Model Engineer的Issue 4719目录

Parklands Railway On Sunday May 28th I had the pleasure of attending the first full running day of this year's Parklands Railway Week, up at Hemsby on the Norfolk coast near Great Yarmouth. The Parklands railway is a 7¼ inch gauge railway in the grounds of a holiday park created by the late Don Witheridge and the railway week has now been an annual event (except during covid, sadly) for over 40 years. There was a total of 23 engines present when I visited and most were staying for the entire week. I include here a couple of pictures of visiting locomotives to be going on with and we hope to include a more comprehensive report in a forthcoming issue. Summer Events There are two events coming up in July…

Published work My first printed item was for a Keighley Scout magazine and I was about 15. It was printed without being offered for corrections, proofreading, or similar, and I am ashamed to read it now. My first paid contribution was to the magazine Practical Wireless in February 1967, about setting up a workshop. I bought a short-wave receiver with the proceeds. Thus began my meteoric rise to inadequacy… Over the next 55 years I was published in over 20 different periodicals, including the short-lived Yorkshire on Sunday, Mensa Magazine, Ham Radio Today, Electronics Today International, Practical Electronics, Radio Communication (from the Radio Society of Great Britain) and Model Engineer. Before I began my regular Club News column, I edited the Northern Heights Amateur Radio Society (Halifax) newsletter for several…

Having started to build Elidir, a 7¼ inch narrowgauge quarry Hunslet locomotive, and with A-level studies also underway, the author has discovered that the long daily journey to Brighton, coupled with more homework than he has ever seen in his life, are not conducive to steam engine construction. Taking this into account, he has revised Elidir's timing estimate upwards to eight years, certain in his belief that it could not possibly take longer. Perceptive readers might disagree with his conclusion. Progress, or lack thereof ‘Never judge a man until you've walked a mile in his moccasins'. Sound advice, if ever I heard it, and, in just twelve words (thirteen, if you count ‘you've' as two words, which you shouldn't) it neatly captures the idea that we all have constraints, and…

How to go about designing a brake installation – calculations All engineering is a combination of the theoretical and the practical. It is senseless just to pitch-in and make things without first planning what has to be achieved and how to do it. The steps in designing a brake installation are straight forward and involve the following: * Firstly – establish each individual wheel load, by estimation, calculation or actual weighing. It is worthwhile to actually weigh the wheels using a simple forked end lever at the wheel rim, fulcrum, spring balance and a series of weights (photo 6), taking care to eliminate any ‘stick-slip' at the axleboxes by inching the locomotive backwards and forwards a few times. * The next thing to do is to select the ‘brake percentage'.…

The BHLR has seven motor points and ten spring points. The point motors (photo 13) are mini-linear actuators type JS-TGZ-U1, 12-24V, 1 amp off load. The maximum current is 3 amps. They have 50mm throw and exert a force of 750N (168 lb). Each point motor is fed from a 24V DC supply. As the motors can work on 12 to 24 volts, this gives a wide range of distances at which they can work from the power supply. The actuator has internal limit switches, limiting its throw to 2 inches. The point throw is about 1 inch and, as the drive is via compression springs, a 1½ inch drive-rod throw is sufficient, so external limit switches are provided. The drive springs are not fully closed when compressed. Therefore, motor…

June 18 Bradford MES Public running day, Northcliffe, 13:30. Contact: Russ Coppin, 07815 048999 18 Bristol SMEE Public running at the Ashton Court Railway BS8 3PX, noon17:00. Contact: secretary@ bristolmodelengineers.co.uk 18 Canterbury MES Public running. Contact: ginapearson@btopenworld.com 18 North Wilts MES Public running at the Coate Water Railway, 11:00-17:00. See www.nwmes.info 18 Taunton Model Engineers Public running, Vivary Park, 14:00-17:00. See www.tauntonme.org.uk 18 Warrington and District MES Running day at the club track. See www.wdmes.org.uk/events 22 Sutton MEC Afternoon run from 12 noon. Contact: Paul Harding, 0208 254 9749 24 Brandon and District SME Running/family day, Weeting track. See www.brandonanddistrictsme.com 24 Bromsgrove SME Modern Traction Day – all gauges welcomed, 5, 3½, 2½, G1 and 16mm. See www.bromsgrove.co.uk Contact: Doug Collins, 01527 874666 24 Erewash Valley MES Narrow gauge gathering…

Piston The next part is the piston. If you've been able to create the previous parts, it will be easy (fig 49). Step P1 – Create a Part Studio and make the sketch of fig 50 on the Top plane. Use the Trim tool to remove all segments not needed from the rectangle construction. Step P2 – Extrude-New 32mm to create the cylindrical shape of the piston. Step P3 - Extrude-Add 8mm of the sketch rectangle in the opposite direction to the previous step. Step P4 – Create a sketch fo the crankpin hole – fig 51. Step P5 – Extrude-Remove to create the crankpin hole. The Hole tool could be used instead. Step P6 – Use the Fillet tool to create the shape in fig 52. Step P7 –…

Machining the attachment The parts list is shown in table 2 and parts are illustrated in figs 20 to 38. Here are some notes on machining some of the parts. Bracket (See fig 20, part A1) The rear part must suit your toolholder. Guide (See fig 21, part A2) The dovetail is checked with WPPins (‘with plate pins', as described in Model Engineer issue 4588, June 2018, see photo 9). Slider (See figs 22 and 23, part A3) The parts A and B are welded together (see fig 19, Part 2, M.E.4717, May 19) and then annealed by heating in the fireplace overnight. All of the machining is done after welding except the groove in part A3B. The 2.5mm diameter oiling hole must be drilled before dovetail machining. Rub the…

Silver brazing rods are incredibly expensive and the range of alloys is so vast I could write a book just on the first principles applied in choosing the correct rod for a specific application. Fundamentally, silver brazing alloys with a silver content above 15% will work just fine and generally the model engineering codes will stipulate something similar as a minimum. Cadmium bearing silver soldering alloys have a much wider melting range. This makes brazing and reheating easier because the lower melting constituents tend to flow more readily into the capillary gap, leaving the higher melting parts behind to form a nice fillet. Cadmium doesn't like to stay in solution at brazing temperatures; this fortuitously results in subsequent heating operations not re-melting existing joints due to the lower cadmium content.…

We editors often have to cope with (and find) papers on which are salient details for the matter in hand. The dull people of this world label paper trays and desk tidies as In/Out/ Pending. Others, with their thoughts elsewhere, have created some more imaginative versions: Cricketer, - In/Out/LBW (or 'Let the Beggars Wait') Radio Amateur - Receive/ Transmit/StandBy Writer of the Hokey Cokey…? Rowing coach - In/Out, In/ Out, In/Out… Psephologist - In/Out Thoracic surgeon with stethoscope, breathe in…..and hope he doesn't forget, Publican, Inn… Club News editor - in this issue: Pickering Experimental Engineering & Model Society Newsletter begins with a highly implausible tale from chairman Jonathan, of how US Ford automatic gearboxes are marked for the different performance offered. However, I did see a US car in the…