Monday, 25 May 2009

08 Shunter Progress

In the last month or so I've begun construction of the 2mm Scale Association kit for the BR Class 08 shunter. I've found Graham Ross' blog about the construction of this kit very helpful.

Here is an early view of the frames, with bearings and PCB spacers attached. You can also make out the phosphor-bronze springs, following the method of Mick Simpson. The frames have half-etched holes intended for these. As recommended, the springs came from straightening out Farish N-gauge coupling springs. With this method you also have to shorten the muffs on the axles, which I did by a combination of stanley knife and filing.

This view was taken this morning, showing the chassis with all wheels and gears fitted for the first time. I opened out the muffs on the axles with a 1.5mm drill, so that the wheels are an easy push fit. Hence I will be able to correct the misaligned balance weight on the right-hand wheel! I think when I am happy with the drive I will have to glue the wheels in, by means of the perpendicular hole drilled in the centre of each muff. Unfortunately one of the large balance weights disappeared in between cleaning up and glueing in place, so I had to make a replacement by carefully filing a piece of spare nickel-silver fret.

video
Finally here is a video of the first "test run" with the motor attached. There is still work to be done in getting it running smoothly. Before this video was taken I found that one of the spur gears was locking, which I seem to have cured by opening out its bearing hole slightly (perhaps it was a result of the axle bearings being opened out to 1.6mm for the springing system?).

Sunday, 3 May 2009

Trackwork

As I haven't posted anything about my Inverneuk layout for some time, here is a photo sequence illustrating the method used for trackbuilding.

I used plain rail and PCB sleepers, following closely the excellent instructions in the Beginner's Guide. Building turnouts turned out (sorry) to be much easier than anticipated, having been one of my two main concerns about working in 2mm scale (the other is building working locos, of which more anon). Although I used the standard jig for building plain track, I didn't use a jig for the turnouts, simply building directly on to an Association plan. For simplicity I decided not to design my own tighter turnouts. No chair-plates were used (Inverneuk is a light yard anyway). Two further points. Firstly, I find that running a file along the outsides of the chairs after construction gives a more uniform appearance. Secondly, you can see the gaps filed in the sleepers: these were filled with milliput after construction.

In a departure from more normal practice, the next thing I did was not to fix down the track. Instead I constructed it in several sections, and, while they were still loose, soldered dropper wires to each length of rail. Corresponding holes were drilled in the baseboard. Away from the layout I then sprayed the track sections with primer and brush painted the sleepers and rails with acrylics. However, I'm not convinced acrylics were the best paint for this as they tend to peel off and have had to be re-touched since. The idea of painting the track before fixing follows an article by Bill Blackburn in the 2mm Magazine where he describes how he lays and ballasts the track at the same time.

Here we see a section of track in the process of being layed, alongside a completed section. Pins are prepared to hold it in position, then PVA glue is spread in quite a thick layer underneath, before fixing down the track. At the same time dropper wires are fed through their holes. Then, while the glue is still wet, ballast is sifted into place. I found it advantageous to tamp the ballast at this stage too. After allowing the glue to set the layout was shaken upside down to remove loose grains, and the ballast was touched up where required. At the same time stray grains that had stuck to the sides of the rails were removed.

The choice of ballast material resulted from some experiments. I settled for a mixture of Carr's ash ballast and sand from the local beach. Here is the real thing, on the Kyle line.

And here is the finished track!

P.S. Inverneuk now appears in print (2mm Magazine for April/May 2009).