Tabla de contenidos para Issue 4707 en Model Engineer

Martin Evans can be contacted on the mobile number or email below and would be delighted to receive your contributions, in the form of items of correspondence, comment or articles. 07710-192953 MEeditor@mortons.co.uk Happy New Year Let's hope so! This year started rather badly, with Putin's disastrous invasion of Ukraine. This led to rising fuel prices and, consequently, rising inflation. These two factors were not without consequences, of course, and were compounded by freezing cold weather earlier this month (now somewhat abated, mercifully) and what we will, I am sure, come to recognise as the Christmas 2022 General Strike. Add to this the extra pressure on social services of uncontrolled, and apparently unstoppable, immigration, and a health service that is buckling under the strain of it all, as well as the…

Continued from p.754 M.E. 4705, 2 December 2022 Fitting the cylinders I have left the final fitting of the valves (described last time) until the connecting rods, crossheads and bearings have been made and before they can be fitted the cylinders and the slide bars need to be fitted to the frames. Therefore, this instalment will cover the work involved to get the cylinders ready for fitting and it was at this stage that I realised that the draincocks also need to be made and fitted along with their linkage. Draincocks I then paid attention to the draincocks and here I learnt something - many thanks to those who helped me here. I wasn't aware that there relief valves fitted to the draincocks. Interestingly, these were kept even when, around…

HIT AND MISS Continued from p.45 M.E. 4706, 16 December 2022 Crankshaft This started out so well… First the webs were made and the crank pin heat shrunk in place (photo 8). Holding the end of the pin, a series of flats were machined (photo 9) which would later be finished by hand. So far, so good. Now it starts going wrong. The crankshaft was machined then heat shrunk into the webs. I didn't allow for the contraction of the steel though, which pulled the shaft out of true. I did manage to straighten it on the press, then machined the other end of the webs (photo 10). For security, I drilled and pinned the shaft to the webs. It didn't help. I'll jump forward a bit here. When the…

Continued from p.12 M.E. 4706, 16 December 2022 Having finished Bluebell and now seeking a new project, we left the twelve-year-old author who together with his parents and Our Expert, an unnamed but much-appreciated steward at the Brighton Modelworld exhibition in 1981 - had decided that a six-wheeled tank engine called Rob Roy would fit the bill rather nicely. First hurdles, first stumbles Over the course of the next few months, I read, re-read and re-re-read my coveted Rob Roy book with enormous enthusiasm (photo 20). I didn't understand all of it, if I was honest, but the pictures were great and I especially liked the penultimate chapter which explained how to drive the finished engine; I read that chapter a lot more than the rest. In my mind's eye…

Dear Martin, I was most interested to read about the Molesworth pocket book in Model Engineer (M.E.4705, December 2nd). I have got one which belonged to my father and was a permanent item on his desk all through his life. It is a 27th edition which he had been given for his 21st birthday in 1917 while studying civil engineering at Glasgow University. The copy I have has got a Hurst's Architectural Surveyors Handbook included which increases the size to 1942 pages and means it is 4m=3/4 by 3 by 2 inches thick. It is still in relatively good condition considering it is 105 years old. Kind regards, Ross Dalziel Dear Martin, I have been reading through my latest issue of Model Engineer and came across illustration No.5 in the…

Continued from p.23 M.E. 4706, 16 December 2022 The first part of this article described the processes that contribute to heat loss (i.e. conduction, convection and radiation). It also explained why lagging a pipe could, in principle, cause an increase in heat loss rather than a decrease. This is because of the resulting increase in circumference (and hence area) of the outer surface. The resulting increase in convection and radiation can outweigh the decreased conduction. This effect is likely to be particularly marked with small diameter pipes where adding a layer of insulation will result in a larger percentage increase in surface area than is the case with large pipes. The first part also showed that, unlike the situation with many pipes in the industrial world, when calculating heat loss…

Continued from p.35 ME. 4706, 16 December 2022 The next item to describe is the smokebox. This is basically a brass tube, 4¼ inches outside diameter and 3½ inches long with a section removed at the bottom, to clear the cylinder assembly and the sides bent outwards to sit inside the frames. Photograph 41 shows the construction. Here I am making sure that the holes I have drilled for the hinge pin are square to the cast-in smokebox door hinge straps. Unfortunately, the first effort went adrift and photo 42 shows remedial action in progress. I have cut a thread in the errant hole and inserted a brass screw. This will be silver soldered in place and a new hole drilled in the correct place. Photograph 43 shows the smokebox…

GRASSHOPPER Continued from p.28 M.E. 4706, 16 December 2022 All dimensions are in mm Tolerance for all parts in the article - unless otherwise stated: Non-functional (i.e parts that do not fit all match) ±0.1mm Functional (i.e parts having to match) ±0.02mm Item 18 - Piston Rod (fig 29) 6mm diameter silver steel * Face silver steel at each end bringing to 99.5 length. * Machine Ø5 × 7. Thread M5. Chamfer end of thread 45 degrees × 1. Undercut 1 × 0.5 to remove thread 'runout'. * Turn around, machine Ø5 × 15. Thread M5. Chamfer end of thread 45 degrees × 1. Put to one side. Item 19 - Piston (fig 30) 70mm diameter × 7 inch acetal * Prepare blank to Ø68 × 10. * In the…

Waterwheel Clock Eric Rumbo makes the ball cage and driving electronics for his version of a skeleton clock. We Visit Bristol SMEE John Arrowsmith spends a pleasant day at the Ashton Park track of the Bristol Society of Model and Experimental Engineers. Grasshopper Martin Gearing makes the link anchor mount whose main purpose is to support one end of the beam of his grasshopper engine. Hit and Miss Engine Ian Couchman casts the piston and connecting rod for his ‘hit and miss’ internal combustion engine. Oscillator Hotspur makes a start with adding the fittings to the vertical boiler for his triple cylinder oscillating engine. ON SALE 13 JANUARY 2023…

Write to us Views and opinions expressed in letters published in Postbag should not be assumed to be in accordance with those of the Editor, other contributors, or Mortons Media Group Ltd. Correspondence for Postbag should be sent to: Martin R. Evans, The Editor, Model Engineer, Mortons Media Group Ltd, Media Centre, Morton Way, Horncastle, Lincs LN9 6JR F. 01507 371066 E. MEeditor@mortons.co.uk Publication is at the discretion of the Editor. The content of letters may be edited to suit the magazine style and space available.Correspondents should note that production schedules normally involve a minimum lead time of six weeks for material submitted for publication. In the interests of security, correspondents' details are not published unless specific instructions to do so are given. Responses to published letters are forwarded as appropriate.…

Continued from p332 M.E. 4698, 26 August 2022 Advanced thoughts and musings on the motion First observations of the motion and drive to the wheels, when I was given permission to survey No.13 in the National Narrow Gauge Museum in Tywyn, Wales, lead me, at first, to consider it to be generally conventional in its layout and operation. At this time, I was only in possession of an A4 photocopy of the general arrangement drawings of the prototype, kindly provided from the archives of the museum.When reviewing this drawing, together with two slightly more detailed ones found after some online research, I discovered they formed part of the paper Samuel Geoghegan, Engineer to the brewery, presented to the Institution of Mechanical Engineers at its Dublin Meeting in July 1888 entitled…

January 3 Taunton Model Engineers Meeting, Stoke St. Mary village hall – ‘Lots Road Power Station’ by Tim Griffiths, 19:30-21:30. See www.tauntonme.org.uk 4 Bradford MES Bits and pieces evening, Saltaire Methodist Church, 19:30. Contact: Russ Coppin, 07815 048999 4 Bristol SMEE Talk: ‘Railway Level Crossings’, Begbrook Social Club 19:30. BS16 1HY. Contact: secretary@bristolmodelengineers.co.uk 5 Sutton MEC Bits and Pieces evening 20:00. Contact: Paul Harding, 0208 254 9749 5 Warrington and District MES Natter night, St Mary Magdalene Church, Appleton Thorn, 20:00. See www.wdmes.org.uk/events 8 North Wilts MES Public running at the Coate Water Railway, 11:00-17:00. See www.nwmes.info 8 Sutton MEC Track Day from noon - 16:00. Contact: Paul Harding, 0208 254 9749 15 North Wilts MES Public running at the Coate Water Railway, 11:00-17:00. See www.nwmes.info 17 Taunton Model Engineers…

Lowmex, the muchacclaimed model engineering exhibition, was back with a bang! It was held at a new venue, the Energy Skills Centre building at Lowestoft East Coast College, which meant that there was more space for displays, comfortable visitor movement and easy parking. The clocks went back on the last Saturday in October, giving the exhibitors a very welcome extra hour in bed so they could re-charge their batteries ready for the Sunday. I would like to give you a small taste of what was on show there. Halesworth and District Model Engineering Society (HDMES) is the parent club (LOWMEX being an independent subcommittee) and those members presented a large and varied display of models, forming the core of the exhibition in the main hall. One of the smallest exhibits…

Starting April 2002 Model Engineer published a construction series for a 'Ferris Wheel' skeleton clock by Richard Stephen. Although not involved in clockmaking at the time I followed the series and wondered why the Ferris wheel was not made concentric with the minute arbor. It would have meant a more attractive arrangement with the balls, not half hidden, but surrounding the dial. I also thought that 'Waterwheel Clock' would be a more accurate description for this type of clock. Having subsequently picked up the clockmaking bug I decided, in 2019, to design and build my own skeleton clock and this led me to take a second look at Stephen's. I began by reconfiguring it to make the Ferris/waterwheel (henceforth referred to as a 'cage') concentric with the minute arbor and…

Mallard, an LNER A4, streamliner shown in photo 1, is my latest locomotive project and it is worth remembering that some projects do not come to fruition for many years. This project has its roots in a visit to the National Railway Museum at York some 40 years ago and photo 2 shows Fiona, our daughter, standing in front of Sir Nigel Gresly's A4 locomotive, Mallard. The search, through our old albums, for this photo was prompted by a call from Fiona saying she was standing in front of Mallard once again. Well how could one resist, especially as I was looking for a new project after finishing my LNER V2? Should the project start from scratch … and in what gauge? The gauge question was easily answered as the…

Dear Martin, I have just completed my book on building BR Standard engines but I was just wondering if anyone else was daft enough to build any of the smaller locos to the works drawings. Anyway, I do know that several other people are building them and the detail is fantastic. I do know that Bob Shepard is building a beautiful 9F all to the works drawings and I have drawn up the Britannia, the 2-6-4 tank (which this book is all about), the Class 4 tender engine 75000, and I know of someone who is building a Class 2 to the works drawing but I have lost contact with him as Don young drew up the Ivatt Class 2 but he put BR tender axle boxes on it and…

Ron Fitzgerald takes a look at the history and development of the stationary steam engine. Continued from p.771 M.E. 4705, 2 December 2022 The completion of Matthew Murray's new engineering factory in Leeds confronted Boulton and Watt with their most formidable challenge. For five years Murray had disregarded their legal menaces and by the time that the patents lapsed he had built at least ten engines, almost certainly all with separate condensers (ref 210). When threatened with legal action, other builders had retreated from using condensers until after 1800 but Murray's persistence gave him a lead which he used to build up his expertise. The end of the patents levelled the field and future competition should have been a matter of price, quality and salesmanship but one final joust in…

Introduction I had rewound a single phase two-speed motor for different speeds than for which it was originally wound (ref 1). As the design of the new windings was subject to a lot of estimation, I realised that I should really measure the output of the motor to check its performance. Having looked through the available literature, I discovered that there appeared to be a simple method of determining the performance of an induction motor from two simple tests: the 'no load' test and the 'locked rotor' test. These are described by Langsdorf (ref 2) who uses the two tests to plot a 'circle diagram' from which the entire performance of the motor can be derived. The characteristics that can be derived are the power input and output, phase currents,…

First a correction and an apology. In M.E.4702 the caption to photo 1 erroneously referred to Brighton. This should have read Bournemouth. I apologise to Chris Bracey, Keith Burridge and B&DSME. There appears to be an eddy in the space-time continuum (what’s he doing there?) in between my basement workshop and the rest of the house. I spend maybe 10 minutes down there and, when I return, birthdays have come and gone, dynasties have fallen and aeons have passed. Heading home from the supermarket, we broke down on a roundabout trying to reach home after a series of dashboard warnings. Fortunately, we were only about 200 metres away. This caused some considerable delay, stopping all the local traffic, including one bus driver who was particularly vexed. Calling the AA, we…