Tabla de contenidos para June 2025 en Model Engineer & Workshop

Ineeded and wanted to be able to clean my Myford lathe and in the restricted space of my workshop I am not able to get around the back easily. In fact, it is more of a commando exercise warm up to struggle through the obstacle course of lathe, shelving, detritus and the bits that have ‘gone over the edge’. Also, I have added an auto-stop (I must get around to adjusting it properly some time) and this makes scrabbling under the lathe challenging. I decided on some raising blocks and searched online, where I found that raising blocks seemed quite costly for what they are. Looking at some posts on the Model Engineer website, various people had made their own. The basic idea is to have four blocks, threaded so…

Having recently constructed a four-cylinder oscillating engine it was found fiddly and time consuming to repeatedly assemble and dismantle the big ends. They followed the conventional pattern of a split bearing clamped together by a bolt on each side. Since the next project was a highspeed twin-cylinder engine, I wanted the big ends to be as lightweight as possible and, in particular, easy to take apart and put together. The drawing, fig. 1, shows the result. In the course of production I felt I'd seen something similar. So it proved: I'd been beaten to it by about 150 years. On vintage beam engines the link motion employs a similar strap, held in tension by opposed wedges, see photo 1 of a model beam engine. In the present design a single…

The tool works in a similar way to a roller clutch bearing, but instead of locking in tapered grooves, the rollers move around a conical core. The tool is fitted inside a tube, where it enters the tubeplate; the tool is turned and the rollers move outwards, expanding the tube into place. THE SLEEVE If the tube to be expanded is, say, 1/2” internal diameter, then make a small cylinder approximately 1” long, leaving sufficient to grip it at the end. Turn the outer diameter to 0.498” and drill 17/64” down the middle just a little longer than the 1”. Place the part in your indexing head and set it over about 5 degrees off centre to the axis, then mill four equally-spaced 1/8” wide by just over ¾” long…

This tool is inspired by the Moltor knurling tool, photo 1, which was a scissor type tool squeezing the work between two opposed knurling wheels. This approach minimises sideways forces on the lathe spindle. Editor's notes: Due to space constraints and to avoid introducing errors by renumbering part references, the drawings will appear across the two parts of this article in numerical order, not the order they are referred to in the text. The article makes a distinction between ‘crush knurling’ where the knurling wheels rotate on an axis parallel to the work making a linear contact, and ‘cut knurling’ where the knurls are angled so they only contact the work around one point, requiring less force but requiring a more complex geometry. FIRST FUNCTION: A CRUSH KNURLING TOOL This…

After using the press tooling to form some square sections I found it was difficult to hold the base die in the correct position under the former all the time, as it would sometimes move around when using larger pieces of material. This required a solution. The answer was to make a sub base with locating pins on the top to locate the dies, photo 1, and a locating ring that fits the base bed hole. Photograph 2 shows the press without a bed fitted, and photo 3 is the one-part bed with the locating hole fitted. The materials for the sub base and locating ring to hold it in position are shown in photo 4. The material for the sub base is a piece of aluminium 120 x 130…

MATTHEW BOULTON Matthew Boulton was a key figure in the industrial revolution, known for his pioneering work in manufacturing and engineering. Born in 1728 in Birmingham, Boulton was instrumental in the development and success of the Soho Manufactory, which became a hub of innovation and production. His partnership with James Watt was particularly significant, as it led to the commercialisation of the steam engine, which revolutionised industry and transportation. Boulton's contributions extended beyond engineering; he was also involved in coinage and metallurgy, playing a crucial role in the introduction of new minting techniques and machinery. His dedication to improving industrial processes and his entrepreneurial spirit left a lasting impact on the industrial landscape of his time. JAMES WATT James Watt is celebrated for his contributions to the field of engineering…

The article by Stewart Hart on making small threads in ME&W 4763 brought to mind some more classic tips for minimising the breakage of very small taps. The first is quite simple – drill a larger pilot hole, the usual advice is to choose a size that gives 60% thread engagement, as this still delivers nearly all the strength of a ‘standard size’ pilot hole. In soft metals like many aluminium alloys, you can even go a little larger as the thread will ‘extrude’ a little. Always use a lubricant, if you don't have any specialist tapping fluid, you can use cutting oil, or at a push, ordinary oils. For very small taps you can even rub them against a wax candle. For aluminium use paraffin or a very light…

A WATER PUMP I'll describe the water pump next because it completes the motion and cylinders and from then on they can be carefully sealed-up at any time to suit your plan. The pump fits in the position occupied by the vacuum pump on the full size and is made to look as much like it as I can. It appears ideal for a little casting but my rules are that there will be no new castings. In any case, there are advantages in a fabricated assembly as the positions for all the flanges holes can be accurately marked out and drilled and alignment should then be fairly simple, given that the matching holes in the motion bracket have been accurately positioned by a laser. It is important that the…

Readers! We want to hear from you! Drop us a line sharing your advice, questions or opinions. Why not send us a picture of your latest workshop creation, or that strange tool you found in a boot sale? Email your contributions to meweditor@mortons.co.uk. RUSTON NAME PLATE Dear Neil, I live in Yackandanda, with my son Steven. My wonderful wife, Ann, sadly lost her fight with cancer in 2013. Back in about 2006 probably, Ann had been browsing in one of the junk shops in the high street and saw this Ruston Name plate. She just had to buy it! I screwed it on the kitchen wall, as is, a temp arrangement- and I have been intending ever since to restore the gold colour paint on the lettering and centre wheatsheaf…

Continued from Model Engineer & Workshop issue 4764 There are two things missing from the valve gear as it was left in Part 14 (ME&W 4763) and they are the weighshaft and the return spring, which is largely there for decoration. Plus, if you want to finish your chassis off you will also need the vacuum cylinder as it is quite visible - and even if you are not intending to fit the vacuum brakes on your engine it would be very nice to see it in there. I was speaking to a gentleman at a Harrogate Exhibition one day who was from Northern Ireland and he was building a 7¼” gauge 4MT but his name escapes me. (I think it was perhaps Geoff.) He saw my 4MT on our…

THE UTS METHOD Over the years the thickness of a boiler shell has been determined by multiplying the Ultimate Tensile Strength (UTS) of cold worked (or cold drawn) copper by the Working Pressure (WP) then by an arbitrarily large safety factor (SF), typically 8. A Temperature Factor is also sometimes applied. This will be called ‘The UTS Method’. The fact is that when copper is heated during the brazing (silver soldering) process, the strength of the material is dramatically reduced in the heated zone because of the annealing effect, see fig 1. The original UTS figure used to determine the boiler thickness, therefore, becomes invalid. The yield strength of annealed copper can be as much as one sixth of the original cold rolled copper material. The calculations below illustrate that…

I am seventy-eight years of age and a regular reader of Model Engineers’ Workshop magazine. In the years of my employment I was an electrical engineer. Now-a-days, the time is not measured in nanoseconds but hours; the frequency not in gigahertz but a few kilocycles when the machinery is misused. The budget which I shared is not hundreds of thousands of pounds but only what one can selfishly remove from one's pension. When the job required a lot of muscle, it was always for somebody else to do, whereas now one has to do everything for one's self and, to my great surprise, I like it. Now, to the subject. I have a small workshop and, when one puts a lathe and a milling machine into it, the available space…

Nowadays, there is a great range of tooling available specifically for the purpose of boring into metal. One example is the adjustable boring head, a rotating tool that fits directly onto the spindle of the machine, photo 51. The boring head is fixed to a machine spindle that moves linearly in one axis only (y axis milling machine and boring mill), or none (lathe). The method used to reposition the cutting tool and progressively increase the size of the bore is different between the boring head and the boring bar that is used solely on the lathe (ME&W 4764). In some respects, the boring head is a rotating tool post. In early versions of the boring head, the tool or cutter of the boring head was seated in a recessed…

I had initially designed the selector pivot pin to be retained by a circlip. This is shown in one of the early 3D views which John Slater did for me, render 1 (see part 1), as at that time I was having great difficulty working out where everything was from the mass of lines on the drawing. This was not helped by getting used to a new drawing package which replaced my faithful AutoCad. When it came to starting to assemble the unit onto the lathe, this circlip idea seemed to be a bit of a tall order, given the room available and the distance this item was from the end of the sheet metalwork cover on the headstock. Photograph 7 gives a pretty good idea of the position of…