Innholdsfortegnelse for Issue 4697 i Model Engineer

Continued from p.223 M.E. 4696, 29 July 2022 Building the frames The frames were cut from an African hardwood known as Idigbo and finished to 25 x 50mm (figs 11 and 12). My local timber merchant was very co-operative, supplying all hardwood cut to size including a Birch plywood base board for a very reasonable £38. It’s best to get the timber cut slightly longer than the drawings and then square up in the mill with a very sharp cutter. Add an off-cut of the same material as packing so the cut does not lift the fibres of the wood at the edge/end of the cut. Note that Idigbo is slightly acidic to ferrous metals so best not to leave the shavings on the mill table overnight. The headstock for…

For whatever reason, engineering remains a largely masculine occupation but go back a hundred years and it was even more male dominated. Women engineers of the 1920s and later had to fight against real discrimination in order to make their way in their chosen profession. Those that succeeded were often brilliant at their work – they simply had to be exceptionally good to survive. One such success story is that of the remarkable Dorothée Aurélia Marianne Pullinger (photo 1), creator of the Galloway car. Dorothée was born in France in 1894, the oldest of twelve children. Her father was Thomas Pullinger, a car designer who had worked for Darracq. He brought his family to Britain in 1902 and Dorothée attended Loughborough Girls Grammar School. Her father worked for various car…

A Modelworks Rebuild Continued from p.136 M.E. 4695, 15 July 2022 The finished model This is the concluding article in this series. The model of a BR Standard Class 7, 70013 Oliver Cromwell is now finished and it passed its club hydraulic and steam tests in March 2022. Now, I finally play with it and draw a line under hours of enjoyable construction, but also some stress at times when things went wrong. I purchased the slightly tired looking Modelworks engine three and a half years ago, I have spent 25 months of regular five or six days-a-week work in that period (thank you Mr. Covid) and the diary records 550 days spent. If we say six hours for each day, that is 3,300 hours. And all for a rebuild!…

IMLEC came to the Guildford club this year and with 25 entries was held over the weekend of July 22-24, just missing the heat wave. This was a relief to most of us at our club and in fact for a while it looked like it might even rain. It did however stay dry and it was ideal weather for playing trains. In the previous two weeks the club had completely cleaned its 1450 feet of raised track to give the competitors the best rail surface for their runs and we even closed the track to our club members so the track could be kept squeaky clean for the event. It was rather disappointing that the track soon became greasy again and on Friday just about every locomotive was slipping…

Continued from p.149 M.E. 4695, 15 July 2022 Safety valve assembly The prototype safety valve configuration was closely followed in the model (photo 123). It looks incredibly simple but that’s where the simplicity ends. Any friction in the system will adversely affect the repeatability which needs to be avoided. Having said that, it pays to make sure the spring assembly is properly aligned and moves with no resistance, allowing the spring to do its work unhindered. The other stumbling block with safety valves is the sealing surface for the actual valve, which is as good a place as any to start. The valve spindle is machined from solid stainless bar (fig 29). Starting with the thinner part of the spindle, this is machined in the three-jaw chuck the usual way.…

Continued from p.215 M.E. 4696, 29 July 2022 Back now to the cylinder block. The timing gear pockets need to be produced in the front face and the CNC is the obvious choice (photo 109). A modification is required to the camshaft timing gear; two M3 holes are produced at right angles to accept grub screws (photo 110) and two corresponding flats are produced on the end of the camshaft to locate and secure the gear (photo 111). To ensure the second flat is at 90 degrees to the first it is located squarely against the vice jaw using feeler gauges. It’s a good idea to align one of the flats with the centre line of No. 1 exhaust cam; this can then be used as a visual indicator for…

I can’t quite remember how it came about but I think it was something about the length of a cricket pitch. Anyway, some time ago, at the Guildford Model Engineering Society’s Rally, I found myself explaining to one of our French members all about acres, furlongs and chains. He seemed very interested and remarked how logical it all was - he even made notes. Others who were there also appeared interested and it occurred to me that it could form the basis of this article in which I ramble on about my thoughts on length measurement in general. There is quite a lot that I would like to say so I have divided it into two parts. In this first part I will just ramble on about the old methods…

This year the rally was again held at the Fareham Society of Model Engineers in Hampshire (photos 1 and 2) and they are the first club to have held it four times. The weather forecast for the weekend was good so I was looking forward to an interesting weekend with lots of good running and exchanges of ideas and comments. The Fareham Society is very fortunate in owning their own site and, as they explained to me, everything you see when you enter the ground belongs to the club - there are no outside interests to complicate the running of the society. These days, to have that sort of security is a very favourable position to be in and gives the committee the confidence to plan ahead. When I arrived…

A locomotive is, next to a marine engine, the most sensitive thing man ever made. Rudyard Kipling There are things made for aesthetic and spiritual purposes; they have been created in all times. Their impact on the mankind’s evolution is indisputable and their historical role is enormous. A lot has been said about them; they occupy their well-deserved places in museums and private collections. They adorn home interiors, building fronts and proudly raise their spires to the sky. I leave their description to art historians. I want to talk here about objects that have a purely practical meaning which at the end of their service life are sent away to be melted down. What makes us stop and wait for a locomotive appear from behind the hill and then stare…

Introduction I created and made a larger version of this engine some 20 years ago as a training course final test piece and must confess to having only recently discovered that its true description is not that of a ‘Grasshopper Beam Engine’ (which perfectly describes its action) by which I’ve always known the design but should be referred to as a ‘Half Beam Engine’ invented in about 1795 and built commercially from 1801 by Oliver Evans, an American engineer (see Model Engineer vol. 187 No. 4156 p.324 for full details). The version of my engine described here is primarily intended as a training project for beginners – to give experience – and assumes access to basic facilities. I have chosen metric dimensions because I refuse to pay the premium now…

August 13/14 West Riding Small Locomotive SocietyRally/Open Weekend. Contact: Stuart Merton on 01132 523258 or wrslsec@gmail.com 14 Guildford MESOpen Day, Stoke Park, Guildford 14:00 – 17:00. See www.gmes.org.uk 14 North Wilts MESPublic Running, Coate Water Country Park, Swindon 11:00 – 17:00. Contact: Ken Parker, 07710 515507 17 Bristol SMEEZOOM Meeting – BRIMLEC/IMLEC Review. Contact: secretary@bristolmodelengineers.co.uk 20 Cardiff Model Engineering SocietySteam-up and Family Day, Heath Park, Cardiff. See www.cardiffmes.co.uk 20/21 Model Tram and Railway ExhibitionNational Tramway Museum, Crich Tramway Village. See www.tramway.co.uk 21 Bradford MESRunning Day, Northcliff R ailway 13:30 – 16:00. Contact: Russ Coppin, 07815 048999 21 Bristol SMEEPublic Running, Ashton Court Railway, BS8 3PX, noon – 17:00. Contact: secretary@bristolmodelengineers.co.uk 21 North Wilts MESPublic Running, Coate Water Country Park, Swindon 11:00 – 17:00. Contact: Ken Parker, 07710 515507 25 Guildford…

Continued from p.226 M.E. 4696, 29 July 2022 Reverse engineering At this point, I had a perfectly good motor which worked yet I had no use for it in its original form. It seemed an act of unspeakable vandalism to attack the windings and destroy a perfectly good working motor but I needed to determine the turns for each winding. I dismantled the motor and after removing the end bells, I was left with the rotor still inside the stator, as the motor had two large fans – most unusual – and hence I had to remove at least one fan to be able to extract the rotor. The fan at the non-drive end seemed to be moulded onto the shaft and, since it did not have any easy way…