Indholdsfortegnelse for Issue 4701 i Model Engineer

MARTIN EVANS Editor DIANE CARNEY Assistant Editor YVETTE GREEN Designer By the time you read this, over two weeks will have passed since the funeral of our late, great monarch, Queen Elizabeth the Second. The entire occasion, from the departure from Westminster Hall, to the committal of the Queen’s coffin to the Royal Vault under St George’s Chapel at Windsor, was an event of the most staggering brilliance and precision. All those involved in the various processions and services performed faultlessly, as we have come to expect in this country, and I believe that no other country could have mounted a spectacle anything like it. On top of all that, it was all done under the gaze of virtually the entire leadership of the world and in front of an…

Continued from p.470 M.E. 4700, 23 September 2022 When John (photo 23) and I checked the locomotive we found that although it had run well, the motor was very hot. Furthermore, there was a lack of regenerative braking because the motor had to be driven through a relay to reverse it. In addition, we think that the motor was series wound and, with the regenerative braking needing a permanent magnet motor, we started to think about changes. I also felt that the chain drive was noisy so after a few weeks running at other tracks John bravely decided to fit the other motor which I had given him months before, and the Mark 2 was born. We also then discovered that the Mark 1 motor, to be used on a…

Continued from p.457 M.E. 4700, 23 September 2022 Time to move onto the exhaust pipes. Now, along with soldering, bending thin walled pipe has never been one of my strong points but I did have some success a few years ago bending 5/16 inch diameter brass pipe with a 0.015 inch wall thickness. On that occasion it was for the eighteen fuel intake and exhaust pipes for a nine cylinder radial aero engine, where I made a dedicated pipe bender for that sole purpose. Its probably worth a few lines and a couple of photographs to demonstrate the process of producing a dedicated pipe bender and the processes involved with preparing the tube for bending as I used the same fixture and pipe section for the Demon exhaust. To minimise…

The dynamo pulley is shown in photo 15. It’s made from three discs of steel bolted together. Two of the discs are chamfered to fit the tapered sides of the drive belt and the smaller disc (in between) is left plain. Photograph 16 is the setup I used in my lathe to turn the tapers. I had to mount the cutting tool upside down while running the lathe forward to stop the chuck coming unscrewed. Photo 17 is one side of the pulley finished. Photograph 18 is a side elevation showing the nonstandard seat that I fitted. To accommodate the extra width, I reduced the length of the bonnet and inclined the two rear struts as you can see in the picture. Also, in this picture, you can see the…

Lord Nelson Class 4-6-0s Tim Hillier-Graves Before the Bulleid Pacifies the Lord Nelson class were the Southern Railway’s most powerful locomotives, if not, as their public relations people claimed, the most powerful in Britain. Richard Maunsell had a hard task designing new locomotives for heavy boat trains when the Southern’s electrification programme made great demands on resources. It was never a large class, just sixteen engines in total, and arguably not as successful as hoped. Yet they were known as ‘Whispering Giants’ and could achieve impressive performances especially after improvements by Oliver Bulleid. Tim Hillier-Graves has produced a throughly worthwhile account of these engines, with an informative assessment of the engineering developments involved. Their originator, Richard Maunsell, had an unusual career progression starting in Inchicore Works, Dublin, moving to the…

Continued from p.443 M.E. 4700, 23 September 2022 Construction An aluminium block measuring 2.5 x 2 x 1.5 inches was cut by band saw from bar stock. Accuracy in marking out cylinder and crank centre lines, to ensure intersection, and crank pin to be central to the cylinder bore was essential. The crankcase was through bored with additional material removed to accommodate the crankshaft ball race. Cylinder location height, above the crank centreline, was critical in relation to porting and events timing. A trial assembly of crankshaft, cylinder, piston and connecting rod demonstrated ports were fully open for the exhaust at BDC and the inlet at TDC. Next the crankcase was drilled and tapped 6BA for clamping the cylinder head, cylinder and cylinder block with four studs. A circular aluminium…

This annual event is held over two days in Onslow Park just outside the town and was the first show for two years. The anticipation of a good event was very high and the weather helped with fine dry sunny days which attracted large crowds to this area of Shropshire. Organised by the County of Salop Steam Engine Society, the event was widely advertised and promoted. My early arrival at the park ensured that those interesting moments and glimpses of preparation were easily accessible before the anticipated large crowds began arriving. With about 25 different classes ranging from the mighty showman’s engines to prams and pushchairs there really was something for everyone. As I said, my arrival coincided with the early morning preparations and, with the crisp morning air, the…

Sowing the seed For most of my life I have been a clock enthusiast and over the years I have made several clocks to my own design and those of John Wilding and Claud Reeve both of who I am sure are well known to long standing readers of the magazine. I have to admit that compared to making a scale railway engine/locomotive or other type of stationary steam engine, making a clock is a relatively simple and much quicker project to undertake. Indeed, I know of several model engineers who occasionally take a ’year off’ to make a clock or have made a clock in their spare time between projects. Depending on the design of the clock, a simple timepiece can be made in much less than a year…

Continued from p.452 M.E. 4700, 23 September 2022 The third part of this series provides the details of the wrappers and the fabricated barrel. There are two wrappers: the inner firebox wrapper (fig 4) and the outer wrapper (fig 5). Figure 6 provides the details of the positioning of the firebox stays. NOTE: the positioning of these stays in fig 1 (Part 1, M.E.4699, September 9) is incorrect and the stay locations should be taken from fig 6. Both wrappers need to be accurately marked out and cut from the copper sheet, cleaned up and filed square and to size. When marking out the wrappers, the centreline must be scribed and then centre dotted at each end of the line for future reference. It is important that the centrelines are…

Continued from p.467 M.E. 4700, 23 September 2022 Item 2 – Main bearing carrier (Fig 9) Two required – 5083 aluminium plate * Bring the two 10mm thick blank edges square and to overall size, 74.5 x 40, the 40 being ± 0.02. Set up one main bearing carrier on suitable parallels with the spindle in the centre of, and 54.5 from, one end face. Centre drill and drill 012. Bore 012.7 and ream 013. Repeat on the second carrier. * Clamp with the mounting face uppermost (bearing hole nearest vice base) with the longer edge against the fixed jaw. * Locate the spindle in the centre of the width and thickness. Centre drill and drill 03.3 x 15 deep, Tap M4 x 12 deep in the two places indicated.…

Continued from p.459 M.E. 4700, 23 September 2022 Proposed design From the foregoing, it can be taken that the design based on the original two-pole and 16-pole windings is the most likely to have a satisfactory outcome. Naturally, access to induction motor design software would make the task so much simpler but, after enquiring and finding that one type of commercial electric motor design software costs more than a new lathe, let alone a new motor, I decided to use this rather primitive method based on the original windings instead. If you are so incredibly well motivated to design a motor from scratch, Kent (ref 10 – see M.E.4696) and Upadhyay (ref 16 – see M.E.4698) both give a full method for three-phase motors and Yeadon & Yeadon (ref 2…

October 9 Cardiff Model Engineering Society Public running, Heath Park, Cardiff 13:00 – 17:00. See www.cardiffmes.co.uk 9 North Wilts MES Public Running, Coate Water Country Park, Swindon 11:00 – 17:00. Contact: Ken Parker, 07710 515507 13/16 Midlands Model Engineering Show Warwickshire Event Centre. See www.meridienneexhibitions.co.uk 16 Bradford MES Running Day, Northcliff Railway 13:30 – 16:00. Contact: Russ Coppin, 07815 048999 16 Guildford MES Open Day, Stoke Park, Guildford 14:00 – 17:00. See www.gmes.org.uk 16 North Wilts MES Public Running, Coate Water Country Park, Swindon 11:00 – 17:00. Contact: Ken Parker, 07710 515507 19 Bristol SMEE ZOOM Meeting – Holden F5 Locomotive Trust. Contact: secretary@bristolmodelengineers.co.uk 22 Cardiff Model Engineering Society Steam-up and Family Day, Heath Park, Cardiff. See www.cardiffmes.co.uk 23 Bristol SMEE Public Running, Ashton Court Railway, BS8 3PX, noon –…

Continued from p.433 M.E. 4700, 23 September 2022 Steam ejectors Two sandboxes are steam driven and the other two are gravity fed. The ejectors, fitted to the first two, fed with steam, ‘blow’ the sand onto the track. I intend to have the ejector removable as with the full-size rather than braze it all up as Don has drawn – this is both for being able to service it if required and also to make it look more like the prototype. Gravity gear The two other sanders are gravity fed, by opening a valve inside the sandbox. In operation, the valve rocks (twists) from side to side which opens and closes the feed hole allowing sand to drop through the hole, its pipework and under the leading wheel. I countersunk…

The atmospheric railway and its successors Railway history treats the atmospheric railway as a great failure, along with the broad gauge and the first Tay Bridge. Often associated with Brunel, it was slated as a system that never worked properly, was inflexible, wasted money, didn’t last long in service and, best known, rats ate the sealant leather! That picture is not wholly fair. Atmospheric railways were popular with the public and generally worked well. Two lines worked for more than ten years. These railways could be fast, quiet and anticipated features of modern high speed railways – and the atmospheric principle is still used. You may see it operated near your home – and modern atmospheric railways have been created (photo 1). Engineering failures aren’t always caused by bad engineering;…

It is now about three years since I laid the first of the new concrete sleepers for my 5 inch gauge railway and wrote the series of articles about it. Since then, many more have been laid amounting to about 2500 in total. I thought it was time to produce a report on their efficacy and review some of the design details. Most of the track is supported by a ribbon of concrete about 14 inches wide by 3 – 4 inches depth, unreinforced. This has been in place for between 20 and 25 years with no visible movement. The old wooden sleepers were screwed down at intervals to resist track movement, a successful method for shady environments but pretty hopeless in full sun where sleepers crack and shrink. Sideways…

Sheffield’s Kelham Island Museum recently had a talk on model steam locomotives with examples of the real thing on show, part built, under restoration and in full working order. Outside, in the sunshine, was Atlas, driven by Polly Engineering’s Neil Ritchie along with Harry, from Wortley Top Forge Model Engineers to meet, greet and explain. The working Atlas, from Polly Model Engineering, glistened and shone in the sunlight like a great big glistening, shining thing, and if visitors wanted to drive it, Neil would explain the controls and allow them to drive up and down a short length of track. Judging by the cries of excitement and delight as they did so, we have a few converts to add to our numbers. I was intrigued by the way the portable…