Tabla de contenidos para July 2024 en Model Engineer & Workshop

Busy in the Workshop Recently a 'popular social media site' has been sending me multiple advertisements for turntable weights to keep LP records from slipping, and to help flatten out slightly warped records. I haven't bought an LP since last year, but I have a couple of hundred dating back to the early sixties, so unfortunately there are a few that could do with a bit of a 'steadying hand'. It seems more than a little profligate to buy such a thing when I have a workshop full of all the required bits, so I thought I would knock one up as the basis of an article for readers relatively new to turning. As I'm now in a part of the world where steel stockholders are less abundant (one thing…

In the previous instalment I showed how a change in approach from the traditional to one of using shallow but fast cuts can improve how face/shell mills perform on hobby size machines. This time I will show how a change of insert can further improve finish, speed up the machining time and also put less load onto a lighter machine. Insert Types Although there are many styles of insert for the vast array of holders on the market, they can generally be divided into two main types: Those that are designed for cutting ferrous metals such as steel and iron and those designed to cut aluminium and other non-ferrous metals. The ones for ferrous tend to have a blunter cutting edge as they are moulded from powder and then just…

Imust have got the idea from somewhere: a magazine, the net, somewhere. I know I didn't invent it. But it looked very interesting and seemed to have a lot of potential. So, I decided to make a pair. To begin with, steel angle is available in lots of sizes, but anything as wide as what is needed here is also unnecessarily heavy. So I decided to pay a visit to my usual steel source and as luck would have it, found a piece of 90 x 50mm tube about 240mm long, wall 5mm thick. Close enough to what I had in mind. The ends were cut at anything but right angles, but I decided that didn't really matter. So I duly bought it, got it to the workshop, grabbed the…

Our apologies for any confusion from the wrong date on last month's announcement, we are reprinting the basic information here to remind readers you have about six weeks to put in your entries. Funded by many donations in his memory, the Stevenson Cup was first awarded in 2018 in memory of the late John Stevenson. The cup is engraved “John Stevenson, 1948 – 2017. Remembered by his many friends” with “Awarded for Excellence in Practical and Useful Workshop Equipment” on the plinth. The John Stevenson Trophy is presented for just that, a well-made and usable piece of tooling, a modification to a machine or an accessory for a tool where the fact it works well is more important than making it look good. Unlike judged trophies, we decided on a…

Quick-Mount DTI This month's winner is Mike Hurley from the West Midlands, who recommends a way of speeding up using a dial test indicator. This is nothing particularly clever or innovative, just something that saves me masses of time on occasions. Simply a sturdy fabricated bracket with attached (plunger type) DTI that engages into a spare QCTP holder. When setting a 4 jaw chuck or simply testing runout it is the matter of seconds to fit without all the fiddling about with magnetic stands and trying to ensure the tip is at centre height. Most useful 30 minute 'quick' job I've ever thrown together! Mike Hurley Editor's note: Following last month's article by Jacques Maurel, I received some comment that a 'dial test indicator' has a swinging arm and a…

It's sometimes a surprise to find that a skill tested by one of your hobbies find application in another. In this case, it was the experience of fitting a velum skin to a banjo mandolin, probably about forty years ago. Once popular instruments, there were a whole assortment of banjo-style versions of popular stringed instruments. The banjo ukulele was a rather louder version of the traditional ukulele, and the preferred choice of George Formby. But to return to the point in hand, 3D resin printers, photo 1, use a UV-transparent film (usually about 95% transmission) to seal the bottom of the printing vat, photo 2. The material is Fluorinated ethylene propylene (FEP) a copolymer of hexafluoropropylene and tetrafluoroethylene that is essentially a thermoplastic version of PTFE. Over time, the FEP…

As described in the previous issue, the follower arm of the micro-milling contraption is attached to the motorised guide-plate via two springs plus a link. The guideplate moves in a series of straight lines that approximate to the shape of the template while the follower on the end of the lever is held against the edge of the template, fig. 15. Positions of the guide-plate are defined as the number of steps moved by the X and Y stepper motors from a reproducible reference point (REF) which is defined by the lower and right-hand optical limit sensors of the slides. As described previously, the sensors used enable position to be detected with a reproducibly within two thousandths of an inch which is more than adequate for holding the follower against…

BEGINNERS WORKSHOP These articles by Geometer(Ian Bradley) were written about halfa century ago. While they contain much good advice, they also contain references to things that may be out of date or describe practices or materials that we would not use today either because much better ways are available offor safety reasons. These articles are offered fortheir historic interest and because they mayinspire more modern approaches as well as reminding us how our hobbywas practiced in the past. IN NUMEROUS operations-drilling, filing, assembling, etc.-clamping is advantageous even if not strictly necessaiy. It can free both hands for the operation, prevent movement where parts have to be kept in alignment, and save broken drills and damaged fingers where otherwise there would be a want of control, as on machine drills. If…

As an initial test I planned to use the blue grit 8” grinding wheel that the grinder came supplied with, but I was far from happy how this ran on the spindle, to my mind it had far too much wobble. From Harold Hall's book he mounted the complete grinder on the cross slide of his lathe and running the motor and using the lathes compound slide he trued up and reduced the diameter of the spindle, I wanted to avoid this if possible. Inspection of how the grinding wheel interfaced with the spindle indicated the possible cause of the problem, the spindle is ½” diameter that matches the bore of the grinding wheel but the remainder of the shaft is only 5/8” diameter only giving a small face for…