Rolling Stock
A record of the refurbishment of the TT gauge model railway layout
When the layout was acquired it came without it's rolling stock. This posed a real problem as there was a timetable to operate the layout to but it didn't specify what Locomotives, coaches and wagons would be needed to run with...a bit of detective work was required. The layout was built for Tri-ang rolling stock but it seems that Society intermediate standards work as well so I will be using a mixture of Ready to Run and scratch built items.
Rolling Stock projects
Whenever I start to build or modify any item of rolling stock I start by opening a 'project box'. This is usually a small box, often margarine or Ice cream sometime a shoe box and big enough to hold the completed model. This box is labelled to show the specific project as I always have several projects on the go at once. The first item to find is one or more drawings, reduced to 3mm scale of the subject and this allows me to mentally work through how I'm going to do the project and note the steps required. It also allows me to decide which components I'm going to need whether to buy or make. There are usually a couple of sheets of paper inside the box with sketches, dimensions and references for the work needing doing which are noted as I work through the design and manufacture of the model.
Tri-ang Wheel bearings
It's fair to say that Tri-ang rolling stock doesn't really roll...it more or less has to be dragged and with Exeter central having a continuous gradient this is proving to be a big problem. I have adopted the well established method of fitting PTFE bearings to Tri-ang models and this is how I do it. Materials are bought from E-bay, PTFE tube can be listed as Ink jet printer tube and I have a range of sizes but generally only need sizes 20 (1.4 mm O/D) and 18 (1.6 mm O/D). The new axles are Ideally 1 mm diameter hard steel but I use 25 mm dress makers pins which are about 0.7mm so there is a bit of slop but it seems to work fine. The picture shows some tube in brown and white
1. Knock out the axle by using a small, blunted nail tapped with a hammer. (I bought a 1.5mm pin punch to do this)
2. Clean up the wheels and place a 7 mm length of size 20 PTFE tube into each axle hole. It mustn't protrude from either end of the wheel moulding.
3. Using some hardwire side cutters, trim the pin to length (usually about 21mm) but check with the chassis you are working on.
4. Insert a 2mm length of size 18 PTFE tube into each axle box. NB, the first one can be placed on the pin and positioned when it is inserted.
5. Assemble the wheels in the chassis and pass the steel pin through the centre tubes of the axle boxes and wheels. To improve running, I now insert a small 'washer' of 0.375mm (15thou) plastic sheet between the axles stubs, secured with a liberal dollop of impact glue to fixe the wheels back to back.
6. Squirt a small drop of impact adhesive into each axle box to hold the pin in place.
The appearance can be improved by gluing a small plasticard rectangle over each end as an Axle box cover. The axle box casting is sloping so can benefit from being filed vertical.