locate and I hadn’t expected them to be produced from precious secure the gear (photo 111). metal - well judging from the To ensure the second flat is prices they must have been! - at 90 degrees to the first it is and that was before carriage located squarely against the and import charges. After several quotes from suppliers vice jaw using feeler gauges. both in the UK and the USA the cheapest by a long way It’s a good idea to align one of (for all the spur gears) was the flats with the centre line HPC Gears. I’ve sourced the of No. 1 exhaust cam; this water pump gears and the distributor drive gears from 110 different suppliers which I’ll cover when we reach the Crankcase assembly set to machine timing gear pockets. Centring the two M3 holes in the timing gear. appropriate stage of the build. 111 112 Machining the first grub screw locating flat. Setting the manifold bore true to the machine spindle. 268 Model Engineer 12 August 2022

LITTLE DEMON 113 114 Drilling. Final boring to size. Now that the cylinder heads the bore transfer. With the distributor bore in the blower a radial slot that will allow and manifolds have been head and manifold assembly rotation when timing the successfully bolted into their secured to the block the bore manifold was generated at engine were generated on final positions on the engine is clocked true beneath the the CNC (photo 116) and the block it’s time to transfer the machine spindle (photo 112). the same time as the single internal detail was produced position of the distributor The bulk of the material is in the same way (photo 117). bore in the manifold to the removed using a suitable stub carb version and so should A mating distributor cap was block. As this needs to be a drill (photo 113). Final size is be a pretty close fit to the also generated on the CNC close working fit in the engine achieved by boring. The bore bore in the engine block when from a convenient piece of block I prefer to line bore both in the cylinder block needs black nylon (photo 118). A components rather than just to be a good sliding fit to the assembled - but may need a programming hint for any drilling the cylinder block. It distributor, while the bore CNC-ers: if the diameter of the is envisaged that the single through the manifold needs revisit in order to allow the upstanding terminal bosses is carb manifold will be used to be enlarged by about 0.020 programmed at 6mm, then by for running the engine so it inch to allow for movement distributor shank to pass into using a 2mm diameter cutter is used as the reference for on assembly (photo 114). The it should produce the result the engine block. shown in photo 119. 115 The distributor body was Two of the internal Turning the distributor body. components were produced machined from a suitable at the same time. The rotating 117 disc that houses the eight piece of aluminium FC1 (photo magnets that operate the The internal detail. 115). A mounting flange Hall sensor was generated that will mate against both complete on the mill, then set in the lathe and parted off to manifold blocks, along with finished length. The bores were made 0.124 inch diameter to 116 accept the 0.125 inch body of the magnet (photo 120). The Generating the mounting flange. distributor rotor was produced from a piece of Tufnol sheet. 118 The brass contactor strip was produced from sheet brass Mating diameter in the distributor cap. 2mm wide and 2mm deep. The >> slot in the rotor was produced using a 1.5mm diameter carbide cutter on a keyway cutting cycle in order to leave a 0.002 inch clearance for the bonding. Once bonded in position the initial face clear cycle was 0.2mm deep on a round pocket cutting cycle (photo 121). A circle cutting cycle produced the round blank, which was set in the www.model-engineer.co.uk 269

119 120 Finished distributor body. The magnet mounting rotor. lathe to produce the 0.250 inch 121 122 diameter hub and a 0.125 inch diameter hole for mounting on Facing the rotor face and brass electrode. The finished rotor. the drive spindle (photo 122). The drawing and instructions at designing a few fantasy All subsequent R values will be although the accompanying for setting the timing do say the last value plus 60 degrees, G-code is correct the control that the brass contactor strip components but, in the end, so the next R value would be doesn’t appear to have a home should be glued to the top face R-120. of the rotor once the engine when it comes to writing a reference and sends the cutter timing has been established, G68 is not only useful for off on a walkabout. I find I can but I left the rotor end of the program for the mill I’m still machining features at regular cure this by simply rebooting drive spindle plain, without very much old school and I find intervals but also for plotting the drawn flat shown on the it far quicker to use a mixture holes at different angular the computer, but with this drawing, so without the rotor’s of G-code and conversational positions on a fixed PCD. securing grub screw locking wizards, rather than draw out in mind I always prove a G68 and locating against a flat Rather than incorporate the program by running the first on the drive shaft, the rotor the CAD component and put it Z minus feed moves in the sub couple of angular moves on a can be correctly positioned routine I find it easier to run and locked during the timing. through a CAM post processor. the program to cut at all six piece of scrap material before That’s my choice; I’m not positions at one depth then saying that one method is any I programmed the clearance add the next Z minus move running the whole program better than the other. via the edit as sometimes - cutter path for the wedge but by no means always - my on the actual work piece. We’ll return to the distributor Mach3 control bombs when on final assembly, but now to shape pockets then called up running G68 and by not having On this occasion, due to a finish off the single carburettor G68 co-ordinate rotation to the Z moves in a sub routine manifold by producing the air repeat it at six sixty degree it makes it a whole lot easier combination of cutter diameter filter - or as our transatlantic to reset. As I say, G68 does and the angular start and finish cousins like to call it, the air positions to create all the strange things to my control, positions, the web between scrubber. especially when using the pockets in one cycle. conversational wizards to the pockets turned out to be This may be a bit boring for create arcs, as the graphics conventional machinists as, Incorporating G68 is so in the wizard display window slightly tapered rather than again, I took the CNC route to aren’t always the same as produce the six wedge shaped easy. There’s only one simple those that appear in the parallel as drawn. I could have pockets around the body program run window and which will channel the air to rule to remember: all rapid and gone back and reprogrammed the carburettor. feed moves must be within a the pocket, using a smaller I have mentioned in previous builds that I don’t have a CAD sub routine. After the program diameter cutter to generate a capability but this is no longer strictly true as I signed up to header the next two lines are: smaller corner radius rather the recent series of tutorials for the Albrie CAD package in MEW G68 A0B0R-60 (Using a than forming it with the cutter and had a lot of fun following the step by step instructions Mach3 control A = the X centre itself, which would probably to produce a 3D scribing block. I did have several attempts position, B = the Y position and have had the desired effect on R = the angular rotation). the web … but … M98P1001 (Call the Back in the early 1970s I subroutine at the above spent several happy years position.) working for a one man 270 Model Engineer 12 August 2022

LITTLE DEMON 123 124 The air scrubber pockets. Engraving air scrubber cover plate. band construction business 125 126 building swimming pools and surrounding hard landscaping. Generating cover plate diameter. M2 thumb screw. On one job we had to build a large retaining wall against the aluminium sub table and 127 an excavated bank using the position taken as absolute reclaimed sandstone blocks zero. This would be used to Air scrubber in position. salvaged from a church captivate the finished plate demolition. These were, as you at the end of the cut circle can imagine a bit on the big cycle. The first operation was side, but as we were on a price to drill a 2mm hole in the plate for the whole job, we motored at X0Y0. Only because I can, I into it laying several more engraved ‘Little Demon’ around courses that the usual three a the centre of the plate using day. The next morning when a font named ‘Action Man’ we arrived back on site the (photo 124). If this doesn’t look customer was waiting for us attractive on final assembly, and demanding an explanation the cover can be reversed to as to why all the blocks were show the plain face. leaning inward at an angle rather than sitting vertically A cut circle cycle completed as he was expecting. Ted, the the manufacture of the cover chap I was working for, quick plate (photo 125). The M2 as a flash said that in order to thumb nut for securing the properly retain the bank the cover plate to the scrubber blocks had been deliberately body was produced in laid on the incline. The stainless steel 303. First the customer seemed to accept body was turned on the lathe this, but my first job of the day and the chuck transferred was to make a large wooden to the mill where the three angled square to match the scallops were generated. profile of the subsided blocks Finally, back to the lathe to in order to carry the same angle be parted to length (photo to the top of the wall. The moral 126). The completed single of the story is: sometimes carburettor manifold is shown the best way to overcome a in photo 127. mistake is to emphasise it and make a it feature! ●To be continued. Photograph 123 shows the air scrubber with tapered webs between the pockets. For a bit of contrast, I made the scrubber cover plate from 1/16 inch thick brass. As this was to be completely generated on the CNC, a M2 hole was drilled and tapped in www.model-engineer.co.uk 271

Rewinding a Two Speed MotorPART3 Reverse engineering 6 Graham At this point, I had a perfectly Astbury good motor which worked learns a yet I had no use for it in its lot about single-phase original form. It seemed an induction motors and act of unspeakable vandalism describes ‘The long and to attack the windings and winding road that leads destroy a perfectly good to a 2-speed single- working motor but I needed to phase motor’. determine the turns for each winding. I dismantled the Continued from p.226 motor and after removing the M.E. 4696, 29 July 2022 end bells, I was left with the rotor still inside the stator, as the motor had two large fans The purpose-made bearing puller to fit the fan openings. – most unusual – and hence I had to remove at least one fan Having dismantled the search on noise in induction to be able to extract the rotor. motor, I counted the rotor motors to make sure of that. The fan at the non-drive end bars, as the ratio of rotor bars Apart from Appleman (ref 3 seemed to be moulded onto to stator slots can create a – M.E.4695, July 15), which the shaft and, since it did not problem with noise caused by was predominantly concerning have any easy way of fitting a harmonics. It can be imagined single phase motors with bearing puller, I decided that that if the rotor has 32 slots one main winding and a I should leave that fan alone and hence teeth and the stator starting winding, I found that and investigated the other fan. also has 32 teeth and slots, Hildebrand (ref 12) gave a This was mounted between when the rotor goes round, simple rule for minimising the rotor and the drive- the magnetic flux from the noise in any induction motor end bearing with very little stator teeth passing into the which was that ‘…a motor will clearance at all. Fortunately, rotor teeth will tend to hold the be quieter if the numbers of there were two small cut- teeth in alignment and as the poles, stator slots, rotor slots, outs moulded into the fan, teeth move, the flux will jump difference of stator and rotor presumably to fit a small to the next tooth, resulting in slots bear a simple multiple bearing puller to allow the uneven rotation of the rotor. relationship and the motor is bearing to be pulled off the This is known as cogging and quieter the larger the greatest shaft (photo 6). Unfortunately, is a function of the number common divisor of these my bearing pullers were all of poles, the number of stator factors…’. Taking the stator, three-legged and too large slots and the number of rotor rotor and proposed changes to fit the slot, so I had to slots. As I was proposing to to the number of poles into make a small puller. This was alter the number of poles, account, at the two different described previously (ref 11). by altering the speeds from speeds the salient numbers 2-pole and 16-pole speeds to are laid out in Table 1. Table 1. Factors for predicting motor noise (after Hildebrand) 4-pole and 8-pole speeds, I thought it prudent to check This should give a relatively Number Four pole Eight pole that this would not produce quiet motor. This also agrees Poles speed speed problems with noise. I decided partly with Appleman (ref 3), to have a further literature who states that conditions to 4 8 be avoided are: Stator slots 32 32 Rotor slots 40 40 Difference between stator and rotor 8 8 Greatest common divisor 4 8 272 Model Engineer 12 August 2022

ELECTRIC MOTOR 1. an odd number of slots in 7 8 the rotor, 2. a difference in the number of rotor and stator slots being half the number of poles, 3. the number of slots on the rotor and stator differing by the number of poles. In the case of the washing The rotor showing the skewed slots. The windings from one slot separated from the rest. machine motor, in its original form of 2 and 16 However, Appleman also be satisfied on the 4-pole high photo 7, the rotor is indeed poles, it avoided all three of states a 'general condition' speed, but not necessarily skewed by one slot. Whilst the Appleman's conditions in the of ‘...any rotor with a number on the 8-pole low speed as above did suggest that there 2-pole mode but condition 2 of rotor slots divisible by the the difference between the might be a problem with noise was present in the 16 pole number of pairs of poles of the stator and rotor slots is equal for the 8-pole speed, I decided mode, as the difference fundamental and which differs to, rather than more than, to go ahead anyway and hope between the stator and rotor from the number of stator slots the number of poles. As the that I would be successful slots was 8 which is half of by more than the number of original motor was actually with this rewind as a 4-pole/8- the number of poles. In the poles will probably be a quiet quiet on both speeds, I was pole motor. rewound form of 4 and 8 rotor’. Again, in the original reasonably satisfied that the poles, all conditions would be motor, this was not satisfied motor would not be noisy. Counting the turns avoided in the 4-pole mode, when running in 16-pole mode, Also, Appleman states that but condition 3 would be as the difference between skewing the rotor slots would Before I started anything present in the 8-pole mode. the rotor and stator slots was reduce the effect of noise, too drastic, I measured the Consequently, I would have less than the number of poles, with the most effective resistance of the windings so to hope that whilst two but was satisfied in 2-pole skewing being one complete that I could be sure of which conditions were avoided as mode. In my case, this would stator slot. As can be seen in winding I was about to count. in the original windings, the There were four windings – different condition that would one main and one auxiliary for be present did not give rise to each speed, arranged with one unacceptable noise. common point wired up as in fig 10. The resistance of the Wiring of the motor washing machine motor windings was as in Table 2. coils and the speed changing switch. From these values, it is apparent that the two 16-pole windings are the same and the motor is easily reversible with a single-pole changeover switch. Since the main and auxiliary windings are identical on the 16-pole speed, the supply can be fed to either winding and the capacitor could also feed either winding, so the motor can be reversed easily by simply changing the connection to the opposite side of the capacitor, as in fig 10. For a washing machine, this is the typical modus operandi of the drum when washing - rotating one way and then reversing. Table 2. Original winding resistances Fig 10 Winding Resistance >> 2-pole main 15 Ω 2-pole auxiliary 39 Ω 16 pole main 54 Ω 16 pole auxiliary 54 Ω www.model-engineer.co.uk 273

However, with the 2-pole 9 10 winding, the auxiliary winding has a much higher resistance The wires collected into bunches for counting. The wires cut off for ease of removal. than the main winding. The 2-pole motor has roughly twice 11 12 the power (and hence twice the current) so had the main The thermal cut-out itself. and auxiliary windings been identical, a larger capacitor The thermal cut-out embedded in between the windings. would have been required for the 2-pole speed. By using a few odd ones as individual This would, without the thermal readily available (search for thinner wire with more turns, wires (photo 9). This allows an fuse, possibly result in a fire 'resettable thermal fuse' on the the ampere-turns can be easy way of counting the turns inside the motor, so the fuse Internet) and are cheap and maintained, but the actual without losing count when The cuts off the supply should the simple. However, because the current required to be fed to Boss calls you in for lunch… motor get too hot. This was thermal fuse is self-resetting the auxiliary winding is reduced (no, not Bruce Springsteen – a self-resetting thermal fuse and wired directly into the considerably so allowing a the wife!). I also measured the but, although I could determine motor supply, it would not smaller capacitor to be used. wire diameter on five separate the maker from the markings trip the no-volt release on the This is a very good design wires to get an average on it, it did not seem to be a contactor and on resetting feature for a two-winding diameter. If all the wires are device in current manufacture would restart the motor. Whilst motor as the auxiliary winding counted through every slot for so I was unable to determine this is of little consequence in on the 2-pole speed can draw both windings it would involve the operating temperature. I a washing machine, it would be the same current as that on counting 64 separate coils, guessed that the temperature an inherently unsafe situation the 16-pole speed. This allows so I counted them in a few could have been 175 degrees in a workshop and so I decided the same size of capacitor adjacent slots only until I had C based on the marking ‘T175’ to discard the thermal fuse and to be used for both speeds. counted the same number at at the bottom right in photo 12. use a different type of overload The methodology behind this least five times. This makes it However, since the stator slot trip. This will be described later. design is discussed by Trickey more likely that I had counted insulation was 0.2mm polyester Of course, such a thermal fuse (ref 13). However, the motor accurately. That way, if the film which has a temperature could still be used if not wired cannot be reversed in the same odd wire is missed it is of less class of Class F corresponding directly to the motor but kept way as the 16-pole speed, as consequence when the totals to 155 degrees C (ref 14), it electrically separate and wired the main winding would then are worked out. would seem doubtful that the in series with the ‘Stop’ button be fed by the capacitor and operating temperature was as of the motor starter. the auxiliary winding would be I then cut off the winding high as 175 degrees C. These connected across the supply. close to the end of the slot over-temperature trips are lTo be continued. When spin drying, the washing (photo 10) which allowed all machine always rotates in one the wires to be pulled out easily REFERENCES direction only, so this is of little from the other end. Eventually consequence for its original I removed all the turns for the 11. Astbury, Graham, A Small Bearing Puller, Model Engineer, purpose. 2-pole auxiliary winding and, 224, 698-700 & 757-9, Issues 4638/9, (2020). having removed the inter- At this point all the non- winding insulation, it revealed a 12. Hildebrand, L.E., Quiet Induction Motors, Journal A. I. E. E., destructive testing had been thermal fuse embedded in the 49, 7-11, (1930). undertaken and the next windings (photos 11 and 12). stage was to determine the This is a safety feature included 13. Trickey, P.H., Design of Capacitor Motors for Balanced actual number of turns in each in the main supply to the motor Operation, Trans. Am. Inst. Elec. Eng., 51, No.3, 780-785, winding. This would require (the black wires in photo 11). If (1932). actually cutting the wires the capacitor were to fail, then and destroying the windings. the motor would not start and 14. International Electrotechnical Commission Standard IEC Therefore, grasping the nettle would draw the stall current. 60085: 2004, Electrical insulation - Thermal classification. or biting the bullet so to speak (do people actually grasp nettles and bite bullets?), I carefully pulled out one section of the winding which went down one particular slot (photo 8). I numbered this arbitrarily as slot 1 so that I knew how the winding was originally done. This was part of the 2-pole auxiliary winding and was wound through slots 1 and 16. I cut through this part of the windings, counting the turns by collecting sets of 10 wires together and twisting them into a bunch, leaving the 274 Model Engineer 12 August 2022

www.model-engineer.co.uk/classifieds/ FREE PRIVATE ADVERTS Save a stamp! You can now place your classified ads by email. Don’t waste time scanning the form, just send the text of your ad, maximum 35 words, to meweditor@ mortons.co.uk, together with your full name and address, a telephone number, whether it’s a for sale or wanted and stating that you accept the terms and conditions for placing classified ads – see below. Please note, we do not publish full addresses or website links to protect your and other readers’ security security. Coronavirus advice is changing! Please follow local government advice in Wales, Ireland, Scotland or England as appropriate, especially if you are considering buying or selling items for collection. Tools and Machinery Harrison Lathe, older type and clutch Parts and Materials ■ Boxford ‘C’ gear change, cabinet most other bits, buyer collects. ■ Boxhill 5” Gauge Loco - Drawings, mounted 4 ½” lathe. All change gears, T. 07535 301667. Stanford-Le-Hope. 8 Sheets. Laser Cut Frames & Buffer 240V, many extras. Buyer collects. Beams. Wheels. Eccentric Straps. T. 01395 264080. Exmouth. Devon. ■ Myford ML7B Lathe c/w gearbox, Hornblocks. Axleboxes. Motion Plate & clutch vertical slide, four jaw ind chuck, Bushes. As new (Reeves), un-started ■ Warco WM14 milling machine with 3 two three jaw c/c chucks, two tailstock project. £300 o.n.o. axis DRO. Good condition. Four years old chucks, 7” face plate, lathe carrier, 23 T. 07740 184522. Bognor Regis. but only used for two. Buyer to collect. No2 MT Drills, 30 Reamers, 20 milling £500. Call or text cutters, £1595 ono. Magazines, Books and Plans T. 07500 708019. Coventry. T. 07542 113567. Holywell. ■ Drawings for Traction Engine ‘Thetford Town’ by R.H. Clark, Ami ■ Colchester Student Lathe, 4 different ■ Fobco Bench Drill with compound Meche, all checked and signed, drawings chucks, numerous accessories, however cross vice, drill has seen much use hence numbered 1-16 but 4 missing, all good needs motor. Granville Lathe, including low price, £75. T. 01904 781832. York. and legible, £25 plus postage, also full accessories, 2 pillar drills. Part finished set ‘Hielan Lassie’. model railway engine and traction ■ Mini lathe, 4 speed, 2inch chuck, T. 01915 283408. Sunderland. engine. T. 07777 644646. South heavy metal case (40x14x11 inch) plus Nutfield, Surrey. large wooden box containing 36 collets, Wanted tool holder, dial gauge and various other ■ Shaping machine and small milling ■ Workshop with Universal Miller parts. £110. machine. Inverter, 3 phase Kerrys Lathe, 2 wood T. 01372 453780. Leatherhead. T. 01429 281741. Hartlepool area only. lathes, Lorch lathe 16” depth, board saw, 2 speed, back geared Puller drill, Models ■ Wanted to fit Smart & Brown lathe chucks, collets, turning tools, drills, 10” ■ New and Unused 5’’ gauge locomotive 1 3/4” 8 tpi 7” face plate ,chucks ,chuck rotary table vice vernier all measuring boilers for Sale. Both with certificates backplates etc equipment, lots more, buyer collects. of construction and testing. Crab - Don T 01609 775861 North Yorkshire. T. 01142 334758. Sh field. Young design £3,500 ono. Duchess - Michael Breeze design £5,500 ono. T. ■ 48 dp gear cutters. P.A. 14 ½ degree, ■ Elliot Mini Mill small vertical milling 07745 218 071. East Midlands. number 4 and number 8. Required for machine, top quality British made my Jeremy Howell V-twin build. precision machine full set Hardinge ■ 5” gauge Garden Track, approx. 290 T. 07845 687844. York. collets single phase, substantial machine ft in mainly 8ft sections. PNP Railways on cast iron cabinet, ideal for precision moulded polypropylene sleepers, 5/8” model engineer, good useable condition, F/B aluminium rail in plastic chairs, two £650, quick sale. hand-built points (teak sleepers). Where T. 01268 734589. Basildon. curved, 18ft minimum radius. £1000. T. 01482 898434. Hull. ■ Clark 16mm Bench Drill, hardly used, very good condition, single phase, virtually unused, £125. T. 01268 734589. Nr Chelmsford. ■ Ml7 k38162/stand chucks 4jaw 3jaw drill chuck / fixed steady casting for travelling steady / change wheels (12 years use ) £750. Meddings drilltru £210. Nu-Tool mill new leadscrew & nut Posilock&collet chucks £550. Ferm metal bandsaw £140. T 0757 2892143. Grantham. ■ New cross-slide screw & nut for 5” www.model-engineer.co.uk 275

Ron Fitzgerald takes a The Stationary look at the history and Steam Engine development of the stationary steam engine. PART 36 – MATTHEW AY AND THE ROUND FOUNDRY The Greensand Foundry Continued from p.164 M.E. 4695, 15 July 2022 The insurance policies give Fig 105 an overview of the way James Watt Junior’s sketch plan of Fenton Murray and Wood’s site in June 1802. in which the engineering This letter and the plan were was never short of land and works of Fenton, Murray and part of a sustained campaign eventually owned more than he Wood grew in the five years of industrial espionage on could use.) Also shown on the following the partners’ initial Watt’s part (reciprocated plan was the maltkiln which with equal energy by Murray) was then owned by the widow land purchases. The earliest which also extended to active of the maltster, Kirby. Watt had obstruction of Murray and approached the widow Kirby policy, entered in May 1796, Wood’s progress. The main to see if she was prepared to shows that the first building reason for drawing the plan rent the maltkiln to him, his to be built was the Greensand was to show ground adjoining purpose being to have a ready on the east side to Fenton, outpost from which Murray’s Foundry which the later Murray and Wood’s premises activities could be observed. which was owned by Peter She rejected his overture. 1804 Royal Exchange policy Garforth, Marshall’s close specifically describes as a friend. Garforth, an otherwise Covert and hurried in its loam foundry and adds that it astute businessman was origins, the plan contains duped by Watt into selling this several errors but none included a brass foundry. The ground to Watt’s covert agent, materially detract from its the Leeds solicitor Upton, in value as a documentary next surviving policy, dated order that Murray’s expansion source. The Greensand in that direction might be Foundry is shown as a shaded November 1798, records the forestalled. (This proved to block at the north eastern be one of Watt Junior’s more corner of the site and the erection of a second iron futile gestures as Murray Drysand Foundry, similarly shaded, lies on the western foundry. James Watt Jnr., writing to Matthew Robinson Boulton on the 12th June 1802, describes the two foundries standing on the site at that time. The first he says was the: ...Dry Sand Foundry ...about 20 Yards long & 12 wide with two Air furnaces & 3 Stoves, one 20 feet by 13 wide for Loam, another 17 feet by 13 for Boxes and a third, 17 feet by 9 for Cores… The second was the: …Greensand Foundry ...on the opposite side of the Yard about 15 Yards distant & is nearly of the same dimensions, with 2 Air Furnaces & a Cupola, which is about 8 feet high & 20 Inches Diameter but no stove, the cores being dried in those of the Dry Sand. The bottom of their green sand foundry (which is a distinct building from the dry sand one) consists for about 4 feet deep of …sand… On the reverse side of his letter Watt drew a sketch plan that showed the location of the two foundries (fig 105). 276 Model Engineer 12 August 2022

STEAM ENGINE side, separated from the Fig 106 Greensand Foundry by open ground that subsequently Murray and Wood’s Greensand Foundry following restoration (photographed by the author in 2021). became the works yard. The maltkiln Watt places certainly the oldest surviving The chimney was matched by addition of a king-post and >> to the west of the Drysand foundry buildings in the a second identical stack at the heavy timber flitches attached Foundry with what became world. As might be expected other end of the arch although Foundry Street between the of structures of this age they this was removed in the later to the sides of the tie beam. two buildings. What was to have undergone change and nineteenth-century to make The evidence suggests that it become Marshall’s main mill rebuilding but appreciable way for a core stove built when has acted as the support for site in the nineteenth-century amounts of the original Number 4 Foundry was added. a post crane, the top bearing is shown as open land at the fabric survive. The Drysand This pair of chimneys almost pivot of which was supported western edge of the plan with Foundry was converted to an certainly served the two air a street in front, at that time erecting shop after 1860 but furnaces that Watt remarks by a beam spanning between known as Peter Street but the Greensand Foundry was upon in his 1804 letter. On the the trusses II and III. This later, Marshall Street. Murray’s still identified as a foundry other side of the wall, more house (Steam Hall, which has when the site changed hands recent building has obscured pivot bearing was steadied by been radically mis-located by in 1895 and at that time it converging iron tie bars that many historians) is placed continued to include the any signs of whatever may extended to cast-iron wall close to its correct location brass foundry. At what point have existed but the first maps plates attached externally by Watt but on the wrong side subsequently it ceased to be of the site show an outshot or to the west wall at the outer of Marshall Street. As far as used for casting is uncertain corners. A crane in this position the foundries were concerned, but by the nineteen-eighties shed extending between the would be suitably located to the situation shown by Watt neither building contained any two chimneys and it is likely serve a casting pit in the sand in 1804 can be identified with foundry plant or structures. that the furnace bodies were floor placed at the mid-point that recorded in the November The Historic Building Survey situated within this shed and between the air furnaces. 1798 Royal Exchange carried out in 2003 had to hence external to the east wall. insurance policy, immediately rely entirely upon the building In this they would be similarly The west wall of the after Murray’s second foundry structure to interpret the arranged to those of the Soho Greensand Foundry is locally was completed. features of Murray’s period Foundry and also, probably thicker by one half brick over assisted by a limited amount more pertinently, similar to its length between the window Watt must have keenly of below ground archaeology. the furnaces at Low Moor openings, reducing to one observed the differences Ironworks which may have and a half bricks thickness between his own works and The Greensand Foundry (figs acted as a direct model for at the two ultimate bays. The Murray’s. In terms of the 107 and 108) is a three-unit Murray and Wood. present double-leaf door in foundry capacity most obvious block with the foundry forming the centre of the elevation is was Murray’s complete the core unit, measuring For most of the twentieth recent but below the threshold separation of the drysand internally 51 feet in length on century the building was roofed the wall foundations remain work from the loam and a near north-to-south axis and in corrugated asbestos sheets in place proving that it was greensand thus avoiding cross 35 feet 6 inches wide, east- but the insurance policies formerly continuous across contamination. The depth of to-west. Where the original stated that it was slated when the door gap. At the north sand in the Greensand Foundry wall construction survives end, the transition between was stated to be four feet but it is identifiable by the use new - at this period Yorkshire the thickened section and doubtless a deeper casting pit of hand-made brick, laid in stone flags (vernacular the reduced wall section existed somewhere in the floor. white lime mortar. The east thackstones) rather than Welsh is marked externally by a Watt says that both foundries wall has been partially rebuilt slates. There were originally significant discontinuity in the had two air furnaces but but surviving older brickwork four timber trusses (I – IV brick coursing supporting the only the Greensand Foundry dating from the first phase of numbering north to south) but argument that the thickened had a cupola, 20 inches in construction includes part of number IV has been replaced section is not original. diameter and 8 feet high. The a square chimney base and a in steel. The remaining three core and loam drying stoves long-span firebrick arch above trusses are built up from Baltic Two alternative possibilities were located in the Drysand which is early style brickwork. pine framed as queen-post with may account for this Foundry. Because of the princess-post spans. The outer increased thickness of wall lack of a Murray archive it is two are similar but the central construction. The first is that not possible to say whether his foundries avoided the one has been stiffened by the the stresses imposed by the tribulations that affected Soho crane were passed through but the Boulton and Watt correspondence does seem to suggest that Murray’s success was more rapidly achieved. Both of the foundries survive today and after a long period of neglect they have recently been renovated for new uses (fig 106). The two buildings are almost www.model-engineer.co.uk 277

278 Model Engineer 12 August 2022 Fig 107 The Greensand Foundry. Ground plan. Survey by Structural Perspectives in 2005.

www.model-engineer.co.uk Fig 108 The Greensand Foundry. Sections and roof trusses. Survey by Structural Perspectives in 2005. >> STEAM ENGINE 279

The form of first-generation Fig 109 fire-resisting construction used in the ground floor of Peel Williams’ Phoenix Foundry in Ancoats, Manchester. The left-hand building is the foundry with its open front and its furnaces. this building is a distinctive innovation that places it Fig 110 amongst a small number of contemporaries and within five years of the first known example.That it should be confined to the ground floor of the pavilion is doubtless related to some functional purpose, the nature of which is now lost. John Southern’s sketch of the brick arch and timber beam floors as used by William Strutt. the roof trusses to the wall but relatively more complete was not made until 1895, it Ditherington Flax Mill. After causing distress and the wall is the building at the north does locate the activity at Marshall’s B Mill had been was subsequently rebuilt end. The internal floors are reconstructed but sufficient the southern end of the main destroyed, in an unusually in strengthened form. The remains to show that it foundry floor. In the present building, the wall that divides amicable gesture, Lawson second possibility is that, originally had at least three the main foundry floor from the showed Marshall a sketch when first built, the foundry floors and possibly four. The southern pavilion incorporates by Southern (figs 110 and was open-fronted on its west floors were of timber beam three flues that have been 111) of the fire resisting floor elevation towards the yard. and floor boarded. In the past removed at the lower level but system used by William Strutt the walls have been lathed and How common a practice this plastered. At ground floor level remain in situ above. Below- in his factories at Milford and there were at least two arched ground archaeology confirmed Derby. In Southern’s words the was generally is uncertain but that these flues related to system involved: door openings through the brass melting furnaces. Peel Williams’ Phoenix Foundry wall dividing the foundry floor ...throwing brick arches from the ground floor of the Between each of the in Ancoats, Manchester, which pavilion. This pavilion building flues there were four arched between beam and beam dates from a slightly later is likely to be one of the two openings into the south buildings and described in somewhat thus and tying the period, has such an open front pavilion. The upper storeys (fig 109). the 1796 Royal Exchange beams together by iron bolts to Insurance Policy, most of this pavilion were removed The Peel Williams foundry probably the joiner’s shop. following a fire but the prevent them from yielding to remains indicate that there building has another similarity It has been previously noted the (force of the arches)… with Murray’s Greensand that the 1800 Royal Exchange were at least two storeys above the ground floor and Southern’s letter was written Foundry in that the foundry policy included within the that the second floor was of itself is flanked by pavilions. conventional timber beam in February 1796 and Murray’s The insurance policies relating Greensand Foundry a brass construction with bridging Greensand Foundry with its to Murray’s buildings contain casting foundry. Brass was joists and floor boards. The pavilions was sufficiently reference to a pattern store structure spanning over the complete to be insurable by melted in crucible furnaces ground floor adopts a different and a joiner’s shop which pattern of construction. In a May 1796. The suspended and the crucibles containing previous part of this series, floor over the pavilion’s ground are stated to adjoin the main the earliest history of fire- floor included Strutt’s method molten brass were man- resistant industrial buildings of construction using timber foundry building. As will be handled for pouring into flask beams and brick arches. At moulds laid out on the foundry was described in connection some point in the past the brick seen from the survey ground floor. Although the earliest plan arches have been removed plan, buildings are attached to to show the brass casting area with Marshall and Benyon’s but the timber beams remain the foundry at the north and within the Greensand Foundry with the skewbacks which supported the arches. Traces south ends. The continuity of of the brick arches can be seen the type of brick and coursing in the brick wall between the shows these to be part of the same period as the foundry. Both have been heavily altered 280 Model Engineer 12 August 2022

beams and the wrought iron tie Skempton and Johnson’s drawing of the Strutt fire resisting floor system. STEAM ENGINE bars between the beams are Fig 112 Fig 111 still in place (fig 112). The remains The form of first-generation of the fire fire-resisting construction resisting used in the ground floor of floor in this building is a distinctive the South Pavilion innovation that places it of the Greensand amongst a small number of Foundry. Survey by contemporaries and within Structural five years of the first known Perspectives example. That it should be in 2005. confined to the ground floor of the pavilion is doubtless 281 related to some functional purpose, the nature of which is now lost. One possibility is that it formed the earliest core stove. It has previously been stated that Watt Jnr. had placed the core stoves for both the Greensand and the Drysand Foundries in the latter building but the Greensand Foundry was in operation for two years before the Drysand Foundry was completed. It must be assumed that over this period any cores that were required by the earlier foundry were dried in some alternative stoving facility and it may be that this fireproofed chamber served that role. Possible supporting evidence for this theory is to be found in the four arched openings that communicated between the main foundry floor and the pavilion ground floor. These would facilitate the transfer of cores between the two sections of the building but more particularly with the area used for brass casting which used cores most extensively. It is also notable that the floor of this chamber was laid in Yorkshire flagstones and in the west wall a large doorway opened into the yard, with an early cast-iron lintel spanning over. The traffic through this door opening must have been heavy, possibly involving iron or iron-shod wheels, as the flagstones were shattered in a fan pattern radiating over the western half of the floor. This could well be related to the use of the chamber as a stove. Core stoves construction will be discussed more extensively in connection with the Drysand Foundry. ●To be continued. www.model-engineer.co.uk

Roger’s Ramblings on Measurement PART 1 – CHAINS ARE FOR DRAGGING THROUGH BUSHES Roger Ican’t quite remember how it of land measurement and equal to 1 mile which means Curtis gets came about but I think it was how convenient they are to that 1 square mile is equal to the measure something about the length use. In Part 2, I will get a bit 640 acres. of the countryside. of a cricket pitch. Anyway, contentious, discuss what I some time ago, at the Guildford see as the two major flaws in But there is more. A chain 1 Model Engineering Society’s the metric system and muse is made up of 100 links and Rally, I found myself explaining about what might have been. 25 links or ¼ of a chain (5½ A measuring to one of our French members yards) is one rod, pole or chain. all about acres, furlongs But before I begin let me perch, which is another land and chains. He seemed very make it absolutely clear that measure which is still used. 282 interested and remarked how I have no desire whatsoever I have an allotment on which logical it all was - he even to change things. Like most I grow vegetables and even made notes. Others who were engineers of my generation I to this day my annual rental there also appeared interested was brought up on the Imperial demand refers to it as being and it occurred to me that it system but have had to of ‘10 rods or thereabouts’. could form the basis of this change over to the S.I. (metric) That is 10 square rods which article in which I ramble on system of units. Most of this is about 300 square yards. about my thoughts on length change occurred during the This is the traditional size for measurement in general. time I was teaching surveying an allotment and is enough and civil engineering and I to keep a family in vegetables There is quite a lot that I now consider myself multi- all the year round. Those of would like to say so I have lingual in measurement units you who are good at sums will divided it into two parts. In and generally use whatever have worked out that there are this first part I will just ramble is most convenient at the 160 square rods to the acre. on about the old methods time. However, as we shall see later, there is one application Now let’s go back to the in which I would never even chain. The surveyor’s chain, consider using anything but or Gunter’s chain, after its the old Imperial units. inventor in 1620, is, as you would expect, 22 yards long, So, let’s start at the it is made up of 100 links and beginning with what I was is similar to the one shown in explaining at the rally. As photo 1. most of us know, a cricket pitch is 22 yards or 66 feet The links are typically made long, which in land surveying of 10 or 12 gauge steel wire. It terms is 1 chain. Now 10 has brass handles with swivels chains is one furlong which at each end and there is a tag is about as long a furrow that at every tenth link. The round a horse and man can plough one is at the centre and the before they need a rest. And others have points indicating if we take a plot of land that the number of tens of links is a furlong long and a chain from the end – so the two wide we have an acre which is three-point tags are each 30 about as much as a man with links from one of the ends. a horse can plough in a day. A couple of simple sums show The surveyor’s chain is a that an acre is 10 square very clever and extremely easy chains or 4840 square yards. to use measuring implement; it can be dragged through Those who go horse racing bushes and streams and will know that eight furlongs is is easy to read even when covered in mud. It also lends Model Engineer 12 August 2022

RAMBLINGS itself to a very simple way of links was 1 foot long (that THE BUILDERS surveying the vast amount shown in photo 1 is an My next-door neighbours were having some work done on their of detail that needs to be engineers’ chain). On linear house and I could not help but overhear two builders discussing included on a map or plan civil engineering works like a problem whilst working on the roof. They had clearly taken though there is not the space roads, canals and railways several measurements and were using expressions like ‘twelve here to go into the details of the location of any feature fifty’, ‘fourteen hundred’ and ‘two fifty’. When they had resolved the process. These days we was and is referred to as its the problem one of them said “Right oh, I’ll go and get a bit of have air photographs and ‘chainage’. So, a bridge that six by two”. GPS and the chain surveying was located some 1563 feet process is largely forgotten. from the nominal beginning The Imperial system is clearly not dead. of the job was referred to as You may think that a link being at chainage 15+63 i.e. therefore 200mm long, which many links, it can become that is 7.92 inches long is 15 engineers’ chains plus 63 is close to the length of a link tangled and believe me you do somewhat inconvenient but feet. When metrication came on a Gunter’s chain, but it not want to have to try and sort this is not so. The largest scale in there was a move to use means that you either have to out a tangled surveyor’s chain, at which the Ordnance Survey the term ‘metrige’ instead but divide the link count by five or especially one with 150 links. produced Imperial maps was this never really took off and double it and divide by ten to 10 feet to the mile which is 1½ to my knowledge the term read a distance. This brings me to what I see inches to the chain or 1:528. ‘chainage’ is still used in the as the two fundamental flaws (The largest scale modern UK even though the distance is It gets worse. Though 100 of the metric system. The first maps are 1:500.) At this scale measured in metres. link (20m) metric chains are is entirely down to the French one link is 15 thousandths available it was decided that it (apologies to our French of an inch (0.4mm) which is With metrication came was a bit short for engineering colleagues), though as we about the width of a line on the metric chains but there is a purposes and would be better shall see there are very sound plan so to survey detail, such problem. How long do you to have one of a similar length and logical reasons for doing as the positions of buildings make a link? Clearly to make to the engineers’ chain (30m) what they did, and the second and fences, to half a link is them 1m long is just not and for this a metric chain is down to human anatomy. I definitely good enough. practical and a chain with 100 needs 150 links. To fold and will ramble on about these in links of 1mm will not even hold a 150 link chain needs the the second part of this article. The old civil engineers so go around your wrist! Even hand and strength of Goliath. liked the chain as a practical resorting to centimetres which Furthermore, if you drop it, ●To be continued. measuring device that they are not a preferred SI unit which is very likely with so invented their own version does not work. Metric links are in which each of the 100 NEXT ISSUE Content may be subject to change. Driving Truck David Allen adds the superstructure to complete his 5-inch gauge driving truck. IMLEC Dave Tompkins reports on the last day of the International Model Locomotive Efficiency Competition at Guildford. Oscillator Having completed his three-cylinder oscillating engine, Hotspur starts work on a suitable boiler. Dreaming Spires John Arrowsmith spends a weekend in Oxford, at the club’s rally in Cutteslowe Park. Roger’s Rambling Roger Curtis continues to fight a rearguard action against metrication, arguing that the Imperial system is far more in tune with Mother Nature. ON SALE 26 AUGUST 2022 www.model-engineer.co.uk 283

Britannia Class 7 PART 13 - PAINTING AND DETAILING Locomotive in 5 Inch Gauge A Modelworks Rebuild 134 Norm Norton takes a renewed look at this popular, kit-built BR Standard Pacific. Continued from p.136 M.E. 4695, 15 July 2022 We make prototypical engines and hope that what we finish with might be a reasonable representation of full size. The finished model I purchased the slightly tired engine underneath and I chose looking Modelworks engine to keep its original given This is the concluding article three and a half years ago, number and name. The only I have spent 25 months of Modelworks parts left are the in this series. The model of a regular five or six days-a-week heavy bits: frames, wheels, work in that period (thank you cylinders and motion parts (all BR Standard Class 7, 70013 Mr. Covid) and the diary records recut and shaped), smokebox Oliver Cromwell is now finished 550 days spent. If we say six and deflectors, plus the boiler. and it passed its club hydraulic hours for each day, that is 3,300 Almost everything else you see hours. And all for a rebuild! is new build. and steam tests in March 2022. Now, I finally play with I am pleased and happy to Photographs 134 to 138 it and draw a line under hours say that it is a Modelworks show the model and photo 139 of enjoyable construction, but also some stress at times when things went wrong. 135 136 The window frames are made from two sections of brass held together with 14BA In their day, Britannias would have had all the pipework below the running CSK screws. 1mm thick glass is sandwiched between the two frames. The sliding plate painted black. I have taken a small ‘builder’s liberty’ by leaving it in side windows are also glass and edged with mahogany laminate. bare copper, just as the full size engine is today. 284 Model Engineer 12 August 2022

BRITANNIA shows the real, ‘big’ engine in 137 2019. I have been fortunate in having this full-size engine A characteristic of a BR Class 7 is the boiler line rising to join the firebox, then falling before meeting the cab. available to see. If we make a prototypical model then we deciding to make the Hewson The Metcalfe exhaust and right model injectors that hope it might have a feel of the injector (photo 136) is a real thing when it is finished cab that upset my plans for dummy but water from the are hidden beneath the cab and I am reasonably happy tender hand pump feeds floor. that this one does. I confess a simple and quick rebuild of through it and on up to a top now that the painting of my feed clack. The two injector The black rubber water model is not strictly 1950s BR this Modelworks engine. Once steam valves in front of the Standard; yes I have made all I saw it finished with all the cab are worked by universal supply pipes in photo 141 the top pipework green but the rivet detail I knew I would have joints and they feed the left under-cab pipework should all use screw-on couplings to be in black (photo 140). I have to continue the rebuild to the chosen to leave it in copper; it connect to the engine. The does lift the appearance and same standard or be unhappy I am using the excuse that it nature of the bend is exactly does look like Cromwell today. with what I had made. as per prototype; it copes with The line of the boiler and cab at the top has come out well but the cab does sit too high as the firebox is 12mm too tall (photo 138) – I can't do anything about that. It was 138 139 The tender tank is held onto the frames by just four central 2BA studs. Above is the real Britannia in 2019. Compare this to the model in 2022 in The brackets where it meets the buffer beam are dummy. photo 134. Not quite the same viewing angle, but they do feel related. 140 141 The tender water pipes attach to the engine by prototypical spin on couplings, with an O-ring providing the seal. The small chains stop the pipes falling in the dirt when the tender is uncoupled. The steam pipes feeding the valves are wrapped in thin cotton shoelace, sealed >> with PVA and painted. The valves are operated through universal joints and the steam is delivered to working model injectors under the cab floor. www.model-engineer.co.uk 285

142 143 The interior of BR Standard cabs was black and not green. The firebox doors have been ‘chemically black’ treated. Britannias Not many ceilings would have stayed off-white for long. did not have red reverser handwheels, although some 9Fs did. flexibility and the couplings 144 145 are simple for two fingers to spin on and off. The higher LEFT: This is a driver’s eye view. There is easy cab access with the large tender bulkhead insert removed. connection behind is from the The tool tunnel adds interest, without getting in the way. The footrests are on the tender which means that tender hand pump. It uses heavier wall fuel injector hose I can work all the controls by hand, but a small handle makes operating the reverser much easier. and the ends are connector RIGHT: With the cab roof and bulkhead insert in place you would have fun trying to fire and drive this! crimped. The little chains stop the pipes falling down into tested steam brake valve now 146 the dirt when the tender is decided it liked leaking all the disconnected. time. The water gauges also It looks nice, but there are some problems here with tender and cab gave me problems and next alignment caused by the boiler height and an over-long drawbar. Below the cab in photo 142 time I would do things a little is a dummy 10X injector, but differently. the model injector does feed through this and up to the I sorted out its working with left hand top feed. The often compressed air for the big quoted need for ‘short and leaks, then hydraulic tested easy feeds for the injector’ are and steam trialled at home. I not strictly to be believed; it is arranged for fifteen feet of track working fine at the moment. by linking two trollies and was mightily relieved to find that the The cab shell lower interior PTFE head piston valves did in photo 142 is green but I not bind and that the industrial think the standard should be stainless and PTFE regulator black. The driver has been ball valve I have found worked treated to foam cushions with waxed material covers (photo 143). We will see what happens when a piece of burning coal lands on them! Photographs 144, 145 and 146 show further details. Commissioning Commissioning is a word often used for making built machinery work and in the case of small engines it is not an insignificant task. Once painting and reassembly was finished I had the job of finding out whether it was leak tight. A few pipe connectors had to be sorted out; one water valve did not flow and the whole pedestal had to come out as the previously 286 Model Engineer 12 August 2022

BRITANNIA 147 148 Preparing the engine in Gilling East steaming bay. (Photo, Mike Lock). 149 The track is fully signalled which makes it so interesting and needs concentration. About to set off for its first trip to collect a train from the yard. Sometimes you are stopped long enough to be able to take a photo. One of the signals will drop to show the road is set. perfectly - I was able to run the in the village of East Gilling, pipework steam leaks that The tender now has coal engine forward and reverse, not far from the North Yorks came and went, driving with drain cocks open, up and Moors Railway. truck seat broken and the dust and bits in it, the cab is down the fifteen foot. A very valve timing has moved filthy from ash rising through satisfying session. Next day, This five-inch Oliver Cromwell somewhere as she would not the fire door after disposal, another steam test and another performed excellently over notch-up and sound correct. the paintwork spotted with hydraulic to find out what had three days, being in steam for I am also unhappy with the opened up - and then the Club around ten hours and covering prototypical length of the oil and water stains and oil is official test a few days later nine miles pulling a variety of tender front buffers (photo dripping from the motion. I am when I knew all was good. 145) – they require that you pleased that I just escaped trains (photos 148, 149 and fit an excessively over-length the emotional trap of thinking Just a week after the official 150). drawbar to prevent them going ‘this is too precious to use and steam test I had the great solid on tight curves and get dirty.’ But should I have fortune to be booked into I have no problem in telling throwing the bogie or tender spent so much time turning a weekend GL5 Club event you, also, what went wrong, off the track. I am going to cut a Modelworks engine into a (photo 147). This was at the including:- a bogie wheel those buffers right down! better looking example? Well, I kind invitation of Ryedale SME coming loose from its axle, the am very content with it, it gives who run an outstanding track front bogie being too lightly All these jobs are to do me great pleasure and that loaded causing worsening now we are back home. The enjoyment will continue by derailments, various minor injectors worked perfectly, the using it and not putting it in a fire was kept just about right glass case. 150 by the exhaust draw and even the steam brake worked. The I want to acknowledge and I am indebted to ‘Thompson Locomotive Engineering’ for this image and for posting the regulator was a delight to use. thank the following people: video film on YouTube (search GL5 Spring Event 2022). The engine has a nice exhaust These are the key things that Doug Hewson for his earlier note, that I am pleased has worked out, and the sound of the Mk1 coaches over the make an engine pleasant to series of articles in Model rail joints is wonderful! And, yes, apparently BR did run milk tankers behind express drive. Engineer on this same subject passenger trains, but my apologies for still having a light engine head code displayed. of a Modelworks upgrade – he Once you have experienced gave me much inspiration; ground level driving, with Geoff Watts of Northampton true rolling stock, working SME whose generosity to the timetables and full signalling, club resulted in me purchasing I am afraid that, for me, going this engine and Chris Orchard, a colleague who helpfully round in circles on a raised track just does not have the sowed the seed that resulted same appeal. in my writing this series. ME www.model-engineer.co.uk 287

12 Drivers eye view of the approach to the tunnel on the ground level track. The impressive footbridge over both the raised and ground level tracks. The 2022 Sweet Pea Rally John This year the rally was did attend had a very good 3). Malcolm was quickly Arrowsmith again held at the weekend. At these events the followed by Chris Ball from finds Fareham Society of steaming bays are always the the Nottingham SMEE (photo that Sweet Peas are Model Engineers in Hampshire place to be early in the day and 4) who was again making flourishing in Fareham. (photos 1 and 2) and they it was no exception this time, it look so easy. However, are the first club to have held with a number of locomotives Chris is a regular fireman on 288 it four times. The weather being prepared and steamed. the full-size locomotives of forecast for the weekend was the Great Central Railway good so I was looking forward Usually, there is an unwritten at Loughborough, so if he to an interesting weekend competition to see who can couldn’t get his locomotive with lots of good running be first on the track and going well then the rest of us and exchanges of ideas and unsurprisingly Malcolm High didn’t have much of a chance! comments. maintained his record with his The only 7¼ inch gauge familiar Adele Marie, an 0-4-2 locomotive in steam was the The Fareham Society is very tender version of the ‘Sweet regular performer Jacquie O, fortunate in owning their own Pea’ model which was taking an 0-4-2 version of the design site and, as they explained to the track in its stride (photo me, everything you see when you enter the ground belongs 3 to the club - there are no outside interests to complicate A happy Malcolm High leaves the station to travel round the circuit. the running of the society. These days, to have that sort of security is a very favourable position to be in and gives the committee the confidence to plan ahead. When I arrived on Saturday morning there was a buzz of activity about the grounds which augured well for the weekend. However, it turned out to be a little disappointing for the club because the attendance was down from previous gatherings, probably because of the high cost of travelling these days, but nevertheless those that Model Engineer 12 August 2022

SWEET PEA RALLY 45 Chris Ball from Nottingham runs past the steaming bay with Ernie steaming well. 6 Phil Owen from Blackgates slows to stop in the station. The small display of working stationary engines in front of the clubhouse. (photo 5) owned by Phil Owen. hosts had put on little display This engine was in steam for of stationary engines which 7 the greater part of the day and were all very well made a number of other drivers were and added to the overall given the opportunity to take atmosphere. A nicely made the regulator. It is an excellent Cross Engine was the work of engine to drive and performed Charles Read and was quietly well on the Fareham track. working away powered by a small boiler plant that Chas Away from the track the 8 A detailed Cross Engine built by Charles Read. The boiler plant owned by Brian Fisher. >> www.model-engineer.co.uk 289

9 10 The 1930 Austin 7 owned by Clive Addis has been in the family for 85 years. A double electric version of the engine owned by Phil Brien from the Fareham club. 11 12 An excellent little ‘Sweet Violet’ 3½ inch gauge version of the engine. picked up second hand, not gravity fed from a tank in front Brian Holland from Oxford concentrates on the line in knowing what condition it was of the passengers, the shock front with his 0-6-0 Metre Maid Fair Rosamund. in. However, it was cleaned absorbers are made of wood up, tested and passed all the and apparently are useless in solid looking appearance. such is the layout that with the required conditions and here wet weather. When Clive tried Meanwhile three generations 7¼ inch gauge track running it was powering his engines to replace the tyres he had to round the outside, four lines (photos 6 and 7). Adjacent to wait for sufficient numbers of the same family were come together in one part of this set-up Brian Fisher had to be required before they enjoying their track time. the site so that four trains can his small boiler plant (photo could be made. There are no Regular attendee Brian Holland be side by side all appearing to 8) working away powering a door locks and the advance had his 0-6-0 ‘Metre Maid’ go in different directions but in well-made Steeple Engine. A mechanism in the distributor running well (photo 12) and fact are all proceeding towards couple of other interesting can be adjusted from inside with him was son Paul (photo the main station. exhibits were on the site, the car. It seems motoring 13) and grandson Martin (photo one of which was a 1930 in those days was a lot less 14), who were making the Other locomotives going Austin 7 motor car (photo complicated than it is today. most of the excellent track at well during their time slot was 9). It was bought by the Fareham. The raised track itself the 5 inch gauge Sweet Jay present owner’s grandfather One of the more unusual is about 450 metres long and from the Hereford SME driven and Clive Addis told me that locomotives on site but not it has been in the family in steam was the Mallet style for 85 years. He personally electric 2-4-4-2 of Phil Brien, renovated it to the condition a Fareham club member. This it is in today about 40 years engine always creates a lot ago, so you can see from of interest when it is on show the photograph what a good (photo 10). Alongside it was job he made of it. Compared a nice little 3½ inch gauge to the modern car it has ‘Sweet Violet’ version of the remarkably few refinements. design (photo 11). I don’t know For example, the petrol is who built the locomotive but it was well made and had a very 290 Model Engineer 12 August 2022