Sommaire pour November 2024 de Model Engineer & Workshop

Caveat Emptor By the time you read this, I will be, hopefully, demonstrating 3D resin printing with the Society for Model and Experimental Engineering at the Midlands Model Engineering Exhibition. Naturally I want this to go well, so I decided to change the FEP film on my printer. I opened up a new packet of film, clearly marked with the correct size, only to find it contained five films to fit a smaller printer. The price of film varies a lot, and I succumbed to the temptation of ordering a packet of the correct size from overseas at a competitive price; the delivery time was reasonable, and it arrived last week. Fitting a new film was straightforward, the Halot Mage Pro doesn’t have locating pegs, just screws making the task…

Simon Davies completes the construction of his tool tip setting device. The locking cam, fig. 2, relies on the machined surface under the bed normally used by the tailstock locking plate. Using a cam means that attaching the tool and locking it into place is a simple and swift process. The overall length of the locking cam should be slightly less than the maximum available space under the bad. The curved cam shape only needs to provide clearance to the cam when it is inserted into place and tightened by the M6 bolt. In use, the cam is rotated to be in line with the bed and the unit located on the V groove. The cam is then rotated 90° clockwise until it locks in the sheers and the bolt…

I have always understood that one way to clamp a workpiece to a milling table is as shown in photo 1, using clamping bars on the workpiece, with a support at the back and using tee nuts in the table tee slots with studs and flanged nuts. However, I recently came across an old MEW article by Mike Haughton and David Jones (MEW 186, February 2012) regarding broken machine table tee slots. As they say, milling machine tables are usually made of cast iron, and not steel. And that although cast iron is strong in compression it is weak and brittle in tension, and it is not uncommon to see machine tables with broken tee slots. What is more, as Steve Fisher has described (MEW 189, May 2012), it is…

I had seen an advertisement with a well-priced offer for a 100mm diameter rotary table at Axminster Tools and co-incidentally I was on holiday in Dorset the following week I placed an order for me to collect when there. The table is of a Verco type of design but with no identifiable maker. It is however a very good quality device, so I was pleased with my purchase. On arriving home I first had to replace the rectangular base locating pins as these were too wide for the slots in the table of my milling machine. Rather than make new rectangular pins I turned circular locating ‘buttons’. These had a diameter to fit the groove already in the rotary table base and a slightly smaller diameter to suit the milling…

When starting to assemble the motion work on my two 4″ scale single crank compound Burrell traction engines, photo 1, I needed to make a spectacle plate and frontplate. These are steel plates bolted above the boiler and between the hornplates. The spectacle plate, at the front, carries a casting for the throttle and singling valve operating rods and has cutouts for the connecting rod, valve gear eccentric rods and governor drive belt. The frontplate, at the rear (a hangover from portable engine terminology) carries the steam distribution casting, the pressure gauge and has a cutout for the water pump drive rod. On some engines these plates are flat sheet with angle bolted on that can, in turn, be bolted to the hornplates. However, on the Burrell these plates are…

The original request was simple, for a lock or bolt on an internal door, and my initial thought was what simple solution would look neat and be easy to use. I soon realised that the original door lock, which was a typical combination of a sprung latch on the handle and a mortice lock was still in place. It transpired that any unused keys which had come with ownership of the house many years ago had been long lost. I measured up the lock, photo 1. The house is at least 130 years old, but the vertical arrangement of handle spindle and keyhole suggests this is a more modern design (Victorian locks generally have them one behind the other), but it was still several decades old. The most important dimension…

Assembling 3D Printed Pipe Parts TIP OF THE MONTH WINNER! This month’s winner is Brian Hooper with a tip for easing the fit of 3D printed parts. As part of adding a vacuum system to my mobile work bench I decided to make the air connection components with my 3d printer. After taking great care with my measurements I still found that the flexible tube connections were too tight to fit. I decided to insert the tubing into hot water to soften the plastic to assist fitting. I found the 3d printed part became soft but retained its shape. Making the final fitting easy. The bottom line is dip tight parts in hot water to get that final fit. Brian Hooper We have £30 in gift vouchers courtesy of engineering…

We can now share the results of the 2024 Stevenson Trophy Competition. This is the fifth time the trophy funded by readers and members of the www.model-engineer.co.uk forum in memory of John Stevenson has been awarded. In accordance with John’s feelings about competitions and ‘glass case models’, all entries had to be a piece of practical workshop equipment i.e. a tool, jig, fixture or a modification to or accessory for an existing piece of equipment. The entries were all profiled in issue 343, September 2024, and online voting, open to all readers and forum members, ended on the 30 September. Voting was initially brisk, but then went a bit quiet, but we had a big rally at the end of September with nearly a third of the votes arriving in…

THE DUCTILITY of most metals and alloys is one of their most useful characteristics, enabling many operations to be performed that would otherwise be impossible. For without stretch and flow in metals there would be no simple operations like riveting and bending, nor manufacturing processes such as rolling, wiredrawing, forging, panel-beating. Equally, however, there are occasions when it is undesirable for metals to change their shape, if no more than because subsequent rectification will be necessary; and with recognition of such cases a considerable amount of trouble and wasted effort may be avoided. Common processes where pressure is (inadvertently) put on the metal are shearing and chiselling. Thus, in cutting a strip from a piece of sheet, as at A, using shears, there is always a tendency Tor the strip…