Tuesday 11 March 2008

For The Signal Is At Green

And following on from that short interlude, here at BBC 2(mm) we return to our scheduled programme of botching and struggling that is "How (not) to build a D49".

Well actually, and touch a very woody piece of wood, things seem to be back on track. The signal is up (or down, or green depending upon your prototype) and I think the end is in sight!

First up, the smokebox saddle was bent up and soldered onto the footplate. Then I set to manufacturing the boiler. Bob provides a lovely template to glue onto your brass tube which gives all the necessary positions and cuts, providing of course you glue it on square. I did my best to get it so, but whilst square, there was a little bit of overlap where the two edges met underneath the boiler. Was the template slightly too large or is this intentional? Using the handrail holes, which should be just above the centre line, as a guide, I'd say the template is accurate. As you can see, this loco will be finished in the rather rare "paper and inkjet" livery; locos tended only to carry this in the early months of their lives. At the moment, the boiler is located solely by the screw inside the cab.

The toughest part of the manufacture is shaping the firebox. Making the cuts with the piercing saw is not a problem. Opening up the flaps and getting them to the right shape is a bit more tricky. There is an etched insert to use as a guide, but this took quite a lot of fiddling to get right. Here we see the insert and associated nut soldered inside the shaped boiler.

Another important point is to get the rear of the firebox dead square; otherwise when the screw is tightened, the boiler will stick off at an angle, to one side or the other, or up into the air! A similar problem will arise if the nut is not square to the firebox back.

It's all getting a bit exciting now! The boiler is on the body which in turn is on the chassis, and the character of the loco is starting to become evident. At this point I'm also making sure that there is adequate clearance between the wheels/flanges and the firebox sides. In this shot more metal needs to come off.

Don't forget that if you miss any instalments of this exciting series, you can now catch up at BBC iPlayer. Alternatively just scroll the page down...

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