Tabla de contenidos para March 2025 en Model Engineer & Workshop

Two people on opposite sides of the World had a mutual love of the handsome Beyer Peacock 2-4-0 tank locomotives, synonymous with the Isle of Man Railway. Jim Woods completed his 5 inch gauge ‘Manx Peacock’ almost a quarter of a century ago and, six years later, accepted a simple commission for a sister engine. HOW IT ALL BEGAN Jim writes from Dunedin, New Zealand: Way back in 2000, I completed a 5 inch gauge Isle of Man 2-4-0 T locomotive to the design of Mike Casey. I brought it over to the UK that year to compete in IMLEC which was held at Leyland. The locomotive was so new, I had to finish the lining out at Alan Bibby's house once I had extracted it from HM Customs at…

I bought my X1 mill about fifteen years or more ago. Having made many modifications to it including CNC conversion one modification I never got around to was changing the spindle to a belt drive system. The machine has stood redundant for about the last five years. Moving house was one reason but the main reason was the motor drive gear broke for about the fourth time. So one day recently, I decided to try 3D printing a replacement gear, this turned out to be quite successful. When I went to fit my home-grown gear and started stripping the spindle drive motor, I thought why on earth am I even doing this? I had seen several articles on changing the spindle drive mode to belt drive, all of which gave…

Continued from p. 196, ME 4761, 24 January 2025 HARTNELL GOVERNOR Of all the component parts of the mill engine model the governor is the one that is going to be the most difficult to make functional. At the time of writing, it certainly looks the part but just how good it will ever be at controlling the engine speed remains to be seen. The governor body is made from three small gunmetal castings: the gear housing, its cover and the column, fig 33. The only one of these that is available to buy is the body, the other two have either to be cast at home or fabricated. The finish on the body casting was rough and I machined it all over, photos 201, 202 and 203 show the…

A recent modelling project was to builda 7/8” (22.22mm) scale version of a small 16mm scale 0-4-0 model geared steam locomotive known as Cracker. This Cracker XL would hopefully be as easy to build as the original. To this end Meccano gears would be used and the power would be provided bya single, double acting oscillating steam engine as fitted to Mamod locomotives, photo 1. Having a clock repairing background, instead of calculating the centre distance between the gears’ axles and then either marking out using dividers or usinga DRO on a milling machine; I decided a simple gear depthing tool would be better. The traditional depthing tool, photo 2, as used in clock making is quite a complex bit of kit as it has to accommodate different sizes and…

AT LAST! 3D METAL PRINTS FOR MODELLERS Readers and Forum users may have spotted advertising by PCBWay, many may already use them to source printed circuit boards for electronic projects. They have now started offering a metal 3D printing service, potentially a gamechanger given the difficulty we all have in sourcing castings to our own designs. I spoke to one modeller who has been most impressed by their results, so this does seem very promising. PCBWay offers comprehensive metal 3D printing and CNC machining services to meet diverse manufacturing needs. Their metal 3D printing capabilities enable the rapid production of highquality, functional parts, facilitating both prototyping and low-volume production. Utilising advanced technologies such as Selective Laser Melting (SLM), PCBWay can produce complex metal components with precision and efficiency. In addition,…

Continued from p216, ME 4761 (24th January 2025) THE VALVE GEAR A notable thing about the BR Standard engines is that several of them have similar valve gear, fig 42, and the 2-6-0 Class 4 tender engine is one. One thing I missed off last time, but shall deal with here, is the crossheads, fig 43. I had these cast in stainless steel, for obvious reasons, but they still need a bit of machining, such as the hole for the little end bearing which also requires countersinking as well as reaming. Photograph 95 shows the pair of stainless steel casings; it's my understanding that these are identical to the Black Fives and quite a lot of other LMS engines. Photograph 96 shows the crossheads once I had cleaned them up…

In addition to the drilling speed, the rate of feed, or feed rate, of the drill bit into the work (mm/min, or, inch/min) also affects cutting performance. If the feed rate is too great, the drill bit is at risk of breaking. If the feed rate is too little, the cutting edge may become blunt, ref. 2. The feed rate of a drill bit is described as the speed that it progresses through the material. For the drill bit, feed rate is sometimes called the penetration rate (Vf), ref. 17. The feed rate (Vf, mm/min) is calculated by multiplying the feed per revolution (fn, mm/rev) by the spindle speed (n, rpm). (Vf) = fn x n. The feed rate of a drill bit is not only dependent upon the spindle…

Trevithick's policy of devolving manufacture of the patent engine to established engineering concerns raises the issue of the extent to which design and development was allowed to move away from his direct influence. There is evidence that both Coalbrookdale and Samuel Homfray in South Wales showed some independence and it is more than probable that his chosen builders in Bridgenorth, Manchester and Liverpool felt a growing freedom to innovate. Increasingly, Trevithick was based in London and his direct contact with the provincial engineers was limited to periodic visits without the facility for ready travel that railways were to offer half-a-century later. Trevithick's furthest outpost was Newcastle upon Tyne where, writing to Giddy from Coalbrookdale in September 1804, he says that following an excursion to the North-East, he found four engines…

My dad and a mate decided, over 50 years ago, to build not one but three locomotives to the LBSC ‘Bantam Cock’ design, first serialised in Model Engineer in 1945. One each and one to sell. I remember thinking at the time, ‘by the time I get to big school, I will have a locomotive to play with’. Here we are over 50 years later, and I have one part finished locomotive, photo 1, the mainframes for a second (CNC machined as a pair I believe) and enough castings and boiler plates for all three in a crate stamped Reeves. My dad passed away 10 years ago, and it has taken a few years to get a workshop built and the contents of his workshop transferred. A false start was…

I recently machined a set of gears for a model gearbox I am making. I wanted to use up some short bar stock offcuts I found in my scrap box rather than use new stock. Such offcuts, particularly when reduced to discs can be tricky to hold in the lathe, especially when they need to be machined all over with bore and outside diameter concentric within tight tolerances. Gear blanks also require careful preparation and can be tricky to hold accurately such that a concentric gear results. Of course, these problems can be overcome using time-honoured workholding methods and typically some sort of stub mandrel is made to hold a gear blank by its pre-made bore for machining the outer surface and cutting the teeth. Once disturbed in the chuck,…

I have decided to upgrade the cross slide on my M Type Drummond/ Myford lathe. There was a problem with the leadscrew as a previous owner who didn't understand that the grub screw clamps on to a ramp on the side of the leadscrew and then you tighten the outer handle nut to take up play in the end float, photos 1,2 and 3. There was a hole drilled where the grub screw tightens so I was unable to adjust the play as the grub screw only goes into the drilled hole. I had thought of welding the damage but not knowing the material and only being 5/16” diameter, it would probably bend as well. Another problem - there was about 0.010 to 0.015” backlash in the thread on the…