RosiesBoss Posted October 8, 2015 Share Posted October 8, 2015 Introduction I love to “tinker”! I have found that I get the most pleasure from making or customising my models. Many modellers take great pleasure just from using unaltered RTR models, but most of my “jollies” come from the completion of challenging projects. Recent models have included the motorising of a GBL City of Truro and a GBL Caledonian Single (and provision of suitable coaches). Details may be found here: http://www.rmweb.co.uk/community/index.php?/topic/96216-motorise-gbl-city-of-truro/ http://www.rmweb.co.uk/community/index.php?/topic/102076-motorisation-of-gbl-caledonian-single-and-upgrading-of-her-coaches/ Recently, my local newsagent received a couple of GBL Stephenson’s Rocket models. (We’re a few months behind the UK with this part work.) I took one look and decided I had to try to motorise one, so one of them followed me home. About 15 years ago, I re-motored a Tri-ang “Rocket” belonging to a former workmate and noted the use there of split axles and split chassis to achieve power pickup. I chose to go down a different path with this project. Aims Modify the GBL model to run on normal 12V DC. Utilise as much as possible from the GBL static model, with minimal structural changes. Only use other parts from existing stocks in my scrapbox. No further purchases except matching paint. Parts One GBL model 1 pair Romford 18mm dia driving wheels & axle 1 pair Romford driving wheel crankpins 1 pair Alan Gibson 10mm inside bearing wheels 4 Romford top-hat bearings 2 pairs 12mm dia Peco wheels 1 Mantua/Tyco 4-wheeled trolley 1 “pre-loved” Dublo connecting rod – probably from a Duchess 2 8BA nuts/bolts/washers 2 12BA nuts/bolts/washers Yellow paint: “Railey Paint” marigold 111 Black paints: Humbrol satin and matt enamels Reconstruction The first job was to completely strip each of the three constituent models to parts, to work out what could be re-used. While they were stripped, I reviewed what self-propelled chassis I had in stock among my spares. I did consider the following – all related to my H0 tram collection. (For more details on that, see http://www.rmweb.co.uk/community/index.php?/topic/77505-rosemount-tramway/.) Mantua/Tyco 4-wheeled trolley Mehanotechnica 4-wheeled trolley Bachmann Brill trolley power bogie Bachmann gandy dancer chassis Bachmann Underground Ernie 4-wheeled work vehicle Black Beetle 30mm wheelbase power bogie None of the above would fit within the outline of the loco or tender and have enough “grunt” to propel all three vehicles. However, both of the trolleys had about the right wheelbase and could fit inside the coach. I chose the Mantua/Tyco one, as it was heavier and both axles are powered, giving a reserve of power in case extra coaches became available. After stripping the GBL models looked like this: Loco: Tender: Coach: The dummy fixed wheels on the chassis of the loco were ground off. Holes were then drilled for new axles: 1/8” for the driving wheels and 2mm for the trailing wheels. New wheels were test fitted and adjusted as necessary. Crankpins were fitted to the driving wheels. I then carefully removed the cylinder/slidebar assemblies to work out how to design and fit working crossheads and connecting rods. I discovered that I had to cut away the dummy crossheads, using a miniature saw and a sharp scalpel, finishing off with fine files. Each new crosshead was made from a 12BA screw, two 12BA washers and a 12BA nut. New connecting rods were made from an old Dublo Duchess con rod, re-using one existing hole for the crankpin on the wheel, and then drilling a clearance hole for the 12BA bolt at just the right distance from it, after checking it against the cylinder assembly dry-assembled on the body. Everything was test fitted and checked for ease of rotation, then the crosshead/slidebar/con rod group was glued to the body. In this case, the bolt head and first washer are trapped between the slidebars and the boiler. The nut was secured to the bolt with black nail polish. The tender was easy! The cast metal chassis with fixed wheels was simply discarded. A 2mm dia hole was drilled from the outside through the centre of each dummy axlebox. A brass “top hat” bearing was then inserted from inside and then a pair of 12mm dia Peco wagon wheels was test fitted and the bearings adjusted to permit free rotation of those wheels. The coach was the real challenge. The trolley chassis was slightly shortened to fit inside the coach. New attachment holes were then drilled. Most of the coach floor was then cut away, leaving enough to attach 8BA bolts for both a new coupling to the tender and to attach the trolley chassis. The coupling is just a suitable length of modellers’ brass, which is attached to the tender using one of the fixing points formerly used for the dummy chassis. Dry-assembled, but still lacking the cylinder assemblies and touching up of the paint, the model looked like this: The model was then stripped and the wheels and some body parts were then painted as necessary. It was then re-assembled, cylinder assemblies finally glued into position and the outer washer of each crankpin soldered into place. Re-assembled, the model now looks like this: Reflections The model is now fully functional. It copes with setrack down to Radius 2 and just glides along. When in motion, it’s not too obvious that there is a large mechanism in the coach, even though the wheelbase is not quite right and some of the motor can be seen between the wheels. The eye is just drawn to the movement of the loco’s driving wheels and rods. The model does not pretend to be a precise museum-quality example. Rather, it is a fairly robust one which can be handled and run in an exhibition setting. I did achieve all of the aims listed above. The project cost (apart from existing items in the scrapbox) was A$25.95 (about GBP12.20), comprising $19.95 for the GBL model and A$6.00 for the paint. Current prices for similar Tri-ang and Hornby combinations available on eBay are in the order of A$250. I think I have achieved value for money! This model and some of my other vintage trains will be seen on the St Luke’s Railway Modellers display, together with Hornby live steam, at our club’s exhibition on 14-15 November 2015. Other details are: Saturday 14th November: Exhibition 9am to 5pm Sunday 15th November: Church Service 9.30am – 11am Morning Tea: 11am Exhibition 12noon – 4pm Where? St Luke’s Anglican Church 155-157 Galston Road Hornsby Heights, NSW, Australia Link to post Share on other sites More sharing options...
Londontram Posted October 11, 2015 Share Posted October 11, 2015 A great idea and well executed, I was thinking along the same lines as you as I have a selection of tram bogies in stock but I've got so much on with other projects I gave it a miss this time but seeing how simple you make it look I wish I'd had a go now. Well done Steve Link to post Share on other sites More sharing options...
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