Model Engineer & Workshop June 2022的目錄

Print and Digital Versions It seems that the production of the print version of MEW has continued smoothly with the transition to our new publishers, Mortons. Unfortunately, the change has introduced some delays to the processing of the digital versions for Pocketmags and the digital archive at www.model-engineer.co.uk. There may continue to be some minor delays until the subscription service is brought fully in house at Mortons. Please accept our apologies for any inconvenience and be assured that the difficulties are being addressed. Tailstock Tales We are currently running a short series by Murray Lane on his capstan feed tailstock for Myford lathes. This is a beautifully made accessory using the traditional approach of making patterns and having castings made. It’s much in the tradition of projects by his late…

These articles by Geometer (Ian Bradley) were written about half a century ago. While they contain much good advice, they also contain references to things that are out of date or describe practices or materials that we would not use today either because much better ways are available or for safety reasons. In particular, never use abrasive cloth on a lathe without a backing board. These articles are offered for their historic interest and because they may inspire more modern approaches as well as reminding us how our hobby was practised in the past.…

Marking out has never been an activity that I have excelled at but it is a fundamental activity and its accuracy determines the success of most jobs. Two basic operations are scribing lines and centre potting hole centres. The former utilises the trusty scriber and the latter a centre punch. For many years I have used an automatic centre punch for most jobs although I purchased one of the optical assisted ones where a Perspex viewing piece is exchanged for a punch when the hole has been centred on the job. This is particularly good for use on large area work. The sharpness of the point on the scriber and centre punch has a large bearing on the accuracy and although I touched up mine many a time on an…

Around the beginning of the Millennium, I spent many satisfying hours constructing the ¾ Second Pendulum Clock as described in John Wilding’s excellent series of constructional articles, serialised in Model Engineer. That clock is electrically impulsed, based on a Hipp Toggle mechanism that detects when the pendulum swing amplitude has decayed too much and causes a pair of contacts to close, energising an electromagnet to give the pendulum an impulse that will keep it swinging for another 80 swings or so. The pendulum experiences some mechanical interference in the form of the loads imposed by the Hipp toggle itself and the gathering pawl which drives a count wheel, which in turn drives the motion work of the clock, so it doesn’t operate as a free pendulum, but the arc of…

3d printers are a useful tool. They allow the model engineer, within the confines of our own home, to turn designs or concepts into manufactured objects or prototypes, rapidly, without extensive costs. The downside is that additive manufacturing does not yet produce objects which are made of strong, durable and more robust materials. Because of this their use is limited in the present-day model engineer’s workshop. This article does not describe a way around the present limitations but suggests an additional post processing step which changes the characteristics of a 3d printed object to make it more useful in our hobbies and in the workshop. That process is electroplating. In late 2019, I dipped my toe in the 3d printer market. Rather than invest in a FDM machine (Fused Deposition…

Once you have fitted out your workshop and obtained commoner workshop machines, such as a lathe and milling machine you may well want to just put some time into your new hobby. Sooner or later, however, you will come across jobs that would be made easier by some more specialist equipment. Here is some other equipment you may want to consider finding a home for in your workshop. An obvious accessory is a decent bench vice. A 75 to 100mm (3 to 4”) vice is the ideal for most workshops. Make sure the vice is securely attached to the bench and that you have plenty of space on both sides of it and fix it so that anything held vertically in the jaws hang down in front of the bench…

The inside faces at these points of the casting are machined to take the head of the pull bolt photo 18. The cam shaft position grub screw was then drilled and tapped photo 19. Multi carbide insert cutters were used for much of the machining as they can cut over a wider area and remove metal quicker as well has staying sharper for a longer time than high speed cutters. However, when sharp corners and close tolerance requirements are required HSS cutters were used. The boring of the barrel hole through the tail stock body was carried out in the lathe that the tail stock was going to be used on. This ensured that the tail stock barrel bore would be truly in line with the headstock centre line; hence…

My attention was drawn to the rather specialised area of bevel gears by friend Pete. He had been approached by a relative wishing to build a model traction engine. Unlike model railway locomotives, these are fitted with a differential gear, usually housed in a rear wheel and containing a number of bevel gears. Knowing my interest in gears, ref.1, it seemed reasonable that I might be able to help. It soon emerged that I could not! But Pete had done a lot of research and provided me with a number of useful references. That sparked my interest, but not much understanding. I then had to spend a few hours with ref. 2 getting to understand the nomenclature and find what constituted current practice for a model engineer. Bevel gears come…

I was constantly moving piles of wire on reels about my bench, or they vexatiously fell over, so I designed a stand which would keep them in order and be readily available. My wire ‘tower’ resembles a kitchen mug tree. The ‘arms’ are angled upwards so that the reels do not walk off the ends, and are spaced every 100 mm, 120 mm would be better. It could also be more substantial. As it is, it is bolted down to the bench and restrained at the top. My spools of enamelled copper wire needed storage, but not dispensing, as they are small enough to be taken down when required, so I used No 8 x 50 mm woodscrews suitably spaced in the end of my bench shelving. One spool was…

TIP OF THE MONTH WINNER! This month’s winner is Howard Dean with a tip for a lathe stop that can also be used on many other machines. Sometimes when working on projects which require repetitive machining it is nice to have a lathe stop, the attached pictures are of a simple stop I have made for my Chester DB 10 super B lathe. When not in use it is locked under the chuck and having an aluminium locking piece it cannot hurt the bed. Simple but effective. We have £30 in gift vouchers courtesy of engineering suppliers Chester Machine Tools for each month’s ‘Top Tip’. Email your workshop tips to meweditor@mortons.co.uk marking them ‘Readers Tips’, and you could be a winner. Try to keep your tip to no more than…

Having been impressed by the performance of the tangential turning tools that i have made, as well as purchased; whilst doing some fly cutting, the thought came that maybe a tangential flycutter might be a useful tool. The eventual result, although not that initially envisaged, is shown in photo 1 A little thought showed that the relative motion between a milling cutter and the workpiece is the same as that of a lathe tool and the work in the chuck. The first thought was to modify a number 3 Morse taper (3MT) stub arbor to carry a holder for the toolbit, in an angled slot. This would provide a means of adjusting the swept radius of the cutter and make the toolholder simpler to make, by removing the need for…

Cutting the slot for closing the clamp is next. Drill the bottoming hole for the slot first. This will probably have to be done by marking out and drilling from each end because of the length of the piece. A slitting saw makes a neater job of cutting the slot, photo 10. although one cut with hacksaw functions every bit as well. Finally, drill and tap the holes for the clamps and the height adjusting screw. Closing this slot with enough force to securely clamp the tool blade in place is asking a lot of a pair of M6 screws threaded into cast iron so, studs inserted to full depth and secured with Loctite or similar adhesive should be used instead. In my case one job remained because I had…