z186loh1spz magzus.org by Thomas Swift

LOCO BUILDING FOR NOVICES

BRAKES FOR A RIDE-ON TENDER

JANUARY 2023 ❙ £5.49

THE MAGAZINE FOR MODEL ENGINEERS

Prime Attraction MME show displays Making an electronic loco horn

CHALLENGES OF MAKING THE CHANGE TO ECO LOCO FUELS

CONTENTS

JANUARY 2023

Volume 44 Number 07

10 21 OF THE 06 COAL FUTURE ON TRIAL by Edward Parrott

BENCH TALK – FLATENDED BORING TOOL by Harry Billmore

GAUGE 1 MIDLAND COMPOUND – FINALE by Anthony White

–A 14 ELECTRONICS TWO-TONE LOCO HORN by Julian Harrison 1

7 / -INCH GAUGE RIDE21 ON TENDER PROJECT 4

by Peter & Matthew Kenington

BENCH TALK – 25 MORE LATHE STOPS & GAUGES by Harry Billmore

GAME – 26 HARRY’S UNEXPECTED ISSUES by Harry Billmore

MIDLANDS MODEL 31 2022 ENGINEERING SHOW NOVICE GUIDE 36 CONWAY: TO LOCO BUILDING 39 REVIEWS 40 GENERAL NEWS 41 CLUB/TRACK NEWS 45 DIARY by John Arrowsmith

by Rich Wightman

Veteran line revival effort

Lowmex show returns

Two months of events and meetings

FRONT COVER This month we feature the club and display classes at the Midlands Model Engineering Exhibition and editor Andrew Charman captured this animated scene amongst the Fosseway Steamers outside the exhibition hall. John Arrowsmith’s report begins on page 31.

EDITORIAL

Why we cannot ignore the need to try future fuels

elcome to the January edition of EIM and a new year of model engineering – hopefully we will see a continuation of the rapid return to normality that took place throughout 2022 and lots of highlights to look forward to. This issue kicks off with regular correspondent Edward Parrott describing the latest efforts by the Rugby club to trial more sustainable fuels in their locomotives. This is a very important subject, not least because the future availability of traditional coal is looking increasingly uncertain. You can rest assured that we are going to be giving due prominence to moves to make our hobby ‘greener’ in future editions of EIM, including in a forthcoming issue describing in detail potentially revolutionary boiler technology currently under development in New Zealand, technology that claims to make steam the most environmentally friendly option! Why are we highlighting this? In truth, the contribution of the global model engineering community to carbon emissions is miniscule and any measures we make to reduce our carbon footprint will be virtually unnoticeable in the grand scheme of things. But public perception also has a major role to play and the increasing perception in today’s environment is that steam locomotives are dirty burners of fossil fuels and increasingly out of step with today’s values. It’s an issue that full-size heritage railways are in the front line of, but we in the miniature community need to do our bit too, and show those outside our numbers that we are working very hard to reduce our emissions. We conclude our 2022 Midlands show coverage in this issue, having celebrated what was a very good show. It was also the only major model engineering show held in 2022, and currently it looks increasingly possible that it will also be the only major show of 2023 – the latest confusion over a potential Harrogate show is reported on our news page. We hope the Midlands show does not remain as the only major model engineering event – we need these opportunities to get out and show off our hobby to the public. Andrew Charman – Editor The February issue of Engineering in Miniature publishes on 19th January.

Editor: Andrew Charman Technical Editor: Harry Billmore Email: andrew.charman@warnersgroup.co.uk Tel: 01938 810592 Editorial address: 12 Maes Gwyn, Llanfair Caereinion, Powys, SY21 0BD Web: www.engineeringinminiature.co.uk Facebook: www.facebook.com/engineeringinminiature Subscriptions: www.world-of-railways.co.uk/Store/Subscriptions/engineering-in-miniature FOR SUBSCRIPTION QUERIES call 01778 392465 – the editor does not handle subscriptions. Publisher: Steve Cole Email: stevec@warnersgroup.co.uk Design & Production: Andrew Charman Advertising manager: Bev Machin Tel: 01778 392055 Email: bevm@warnersgroup.co.uk Advertising design: Amie Carter Email: amiec@warnersgroup.co.uk Ad production: Allison Mould Tel: 01778 395002 Email: allison.mould@warnersgroup.co.uk Marketing manager: Carly Dadge Tel: 01778 391440 Email: carlyd@warnersgroup.co.uk

Published monthly by Warners Group Publications Plc, The Maltings, West Street, Bourne, Lincolnshire PE10 9PH. Articles: The Editor is pleased to consider contributions for publication in Engineering in Miniature. Please contact us to discuss your work. © Publishers & Contributors All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the Publishers. This periodical is sold subject to the following conditions; that it shall not without the written consent

of the publishers be lent, resold, hired out, or otherwise disposed of by way of trade at a price in excess of the special recommended maximum price, and that it shall not be lent, resold, hired out, or otherwise disposed of in mutilated condition, or in any unauthorised cover by way of trade, or aﬃxed to as part of any publication or advertising, literary or pictorial whatsoever. Whilst every care is taken to avoid mistakes in the content of this magazine the publishers cannot be held liable for any errors however arising. The reader, in pursuing construction and operation of any product, should exercise great care at all times and must accept that safety is their responsibility. Engineering in Miniature – ISSN 0955 7644

FUTURE STEAM

Coal of the Future EIM intends to highlight the potential for more sustainable miniature steam in future and the efforts being made to achieve it – in this first feature Edward describes the Rugby ME’s experiments with new ‘green’ replacements for locomotive coal. BY EDWARD PARROTT

t the start of 2022 the availability of future coal supplies was raised as a potential problem, with all heritage railways suddenly finding themselves in doubt as to what fuel they’d be able to buy and burn. Welsh Dry Steam Coal is the perfect fuel for steam locomotives, however the washery at Ffos-Y-Fran colliery in south Wales, the only company still mining this coal, had broken down. As the planning permission for the mine was scheduled to end in October 2022 and the coal is only washed for the heritage sector, the company had deemed it uneconomical to repair the washery and so supplies were about to dry up. The supplies were always expected to end in late 2022/early 2023 so the inevitable had just happened a few months early. Kazakhstan in Eastern Europe produces good quality coal, however the war in Ukraine has put a stop to that source for the time being. Various alternative fuels are on the market, although most are manufactured for use in open fires and aren’t necessarily suitable for use in forced fires as is the case with steam locomotives. A number of preserved railways, led in no small way by the 15-inch gauge Bure Valley Railway, have been

JANUARY 2023 | ENGINEERING in MINIATURE

“The old mantra of little and often holds true: getting the fire hot and keeping it hot seems to do the trick...”

trialling alternative fuels, and they’ll be taking the lead for operators of steam engines in finding our future solid fuels. A biomass/coal manufactured fuel from CPL called Ecoal 50 was leading the way at the start of the year, (Photo 1), this comprised of hot-pressed briquettes, 50 per cent anthracite and 50 per cent crushed olive stones, with molasses as the binding agent. This is readily available and has been giving good results, while the manufacturers have also produced a number of ‘blends’ varying the make-up to produce a more productive fuel – these are currently only available to the railways doing the trials. As the year has progressed, however, Ecoal 50 has seen less use and increasingly trials have been made with pressed briquettes of, essentially, coal dust, while among other fuels being trialled is one made from the waste resulting from rapeseed oil production (more on this in a coming issue - Ed). To see whether Ecoal 50 would offer a potential alternative for miniature engines, we at the Rugby ME elected to follow the lead of the preserved railways and trial some of it. Our April Members Running session provided the date, with the locomotives in steam for the trial being our two Romulus designs ‘Myglyd’ and ‘Dr John’, both running superheated copper boilers pressed to 100psi. Both were lit up in the usual way and besides the wood used to light up, both burnt Ecoal 50 exclusively, the bunkers having been

swept out before we started the trial. The Ecoal fuel comes in pressed hexagon briquettes (hexoids?), which are a perfect size for full-size steam (around that of a clenched fist) but somewhat large for our requirements, even in the quite large 7¼-inch engines we usually play with! Two bags (totalling 50kg) were broken down by hand.

Hard break The coal is maybe slightly harder than Welsh, but doesn’t disintegrate into dust when broken. A suitable small contact point providing high stress when given a sharp tap with a coal hammer, usually produced three or four suitably sized lumps and very little by way of useless dust. By volume those two bags broke up into 1½ bags of suitable coal for 7¼-inch, that is 20-40mm grade, a quarter bag of 5-inch coal graded 12-20mm and the remaining quarter bag between dust and 12mm. For running the two Romulus locos, we burnt the 20-40mm graded coal. This size gives a good balance between burning away in a flash and being so large that the fire doesn’t build properly and just draws cold air. At lighting-up both Romulus were in steam quickly, there being no noticeable difference to lighting them up on Welsh steam coal, so all was looking very promising. Once in steam, the two locos were put on the head of a six-carriage set, with a maximum seating capacity of 34 adults (Photo 2). As a Guards training session was in action, a good www.model-engineering-forum.co.uk

FUTURE STEAM

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HEADING: The two Romulus locos provided the motive power for the tests. PHOTO 1: Under study, the Homefire Ecoal.. PHOTO 2: Many willing hands to provide a train load. PHOTO 3: Ecoal burns well with no shortage of steam. PHOTO 4: The train can be left for a period with the fire looking after itself. PHOTO 5: Lumps of clinker pulled out through the firehole door. All photos by the author

public trains running, and we were keen to avoid a clogged mesh skewing results early in the trials. However the ash deposited on the carriages was probably too fine to have been caught anyway. We could try a smaller mesh, but there’s a risk of it clogging more, we’ll have to think on this.

Hot – but not that hot As far as generating steam goes, yes it does, just as you’d expect given that several heritage railways have been running on the fuel. It doesn’t have the heat of Welsh though, despite working hard it was possible to knock it off the boil quite easily by using the crosshead pump or steam pump to fill the boiler. The old mantra of little and often definitely holds true: getting the fire hot and keeping it hot seems to do the trick – I ran a relatively thin fire, filling the box up ahead of gradients as required. The eCoal certainly seemed to take a bit longer to deliver the heat so drivers need to be more proactive than reactive. Again, this behaviour was expected to be more apparent under sustained heavy load, and the requirements may also change under such a sustained heavy load. I have a feeling a slightly sharper blast may be required to force the fire more than before, something we could easily fiddle with on the two Romulus as we have interchangeable nozzles. Good smokebox arrangements are I think

going to be more important than ever. Having had our play, and got to a point where we reckoned we’d given the fuel a real chance to show if there were likely to be any problems, we decided we really ought to see whether there was trouble brewing in the ashpan or in the smokebox, so we dumped the carriages and headed for the steaming bays to see what we would find. The boilers were filled with water to bring pressures down, the chimneys were capped to kill the fires, and we retired to the clubhouse for tea to compare findings. Once the fires had gone out, we pulled the remains and dropped the ashpans, and were actually very surprised by what we found, as the photos show. Clinker was immediately obvious, sitting in the fire itself (Photo 5) and some was pulled straight through the door. I pulled out as much as I could and collected it together on the footplate, and as a result of five hours running we concluded that actually it was a pretty acceptable amount for a six-inch square grate (Photo 6). The story with the other Romulus was pretty similar, however the clinker had adhered itself to the firebars in one lump, which explains why this loco had gone off the boil more towards the end (Photo 7). Dropping the ashpans revealed a considerable quantity of very fine ash, but no indication that clinker had

number of passengers were available for the first couple of laps so the locos had to work hard. The fuel burnt well and there wasn’t any shortage of steam (Photo 3), however it quickly became apparent that they were burning more of the Ecoal than they would of the Welsh. Over the course of the day, we established the bunkers were lasting roughly 2½-3 laps where previously around four had been the norm. Both Romulus were in steam for around five hours, quite a meaningful duration, with a reasonable pause at lunchtime. Like the Welsh dry coal, the loco could be left sitting for a time with an Ecoal fire without using the blower to produce a draw through the fire to keep it alight – this should be expected with these manufactured fuels which are primarily designed for open fires (Photo 4). Neither loco at any point struggled for steam, but of course the real test would be at the next public running day when the results might be slightly different. We would be expecting to be running a six to eight-carriage set, with a seating capacity of 34 to 45 (this depends on how many full passenger carriages and how many Guards vehicles are marshalled in), so that would provide a real test under sustained properly loaded conditions. During testing it became obvious that both engines were lifting ash out of their chimneys. Neither had their spark arrestors in as there were no

ENGINEERING in MINIATURE | JANUARY 2023

FUTURE STEAM

PHOTO 6: Clinker amount produced not surprising for the size of grate. PHOTO 7: Clinker had adhered to firebars in a lump, cooling the fire as a result. PHOTO 8: Plenty of ash but not clinker in the ashpan of one Romulus engine.... PHOTO 9: ...while the other produced a similar story. PHOTO 10-11: Plenty of fine ash in smokeboxes of both locos. PHOTO 12: The reason one of the engines exited the tests earlier than planned...!

formed in the ashpan – a good sign. A few more pieces of clinker came out of my engine (Photo 8) but the story was basically the same with the other Romulus (Photo 9). At the front end was a similar story: both smokeboxes had a quantity of very fine ash, not as much as I expected given a five-hour running session but then we did have the rain of fine ash as we were running, so we know that some of it was going up and out the chimneys (Photo 10-11).

Best laid plans The day of the public running arrived a few weeks later, but it didn’t exactly go to plan! The two Romulus locos set out as planned on the six-carriage train, but after 90 minutes running, Dr John suffered a catastrophic failure of its valve gear and had to be retired, being recovered by my Romulus, complete with all six loaded carriages! We decided to play it safe with my engine, and actually dropped the fire at lunch time and relit a new one ready for the afternoon session – our public

JANUARY 2023 | ENGINEERING in MINIATURE

running sessions are intense and we didn’t want to risk shy steaming due to clinker and then an early failure, especially given we were already an engine down now. As it turned out I found no clinker in the fire bed when I dropped it, so I probably could have kept going for the afternoon. Lighting up was as you’d expect the same as the previous trial, that being a pretty consistent thing from one day to the next. We set out on our train and actually despite our concerns that we might burn even more or that we might need a sharper blast, we actually found for 90 minutes we were running pretty much as we had been before – we didn’t really burn any more of the fuel, and at no point did we think we could have done with more steam. One thing was very apparent though, despite the spark arrestors being fitted, we were still raining very fine ash down on the train. My loco was running as train engine and has a 2mm mesh grid, the club Romulus was running as Pilot and that has

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FUTURE STEAM 3mm perforated metal screens – I’m not sure how a smaller mesh would work, however we wouldn’t struggle with sooting up like some fuels we tried later in the year. For the afternoon session, having lost my running mate, I dropped back to four carriages which is the norm for me. Two drama-free hours passed by, and come the end of the day when dead fires were drawn, we found we had pretty much the same results as during our trials a few weeks previously, so at least we could be fairly confident the fuel was going to be consistent. We’d only bought 5 bags of the Ecoal 50, and that was now gone, so going forward we’d be looking to try something else, or settle on the Ecoal as our fuel of choice. Being the experimenters we are, we opted to try something else! Throughout the year there’s been quite a lot more testing including with our East African Garratt locomotive number 5928 ‘Mount Kilimanjaro’, and as that burns five bags of Welsh in a day, we could be looking at getting through eight bags of alternative fuels.

So far, however, it does appear that the Ecoal 50 could be a workable fuel. Following the trials, our conclusion was that any loco over the size of a Thomas II will probably be okay running on the full-size lumps after lighting up, requiring broken lumps for lighting up, so there’s a greater surface area to catch and build up the firebed. Thomas 2s and under will almost certainly need coal crushed to 20-40mm grade, regardless of whether it will fit through the firehole door. We still have a very good supply of 20mm anthracite suitable for the smaller locos, such as 7¼-inch gauge standard gauge models and down to 3½-inch gauge, at some point though we’ll need to try the Ecoal in a smaller engine to see whether it can perform. Crushing the standard lumps does produce smaller lumps as noted above, so if we can make use of that in smaller models it won’t be wasted. Next time I’ll describe how we have tried some more manufactured fuels and some ordinary lump coal, but I’ll leave you with this image of the Romulus failure! (Photo 12). EIM

12 “As that burns five bags of Welsh in a day, we could be looking at getting through eight bags of alternative fuels...”

■ Edward intends to continue his description of these trials, which are highly relevant to the future of miniature steam, next month. The Future Steam series will also include a study of potentially revolutionary boiler technology under development in New Zealand – apologies that this feature, originally planned for this month, has been slightly delayed.

BENCH TALK

A flat-ended boring tool Harry shows that if you don’t have the right tool to hand, you simply make it... BY HARRY BILLMORE

lsewhere I have described the making of a flat-bottomed pocket. To produce this I did not have a milling cutter of the right size available, so I made the tool that is described here. I started with a taper-shank drill that had suffered the destruction of its edge and tip at some point in the past, so was pretty useless as a drill without major work being done to it.

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BELOW: An old drill with one end machined to fit an ER32 collett and the other ground to a flat cutter. BELOW RIGHT: End of the tool ground to two flat cutting edges.

I turned down the taper on the lathe to fit the largest ER32 collett chuck I have before starting to grind the tip. I ground the whole thing completely flat to start with, before grinding the rake on the cutting edges to about 10 degrees.

Further uses The suitably-modified drill then performed excellently as a flat-

bottomed boring tool and it has wider uses – the same technique can be used to make a sheet metal tool. If you grind the centre into a concave shape so the tips are the part that do the cutting, you will be able to cut neat circles without the drill snatching and lifting material up the shank. EIM ■ More useful workshop tips from Harry on page 25

ENGINEERING in MINIATURE | JANUARY 2023

SMALLER SCALE

Restoring a Gauge 1 Midland Compound Anthony concludes his workshop restoration of an electrically-powered Gauge 1 locomotive with some final details and then the essential testing. BY ANTHONY WHITE Part 9 of 9

s soon as the cab footplate was ready and finalised it was time to sort out the loco to tender coupling arrangement. The exact design is largely immaterial as it’s not visible, and I tend to leave them coupled permanently except for extensive maintenance or repair work. I used most of the original pieces I had acquired but I modified them as they were originally coupled much too far apart. I think it looks better to get the distance from cab side to tender side correct (I made it about 16-17mm depending on the drawing you choose) and to make sure that the footplate of the cab and tender match in height and extension and don’t clash on your minimum radius curve. The original tender coaling plate was about 5mm too high and this involved quite a bit of work to get it down to size, cutting 5mm off all four supports. I use a standard 9ft radius piece of curved track for testing all this as it’s unlikely such a loco will run on track under this radius. You can see the result in Photo 67 where the tender and cab plates are the same height and on a 9ft curve the two hardly just touch. While you’re working on this it is a good time to make the fall plate to cover the gap. In the prototype it has four hinges and while this is reproducible it proved rather fragile and as my grandson, eventual owner of the loco, may not be able to repair any damage I opted for a simpler solution, with two 1mm holes in the rear edge of the cab floor and a couple of matching nickel-silver wires under the rear of the fall plate so that the plate drops into position (Photo 68). It sits nicely, hinges slightly and can easily be removed and replaced even with the loco coupled up to its tender. The fall plate is made from some 10mm scale etched plate – I’m not sure it’s correct for Midland locos, photos tend to show them as having a studded appearance, but I had some to hand. Because of its size I needed a join in the middle but that is prototypical. The join is reinforced by a strip of 0.1mm nickel silver strip underneath and curved as per prototype.

JANUARY 2023 | ENGINEERING in MINIATURE

Electrics and Electronics Before going further with the electrics, I needed to order a radio-control transmitter, receiver, electronic speed control (ESC) and sound card and while waiting for these to arrive I still needed to make and fit a chuff trigger – this consists of a square cam on a driver axle and a microswitch with lever and I needed to decide on a convenient place to fix it. The item that needs making of course is the cam – as I didn’t want to have to take the driving wheels out again it had to be retro fitted. I soldered together two rectangles of brass to make a square of about 11 x 11mm, (12 would have been better) chucked it in the lathe and centre drilled it ¼-inch (the size of the driving axle) then drilled for it tapping in both sides to take two 14BA countersunk screws. Once drilled tapping size, I simply unsoldered the two halves, tapped one side of each and opened out the other side to clear the thread. Then the two halves could be joined over the axle and tightened up and now all that was needed was a convenient bracket to hold the microswitch. I had to use a smaller microswitch than planned – there wasn’t a lot of room as a large chassis cross-piece was now in the way. I could probably have reduced the diameter of this or even done away with it altogether but with the chassis assembled and fully fitted out I could not face the extra amount of work this would have entailed, so I made do with the arrangement shown in Photo 69. The left of the photo shows the setup from above with the cam on the

axle and the lever of the microswitch just below. On the right shot from below shows the microswitch on its bracket fitted over the cam (scarcely visible) fixed to the rear cross-frame

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SMALLER SCALE Speaker installation

spacer. The microswitch is secured with the two 14BA countersunk PHOTO 67: screws holding the two halves of the Tender and loco bracket together, just visible and the close coupled on lever of the microswitch below it but a 9ft curve. out of sight. Because of the way the design PHOTO 68: ended up it did have the advantage of The fall plate allowing the bracket to be fixed by the dropped into right-hand 10BA steel screw to the rear position at rear and another 10BA brass screw ahead of cab floor. of it, working through a brass nut soldered to the bracket. This acted as a PHOTO 69: means, when screwed downwards, to The chuff cam slightly lift the front end of the bracket on the left and and so adjust the point at which the microswitch microswitch went on and off. assembly right. Now was a good time to test the setting and also it was useful to know PHOTO 70: which of the three terminals on the Parts for the microswitch were most appropriate. I loudspeaker did the test by fitting the chassis in the sandwich and the bodywork, upending it in a cradle and assembled unit. connecting the motor to a variable 12-volt power source and the PHOTO 71: microswitch leads to a buzzer. At The under-theabout three volts you get a nice slow boiler repair and steady turning of the drivers and a the loudspeaker regular intermittent buzzing noise so I in position at was happy to leave the screws as set. front of firebox. PHOTO 72: On the left the burred and filed gap in front of the chassis ashpan, at right the new lower shape of the modified speaker sandwich.

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Testing time At last it was time to put everything together and run some tests, first on rollers and then a full track test with a wagon or carriage load to see what she could haul, at what speed and for how long. I also wanted to gauge what the controls were like and maybe make some adjustments to the electronics. Before putting the body on the chassis, I thought it prudent to set up all the leads with appropriately coded plugs so that when the loco and tender are coupled both myself and my grandson know which leads have to be joined. I used the same system as used in the Gauge 1 Bulldog loco described in the book produced by G1MRA. ENGINEERING in MINIATURE | JANUARY 2023

All photos by the author

All this work had resulted in much handling of the chassis and some of the 12BA nuts on the brake gear had started to loosen, one even fell off. The next job was to go over everything and take the plunge, adding some nut adhesive to the various joints. At this point there was little left to do – I was still waiting for the radio gear to arrive so that I could fit it and take the loco for a track test. I did order the cab-side crests from Fox Transfers (www.fox-transfers.co.uk) and checked the weight of the loco to make sure it had enough to prevent driver slip, a job I had been putting off. The loco weighed 2,145gm (with the additional weight I’d added into the firebox in the chassis) which was more than 900gm heavier than my previous 4-4-0 – this had been made of much thinner material, and struggled with wheel slip hauling four bogie carriages on a somewhat oily track but seemed happy enough when weight was added to bring it to just under 2,000gms. So I decided the Compound would remain without any extra weight until the first track test run was carried out.

The speaker was fitted in the front of the firebox, so as to use the boiler as a sound box. It first required me to make a curved piece to fill in the gap where the underside of the boiler had previously been cut away to accommodate the motor in the original model. This was followed by a fixture to hold the speaker in position (Photo 70). On the left are the two parts to sandwich the speaker and on the right the end result. If you’re trying something like this now do read on before doing so as I discovered that the assembly did need a further slight modification. In the next picture (Photo 71), the repair to the rear underside of the boiler on the left looking backwards and, on the right, looking forwards with the assembled loudspeaker ‘sandwich’ in position in the firebox. Screwing the curved repair piece of nickel silver into position has to be done before any other fixings are put in place to make the task as easy a job as possible. It was at this point that I discovered again that the bodywork would no longer fit neatly on the chassis, because the speaker ‘sandwich’ is directly in line with the front of the firebox ashpan I had put in the chassis, right up to the top of the frames. The speaker assembly could not be cut down enough – you need to have at least one bolt or screw here, to hold the ‘sandwich’ together. So I had to do a bit of burring on the ashpan assembly followed by some filing to tidy things up and make everything fit. The result of this modification is shown in Photo 72, the left part showing the cutaway from the firebox ashpan front in the chassis viewed from above. The right side shows the speaker unit from below, as finally fixed to the rear of the boiler with the modification made to its lower edge so that the chassis and body now sit perfectly together.

SMALLER SCALE

73 “It ran well and all the controls worked, but to my horror the chuff cam was slipping and I could not tighten it up...”

weighed 1,227gm, the tender 1,032gm and with the AAA battery pack 1,188gm giving an overall weight of almost 3.5kg. On a short length of track the loco moved off well and if I held it stationary I could double the weight and still have power at the driving wheels to move freely. In fact, by pressing down as hard as I dare without bending the metalwork, I could not stall the motor, the drivers just turned and slipped on the rails. At the other end of the scale on rollers the motor only drew about 100mA at 12 volts and would run down and continue motion to less than 1 volt without hesitation.

Taking to the track From the body there were the speaker and the fire LEDs – these can be seen in the upper part of Photo 73. From the chassis two further leads run from the motor and chuff trigger. Although the leads to speaker and chuff trigger are identical (they are by Miniatronics) and very small, useful in size and rated at 1 amp, they are reversed for the two jobs so that the plug ends cannot be connected incorrectly in error. The same goes for the motor and LEDs, standard radio-control plugs and sockets, but in addition as a belts-and-braces precaution and because there are a lot of them arriving in the tender I have coded all the plugs with different colour paint, although this might not show well in the pictures. The first test was done with the chassis on a rolling road and the bodywork lying separately with all leads joined – it ran well and all the controls worked, but to my horror the chuff cam was slipping and I could not tighten it up. The brass 14BA countersunk screws had such a shallow slot in their heads the screwdriver didn’t grip firmly enough. I had to separate the cam halves, file a shade off one face and replace the original brass with steel screws that had better slots. If it were to continue to be a problem I might have had to

add a tiny grub screw to fix the cam more securely, but it has all remained satisfactory since. These first tests showed the motor flipping over when changing direction although it did not appear to be causing any problems. But it was irritating and not very engineered. So I used a couple of 12BA screws that were sticking conveniently inwards though the nearby frames as holders for a piece of nickel-silver strip sprung between them, with suitable holes to slip over the aforesaid screws, and over the motor as shown in Photo 74. This seemed to do the trick, was very easy to place in position and could just as easily be removed without causing any problem. The motor is the Maxon VML5 10watt B7741 with ball races and wire leads. It is stated to do no load at 10,980rpm. I confirmed this as under test on a measured 12 volts I made it 10,488rpm. But the battery pack is 12 x AA giving 14.4 volts, that I measured as increasing the speed to 12,426rpm. The stall current is quoted as 7.5amps and maximum continuous current as 0.84amps at 6900rpm. So much for some of the theory and static tests but what did it do in the loco turning over the wheels and motion and with a load? First some bench test measurements – the loco

PHOTO 73: At top are the leads from the speaker and fire LEDs coming out of the bodywork and below it the motor leads and chuff trigger from the chassis. PHOTO 74: At left is the strip of metal for stopping the motor swinging around the axle when changing direction. At right it is fixed in position. PHOTO 75: The finished loco completing its track tests and ready for the paint shop. PHOTO 76: The realistic effect of the fire. PHOTO 77-79: Views of the finished loco, a restoration job to be proud of.

JANUARY 2023 | ENGINEERING in MINIATURE

I moved on to track testing where light loco it ran at a shade over 90mph, and with a train of four heavy bogie carriages on a one scale mile circuit with some up and down gradients and running through station turnouts it averaged 80mph. Realistic shunting can easily be controlled down to scale walking pace as it was as controllable as a modern DCC loco, and there was no wheel slip although I’m sure if I had made the load heavy enough some slipping would have occurred. Signal strength and control was good even though the receiver was completely inside the metal tender and there is no external aerial. On its final track test, after the battery had been in use for some 45 minutes, I timed its top speed light engine over a 44 feet length of straight and level track as just over 90 scale mph and for a scale mile, with the gradients and the four bogie vehicles it averaged again a shade over 80mph, which is what I was expecting from theoretical calculations of battery power, motor rpm, gear ratio and driver diameter. This was a satisfactory performance although I thought it seemed more realistic when doing about 60mph. Photo 75 is a still from a video taken during some of the first on-track trials. Although I cannot show you the loco moving under power I can give you an impression of the action with a close-up of the fire though the firehole doors (Photo 76). Although this still doesn’t show the flickering effect the impression of flames is quite realistic. It was now time for all the major sub-assemblies to be taken apart for painting, a job that I gave to John Dopson who is so much better than me with this. But before passing it on to him each part was fully carefully gone over and any surplus solder was cleaned, scraped and filed away. All joints and assemblies were also checked for security. Everything was given a clean in a www.model-engineering-forum.co.uk

SMALLER SCALE

washing machine to remove any oil and grease, then gone over with an airbrush with grit to provide a good painting surface, and finally given a good dusting with an air hose to remove any remaining dust and grit. The final pictures (Photo 77-79) show the final result when it was all back together for final testing and placing in a glass case, its home until its new owner is a little older... EIM

References “Moving on to track testing, light loco it ran at a shade over 90mph...”

Ian Allan ABC of British Railways Locomotives 1948 Edition pt 3, pages 5, 6 LMS Locomotive Profiles No. 13: The Standard Compounds by D Hunt, J Jennison and B Essery. 2010, Wild Swan Publications. This book provides not only a comprehensive history of the Compounds but detailed photographs and original engineering drawings.

Engines of the LMS built 1923–51 by J W P Rowledge, Oxford Publishing Company. Scratch Building GWR Bulldog 3343 Camelot. Gauge 1 Model Railway Association, London, 2020 The Internet can yield a good deal of information. For example, https:// bit.ly/3EDL04a gives a useful number of photos of the preserved Midland Compound No. 1000.

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ELECTRONIC ENGINEERING

A ‘cheap and cheerful’ two-tone loco horn Julian provides a novice’s guide to electronics programming with an effective outcome. BY JULIAN HARRISON

have recently been involved with the challenge of designing and building an electric locomotive as an entry level project for any budding builders and to encourage new members to our club. When we went to the track to test an early trial build we had to fit a horn to comply with the club rules. We had already decided to use some cheap twin-tone 12-volt car horns bought on an online auction site as these kept the cost down which was part of the loco project. These horns come as a twin pack. Each has a slightly different tone and they are designed to be sounded together. As they are so loud we only planned to use one on the loco with just a push-button and a relay to operate it. While testing the early version of our loco I had a drive of another member’s engine. He had used two horns of some sort wired to a three-way on/off/on switch. This gives the option to sound the horns independently or as a manual two-tone by switching one on then the other on in an approximation of a British twin-tone train horn. This system was used on many full-size locomotives. I decided at the time that I wanted an automatic twin-tone horn

“This horn system is very simple to build and has a minimum number of parts. With judicious purchasing it is possible to complete this project for less than £25...”

so set about designing the simplest and cheapest one I could. My plan was that it would work with just the quick press of a button. A switch should be included to allow the driver’s selection of either a short blast or a long blast. We could have gone to one of the model companies that offer various sound systems at various prices but where is the fun in that? This horn system is very simple to build and has a minimum number of parts. With judicious purchasing of said parts it is possible to complete this project for under £25.

Versatile product I have previously used Arduino Microprocessor boards in several projects including digital readout systems for my milling machines. They are a very versatile, cheap and small board that is suited to this project. There are many different Arduino boards available. They offer different speeds, memory, processors, and physical sizes to suit various different projects. I used the Arduino Uno because it is probably the cheapest and most common and because I have several in stock. This board is about 70mm by 50mm so has a reasonable footprint. The Uno has far more speed and memory than we need so there is no need to use the more advanced, and therefore, more expensive models. It can handle a 12v supply and provides

its own 3.2v and 5v switching voltages. It has a 2.5mm socket to connect a stabilised 12v supply and a USB socket for programming it. Photo 1 shows a typical Arduino Uno. Don’t worry about all the different connector blocks. Some have a lot and some have the bare minimum of standard pins. These standard pins are all we need so ignore all the others. These boards can be bought very cheaply often for less than a fiver from the online auction sites. Arduinos are very capable but have one big drawback. They can only supply about 40ma to each pin which is only enough for an LED, relay or electronic sensor. They cannot directly supply a car horn which needs up to 10 amps so we need a relay for each horn. Shields can be obtained with relays on them specifically for this purpose. A shield is a board that is the same size as the Arduino board and that plugs directly into the pins of the Arduino. There are many shields available including relay boards, digital displays, switch boards, communication boards and many others. They are normally far more expensive than the Arduino boards they are built to fit but if you want the most straightforward way to build this project they are the route to take. Many of the full-sized shields only have 3amp relays which are not good enough for the horns. There are some 10amp available but be certain what you are buying. While you are searching for relay shields you will see various others that need to be wired to the Arduino rather than plugged directly in. These are just as good and are what I used. Photo 2 shows my completed self-assembly board complete with four 10amp relays. For the horns you only need two relays but I bought the four-relay board as it was cheaper. The others could be used for other tasks if you decide to learn to write the program yourself, otherwise just ignore them.

Build it yourself Also be aware that many of these are sold as self-assembly kits. If you are happy with this they are a lot cheaper.

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ELECTRONIC ENGINEERING If you are not willing or able to assemble one make sure you buy the ready-assembled units. The other board you will need is a small piece of Veroboard. This is a simple electronic building board that can be used for electronic projects rather than printed circuit boards. It is very cheap and easy to use. Veroboard is a thin board drilled with small holes in a grid. One side is plain board and the other side has strips of copper bonded on connecting lines of holes. Photo 3 shows a piece of board from which the smaller piece I needed was cut from. Score with a Stanley knife and snap is the easiest way to divide it. For this project we need four resistors and this was the easiest way to connect them – we only need a small piece measuring about 40mm square. Other items required are a non-locking push button of your choice, a single-pole double-throw switch of your choice that has two positions (often described as ‘on/on’), four 10k resistors and some thin single-core 1mm electronic wire. If you want to you can fit the finished assembly into a project box but this is up to you. I just glued them together with the Uno on the bottom and the Veroboard on top – hot glue is ideal for this purpose but other adhesives will work. Various pins on the Arduino are used to read the switch and button and to activate the relays.

“Logic is what micro processors work on and, though it doesn’t always seem like it, so do our brains...”

Logical process Before we start building let’s sort out some logic. Logic is what micro processors work on and, though it doesn’t always seem like it, so do our brains. In this project the Arduino will just read or write to and from some of its pins. Making the sound using the two horns is just a case of switching them on and off in a set order, which can be written like this:

The instructions are written into a program which for Arduino is called a ‘Sketch’. Both the delays are written into the Sketch but are dependent on the position of the switch. One www.model-engineering-forum.co.uk

PHOTO 1: A bare Arduino Uno board. PHOTO 2: The author’s assembled relay shield

change throughout the program. We also name a couple of variables that hold the readings of the button and switch. These are virtual placeholders within the processors memory and just hold the current value of the button and switch pins for use in the program. They change so are declared as variables. Because they are not constant the command is slightly different. Declarations are a part of the programming that tells the processor which pins it will be using. We use the command ‘const int’ to set the constants so we have: const int switchPin = 9; const int buttonPin = 10; const int one = 12; const int two = 11;

The variables are set by:int buttonState = 0; int switchState = 0;

They are set to zero when the Arduino first starts up and will change as the sketch progresses. These commands have both declared which pins we are using and named them at the same time. All other pins on the Arduino will be ignored as we have not declared or allocated them.

Colour coded As you type commands in they will change colour when they are correct – you do not need to colour the text as it is automatic. You must remember the spaces between words and the semicolon at the end of every line. The most common programming faults are missing the semicolon, missing curly brackets or not using capitals when required as everything is case sensitive. Capitals are rarely used at the start of a word but are used part way through the command so please be careful what you type. The next section is called ‘void setup’ and will always start with a left-hand curly bracket ‘{’. In this section we do what the title says we ‘set up’ the pins. This sets them to input or output. The horns need outputs so voltage flows out to switch the relays on: pinMode(one, OUTPUT); pinMode(two, OUTPUT);

l When the button is pressed check the switch position. l Is the switch set to long or short? Remember the answer. l Switch on horn one. l Keep the horn sounding for a set time dependent on the switch position (long or short). l Turn on horn two. l Turn off horn one. l Keep horn two sounding for a short time again dependent on the position of the switch. l Turn off horn two. l Wait for the button to be pressed again.

position gives a very short blast while the other gives a longer blast. If you find that the blasts are not as you want them they are easy to change and reprogram once built. Writing the required actions out in their order helps with the sketch design. After setting the pins on the Arduino we just have to use the correct commands to turn the horns on and off. Before we can write the Sketch we need to download a program called ‘Arduino IDE’. The Arduino Integrated Development Environment (https://docs.arduino.cc/software/ ide-v1) contains a text editor for writing the code, a message area, a toolbar with buttons for common functions and a series of further menus. It connects the computer to the Arduino board to upload programs (Sketches). The Arduino IDE can be easily downloaded and installed on any computer. It is completely free and fully working. It is a text editor that you type the programming into and then the IDE verifies the code and tells you if anything is wrong. If all is okay it will load the program into the Arduino board plugged into your USB port. I will describe the programming fully here so you gain some understanding of how it works. Hopefully this will inspire some of you to learn about Arduinos and use them for other projects. There are many very helpful sites and forums where you can get help or information. The sketch splits into three sections. Figure 1 is a copy of my sketch. In the first part we tell the sketch which pins we are using and what we want to name them. Pins 12 and 11 are called ‘one’ and ‘two’ respectively. I have chosen to use these pins for my own convenience. If you have purchased a shield that plugs directly onto the Uno board you will need to change these pin numbers to the ones used to control the relays on the shield. We could call them pin 12 and pin 11 but I find names make it easier to remember what they do. Pin 10 is named ‘buttonPin’ and pin 9 is named ‘switchPin’. These are known as constants because the names will not

PHOTO 3: A typical piece of Veroboard, used for making up circuits. All photos and diagrams by the author ENGINEERING in MINIATURE | JANUARY 2023

ELECTRONIC ENGINEERING Veroboard connect these four pins to 0v and act as what are known as hold-down resistors. When the pins are low the resistors make sure that

The button and switch pins accept an input so need to be set as such: pinMode(buttonPin, INPUT); pinMode(switchPin, INPUT);

Again when you type everything correctly some words will change colour. You will notice in my sketch most lines have a comment after the command. The comment is anything after the ‘//’. The program knows this is just comments for mere humans to keep track of things and it will ignore them. After all the processor knows what to do because we have told it and it does not need to know why. This section ends with a right-hand curly bracket. These curly brackets enclose related parts of the program. The third section of the sketch is where the action happens. It is called the ‘void loop’ and in this sketch will check the button, check the switch, turn the horns on and off and will use the corresponding delays. It will then loop back to the beginning of this section and wait to do it all again. The previous two sections will only run when the Arduino is powered on. They are just the initial settings required to set up the board and make it ready to run the rest of the sketch. This third section will ‘loop’ whenever it is triggered by the pressing of the horn button. It will, in this sketch, run straight through the commands in the order they are written and then wait. If you choose to learn more about programming these boards you will find large ones that take many convoluted paths to complete the end of the loop. Remembering back to when we listed the flow of what needs to happen for the twin-tone horn to sound you will see a remarkable similarity to the void loop programming but using some commands – ‘digitalWrite’ turns pins on or off, ‘digitalRead’ reads the state of pins and ‘delay’ tells the program how many microseconds to pause for. These are action commands that demand a response, for example switching on or off.

“After all the processor knows what to do because we have told it and it does not need to know why...”

they stay low. If they were not held down they could float above zero from any stray voltage in the atmosphere or the loco. It could cause false readings

FIGURE 1

Questions, questions The power used to supply the button and the switch and to energise the relays is all supplied by the board itself at, in this case, five volts. Because the length of the delay depends upon the position of the switch there are also some questions to be asked so ‘if’ and ‘else’ are used. Because the processor works on logic the digital pins we are using only have two states. Low is zero volts. High is supposed to be, in this case, five volts but really is anything just above zero. The four resistors on the

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FIGURE 1: The complete Arduino sketch as it appeared on Julian’s computer screen. www.model-engineering-forum.co.uk

ELECTRONIC ENGINEERING which switches on the relay on the board for horn one:-

and sound the horns when you do not want to. When the program sends the pins high it will react correctly because the resistors are big enough to stop a short circuit happening.

digitalWrite(one, HIGH);

void loop() {

will normally already be present in the IDE text editor. If it has not got one insert a left curly bracket. This tells the sketch to execute everything from this curly bracket until its mate at the end. The first two lines set the variables depending on the state of the input pins. ButtonState will by default be low unless the button is pressed. SwitchState will depend upon the position of the long/short switch. While in standby the variables are constantly monitored by the processor and the loop will start only when the buttonState variable goes high which is when the driver presses the button to sound the horn.

Helpful names It can be seen from these commands why we named the pins and variables. It makes them easier to understand. We firstly need to tell the processor which pins to read for each variable. buttonState = digitalRead(buttonPin); switchState = digitalRead(switchPin);

Next we ask if the button has been pressed. ‘If’ is one of the most-used commands in the Arduino language. This is true of virtually all computer programming languages. The first ‘if’ is the point at which the button is pressed and the processor realises that the button variable has gone high. It will not react to low only to high because we have two equals signs. The double equals forces it to only trigger on high and nothing else. If (buttonState == HIGH); {

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Common sense These commands match our human decision-making processes. A simple example is – If you want a hot drink switch the kettle on. If you want any other drink don’t switch the kettle on. It is not a case of switch it off for any other drink merely just don’t switch it on – there is a difference. Our switch in this project will supply 5v to the pin to send it high and use the longer delay otherwise the delay will be shorter because it will stay low. Delay is set by the number of microseconds in the brackets. One thousand microseconds is a onesecond delay. Notice the curly bracket in this sequence. They surround the delay commands. The commands surrounded by sets of curly brackets will only be run by the previous command. The longer delay is the only thing that ‘if’ can run while the short delay can only be run by the ‘else’ command. if (switchState == HIGH); { delay(1000); } else { delay(200); }

Next we need to turn on horn two and then turn off horn one. I have allowed this very small overlap so the two horns blend together. If we switched off horn one then switched on horn two there would be a miniscule pause, which would give an abrupt change. The noise made by full-size loco horns blends together because it takes a moment for the first horn to stop sounding – this sketch tries to replicate that blending. If we want a longer overlap we could add a delay between them but at present I have chosen not to do so. digitalWrite(two, HIGH); digitalWrite(one, LOW);

We now need the smaller delays for horn two. This is an exact copy of the previous ‘if’ and ‘else’ commands but with shorter delays.

Horn two is turned off after the delay. The values used in this Sketch, as written, will give a long blast of 1000 microseconds (1 Second) and 300 microseconds (three tenths of a second) for horns one and two respectively. The short blast is three tenths and two tenths of a second respectively. I have used these settings for the past few weeks and they seem to be about right. Just over a second does not sound much but when the horns are sounding it feels longer. It is a nice short warning blast to get people’s attention. The sketch finishes with two right curly brackets. The first is the mate to the one placed after the button has gone high. The last closes the entire void loop section. This signifies the end of the sketch and once it is reached the program will go back to check the button again. Curly brackets are probably the hardest thing to understand in programming an Arduino sketch. Fortunately the IDE will help us with them. If any are missing they will show up in the verification process. Your sketch needs to be saved somewhere on your computer. It is a requirement that they are saved inside their own folder. They can be saved onto the desktop but will not be able to be opened by the Arduino IDE until they are in their own folder. If you double-click the icon to open the file it will make a folder for you before it opens the Sketch. You can make a folder and save into that if you wish. The folder can be anywhere convenient including on the desktop. I usually give it the same name as the sketch, in this case ‘longshorthorn’. At the top of the IDE window there are five buttons. The round tick is verify and the right arrow is upload. The three square ones are new sketch, open existing sketch and save sketch. Rolling your mouse over them opens a label for each one. Once a sketch is saved it can easily be opened by double-clicking the file and it will open and run the IDE. To check your programming click the round tick button. The IDE will check the sketch and highlight any faults one at a time. It will show the first one in an orange panel at the bottom of the window and will take you to the faulty line for you to correct it. Once corrected click verify again ENGINEERING in MINIATURE | JANUARY 2023

This is followed by a left curly bracket to tell the sketch to run everything between it and its mate which will be located near the end of the sketch. The easiest way to understand curly brackets is to regard them as boxes which contain some commands and some contain other boxes. This gets very confusing because many commands require their own sets of curly brackets and they can get quite hard to keep track of. Luckily the IDE program helps us out in two ways. If you click your mouse on the right of a curly bracket it will then highlight its companion. When you verify the programming to check it the fault will show which one is missing. The next command switches on horn one by writing the pin high

“A simple example is – If you want a hot drink switch the kettle on. If you want any other drink don’t switch the kettle on. It is not a case of switch it off for any other drink, merely just don’t switch it on – there is a difference...”

Next we set the delay from the switch position. Because we have read the state of the switch we can tell the program which delay to use but we don’t need to tell it too much. We are saying if the state is high(5v) use one delay time, else if it is not use a different delay. This is how the if/else combination works.

if (switchState == HIGH); { delay(300); } else { delay(100); } digitalWrite(two, LOW);

ELECTRONIC ENGINEERING

FIGURE 3

FIGURE 2 and it will take you to the next fault. Repeat until all faults are cleared – a large majority of them will be typos. Figure 2 shows a fault I created to show this. I have removed the semicolon from the ‘digitalWrite’ command that turns off horn two. The error message in the orange box shows you what it is expecting on the line before the pink highlighted line. Once all faults are sorted it will show you the size of the program and tell you it has ‘Done compiling’. Figure 3 shows the errors all corrected. All that remains now in this part is to upload the sketch to your Arduino board. Plug a suitable cable into the USB port on the Arduino and a USB port on your computer. This cable will power the Arduino which will light a couple of LEDs. Drop down the TOOLS menu on the IDE window and about halfway down you should see the board listed. Click the port line and you can then choose the comm port your board is connected to. Usually there will only be one highlighted so just click it to select it. If you now click the round right-arrow button the IDE will verify the sketch again and then upload it to the Arduino board. The IDE will tell you when it has finished. If you watch the Arduino board you will see two of

the onboard LEDs flash as it is uploaded. Assuming it tells you upload was successful you can unplug the board and put it to one side for wiring. Congratulations, you have successfully programmed your first Arduino board.

Building the circuit

FIGURE 2: How a fault on the Arduino IDE appears on the screen. FIGURE 3: The appearance after all faults are cleared FIGURE 4: Schematic of the entire project. FIGURE 5: The layout of the Veroboard.

FIGURE 4

Figure 4 shows a schematic for the building of this circuit. As visible on Photo 1 the Arduino has all the pins marked on the board. As we only need a few you can stick a strip of paper label or masking tape on the outside of the pins highlighting the ones we need. On one side we need pins 9, 10, 11 and 12. On the opposite side we need the Vin, gnd and 5v pins. I glued the Relay Shield on top of the Arduino board with hot glue. Photo 4 shows this. Ensure that none of the soldered connections on the bottom of the shield touch any connections or metal parts of the Arduino. Some UNOs have a large metal guard around the USB connection. Ensure the glue does not foul the USB port as we may need it once the project is built. We need to build the Veroboard which is very straightforward to construct. Figure 5 is a drawing of the Veroboard, its components and connections. The four resistors and four link wires are fitted and soldered

on. The board has a blank face and a copper face – the components sit on the blank face and go through the board to be soldered on the copper side. Ensure you use the correct copper tracks – they should be at right angles to the components as in the picture and that the correct holes are used. Solder carefully to avoid solder crossing to an adjacent copper track. Five of the connections go to the button and the switch so need five wires. If you choose to use all the same cable in this project ensure the wires are more than long enough to reach from where the Arduino is to be fitted to where the switch and button will be fitted. Unless you solder them on individually you will need to label them. I used a short length of alarm cable but network cable will do just as well – these multicore cables keep all the wires nice and tidy. Pick five colours to use and cut the others off. There should be either six or eight wires so more than we need. Solder to the button and switch later. Before I describe the connection a word to those who have bought the shield that plugs directly onto the Uno board. On the veroboard you will not need the wires on RL 0v, RL 12v RL1 and RL2. The direct connections will take their place. Solder a piece of wire to each of

FIGURE 5

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ELECTRONIC ENGINEERING

the remaining Veroboard connections long enough to reach their pins. If you use about 100mm each you can trim later or leave tucked in. Check the soldered side of this board very carefully – I use a magnifying glass. Ensure that there is no solder whatsoever crossing any of the copper tracks. Sometimes there can be very fine stands of solder joining them. They are easy to remove with a Stanley knife. Glue the completed Veroboard to the top of the relays, again with hot glue or something suitable. Silicone sealant or No-Nails will also work but will take longer to set. Photo 5 is a close up of my finished Veroboard glued to the top of my relays. We can now finish the wiring. The wires from the left side of the Veroboard go to their pins on the Arduino board. They are gnd, Vin, 5v, 12, 11, 10 and 9. Route the wires as three of them will need to cross the boards. I routed them across the

centre between the banks of relays. Trim to length and strip about 8mm from the end. The bare wires just push easily into each pin hole. From the right side of the Veroboard RL1, RL2, RL 0v and RL 12v go to their relevant connections on the relay board. They are appropriately marked on the board. Looking back to Photo 4 you can see the small black connector block between the relays. The 0v and 12v connections on the Veroboard go the supply from your loco’s batteries. If you do not have a 12v supply on your loco you will need to fit a voltage reducer board from your main supply. DO NOT supply the Arduino with more than the voltage a 12v battery would supply which should be a maximum of 13v. Do not connect the horns or their supply to the relays yet. Connect your previously soldered wires to the rear of the button and the switch once they are fitted to your loco control panel.

PHOTO 4: Relay shield glued onto the Arduino Uno. PHOTO 5: Completed Veroboard glued on to the top of the relays. PHOTO 6: The completed board assembly. PHOTO 7: Top view of the finished assembly.

The two button wires are soldered each to a terminal on the rear of the button. Switch centre is soldered to the centre connection of the switch. The other switch wires go to the terminals each side of this connection. Solder the switch 5v wire to the terminal that will correspond to the long blast position on the switch. This will be the terminal opposite the throw of the switch. Photos 6 and 7 show the finished assembly complete with all cables and boards. You will notice on these photos that I have stuck labels on various bits to make sure I don’t mix up the connections.

Testing the electrics Turn on your 12v supply to the Arduino – it will need a few seconds

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ELECTRONIC ENGINEERING to boot up. Once booted you should be able to see the onboard LED glowing. Photo 8 shows part of my control panel detailing the horn switch and push button. Move the switch to the short-blast position and press the button. You should hear the two relays click on and off one after the other. If they work move the switch to the long-blast position and press the button again. You should hear both the relays click on and off again but with longer intervals between the clicks. If it works in both positions the programming and wiring are all correct. If not switch off and check all your connections are correct and secure. If it then does not work plug in to a computer, check the programming is correct in the IDE and upload again to the Arduino. Assuming all tests okay you can wire the horns. The larger terminals at the end of the relays are used for this. The com terminal is for your horn supply to suit the horns you are using. We used cheap twin car horns so needed a 10a 12v supply. If you have had to fit a voltage regulator to supply this project ensure it is capable of more than 10 amps. If you have a 24v main supply you can use this for the horns if you buy 24v lorry or bus horns. The n/o connector from the relay goes to the horns – relay one to horn one and relay two to horn two. Both the horns can have their 0v terminals connected together and wired to your 0v or negative on the loco. It is worth wiring your 12v supply to the Arduino through an isolation switch on your control panel just in case. Before fitting to your loco run some glue or silicone across the wires in the Arduino pins to avoid them being accidentally pulled out or vibrating loose.

Operation When you switch your power on you should again wait a few seconds for the Arduino to boot up. With the blast switch in the short position press the horn button. You should get a short blast of the horns. Switch the switch and you should get the alternate long blast when the button is pressed. If the blast times don’t match the switch position either loosen the switch and rotate it through 90 degrees or swap your labels over. If you want to change the duration of the blasts change the delay times in the sketch and after plugging the computer in to the Arduino upload it. As you can see from Photo 9 a laptop is ideal for reprogramming this system once fitted to your loco. The new altered sketch will replace the previously uploaded one. You can do this as many times as you need to get

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the particular blasts that you want. The Arduino/relay/Veroboard assembly can be fitted in your chosen place on your loco with hot glue, silicone, No-Nails, sticky pads or any other method you choose. Just ensure no connections can touch any metal that can short them together. Photo 10 shows my assembly glued inside my control box. Note that the USB can easily be accessed for reprogramming. This controller is fairly straightforward to build and if you choose can be altered to suit your requirements. By carefully adding more digitalWrite and delay commands you can make the blasts double or treble sounds. If you wish you could add more horns to change the sound of the blasts. This will need more relays but if, like me, you bought the four-relay board you already have two spares. If you read and understand the programming you should be able to add the extra horns to the sketch. Do one at a time and test after each addition. You will need to name the extras and set some more output pins to write to. The knowledge to do this is in this article. I encourage you to have a go but keep a copy of your original working sketch so you can load it back in if you need to. Save your new Sketch with a different name. If you choose to do this put a comment on every line so you can keep track of what you have done. At the beginning of my sketch there is a description of the sketch. Rather than using // on every line for this you can start and end it with /*. Everything between these two markers will be ignored by the Arduino.

Wide-ranging uses I hope I have shown you enough to venture into the interesting and useful world of Arduino processors. They

PHOTO 9: Updating the Arduino with a laptop after fitting to the locomotive.

may be useful for other projects you may attempt and can solve some important problems if used. Programming knowledge can be expanded as you need it and there are plenty of forums and people online who will usually help out. There are also many thousands of sketches posted on the internet for free. If they don’t exactly fit your requirements you can always alter them. There are many examples on the IDE program already. They are in the File dropdown menu under ‘Examples’. I hope my Sketch can be hosted by EIM for downloading to save you all the typing and faults but I encourage you to type your own while following this article. I also suggest you alter or add to it to further your knowledge of these very useful boards. EIM

PHOTO 10: Installed and working in the loco control box.

n Readers who would like a copy of Julian’s sketch file can request one by sending an email to editor@ engineeringinminiature.co.uk

PHOTO 8: The horn blast switch and push button fitted on the loco control panel.

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BUILD PROJECT

Building a ride-on tender from scratch Peter and Matthew’s 7¼-inch ride-on tender build, intended as a ‘beginners’ project to teach or practice a broad range of skills, focuses this month on the wheels. BY PETER AND MATTHEW KENINGTON Part three of 11

PHOTO 24: Heating the wheel with a Silvert propane blowtorch, using the ‘roofers’ nozzle – even with this huge flame it took quite a while to heat to the required temperature.

daunting, particularly with the large and heavy narrow-gauge profile wheels we were planning to use. They contain a lot of metal and getting this up to the required temperature of hundreds of degrees (Photo 24-25) is not for the fainthearted and nor is carrying the heated parts to the axles (which were mounted in a vice, Photo 26). The thought of dropping one of them en-route sent shivers down our collective spines! Photo 27 shows what happens when things go wrong... As can be seen in the photo, the wheel is not quite all of the way ‘home’, so what did we do wrong? The answer is quite simple, we failed to allow time for the axle to cool after we had put on the first wheel – the hot axle had expanded sufficiently that the (even hotter) second wheel had not expanded by a sufficient amount to clear all of the axle diameter, along the length intended to house the wheel– much wailing and gnashing of teeth that day! Having failed to shrink-fit our wheels

PHOTO 25: Nearly there... Parts of the wheel have reached ‘blue heat’ which, when replicated across the wheel, should be sufficient PHOTO 26: Wheel snugly fitted to the axle – the discolouration is easy to remove with some light sanding. PHOTO 27: Rookie error! Wheel not quite fully home on the axle. PHOTO 28: Using a home-built (not by authors) hydraulic press in Hereford SME’s workshop – very quick and easy and a lot less scary than shrink-fitting... All photos by the authors

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he next step on the build of our ride-on tender concerned the wheels and we cheated here, using commercial ‘narrowgauge’ profile wheels from a well-known supplier. The cost of these was such that it wasn’t really worth purchasing the material and making our own. Should you wish to do so, a drawing is provided in Figure 23. We tried fitting the wheels to the axles in two different ways (it’s a long story): shrinkfitting and press-fitting. Both worked well and we learnt a lot in the process (particularly our experiments with shrink-fitting), so we will discuss both here. We tried shrink-fitting first, largely because we didn’t have access to a suitable press at the time and could make progress this way, without having to wait until the tool we needed was available (it was on long-ish term loan to another club member). Shrink-fitting is relatively easy, if a little

ENGINEERING in MINIATURE | JANUARY 2023

BUILD PROJECT

All drawings approx half full-size unless stated. All dimensions in mm

FIGURE 23 Tender wheels, to 71/4” Gauge Society ‘narrow gauge’ profile

FIGURE 24

successfully (although we understood why and would be confident of being able to do so in the future), we decided to try press-fitting. Hereford SME’s homebrew press was now available and was simplicity itself to use (Photo 28). The same axle dimensions we had used for our shrink-fitting experiments were used here (in other wrods 0.04mm over-size) and these worked well. The main problem of this approach is obviously whether you have access to a suitable press – it is not something you will need often and so is probably not worth purchasing. On the other hand, most workshops will have access to a heating torch, making the shrink-fit option easier in many cases.

Brake coupling bar 4mm mild steel Brake-ing New Ground Drawn quarter full-size The braking system of our tender is

FIGURE 25 Brake cross bar 4mm mild steel

FIGURE 26

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FIGURE 27A

➔

Brake pivot lever 4mm mild steel

27B

Brake pull-rod (A) horizontal section, 4mm mild steel (B) vertical section, 6mm mild steel

FIGURE 28 Brake pivot rod

JANUARY 2023 | ENGINEERING in MINIATURE

22 ??

perhaps slightly different to the traditional ‘rods and shafts’ arrangement usually found on prototypical tenders. It makes use of as many laser-cut parts as possible, with no need for any thread-cutting (such as on cross-shafts). It is thus very quick and simple to put together, when the time comes. It also requires minimal adjustment. The required laser-cut parts begin with a brake coupling bar. This attaches to the brake cross-bar (see below) and two are required, as the braking system operates on both front and rear axles. The required form and dimensions of this part are provided in Figure 24 and a picture of the completed item, after etch-priming, is provided in Photo 29. Two brake cross-bars are required (Figure 25 and Photo 30)– each connects together the brake hangers on a given axle and distributes the braking force equally to the two wheels on the axle. This is ensured by the single pivot point in the middle (left-to-right) of the cross-bar. The four cut-outs, two at each end of the bar, will need filing to remove the corners on their horizontal (as pictured) sections. The way that this bar fits into its brake hangers is very simple and requires no other components in its assembly. One end of the cross-bar is inserted through the slot in the end of the circular section of a brake hanger (discussed below) and the cross-bar is then rotated by 90 degrees in order to fix it in position. The corners in the horizontal sections of the cross-bar will prevent this rotation from happening, as supplied from the laser-cutter, and will need roundingoff to allow this rotation process to take place. There is no danger of the part rotating and falling out in use, as it is

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BUILD PROJECT PHOTO 29: Brake coupling bar (parts shown after undercoating with etch-primer).

PHOTO 30: Brake cross-bar.

PHOTO 31: Brake pivot lever. PHOTO 32: Brake pull-rod after two parts welded together.

FIGURE 29 Pillow block bearings for brake-pivot rod

FIGURE 30 Brake-pivot cam

FIGURE 32

FIGURE 31

Brake-cam pivot nut Drawn full-size

Brake cam, excluding nut-retention plate Drawn full-size

FIGURE 34 FIGURE 33 Brake hanger, 6mm mild steel Dimensions not as critical as decimal places imply

Brake hanger spacer – stainless-steel tube Drawn full-size ENGINEERING in MINIATURE | JANUARY 2023

BUILD PROJECT

PHOTO 33: Machining slot through which brake handle rod passes – note use of pilot holes to speed machining process (and to save wear on the harder-to-sharpen end-mill) – the second of these can be seen to the left of the milling cutter. PHOTO 34: Brake cam pivot nut drilling – first use a centredrill, with the workpiece supported (such as by a parallel). PHOTO 35: Don’t forget to remove your precious parallel prior to drilling-through! PHOTO 36: Close-up of the pivot-nut. PHOTO 37: Brake-cam with pivot nut inserted. PHOTO 38: Brake cam showing welded-on pivot-nut retention-plate.

JANUARY 2023 | ENGINEERING in MINIATURE

constrained to always remain horizontal by the brake coupling bar to which it attaches. All will become clear when we get to the stage of assembling the braking mechanism. The brake pivot lever (Figure 26 and Photo 31) is a small part which takes the pulling force from the brake-pull rod (discussed below) and applies it to both of the brakecoupling bars and hence to the braking mechanisms for each wheelset. Again, the 8mm holes may need to be cleaned out with an 8mm drill to ensure that they form clearance holes for the 8mm bolts which will be used to assemble the braking mechanism. The brake-pull rod is in two parts: one horizontally-oriented and the other vertically-oriented (Figure 27A-B and Photo 32). This enables both to be laser-cut whilst still ensuring that the required vertical and horizontal holes can exist in what is an otherwise ‘flat’ component (or at least a component cut from flat pieces of metal). The two parts slot into one another and can then be welded (or silver-soldered) together to form a single piece – we TIG-welded ours. The parts are designed to have a long overlap, allowing plenty of weld-length to be applied and thereby ensuring that a strong component can be realised by even the most

incompetent welder (I’m naming no names here...). The two parts also form a rigid whole, once pressed together – a light tap with a hammer may be required to do this. There is no need for additional support or clamping (other than of the complete assembly) prior to welding.

Bend-proof braking Note that the two sections are made from different thicknesses of metal. The horizontal section uses 4mm mild steel, in common with most of the coupling bars for the braking system – this part is only ever in tension (when the brakes are applied) and is unlikely to snap with even the most over-enthusiastic application of the brakes. The vertical section is made from 6mm mild steel – the thicker material was chosen to ensure that the dog-leg section is sufficiently rigid not to buckle with the aforementioned over-enthusiastic braking. The brake-pivot rod (Figure 28) is made from a piece of mild or silversteel. We opted to include ballbearings at both ends of the rod as they are so inexpensive and save the hassle of precisely machining/reaming holes in the frames. The bearings we chose (Figure 29) were flange pillow block bearings, which would accept a 12mm diameter shaft size and have two mounting holes. There are two cams that are located on the brake-pivot rod – one is internal to the frames and which actuates the braking mechanism itself and a second, located externally to the frames, which operates the brakepivot rod when the brake-handle is rotated. We have termed these the brake-pivot cam (Figure 30) and the brake cam (Figure 31) respectively, although there may be better, more standard, descriptive terms for these components (they could also be viewed as ‘cranks’, although perhaps not in the political sense…). The latter also requires a pivot-nut (Figure 32) to allow the threaded rod, which is attached to the brake-handle,

BUILD PROJECT

to move the cam up and down. A small retaining plate needs to be added, to prevent the nut from rotating when in the middle of its travel (Photo 38). The size of this is not especially critical, so long as it covers the majority, or all, of the slot in which the nut travels. Its attachment method is also non-critical; we tig-welded our plate onto the cam, but silver-soldering or the use of a small tapped-hole and retaining bolt would both do equally as well. Even Loctite might do, as there is (or should be, if the threads are clean and made correctly) very little force on this plate. The plate should be placed on the rear of the cam, as it will be fitted on the tender, so it will not be seen from the outside. To attach the brake cam to the brake-pivot rod, we originally planned to use a roll-pin, and the holes for this are shown in Figure 31. When we came to test-assemble the tender, prior to disassembly and painting, we decided it was probably easier to use a

grub-screw (Photo 39), with a suitable indent drilled into the rod when this cam is set at the appropriate angle relative to the other cam (the brakepull cam). This makes brake adjustment relatively simple and will be discussed further later in the build. Four brake hangers are required, all being identical (Figure 33 and Photo 40). Again, a little filing may be required, notably of the ‘entrance’ to the circular part in which the brake cross-bar inserts. This will be discussed in more detail below. Finally we need brake-hanger spacers and mounting bolts. The brake hangers, and hence the brake shoes, need to be offset a significant distance from the inner sides of the frames. They also need to be held rigidly, as this offset distance imparts quite a leverage when the brakes are tightly applied. To achieve the spacing and strength, the design uses M10 bolts as the pivots for the brake hangers and steel tube to form the spacers (Figure

PHOTO 39: Brake cam complete with grub-screw. PHOTO 40: Brake hanger. PHOTO 41: Brake-hanger spacers made from steel tube.

Next month – brake blocks and handbrake levers.

34 and Photo 41). We used stainlesssteel for both the bolts and the tube, though this is probably overkill. The precise configuration will be explained in greater detail when it comes to the assembly of the tender; for the present, it is sufficient to make the spacers from 12mm outsidediameter, 10mm inside-diameter, (stainless) steel pipe. The only operation therefore required is to part-off the pipe to the correct length (4-off of these parts are required). This is a very satisfying job, as four completed parts can be created in a matter of minutes – an important consideration where impatient young apprentices are concerned... EIM

MORE BENCH TALK

Stops and gauges A couple of lathe additions make repetitive machining slightly less of a chore... BY HARRY BILLMORE

recently had to machine 12 bearing carriers for the carriage bogies at the Fairbourne Miniature railway – the lathe I have does is not yet set up with a digital read out so to make my life easier I added a couple of extras on the lathe. One is a simple bed stop that clamps onto the lathe bed to halt the carriage at a set position. The other is a dial indicator – this is held on a magnetic base on the carriage with the pointer contacting the cross slide. I carefully machined the first bearing carrier to get the final set positions correct, zeroed the dial indicator, then proceeded to machine the rest of the carriers with minimal fuss and maximum accuracy. EIM

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RIGHT: A stop on the lathe bed and a dial indicator on the cross slide gives repeatable accuracy when one is machining multiple items. Photo by the author ENGINEERING in MINIATURE | JANUARY 2023

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HARRY’S GAME

Unexpected problems... In this latest month of challenges at the 12¹ ₄-inch gauge Fairbourne Miniature Railway, Harry tackles weird brake designs and yet more wheel issues, among other things... BY HARRY BILLMORE

HEADING: The Barmouth Fireworks over the railway’s Darjeeling loco ‘Sherpa’. PHOTO 1: The failed brake nut, it should have an ear welded into the hole in the tinplate socket that the threaded nut is in.

PHOTO 2: The welded construction of the bell crank required heating up one wing and bending it over to remove the old nut. Note that chequer plate should not be used for structural parts...

PHOTO 3: Machining a pocket to take the nut, milling in a chain to remove the material quickly. PHOTO 4: Finishing off the pocket with conventional milling passes.

JANUARY 2023 | ENGINEERING in MINIATURE

fter the heady heights described last month of delivering the new Simplex locomotive into traffic, followed by an evening train to Penrhyn Point to watch the Barmouth firework display, life in the Fairbourne Miniature Railway workshops returned to normal, with a report coming through of one of the brake van’s hand brakes “feeling weird”. Upon inspection it was found that one of the ears that transmits the force from the thread on the bottom of the hand wheel to the bell crank had fallen off. This combined with a known fault from the pull rod of the brake gear resulted in me lifting the carriage and removing the offending bogie and the bell crank – this proved to be hard work due to the crank being a single welded piece with a tight-fitting pivot shaft that had no way of being lubricated. After the fight to free everything from the coach body, I then had to work out how to repair it. The design has a tinplate box that holds a machined nut, the bottom of this box has a clearance hole for the thread of the handbrake wheel, thus as the handbrake is tightened the nut pulls up against the bottom of the box, which in turn acts on the bell crank with two welded-on ears.

Bending into submission Due to the construction of the bell crank, the only way to remove the broken part was to heat the leg up and bend it out of the way, allowing the nut assembly to come off. I ground off the welds holding the nut in place before machining a new carrier from

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HARRY’S GAME

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PHOTO 5: Checking the fit of the nut in the pocket. PHOTO 6: With leg straightened to hold new nut carrier in place repair is done. PHOTO 7: Brake linkage design by Harry’s predecessor. PHOTO 8: Lack of a clevis on the other end of the pull rod. PHOTO 9: Clevis fitted to brake pull rod with locking split pin.

While doing this work I noticed the brake arm from the air cylinder to the pull rod was made from two 3mm bent sections with two nubs welded on to fit in the outside of the clevis on the brake cylinder. This was because whoever had ‘designed’ the system hadn’t bothered to cut down the cylinder rod to the correct length, allowing a single bar to fit in the clevis as it is designed to do.

Twist no grip The problem with the two-nub design is that if a reasonable amount of brake force is applied, the nubs will simply twist out of the clevis on their thin bars and then the brakes will not work. I cut down the cylinder rod and fitted a 10mm thick bar instead of the 2 3mm versions. I continued working on carriage

bogies as I had two volunteers coming in to do a weekend of carriage maintenance and annual exams, so I wanted to get the two spare bogies I had rebuilt finished to make the most of the volunteer time I had available. The first bogie needed one wheelset turning so I stripped it down, and then found a badly worn and broken centre axle bearing. I replaced this with a piece of machined vesconite which was great fun to machine with ribbons of swarf coming off the tool. With that out of the way I could then machine the wheelset. This proved to be impossible, however, thanks to the weld that someone had poured into the root of the flange – this had then hardened incredibly to the point where the carbide tips were simply polishing it and then being destroyed by the

solid, therefore preventing the problem happening again! After turning the ears on the lathe, I machined a pocket on the mill – my preferred way to do this quickly is to remove as much material as possible with a large drill, grind to a flat point (described elsewhere) then chain drill using a two-point end mill around the edge of the pocket before tidying the edge up by milling conventionally. This method reduces strain on the machine and tool as you are never taking full thickness cuts and it also makes the whole process far faster. With the nut welded into the new holder it could then be put back into the bell crank, and once the arm was heated back up and bent back into position that job was completed and I then moved onto the bogie. The main issue with this had been the main pull rod did not have a clevis on the end of it, which meant that as it pulled on the brake cross-beam it pulled up on the pin that joined the two together and loaded up the split pin which after a while, failed and the pin came out. The short-term solution to this was to replace the pin with a bolt, but this didn’t solve the basic problem, so I added the second half of the clevis to the pull rod and fitted a well-fitting shoulder bolt upside down, due to clearance issues. To prevent the bolt coming out I fitted a split pin through the nut.

PHOTO 10: Bogie centre axle bearing failure, worn nicely and cracked. PHOTO 11: Machining vesconite for the new bogie bearing is very satisfying for massive ‘swarf’.

ENGINEERING in MINIATURE | JANUARY 2023

HARRY’S GAME

15 PHOTO 12: The worn profile of a carriage wheel despite excessive hardness of root weld build-up. PHOTO 13: Machining another carriage wheelset – the built-up root has become so hard it is destroying tips and will not machine – this set is now scrap.

PHOTO 14: Yet another mangled tool tip from welded wheels. PHOTO 15: A nicely finished profile at last. PHOTO 16: With the carrier and outer race cut away, the inner seized race is revealed.

PHOTO 17: The inner race is starting to be scored away.

porosity and inclusions left by the poor welding. Thankfully I had a pair of new EN8 wheelsets ready to go in so I swapped both of these into the bogie. The other bogie needed both wheelsets turning, thankfully the work on these went very well and came out beautifully. The weekend came around and a huge amount of work got done on the carriages, with 19 out of the 21 vehicles having had their annual exams and maintenance completed, though it didn’t happen without its trials. Both of the spare bogies were used up fairly soon and when we came across a bogie that needed all four bearings replacing we were confident that we could do it easily.

Solid state I have never, however, had this bogie apart before, it was one of the last ones completed by my predecessor which is why it hadn’t needed any attention until now. Unfortunately they had put the bearings on without any rust preventative measures, meaning that when we came to remove them, the bearings had rusted solidly to the axle, the bearing puller merely breaking the bearing housing from the outside of the bearing. This necessitated some very careful attention with the oxyacetylene cutting gear, washing the bearing inner race material off the

axle ends. I did this by carefully heating the bearing housing, with the flame parallel with the axle, then putting just enough extra oxygen through to start washing the material away – doing it this way I had great control over where the heat was going and where as a result the stream of oxidisation went. I took full advantage of the break between the hot bearing race and comparatively cool axle stub to ‘bounce’ the oxidation stream off the axle without scoring it. This takes a little practice, but once mastered is very useful! Once a cut had been made on two sides of the bearing inner race I could use a drift to knock the race away from the axle. I then repeated this four times... With all the old bearings off I then had to machine up some of the new style of bearing housings as I had run out of the old style (described previously). Then I could reassemble the bogie with the new bearings and the volunteers could then put it back under the carriage.

Ear-splitting After all the excitement with the carriages, I could then get on with a small modification to the Simplex – the klaxon that is mounted on the handbrake stand had now become unbearably loud in the loco’s newly built cab, so I made a spacer to stick the noisy bit of it out of the rear cab

PHOTO 18: With a cut most of the way through two sides, the seized bearing can be split from the axle and removed. PHOTO 19: The unscathed axle stub ready for a new bearing.

JANUARY 2023 | ENGINEERING in MINIATURE

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HARRY’S GAME

PHOTO 20: Three bogies ready to go under carriages, the closest one is the braked carriage for the brake van.

PHOTO 21: An offcut from Sherpa’s new cranks re-purposed as a spacer for the klaxon on the Simplex loco. PHOTO 22: A brake block ‘pin’ taken from ‘Russell’. PHOTO 23: Russell in the air with wheelsets removed. PHOTO 24: The wear as shown on the centre flangeless driving axle. PHOTO 25: One of the axleboxes removed and cleaned up, note the wear patterns starting on the right of the picture – also visible is a grease hole in the bottom of the vesconite which sits under the axle. PHOTO 26: Score marks far more apparent in this view. PHOTO 27: The cartridge that holds the vesconite, note the chunk that filled in the grease groove at the back of the steel carrier. Also shown is the heat distortion on the steel where it has spun.

sheet. This was made from one of the offcuts from producing Sherpa’s new cranks – with a bit of machining and a slap of paint it’s not nearly so deafening any more. I then started on the major project for this winter, which is a bottom-end overhaul on our 6-inch scale Welsh Highland Railway Hunslet ‘Russell’. Stripping the brake gear off revealed a few oddities, such as machine screws being used as brake-block pivot pins and hex-head bolts with most of the head machined off having been used instead of countersunk bolts... But I eventually got all the brake gear and other encumbrances off the underside

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of the loco and could jack it into the air and pull the wheelsets out. I then put the axlebox underkeeps back on to prevent the frames sagging while the loco remains suspended.

Size of the problem This then revealed a whole load of new issues –the profiles are very worn, and because when the new wheels were made for this loco four years ago they made them to the size of the wheels they took off, so there is not much material to be able to remove before the back of the counterweight will start hitting things such as other rails on pointwork.

ENGINEERING in MINIATURE | JANUARY 2023

HARRY’S GAME

Another feature of the work that was done at Russell’s last overhaul was the fitting of vesconite axlebox bearings in place of roller bearings. These unfortunately have been a failure, the vesconite is badly scored and has worn badly, and it has also PHOTO 29: worn the axle by a shade under 0.5mm Vesconite has off the diameter of the journal. worn the axle The vesconite axleboxes were also material away and fitted into a steel cartridge that was left a step. then pressed into the axlebox PHOTO 30: itself – there is a grease way at one end Setting centre axle of the cartridge all around the up for checking diameter of the bearing and quartering, a stop unfortunately when the vesconite was is set up for one of pressed in, a large burr of it ended up the crank pins. filling the grease passage. It also didn’t help that a PHOTO 31: Dial lubrication hole was not on top of the indicator used to bearing but to the side of it. These two set zero point for factors combined meant the grease bottom of leftthat was being pumped to the axlebox hand crankpin. was immediately being forced out of the front of the bearing to coat the PHOTO 32: crank. This then led to the vesconite Having set bearing picking up and the cartridge leading wheelset ended up spinning in the axlebox – up in same way you can see the heat distortion from with right-hand where it happened in the photos. crankpin on the

PHOTO 28: The heat discolouring shows where the steel cartridge spun in the axlebox.

stop, gap above the indicator shows quartering is incorrect.

PHOTO 33: The hole for the mechanism of the ballast hopper is cut out of the parent wagon.

No quarter given I then slung the centre axle into the lathe to check the quartering between it and the front set, as that is where there have been problems with the rods in the past. To do this I set up a

stop for the right-hand side crankpin over the carriage of the lathe, I then used a dial indicator to set a zero point for the bottom of the left-hand side crank pin next to the lathe chuck. I then replaced this wheelset with the leading wheelset and immediately noticed that there is about an 8mm gap between the top of the dial indicator and the crank pin, showing the quartering to be way off. As a distraction from all of the doom and gloom surrounding Russell, and to allow my mind to work through the problems to find solutions, I then carried on with the work on our new ballast hopper, cutting out the floor of the ex-mines well wagon to allow the mechanism of the hopper to drop through. This proved hard work as oxidised steel, in other words rust, doesn’t lend itself to being further oxidised using a cutting torch. But after a lot of perseverance the hole is now cut and can be reinforced before the hopper is lowered in and all the mechanisms hooked up. Finally, I have managed to do a little more on my 7¼-inch gauge Holmside loco – it has been steamed to check everything works and a date has been set with the boiler inspector. I have also started to fit the ejector and associated pipework a friend of mine has machined for me. More on this to come! EIM

PHOTO 34: The fabricated elbow connection into the Holmeside’s smokebox held in place for pipework planning. PHOTO 35: Harry’s friend’s superbly machined ejector being held in place to work out pipe runs.

JANUARY 2023 | ENGINEERING in MINIATURE

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EVENT REPORT

2022 Midlands Model Engineering Exhibition John describes the Club and Display entries from the big EIM-sponsored Autumn show . BY JOHN ARROWSMITH

he displays, clubs and societies are the backbone of any exhibition and this is certainly true about the Midlands event. This year’s show at the Warwickshire Event Centre on 13th-16th October was an excellent presentation by all concerned and made for a real tribute to the originator of the exhibition Chris Deith. The opening day saw the entrance queue stretching right back to the car park before opening time so a good attendance was anticipated. It turned out to be a great day for the organisers with the old exhibition atmosphere quickly being generated and the visitors filling the hall. The 2022 exhibition was slightly smaller than in previous years simply because of the aftermath of the Covid pandemic – it was not known what sort of reception the event would receive. As it turned out overall it was a great success with good crowds every day and a really interesting and informative exhibition.

Chosen by peers

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PHOTO 1: The winning stand in the club competition by the Melton Mowbray MES. PHOTO 2: Second-placed Kingsbury Water Park MBC produced this varied range of marine craft.

PHOTO 3: Bob Fawcett’s powerful Fowler BB1 ploughing engine on the Melton Mowbray stand. PHOTO 4: Also on the stand was a well-made seven-plank wagon in 5-inch gauge built by Scott Gregg. Photos by the author unless stated

(Photo 1) with the Kingsbury Water Park (Photo 2) display in second place and Hereford SME in third. All were excellent presentations and it would have been difficult to choose a winner. The display by Melton Mowbray provided a wide mix of many different

models from large traction engines to a small simple rail-built buffer stop, and included a couple of really first-class models such as Bob Fawcett’s 2-inch scale Fowler ploughing engine (Photo 3) and a well-made seven-plank mineral wagon

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A central part of the exhibition is the Club Display Competition where all the visiting clubs and societies are invited to select the best display in the halls. The organisers or the official competition judges have no input to the selection process for this award so it is a broad-minded decision by all the stand holders. The award is keenly contested and this year the winners were the Melton Mowbray Society of Model Engineers

ENGINEERING in MINIATURE | JANUARY 2023

EVENT REPORT

7 by Scott Gregg (Photo 4). In addition the excellent display board by David Oliver showing the tools and jigs required to make live steam injectors (Photo 5) was very informative. On the Kingsbury Water Park display the model of the famous steam paddle steamer ‘Waverley’ presented by David Kennedy was a great attraction (Photo 6). Hereford’s display featured a Gauge 1 lockdown project by Gordon Wood which used a fictitious Welsh branch line to show a typical GWR locomotive and train (Photo 7). A selection of under-construction work by the club’s Young Engineers section showed off what young people can do.

Top-class locos There were some excellent locomotives on display at this year’s show including a superb 7¼-inch gauge LNER A4 under construction by Tony Bickerstaffe (Photo 8). Adjacent to this were two O1 2-8-0 locomotives both displayed by Paul Pavior. One was in the traditional GNR green livery while the other was in BR black and both were excellent examples of the prototype (Photo 9). Another fine model which did not feature in the competition section was a very good-looking example of a Midland 4-2-2 tender locomotive presented by Rodger Lewcock (Photo 10). It captured the lines of these elegant locomotives perfectly. The largest locomotive on show was the Ten and a Quarter Railway

JANUARY 2023 | ENGINEERING in MINIATURE

PHOTO 5: An interesting display of tools for making Live Steam Injectors by David Oliver. PHOTO 6: Paddle Steamer ‘Waverley’ on the Kingsbury Water Park display.

PHOTO 7: Part of Hereford SME’s display. PHOTO 8: Tony Bickerstaffe is constructing this superb A4 LNER Pacific from works drawings. Photo: Andrew Charman. PHOTO 9: A fine pair of O1 2-8-0 locos by Paul Pavior.

PHOTO 10: This fine 4-2-2 Midland loco was part of the main display section. PHOTO 11: From the Ten and a Quarter Society was this 4-6-0 Royal Scot.

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EVENT REPORT

PHOTO 12: The well presented Birmingham Society stand. PHOTO 13: The Birmingham stand included this well-made beam engine...

PHOTO 14: ...and Keith Bloor’s 2-6-0 Hughes Crab loco on its building stand. PHOTO 15: USS Missouri took centre stage on the stand of the Midland Meccano Guild.

Traditional appeal

It is amazing to think that in these days of 3D printing and laser machining that the old-fashioned model-making material Meccano PHOTO 16: would still have a great following. The large end of Steve Briancourt brought his massive the Model Steam model of the American battleship RVS display. ‘USS Missouri’ to the Midlands Meccano Guild stand and it created a PHOTO 17: Graham Sadler’s great deal of interest (Photo 15). The Model Steam Road Vehicle delightful Society provided a wide range of Atkinson Steam Lorry, part of the models in different scales (Photo 16) for the exhibition from the full-size MSRVS stand. road tractor based on a 3T Savage traction engine right down to a lovely PHOTO 18: Atkinson steam lorry built by Graham Larger model Sadler (Photo 17). engineering – Also providing a full-size exhibit the 7¼” gauge was the Steam Boat Association of Society stand.

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Society’s un-rebuilt Royal Scot 4-6-0 (Photo 11). This looked a really powerful machine. Back to the club displays again with another fine selection of exhibits from the Birmingham Society which ranged from workshop equipment to a 7¼-inch gauge locomotive (Photo 12). A traditional beam engine on a brick plinth caught the eye (Photo 13) while a good-looking chassis of a Hughes Crab presented on a revolving building stand was an interesting feature on the stand (Photo 14). The Northern Association of Model Engineers had a large display of information highlighting the work carried out young people and what the Association can offer its members.

ENGINEERING in MINIATURE | JANUARY 2023

EVENT REPORT

Great Britain with its steam-powered boat, along with a variety of other boat engines and fittings. On the 7¼” Gauge Society display (Photo 18) were a number of quality models along with lots of information about the Society’s activities such as the regular mini gatherings held in different parts of the country. I am sure if any model engineering group were to consider hosting one of these

PHOTO 19: Simon Mulford’s rebuilt Bagnall 0-4-2 tank loco. PHOTO 20: A useful-looking tool & cutter grinder on the Coventry stand. PHOTO 21: Noel Shelly demonstrates drill grinding. PHOTO 22: The Anzani three-cylinder i/c engine. PHOTO 23: Part-built 4-inch scale Garrett by Richard Betts. PHOTO 24: The 2½”Gauge Association stand was filled.

JANUARY 2023 | ENGINEERING in MINIATURE

gatherings in future it would be much appreciated by the Society. A well-presented display by the City of Oxford SME featured a rebuilt Bagnall 0-4-2 tank locomotive as its centrepiece (Photo 19) and this was accompanied by a range of excellent stationary engines. If it is variety and quantity of models you like then the Stirling Engine Society certainly fills the bill. Three separate displays showed off just about every type of Stirling engine configuration from powering a large Meccano-built Big Wheel to Julian Wood’s latest creation, a Stirling engine-powered hot hair dryer – that must be fun to use. A wide-ranging collection of models on the Society of Model & Experimental Engineers (SMEE) stand portrayed the quality and skills of this group. The intricacies of the Society of Ornamental Turners was ably demonstrated on an interesting stand with a number of these complex machines being used by members. A large display by members of the Coventry ME provided a wide variety of models from workshop equipment to 5-inch gauge finescale carriages. The Colyer-Caseley cutter grinder (Photo 20) must be a useful piece of kit while a triple expansion engine was a fine example of the type. A regular visitor to this exhibition is Noel Shelly with his popular portable foundry demonstrations, but this year for a change he was

demonstrating drill sharpening using a Brierly ZB32 Drill grinding machine (Photo 21). This machine can handle drills up to and including 32mm with either plain or Morse taper shafts and appeared to be quite a straightforward set up to obtain very sharp drills. An informative and compact display by the Gauge 1 Model Railway Association showed off the range of activities associated with this popular branch of model engineering. There was a good mix of engines on the IC Engine Builders Group showing off the complexities of these types of machines. The Anzani 3 cylinder Fan Engine was an unusual configuration (Photo 22).

Outside attractions Outside of course the Fosseway Steamers were busy with their large gathering as illustrated on this month’s cover, and demonstrating some of the operations that used to be steam-powered such as sawing large baulks of timber and stone crushing. Steve Lee also made a short speech to the visitors and the Deith family as a tribute from the Steamers for all the work and effort Chris Deith had made over the years in supporting their efforts at the show. On display inside was a 4-inch scale Garrett traction engine being built by Richard Betts of the Black Country Live Steamers (Photo 23). The National 2½” Gauge Association presented a display with

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EVENT REPORT

lots of locos and information about this popular smaller gauge (Photo 24) while the scenic side of 2½-inch was represented by the Gauge 3 Society which had a range of locomotives and rolling stock on show. On the adjacent Wolverhampton and District stand a superb example of a Sherman Tank was complimented by the chassis of a 2-2-2 Problem Class loco to the Chris Rayward design (Photo 25). Also on the stand was an impressively detailed and very large 7¼-inch gauge model of a Ffestiniog Railway curly-roof van (Photo 26). A new organisation called Train 4 Rail featured a number of models owned or built by young people with special needs, which the organisation is trying to promote within the railway industry as a good career move for all younger people. Both the Heritage sector and Network Rail are very interested in the project and hopefully this will produce additional support for the hobby (Photo 27). Another varied display was that by members of the Bromsgrove SME who had a very nice selection of models on show. Boats in profusion featured on the Knightcoat MBC from old-style sailing galleons to modern Soviet submarines. (Photo 28), while nostalgia was the theme from the London & North Western Railway Society, a small train of wagons with an 0-8-0 locomotive and an 0-8-2 under construction giving a flavour of the old railway. With the Guild of Model Wheelwrights having been disbanded,

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horse-drawn and wooden vehicles and machinery are not seen very often these days. However, a display of wooden farm implements by George King was a real eye-catcher with superb workmanship on show in a wide variety of woods. The Fowler Living Van in ⅛th scale was a case in point (Photo 29). The Welwyn Garden City display covered a wide range of models from military fire power (Photo 30) to small domestic marine craft alongside a selection of stationary engines and radio control cars. The Erewash Valley MES are regular supporters of this exhibition and again they produced an interesting display of their members’ work (Photo 31), while the Federation of Model Engineering Societies had a small informative presentation of the services offered to clubs regarding insurance, guidance on boiler testing and encouraging young people into the hobby.

Right time This exhibition came at just the right time to stimulate the world of model engineering, the pandemic having caused the postponement of so many shows and activities which so many people missed. The show demonstrated that the need for such events is still there and wanted. It also showed what appears to be quite a strong movement of young people getting involved with model engineering, I hope this continues. My thanks to everyone who took

PHOTO 25: Wolverhampton & District ME’s display included this superb 2-2-2 loco chassis. PHOTO 26: Also on the stand was this 7¼-inch gauge Ffestiniog Railway van. PHOTO 27: Young person’s exhibit on the Train 4 Rail stand . PHOTO 28: Submarine on the display by the Knightcote Model Boat club. PHOTO 29: George King’s 1/8th scale Fowler Living Van.

part in whatever way and I hope that it can all be repeated again in 2023 between 12th and 15th of October. Make a note now of those dates and let us see another excellent show with plenty of new models. EIM

PHOTO 30: This powerful looking artillery piece was on the Welwyn Garden City stand. PHOTO 31: Erewash Valley MES put on an attractive display.

ENGINEERING in MINIATURE | JANUARY 2023

LOCO BUILDING

Conway – a first steam locomotive build Rich continues his short series designed to help novice builders facing the challenges constructing a first engine – this month, don’t believe all you see in plans... BY RICH WIGHTMAN Part two of a short series

kay, having read the first part of this series last month you have decided on which loco to build. You have your machines and hand tools. You have your set of plans and some materials to hand and you are keen to make a start. Firstly, if possible get the plans scanned and saved as a PDF file. I have used my home A4 scanner to copy small sections of plans. Using one of the many drawing programmes out there (you can find many free ones online – I use a programme called Inkscape which is open source and is free to download) you can clip just the bit you want and print it out to a very accurate actual size. I found doing this to be of great

JANUARY 2023 | ENGINEERING in MINIATURE

use – you can visualise quite clearly the size of the part you are making and lay said part on the print of the drawing as many times as you want. You can make your own notes on the drawing print and if it gets too dirty simply print another. It means you can keep the original set of plans clean and only use them when needed. If you are buying a new set of plans from one of the suppliers ask that they are rolled and not folded. The crease marks can be annoying and make some of the smaller details and measurements hard to read. I have seen plans for sale, and sold on Ebay for a higher price than a new set, I wonder why? Study the plans well and inwardly

“Had I not read the drawing correction in the magazine a very expensive mistake would have been made by cutting the boiler tube too short...”

digest. If there is something you don’t understand ask a question on one of the model engineers’ forums we discussed in part 1. Someone will answer and explain in detail the problem you are having. Another word of warning here – there are routinely errors to be found on plans. There may be just one or two but some designs are apparently littered with mistakes. This is where a good search on the internet is very useful to see if anyone else has had problems.

Not adding up If the design was published as a series of articles in one of the model engineering magazines they may have published the errors but not always. And the errors can be significant – as an example on Conway the boiler length on the plans is 14 inches but in actual fact it needs to be 14¼ inches. The error was published in the magazine the loco was described in but had I not read that a very expensive mistake would have been made by cutting the boiler tube too short! Even though the error was published the original plans were never altered and still contain the incorrect measurement. So it’s very important that you study the plans and make that sure all the numbers add up! A few more examples of errors I came across on my build, starting with the valve rod guides. Take a close look at the drawings of the valve rod guides and the stretcher onto which they fit or should I say are supposed to fit, Photo 8 and Photo 9. There are six holes in the valve rod guides and four holes in the stretcher! I had made the guides and www.model-engineering-forum.co.uk

LOCO BUILDING stretcher at different times so didn’t notice the error – Hmmm? After a bit of head scratching I decided it was easier to remake the guides than remake the stretcher that was already fitted in the frames. Another example concerns the blast nozzle and jets. This is quite a complicated little part that requires precise machining (Photo 10). I followed the plans religiously, making each part to the dimensions given only to realise too late that the dimension of 11/16-inch (indicated by the red arrow) on the plans is wrong and should be 13/16-inch – another piece of bronze launched unceremoniously into the bin. There is also an error in the dimensions of the horn blocks and a correction to this was published in a later edition of the magazine, stating that their overall height should be 113/16-inch and not 25/16-inch! Yet, if you buy a brand-new set of plans for Conway today they will still contain the errors I have mentioned! I understand it’s something to do with copyright why they have never been amended. The moral of this little tale is that you must take a look at each part, look at where it fits and check that all the numbers do add up.

Measure for measure

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PHOTO 8: Original drawing of the frame stretcher – note the four holes specified for each valve guide... PHOTO 9: ...whereas on the drawing of the guides themselves, six holes are specified! PHOTO 10: More potentially expensive errors – the highlighted measurement of 11/16-inch should be 13/16... PHOTO 11: This unit from Arc Eurotrade is typical of the digital readouts that are available. PHOTO 12: TouchDRO – a free download for use with Android phones or tablets. All photos by the author

Some materials might only be available in imperial and vice versa – for example the frames on Conway are 1/8-inch steel. I managed to source some 1/8-inch material but the most common size these days is 3mm. Near enough you might think but 1/8-inch is 3.2mm. If you make the frames from 3mm and make all the stretchers to plan then the distance between the inside of the frames will be correct but the outside measurement will be 0.4mm (0.016-inch) narrower than the plan. It doesn’t sound much but it could mean alterations to axleboxes, axles and such will be necessary. Most of the fittings you will need such as safety valves, water-level gauges, blowdown valves, cylinder draincocks, blower valves, whistle valves and clacks to name just a few examples have imperial threads, with 26, 32 and 40 threads per inch being the most common. While it is not impossible to make all your own fittings and use metric threads – the plans will have details of

the fittings – you must remember to make all the bushes and such with a matching thread. I have made some, water gauges and clacks, but find the tiny parts too small for my fumbling digits and the commercial ones are reasonably priced. Those of us using older machines – my lathe is a Myford ML7 – are probably working in imperial anyway. My milling machine, however, is one of the Chinese variety and is in metric. Digital readouts are the answer and can be fitted quite easily. I have the example in Photo 11 fitted to my machines, supplied by Arc Eurotrade (usual disclaimer) and which come with its own display. I have each coupled to the free download called TouchDRO (Photo 12) which works on any android phone or tablet. Many people simply modify the cheapo 6-inch digital calipers which work perfectly well and switch between imperial and metric. I have one fitted to the tailstock of the

What shall we talk about next? I know lets debate the imperial versus metric argument. If you are old-school then imperial measurements won’t bother you and you will have taken metrication in your stride. If you are of a younger generation and brought up in the world of metrication then converting back to imperial may be a challenge, but it’s one I think you will have to master. Most if not all of the plans available today were drawn many years ago and have imperial dimensions. Converting all the measurements to metric is not impossible but might not work in certain circumstances.

ENGINEERING in MINIATURE | JANUARY 2023

LOCO BUILDING

Myford with no problems at all (Photo 13). To sum up, I think you will have to become conversant in both imperial and metric measurements. The plans will specify a few different sizes apart from imperial such as number and letter drills and BA size threads. I have charts printed out and pinned to my workshop walls for easy reference. Another decision to make early on is to what degree of accuracy you want your model to be. Do you want a show-standard, accurate down to the last rivet, work of art or do you want a

JANUARY 2023 | ENGINEERING in MINIATURE

PHOTO 13: For ultimate lack of cost a digital caliper can be adapted to serve as a machine tool readout... PHOTO 14: Button-head screws make believable rivets.

loco that is a reliable runner that you can take down to the track with minimal effort and maintenance. I chose the latter.

Changes can be made On Conway I have made a few alterations to the original design, the main one being to fit side tanks rather than the original design’s saddle tank – I did it for no other reason than I prefer the look of side tanks. My tanks are quick-release units being held on with two M6 bolts. The cab is also quick-release and is held onto the loco with eight thumb screws. I have also made split axleboxes which incorporate underslung coil springs instead of the leaf springs in the original design. Where possible I have used stainless steel in my build – the valve rods and brake gear for example are all in stainless steel. They are inside the frames so can’t be seen anyway. The running boards are stainless steel, as yet unpainted and may remain so – they are dead easy to clean requiring little more than a wipe with a rag. The Conway plans mostly specify the use of BA-size nuts and bolts. BA nuts and bolts have a head size smaller than normal which look more to scale. I have used stainless-steel nuts and bolts in mostly metric sizes, some socket-head cap screws, some with stainless-steel nyloc nuts. They are relatively cheap to buy compared to BA and readily available. To do this some holes may have to be drilled slightly larger. For example 4BA = 3.6mm so the holes will have to be drilled to accommodate a 4mm bolt. 7BA = 2.5mm so can easily be substituted by 2.5mm bolts. Also available in stainless steel are button-head screws which I have used around the smokebox to good effect, they look a little like rivets (Photo 14). Whilst I admire the level of skill to which some builders have reached I’m afraid I have not yet mastered the art of riveting nor do I to some degree have the patience. I have tried my

hand at riveting and just could not get it right so I’ll stick with the buttonhead screws for now. Okay, just before we start on the build, what to do about the boiler. If you are building a model purely for show then this is not an issue but if you intend to run it then make a decision early on. This is I believe why we see many unfinished locos for sale, some with all the boiler materials included. Builders get to the stage of needing a boiler and then back out. I will quote Martin Evans from the Conway magazine article; “It seems that quite a few locomotive builders find boilermaking more difficult than machine or chassis work. This is rather difficult to understand, because in many ways, boiler work is easier than chassis work and, furthermore, it does not take nearly so long provided the essential equipment is available. “Whereas in chassis work, we have to work frequently to ‘thous’ (sometimes even to half-thous!), on boilers, we shall not do too bad if we are within 1/32-inch on the longitudinal dimensions, or 1/64-inch on our widths”. It is a little daunting, the idea of making a boiler and I must admit I had been putting it off for quite a while. But the time had come to get on with it. I couldn’t justify the expense of buying a commercially-made boiler, some run into thousands of pounds with a two-year waiting list, so the only option was to do it myself. Firstly, before any materials are purchased, speak to the boiler inspector at your club. He will advise you on what to buy and he will want to see it at various stages of the build.

Boilermaking gear What is the essential equipment? Well you need a hearth of adequate size for a start. Mine is a cheapo Workmatetype bench fixed solidly to a plywood board and mounted on heavy-duty braked castors (Photo 15). I can move it from the corner of the workshop to nearer the door for better ventilation when soldering. It is topped with a sheet of 6mm thick steel that I won from somewhere. I use Vermiculite firebricks on the base and surrounds which can be stacked to suit the job in hand. A propane gas bottle and torch is next on the list. Propane burns hotter than butane, and you will need lots of heat. I initially started with a cheapo torch kit from one of the major tooling outlets which was okay for a start but as the boiler progressed and became larger I was struggling to get enough heat into it. At the time I had access to oxy-acetylene gear which was a great help. The fine flame was great for www.model-engineering-forum.co.uk

LOCO BUILDING

reheating small areas and because it had its own oxygen supply could be used in areas such as deep inside the firebox without extinguishing the flame. The cost of oxy-acetylene is now prohibitive, however, so when I no longer had access to it I set myself up with oxy-propane gear (Photo 16). Propane is readily available at many outlets so is not a problem. For the oxygen I have a bottle that is a one-off payment for deposit, in other words rent-free for life, I only have to pay for refills. At one of the model engineering shows we spoke to the guys on the Sievert stand (usual disclaimer) and bought a torch kit from them (Photo 17). Back home and keen to try my new torch I connected it to the

PHOTO 15: The author’s brazing hearth setup – note the bucket of water close to hand. PHOTO 16: A typical oxypropane torch. PHOTO 17: A good quality propane torch PHOTO 18: Twin outlets on the propane tank are useful.

propane bottle and lit it. To be honest I was a little disappointed, it didn’t seem to be much better. It was not until a few weeks later when the need to do some silver soldering arose that I changed the regulator for the one supplied with the Sievert kit. An amazing difference – it was clearly hotter than the cheapo torch. I haven’t gone into the technicalities but I imagine the regulator and torch are a balanced pair and I think the regulator allows a greater flow of gas. I have since built another boiler for my new loco and had no trouble at all with the setup I have. Y-connectors that have separate valves are available for the propane bottles so two outlets can be used (Photo 18). So to summarise money is well

spent on a quality torch and regulator while an oxy-propane set up, although not essential, is a real asset. Have a bucket of water and a fire extinguisher to hand. A pair of leather welding gauntlets and some tongues are useful as well. I’ll describe more about the actual boilermaking process later on in this series. n NEXT TIME: Rich starts the actual build of his loco with the frames, and then straight onto the boiler... Part 1 of this series appeared in last month’s December 2022 edition of EIM. A digital back issue can be downloaded or a printed copy ordered from www. world-of-railways.co.uk/store/backissues/engineering-in-miniature or by calling 01778 392484.

Making Model Victorian Stationary Engines By Stewart Hart

tationary engines offer a lot to the model engineer – they are generally not that difficult or time-consuming to build and when complete are great to operate or simply display on the mantelpiece, allowing one to say proudly “I made that” in response to the inevitable questions from visitors. In this excellent new 176-page hardback Stewart Hart describes in detail everything you need to know about building such engines, even if this will be your very first model engineering project. The book opens with an in-depth description of what the stationary engine is and how it works, with plenty of easy-to-follow

diagrams making understanding the processes much easier. Stewart then details what one needs in the form of workshop equipment to build such a model, before going on to describe the construction of three specific engines – a vertical cross-angle design, grasshopper haulage engine and open-frame horizontal engine. Dimensioned drawings for the components of all three engines are included along with materials parts lists, and plentiful photos help to make the techniques described more understandable. There is also a chapter suggesting where to progress to next in your model engineering career. This is an excellent book – get a copy and you could sooner than you think have three superb models to impress your friends with! AC ISBN 9780 71984 120 0 Price £19.99 Published by Crowood Press Email: enquiries@crowood.com Web: www.crowood.com ENGINEERING in MINIATURE | JANUARY 2023

GENERAL NEWS

Will there be a Harrogate show in 2023? C

£25k boiler appeal to start Sutton revival P

lans are underway to revive the spirit of a line that was once one of the UK’s premier miniature railways, with the first step restoring its locomotives and rolling stock to operating condition. Built in 1907 to 10¼-inch gauge as a fairground railway in Sutton Coldfield, east of Birmingham, the Sutton Miniature Railway was regauged to 15-inch just a year later, and operated until the First World War. It was then revived in the late 1930s on a longer route through parkland, and ran until 1962 when it closed and its stock, including 4-4-2 Atlantic locomotives ‘Sutton Belle’ completed in 1930, and the 1950-built ‘Sutton Flyer’, was put into storage. In 2000 the collection transferred to the Cleethorpes Coast Light Railway with the aid of a Heritage Lottery grant, and more recently the ‘Sutton Collection’ has moved again to the premises of heritage railtour operator Vintage Trains, based at Tyseley Works in Birmingham. Sadly the site of the former SMR has disappeared under industrial development so the plan is to rekindle the spirit of the former miniature railway by establishing a new line at the Tyseley site, under the umbrella of Vintage Trains. The entire restoration project has been costed at £520,000. The two steam locos, which were both built to designs by renowned miniature railway engineer Henry Greenly, are in need of a total rebuild, which will account for £100,000.

JANUARY 2023 | ENGINEERING in MINIATURE

Restoring the original passenger rolling stock, comprising six enclosed and four open carriages, is expected to cost £20,000 with a further £250,000 going to provide a running line of around 1km around the Tyseley site. Finally £150,000 will be spent on providing station facilities and a running shed to keep the stock under cover. As a first step an appeal has been started to raise £25,000, which will enable the building of a new boiler for Sutton Belle. To gain publicity for this appeal the locomotive was displayed over the weekend of 26th-27th November at the Warley National Model Railway Exhibition, held at the National Exhibition Centre in Birmingham. More details and updates on the initiative, including how to donate to the appeal, are on the group’s Facebook page at https://www.facebook.com/smr.tyseley

onfusion surrounds prospects for a model engineering show at Harrogate in the Spring of 2023. In our November issue we reported on the apparent prospects for a revived National Model Engineering Show, not in Doncaster where the show was last held in 2019, but in its former home of Harrogate. Our story was based on invitations sent to model engineering clubs, for a two-day gathering in the Yorkshire Event Centre at the Great Yorkshire Showground, Harrogate on 24th-25th February. Responsible for the invitations was Simon Boak, who started the National show in 1994 and ran it until it moved to Doncaster. As time has gone on, however, there has been no official announcement of the new show, and no contact made for example with the media. At the time of going to press there was no mention of the show on the Great Yorkshire Showground website. Meanwhile personalities involved with the Doncaster show have stated on social media that there is no connection between the new show and the National event, which they said would not take place in 2023 “due to a lack of trade support.”

Two shows in one? In the latest twist, EIM has seen trade invites and a site plan for a Harrogate event over two halls, stating that the show will now take place on 10th-11th March, alongside the established Harrogate Model Rail show, with one ticket admitting visitors to both events. This date clashes with the established Midlands Garden Rail Show at the Warwickshire Event Centre. Despite the plans apparently proceeding, there have apparently still been no details released to the media or any pre-publicity released, only three months before the event is due to take place. So will it happen? We must hope so as at present the only major model engineering show confirmed to be taking place in 2023 is the Midlands event in October...

Errors and omissions... W

e apologise for a few errors that crept into last month’s edition of EIM. In David Coney’s piece on solving a marine modelling issue the fourth photo was taken by his son Ben Coney, not Ben Crowley. John Arrowsmith’s report on the Midlands Model Engineering Exhibition competition classes states that in Class 5 Stationary Engines, a Stuart S50 built by John Fysh was Commended by the judges. The entry included several quality entries by John Fysh but the particular S50 was built by

John Wing, who wrote to tell us of the error! On the same page (8) the rectilinear engine in photo 11 was made by Brian Holland, not Brian Booth. John Roberts has also written to ask whether the link to a listing of drawing errors posted in Rich Wightman’s article is correct as he couldn’t get it to work. It is a shortened version which apparently may not work on some tablets – the full link is https:// modeleng.proboards.com/thread/3225/ errors-on-drawings www.model-engineering-forum.co.uk

CLUB & TRACK NEWS

Planning for a new year The depths of winter but the clubs remain busy and heading confidently into 2023. COMPILED BY ANDREW CHARMAN

elcome to the Club News pages and it’s another shorter than usual general round-up this month, due to the report on the welcome return of the Lowmex exhibition in Lowestoft – it’s great to see such events coming back to life, especially the regional shows which fulfil a vital function of keeping everyone in touch at a time, as we report elsewhere, that many of the traditional national events seem to be struggling. Not the Midlands show of course, as reported last month and continued in this issue the EIM-sponsored event seems to be back up and running in style, and currently the only major national show that we can say with confidence will be happening in 2023. A sad situation, let’s hope the MMEE doesn’t have to shoulder the burden of a lonely standard bearer for the model engineering hobby for too long and some other national events return. John Arrowsmith’s second Midlands report was so crammed with photos that we couldn’t use them all, quite apart from the ones taken by editor Charman, so we’ve allowed a couple to sneak onto these pages – which is another way of reminding the clubs, please send in pictures of your events, happenings, notable models completed by members... These pages look so much better with lots of pictures on them...

Nominate your youngsters

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ABOVE: A stand-out feature of the Midlands Model Engineering Exhibition on its return in October was the sheer quality of the model engineering on show. Space precluded us last month showing the detail in the cab of Alan Crossfield’s 5-inch gauge GWR Achilles 4-2-2, which was we reported was beaten into second place in its class! BELOW: Judging by the quality evident in the Gresley A4 Pacific under construction by Tony Bickerstaffe, it could well be competing for the top prize at a future show. Photos: Andrew Charman and John Arrowsmith

Entente Cordiale We start this month’s dip into the newsletters with the Romney Marsh ME and in his column club president Bobby Jones describes what sounds like a very interesting afternoon that Romney members were invited to back in June, at the Eastleigh Lakeside Railway near Southampton. The Eastleigh line, which is 7¼ and 10¼-inch dual gauge, celebrated the Golden Arrow train service that formerly ran between London and

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We start this month’s reports with a somewhat urgent parish notice, not from us but the Northern Association of Model Engineers. NAME is reminding all member societies to get their nominations in for the annual Young and Junior Engineer Awards. We were somewhat disappointed to hear that apparently there has so far been little or no response to NAME’s earlier requests for nominations – we’ve stated it many times before but have no hesitation in again reminding readers that encouraging young people into model engineering is essential to secure the future of the hobby in these challenging times. We’ve seen a lot of success in recent times with engineering again becoming a subject of interest to young people, but we must not relax our efforts. The awards will be presented in the early spring so there is still time (just...) to nominate a young member

of your club. NAME secretary Alan Budd also tells us that there is nothing to stop a previous entry that did not win from being entered again; “Some of the entries were just pipped at the post, so why not give them a second chance?” he says. The Young Engineer award is open to those aged between 18 and 26 years inclusive and the winner will be awarded the Birkett Trophy plus £200. There are three classes of Junior Engineer, age 8-10 inclusive will receive a Certificate of Merit plus £20, age 11-13 a Certificate of Merit plus £30, and age 14-17 the NAME Trophy plus £40. Nominations should include as much detail as possible, written, photographic and such like, and Alan reminds clubs that this award is not just for the building of models but also reflects the young member’s conduct and helpfulness within the club. Nominations can be posted to Mr A. Budd, 39 Langford Rd, Arnold, Nottingham, NG5 7HR, or emailed to alan.budd@hotmail.co.uk – go on, there must be someone in your club who would benefit from a little encouragement in this manner? On which note, we received a curious little note recently in the EIM office, from four young enthusiasts who are currently trying to set up a model engineering club at Burghfield near Reading. “We have three quarters of a mile of 5-inch and 7¼-inch gauge track,” Marcus told us, adding “We are in dire need of help as there’s only four of us, we are only 19-25 years old and we are in need of guidance.” He added that efforts to interest neighbouring clubs had been unsuccessful – if you are able and willing to help, get in touch with the editorial office and we’ll pass on your details to the group.

ENGINEERING in MINIATURE | JANUARY 2023

CLUB & TRACK NEWS

ABOVE AND BELOW: More model engineering excellence that caught the editor’s eye at the Warwickshire Event Centre, a 3-inch scale Wallis & Stevens Simplicity road roller and some superb examples of marine modelling.

Photos: Andrew Charman

Paris, and at the event a 10¼-inch Bullied Pacific contrasted with a superb French 4-cylinder compound Chapelon E Pacific in the same gauge. You know what we are going to say – how come we’ve just heard about this, and where are the pictures?

Zooming on The Romney club, by the way, is still making extensive use of Zoom for its meetings, despite the ‘return to normality’. Secretary Adrian Parker says that one advantage of Zoom is that it is easy to book speakers from all parts of the UK or even abroad. The club plans Zoom meetings in the colder winter months and clubhouse meetings at the start and end of the

JANUARY 2023 | ENGINEERING in MINIATURE

running season – a very sensible plan we reckon... Good to read in the latest edition of Trackerjack, the newsletter of the Teeside Small Gauge Railway, that the club committee have decided to hold members running days on the fourth Saturday of each month, in addition to the public running season. More opportunities for members to get together, run their locos and have a natter is always a good thing we think – the most successful clubs are as much a social outlet for their members as they are a local attraction. The Teeside newsletter includes a surprisingly interesting piece on what sounds like a mind-numbing task, Continued on page 44

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CLUB & TRACK NEWS FOCUS

Lowmex returns – bigger and better... T

he Lowestoft Model Engineering and Model Making Exhibition (Lowmex) returned from Pandemic hibernation for its seventh event on the last weekend in October this year, a bigger, better, and brighter show (writes Julie Williams). It had a new venue, the Energy Skills Centre at the East Coast College, Lowestoft, and the extra space was put to very good use. It was all there, spreading over 300 tables, not including the floor exhibits, free-standing models, mobile models and models on their own bases, shown in two large halls and 14 rooms over two floors and two buildings, using the corridors as well while of course there were also outside exhibits. I have to be honest here, said outside exhibits were not treated kindly by the weather, but that didn’t stop skilful flying demonstrations and some steam engines from damply strutting their stuff. The main event, though, was inside – and it was spectacular. The core of the exhibits was provided by Halesworth and District Model Engineering Society (HDMES), the parent club of Lowmex, and the club had the bulk of a very diverse display in the two main halls. Jonathan Welch showed two stationary engines he had built from Tubal Cain’s book Building Simple Model Steam Engines (Photo 1). The larger one on the left is a ‘Wenceslas’, powered by fuel tablets and the smaller one on the right is a ‘Kitten’, powered by methylated spirit. Further round the displays was John Child’s work in progress, a very impressive

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model of the 1:24 90-inch Cornish pumping engine, in preservation at Kew Pumping Station (Photo 2). John has already laid about 7,000 of the estimated 12,000 miniature bricks needed. Kevin Rackham, his wife and three sons all displayed some of their models, a real family affair. Photo 3 shows, being set up, just three of the many models that the Rackham family had on show: at the back is Tom’s 2-inch Fowler Road Locomotive in War Department colours, which Tom is restoring: in the middle is Marion’s 3½-inch gauge ‘Rainhill’: at the front is Kevin’s 5-inch gauge 0-6-0 tank locomotive ‘Pansy’. Also in the display but not in the photo was Chris Rackham’s Gresley A3 ‘Solario’ on his custom-made realistic track or Mathew Rackham’s radio controlled K9, Dr Who’s robotic dog – and the family had other models on display as well. Andy Belcher and Chris Nobbs displayed a large 16mm scale World War 1, Darjeeling Himalayan Railway and Penrhyn Quarry Railway layout, (Photo 4). They also ran a 16mm live steam exhibit in another room with another club.

All sizes, all gauges So many other clubs and societies, as well as individual modellers, showed models ranging from all gauges to a huge 12ft long model of a Cowens 75-ton crane by Charlie Lovett – this was too big to photograph all of it, but Photo 5, showing Charlie attaching the (temporary) nylon cord illustrates the scale beautifully. Charlie also displayed his

previous project, a very large, impressive LNER Gresley Teak Diagram No. 5 1st class combined carriage (Photo 6). Another individual exhibitor was Malcolm Barker who had a large glitzy floor layout of a fairground in the refreshment area, (Photo 7) with classic fairground music as well. He made a collection alongside the model for Great Ormond Street Hospital. There were stationary engines running on air; there were boats and planes; traction engines; showman’s engines; locos; there was a model of just about anything you could name. There were even individual workshop tools, all made by Bernie Towers, and some designed by him, as well as Richard Stratton’s display of workshop equipment that he’s built – he said that likes to make the stuff that makes the stuff! Lowmex doesn’t have prizes, there are no best-in-show or highly commended awards, and it doesn’t have many trade stands, just a few that a modeller would find useful or interesting. What the show does have is wall-to-wall models, made by very skilled like-minded enthusiasts who can talk all day about their hobby. Why not come and have a chat with the exhibitors at next year’s event? It will be up to you then as to which one you think is the best! This year it was the Daleks which stole the show with the public, especially the ‘small humans’... Full details of the show can be found at www.lowmex.co.uk Photos by Julie Williams – details in text.

ENGINEERING in MINIATURE | JANUARY 2023

CLUB & TRACK NEWS

ABOVE: Our editor made a recent visit, in his ‘other role’ at the helm of EIM’s sister magazine Narrow Gauge World, to the Ross-on-Wye works of Alan Keef Ltd, renowned for its mainly narrow gauge railway engineering (a feature on the company will be in the January-February issue of NGW). Present in the workshops were a pair of new and almost complete carriages Keefs are building to a bespoke design for a private 101/4-inch gauge railway in Devon. On this line the stock will operate with a Darjeeling Himalayan-style 0-4-0ST (pictured at right at the Keef open day in September). This engine was built originally in 2014 for the Ferrymead Railway in Peterborough. It seems we are hearing ever more often of more private miniature railways, of increasing complexity, being built by individuals across the country, which can only be good for model engineering as a whole. Let’s hope the owners of such lines stage a few open days!

NOTICE BOARD Notice Board is a free service that readers are welcome to take advantage of. If you have something for private sale, are searching for that elusive casting or drawing, or just want to alert your fellow model engineers to something of potential interest to them, then send in details to the address on page 3, marked ‘Notice Board’ and we’ll put it in! FOR SALE: Myford Super 7 Connoisseur lathe, one of the last original company examples. Exceptional condition, little use, considerable amount of tooling all virtually as new. DRO fitted to two axis, unused since 2007 and continuously stored in dry heated workshop. Email for full specification to EdParrottMyford@outlook.com OIRO £14,000

Continued from page 42 walking the track and replacing rotten sleepers! Well it’s a necessary job, someone’s got to do it... One would be forgiven for expecting Lionheart, the journal of the Old Locomotive Committee to be focusing on much smaller scales at present, with major model railway manufacturers Hornby and Rapido seemingly competing with each other to build 4mm scale versions of OLCO’s signature locomotive, the Liverpool & Manchester Railway’s ‘Lion’, immortalised in The Titfield Thunderbolt movie. Matters model engineering continue to dominate Lionheart, however, the main report being on the latest ‘Lionsmeet’ annual gathering for club members to steam miniature versions of Lion and other early locos. The 2022 Lionsmeet was held at the premises of the Worcester ME, and like just about every other annual event in our world and beyond was the first in three years. Apparently it was a highly enjoyable occasion with several examples of the iconic loco in action on the various track gauges and more under construction examples on display for visitors. The latest edition of The Lobby, magazine of the Brighton & Hove SMLE, proudly declares on its front cover, “71 years of Miniature Railway

operation in Hove Park” and illustrates this with a cover picture of a fallen tree completely blocking the running line! Thankfully the tree, which had been brought down by high winds in early November, did no damage to the club track and was removed within 24 hours by the park’s management.

Lifetime bargain The Brighton journal also includes a heartwarming story by member Harold Turpin who was persuaded some 20 years ago to further his lifetime interest in steam locomotives by buying a 5-inch gauge 0-4-0 loco named ‘Hybrid’ in an auction. Knowing little about how steam locomotives worked when he bought it, especially scale ones, ownership led to membership of the Brighton Club as he learnt to drive the engine on the Hove Park Railway. Having originally bought Hybrid for £950 plus commission, Harold declared “it ended up being my lifetime best value for money – except for my wedding costs of course!” Whoops, we are out of space again – keep those newsletters coming in as we will be back up to a full-size Club News next month. And if you include a picture or two, your submission will certainly be in pole position to make it onto these pages... EIM

n AND FINALLY: You had one job... The Editor had a day out in the smaller-scale world of electric mice at the end of November, visiting the Warley National Model Railway Exhibition, and almost immediately spotted this clanger above the main entrance. Hope the sign wasn’t produced by the venue, because guess where the show was held? Yes, Birmingham’s National Exhibition Centre...

JANUARY 2023 | ENGINEERING in MINIATURE

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DIARY JANUARY JANUARY

Brighton & Hove SLME New Year’s Fun Day, Hove Park.

Grimsby & Cleethorpes ME New Year’s Day free public running, Waltham Windmill, DN37 0JZ, 11am-3pm

12 Worthing SME meeting, Tidal Mills of 3 Brighton & Hove SLME meeting, Bits 14 Romney Marsh ME Members’ Social the Southeast by Alec Vincent, Field Pce, Worthing, Sussex, BN13 1NP, 7.30pm

& Pieces Evening, West Blatchington Windmill, BN3 7LH 7.30pm

4 Rochdale SME meeting, Darkhill 13 Hereford SME meeting, Reactors inside ICI by Robert Davies, Broomy Hill, Hereford HR4 0LJ, 7 for 7.30pm

Afternoon, Rolfe Lane, New Romney, from 2pm

17 Brighton & Hove SLME meeting,

Ironworks by Bob Hayter, Castleton Community Centre, Manchester Road, Rochdale, 7pm

Films with Keith Carter, West Blatchington Wndml, BN3 7LH 7.30pm

18 Rochdale SME auction night, 1

Rochdale SME New Year’s Day Steam-up, Springfield Pk, Bolton Rd, from noon

17 Romney Marsh ME Members’ Social

Romney Marsh ME New Year’s Day Track Meeting, Rolfe Lane, New Romney, Kent, from 11am

18 Bristol ME meeting, Small

Afternoon, Rolfe Lane, New Romney, from 2pm

5 Guildford ME Small Model Steam Engine Group open meeting, Stoke Park, Guildford, Surrey, 2-5pm

Castleton Community Centre, Manchester Road, Rochdale, 7pm

21 Romney Marsh ME meeting, progress 1

7 City of Oxford SME meeting,

on the Brighton Atlantic by David Measuring in space by Graham non-locomotive engines evening, Jones, Rolfe Lane, New Romney, Toplis, Cutterslowe Pk, Oxford Begbrook Social Club, BS16 1HY, 7pm 7.30pm for 7.30pm– contact secretary@ bristolmodelengineers.co.uk 1 Southampton SME New Year’s Day 9 Worthing SME meeting, subject tba, 23 Worthing SME meeting, club AGM, Field Pce, Worthing, Sussex, BN13 Frostbite running, Riverside Pk Rly, Field Pce, Worthing, Sussex, BN13 1NP 7.30pm Bitterne, SO18 1PQ, 11am-3pm 1NP 7.30pm 18 Leeds ME meeting, talk on Eggborough site demolition, Mid Yorkshire Golf Club, Darrington, 7pm 10 Hereford SME meeting, Steve Turner 25 Teeside SMG Members steam-up, 1 Stockholes Farm Miniature Railway gets gossiping aobut two old ladies, New Year’s Day Steam-up, Belton, Preston Hall Museum, nr Stockton, Broomy Hill, Hereford HR4 0LJ, 7 for Doncaster DN9 1PH, 1-4pm http://tsgr.co.uk 20 Brighton & Hove SLME meeting, 7.30pm History of the Welsh Highland Railway by Hef Jones, West 3 City of Oxford SME meeting, A day in 26 Southampton SME running, Blatchington Windmill, BN3 7LH the life of a 747 pilot by Simon Riverside Pk Rly, Bitterne, SO18 1PQ, 12 Southampton SME running, Riverside Pk Rly, Bitterne, SO18 1PQ, 7.30pm Dawson, Cutterslowe Pk, Oxford 11am-3pm 11am-3pm 4 Bradford ME meeting, Bits & Pieces 21 Rochdale SME meeting, members’ 28 Romney Marsh ME Members’ Social projects, Castleton Community evening, Saltaire Methodist Church, A’noon, Rolfe ln, New Romney, 2pm Centre, Manchester Road, Rochdale, 7.30pm 7pm PLEASE NOTE all outside events and public running 4 Bristol ME meeting, ‘Railway level subject to weather – please check with Society crossings’, Begbrook Social Club, 22 Southampton SME running, concenred before travelling to an event. Riverside Pk Rly, Bitterne, SO18 1PQ, BS16 1HY, 7pm for 7.30pm– for 11am-3pm details contact secretary@ bristolmodelengineers.co.uk 26 Worthing SME meeting, subject tba, Field Pce, Worthing, Sussex, BN13 4 Leeds ME meeting, Bits & Pieces 1NP 7.30pm Night, Mid Yorkshire Golf Club, Darrington, 7pm 27 Hereford SME meeting, Progress on the Vale of Berkley Railway by Ian 6 Brighton & Hove SLME AGM, West Raven, Broomy Hill, Hereford HR4 Blatchington Windmill, 7.30pm 0LJ, 7 for 7.30pm 7 Rochdale SME general meeting, Castleton Community Centre, 28 Teeside SMG Members steam-up, Preston Hall Museum, nr Stockton, Manchester Road, Rochdale, 7pm http://tsgr.co.uk 7 Worthing SME New Year Steam-up, Field Pce, Worthing, Sussex, BN13 31 Romney Marsh ME Members’ Social Afternoon, Rolfe Lane, New Romney, 1NP 2-5pm from 2pm 8 Southampton SME running, Riverside Pk Rly, Bitterne, SO18 1PQ, FEBRUARY 11am-3pm 1 Bradford ME meeting, subject tba, Saltaire Methodist Church, 7.30pm ● 11 High Wycombe ME meeting, subject ● tba, Rosetti Hall, New Pond Rd, 1 Lincoln ME meeting, talk by Jim Bailey, The Stone Arms, High St, Holmer Green, 7.30pm ● Skellingthorpe LN6 5TS, 7.30pm

Coming next month in...

Details for inclusion in this diary must be received at the editorial office (see page 3) at least EIGHT weeks prior to publication. Please ensure that full information is given, including the full address of every event being held. Whilst every possible care is taken in compiling this diary, we cannot accept responsibility for any errors or omissions in these listings.

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Uncovering the mystery of injectors More tests with future fuels Rich builds the frame for his novice loco ● An improved Schools class ● ...and much more!

February issue on sale 19th January Contents correct at time of going to press but subject to change

ENGINEERING in MINIATURE | JANUARY 2023

IN G1

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Articles inside

ELECTRONICS – A TWO-TONE LOCO HORN

CONWAY: NOVICE GUIDE TO LOCO BUILDING

GENERAL NEWS Veteran line revival effort

BENCH TALK – FLATENDED BORING TOOL

71/4-INCH GAUGE RIDEON TENDER PROJECT

REVIEWS

MORE BENCH TALK –LATHE STOPS & GAUGES

COAL OF THE FUTURE ON TRIAL