By Garry Hall - updated 5 March 2020
For my sins I am a happy Tri-ang TT modeller and where possible like to use their locos/chassis's etc for modifications or new builds. Repaint/rename is easy, conversion or new build a little harder. Due to certain limitations conversion is not always possible so I have ventured into making some chassis and body kits. I started doing my TT kits well before I joined the 3mm society so knew nothing of the different gauges, chassis width etc. My first one was a 9F which I guessed Tri-ang may have made if they had continued. This was an easy Tri-ang style to reproduce by just measuring and drawing the Britannia chassis outline for motor and fixings. Then I altered the base to accept 5 Jinty wheel sets keeping the centre one as in the Britannia. Wheel spacing was just made to suit the chassis and look reasonable, no attempt at "true scale" was made. I did want a slightly better valve gear representation though. The coupling rods are double thickness, as are the chassis sides, with crankpin holes to suit Tri-ang ones as well as their screws. Spacers were slot and tab giving a strong chassis when soldered up. A new pony truck was also etched to fit in with the design. The tender is a standard Tri-ang chassis but a scratch built top as I wanted the high sided type for something different.
View 9F by Garry Hall
Having managed to win an old BEC 2P kit I needed a chassis for this. The instructions as you will know stated the use of a K's tender drive which has long since been deleted so I decided to try a small Mashima which I obtained as a Tri-ang XT60 would not fit. I drew up the outline as best I could then cut a plasticard one out to see if it would fit, once satisfied The wheel spacing's etc were drawn along with the coupling rods and bogie. As this loco would have to use Romfords the rods and crankpin holes were a lot finer. Due to using a different motor I also drew up a gearbox mount so I could use Romford gears along with the Mashima. This was in two parts as one part had was adjustable slightly for the mesh then soldered to a clip to always keep it in mesh if ever something needed to be changed. As I am not keen on a tender assembly that includes the wheels fitted during building I also drew up a tender chassis to suit. This enabled a separate chassis to drop in and out if required.
View 2P by Garry Hall
After a couple of chassis's I thought about doing a body to fit on the Tri-ang chassis and after a fair bit of searching came up with the N7. This was made to scale drawings, length , width etc but made to fit around the Jinty chassis which I had to measure and draw to check the fit of parts around the motor etc. This meant the chassis could be seen between the boiler and footplate etc but as it would be black then it was not an issues, and, it was similar to a lot of the old GEM and BEC kits. Being drawn in CAD and etched allowed the grills and coal rails to be made as one to aid assembly. Due to the motor size and position a round top firebox was out of the question unless I went completely out of proportion. A new rear pony truck was etched to be fitted into a new drilled and tapped hole in the chassis, or, have a separate fixing (included in the etches) glued in.
View N7 by Garry Hall
Update: 20 March 2020
Although not a WR fan when I saw Lenny Seeny’s 2-8-0 tank engine I thought it would be a good candidate to build a Tri-ang style chassis for it so I ordered one. As usual with Lenny the model arrived in a couple of days and is a nicely finished body. Unlike other steam locos this had a nice big opening underneath for the trusty XT60 motor. As with the 9F I wanted to also use Tri-ang Jinty wheels with drop in slots, flanged on the outer pairs and flangeless on the inner two pairs. I set about drawing a chassis in CAD and printed off a frame to make in thick card which when the motor was fitted caught the firebox so I lowered the angle but still leaving enough metal for strength at its narrowest point. I printed a side and this time made a plastic chassis to prove the motor would fit which it did. I then set about the slidebars and crossheads which I wanted a little better than the Tri-ang Castle design. I made my crosshead from 5 pieces which allowed the connecting rod to fit inside as it should do. I drew this in all four quadrants to check connecting rod and slidebar clearances and then added ancillary items to the drawing. The coupling rod was to have the Tri-ang crankpins fitted after removing them from old rods and then Jinty coupling rod screws for the 3rd set of wheels and Castle ones for the 2nd set. Due to Tri-ang’s wheel insulation method the slidebar assemblies have to be in two parts insulated from each other which I have done with very thin Plasticard. Castle cylinders were removed from an old body and glued, at an angle, over the etched assemblies. The only issue is that due to WR footplate height I cannot use the correct sized pony truck wheels and will source some 8mm ones but for now 7mm Jackson ones suffice. The loco is now a lovely runner and awaiting numberplates which I will order from 247 Developments.