Sommaire pour June 2023 de Model Engineer & Workshop

3D Printing Update I ve been on a very steep learning curve with 3D resin printing since undertaking the review of a Creality printer for the last issue. I'm keeping notes and taking photos to keep track of some of the issues I have come across. The picture is a work in progress I designed in Alibre. One thing I would like to emphasise for anyone looking at this technology is to start off by ordering a big box of nitrile gloves. Using them will help ensure you don't face any problems of sensitisation and allergies in the long term (there have been recent reports of the consequences of sensitivity to UV resins used for gel nails), but aside from this, having gloves on makes everything much more pleasant. I've…

After purchasing this machine, a Model 3 Serial No: 3628, from an advert in the December 2021 edition of Model Engineers Workshop I brought the unit back to Dorset. The machine is heavy, when lifting the surface grinder out of my trailer I had to triple the lifting wire to even raise the unit so that the machine could be lowered onto the wheeled dolly which would allow me to manoeuvre the machine around the garage. Its weight was over 350Kg. Photograph 1 shows the machine in its original owners outside shed where it had been standing for many years. Standing idle had resulted in the machines slideway concertina bellows drying to a point where they started to break when I tried to open them. Photographs 2 and 3 show…

The return of an exhibition in the North of England was very welcome and a return to Harrogate in particular as it is some time that such an event had been held at The Great Yorkshire Showground. It was only a two-day event this time and combined with the model railway section the model engineering was not quite what it perhaps could have been. The exhibition had been organised by Simon Boak and was located in the two halls previously used, except that in the intervening years Hall 1 had been rebuilt into a large well lit and comfortable new exhibition space. Hall 1 held all the model railway exhibits along with some model engineering displays. The main feature of this space was the 200 ftx 50 ft “0” gauge…

The mental gymnastics of using fixed lathe dials are a pain in the frontal cortex for the mathematically challenged like me. Trying to take, say, a 16 thou cut with a dial already set immovably on 77 thou is a special kind of purgatory. Makedo's with felt pen lines on dials and counting each thou aloud help but are no substitute for a proper resettable dial that can be turned back to zero at will. Combined with the hard-to-read standard diecast dials on my Myford ML7, this long-held gripe propelled me to make my own resettable dials with larger, easy-to-read numbers and clearer lines, photo 1. They are such a pleasure to use I am now kicking myself for not making them years ago. The basic design can be adapted…

This is amost unusual book. It's author, who many readers will already be familiar with as the ‘Rivet Lad’ of his eponymous books, has spent his life in engineering and heavy industry. As well as a passion for boiler and bridges, Alan has a fascination with salvaging and reclaiming materials. He built his own home, World from Rough Stones House, from salvaged stone, brick, timber and other materials. As well as his engineering business he also has Dandelion Stone Troughs and Architectural Antiques; hence he is the ‘Dandelion Salvager’. So, what does this book cover? It is a sort of near-random walk through the quirky world of salvaging, chiefly in the North of England. It's also copiously illustrated with pictures of people, places and, mostly, strange artefacts. Alan profiles the…

Ever since Mitutoyo produced the Digimatic Caliper in 1983, digital calipers have been ubiquitous in industry. I bought one of the first ones and used it for over twenty years before treating myself to a new one. But digital measuring devices have drawbacks: • Firstly, any device which converts an analogue measurement into a digital display has a “quantisation error”. For most digital calipers, this is 0.0005” or 0.01mm, which is basically the smallest value which can be displayed. So if a caliper reads 1.9995” we would hope that the actual (analogue) measurement might be somewhere between 1.99925” and 1.99975”, but the instrument gives us no clues. • Secondly, digital numbers look so precise that we are tempted to believe that a caliper reading to the nearest 0.0005” or 0.01mm…

Photograph 1 shows my everyday chamfering tool. This inserted tool can be used for turning and facing but its main use in my shop is chamfering external edges. The insert is forward of the shank However it won't chamfer bores smallerthan about 80mm – there is insufficient clearance – it would rub the work with the shank and spoil it. Photographs 2 and 3 show a broken 6mm HSS endmill (I have a supply) in the opposite end of the shank at an arbitrary 15 degrees. It's held in place with a grub screw. It can be advanced after regrinding. The top is ground to give the same tool height as the chamfer tool. Clearance is ground to suit small bores on the side facing the machinist when the toolpost…

Arthur ‘Artie’ Moore was the son of a millerfrom Pontllanfraith in what was Monmouthshire (now Caerphilly Borough). As a child he'd lost part of a leg to the mill machinery and used a wooden prosthesis. As he grew older, he took up model engineering, building his own lathe, driven by the Gelligroes watermill. On the lathe he made a model horizontal steam engine that won a competition in our own Model Engineer magazine. The prize was a copy of ‘Modern Views of Magnetism and Electricity’ by Sir Oliver Lodge. Reading the book lit a passion for wireless, and around the mill he built his own radio station with aerials, batteries and generators, a spark-gap transmitter and his first receiver based on the ‘coherer’ principle. Over subsequent years he improved his…

BECAUSE of its low carbon content, ranging between about 0.1 and 0.2 per cent., a mild-steel, unlike a carbon steel, will not harden merely by heating to bright red and quenching in water. The process of casehardening, however, increases the carbon content at the surface of mild-steel and, on quenching this layer, hardens in the same way as a carbon steel, though the core of the mild-steel remains soft. The obvious advantages of casehardening are that parts like shafts, gears, gudgeon pins, brake rod pins, screws, etc., are rendered resistant to wear. On the other hand, it is not always realised that special cutters and small tools for aluminium, brass, copper can at a pinch be in mild-steel case-hardened-which in the larger sizes may be more conveniently and cheaply obtained…

I'm a REMAP engineer (see box). Towards the end of 2021 we received an unusual request. It was from a church-well not from the actual church, but from the Parish Church Council, or PCC. They had a problem they couldn't resolve: the church itself is very old and has two very wide steps up from the aisle to the transept, and one elderly person had stumbled and tripped when negotiating the steps; though, luckily, they hadn't been injured, the PCC was very concerned that somebody else could trip and be severely injured. They wanted a handrail on the steps, but despite their best efforts, could find no contractor who could do it, and comply with their rather severe requirements, which were… Its design and appearance must be sympathetic with the…

TIP OF THE MONTH WINNER! Cleaning Abrasive Sanding Belts This month's winner is Keith Beaumont who has an unexpected approach to cleaning clogged sanding belts. If, like me, you partially use a new cartridge of silicone sealant on a job, seal it up and put it away for next time use, only to find it has gone solid when you try to use it. Do not throw it away. Use a Stanley knife to slit open the plastic cartridge and retain the solid lump of silicone rubber. This can be used to clean a clogged sanding belt very effectively, just hold it against the belt while it is running to clean off the imbedded debris We have £30 in gift vouchers courtesy of engineering suppliers Chester Machine Tools for each…