The main wheels were too big to go in my 5" 3-jaw chuck which meant using the 4-jaw and all the process of centering each time. On top of that, it is 8" in diameter which means starting at very low speeds or the motor trips out because of the combined weight. I wanted to copy the original full size wheels as far as possible and the easy route would have been to make a pattern and have them cast. Having driven locos with cast iron wheels and others with steel wheels, the latter are to be preferred because of the traction. Cast iron makes a good bearing and so cast iron wheels are bound to slip more easily than steel. On the other hand, there's the problem of spokes and counter-weights. So finally, I've chosen steel wheels and hand cutting the shapes!
I printed out the inside pattern full size, cut it out, and stuck it to the wheel. Chain drilling and some cutting, removes the main pieces. Next, is to finish them off in the mill by eye. As the lump to be removed is about 3/4" thick, any cutting is a problem. So I chain drilled with a 5mm drill as closely as possible to each other, and then through again with a 6mm. This links most of them together although some bridges had to be cut. For this I used a junior hacksaw blade which I pulled to saw rather than pushed and held in mole grips.

This last picture is the first wheel finished on the mill using a rotary table. It's one of those jobs that needs concentration because, accidentally go the wrong way, and the cutter will climb all over the job. It's the corners where this is likely to happen. I'm quite pleased with the result so far, although there are one or two places where I'll have to 'tweak' it with a file I think. I've yet to decide on the colour to paint the engine and whether to echo this in the wheels or just stick to black. I'll try and get the wheels finished before Christmas, although I've still got the crank pins to make and fit. I haven't completed the measurements for the Walschaerts valve gear yet, so the thickness and placing will affect the crank pin length on the main driving wheel.

It's taken a long time to finish off the wheels, what with Christmas as well, slowing things down but I have managed it. One of the advantages of narrow gauge is that the colour scheme can be anything you feel inclined to do. I didn't fancy painting the engine in war-time colours which was no doubt a very dull colour so as not to be conspicuous. I thought I'd make more of the wheels on this engine by painting them. I used cellulose spray primer and finished the tyres in black cellulose. This gives a good finish which is not too shiny (unless you cut back and polish). This time I've decided to try enamel paint instead of my usual cellulose. And as can be seen in the photo, a rather nice dark green. It's good quality and can be cut back if necessary. I spent some time working on the design so that I could get the sizes of the crank pins correct and their method of fixing.

I have done the quartering in the lathe with past engines, but I had doubts about the accuracy of my last go, so, nothing for it , but to build a proper quartering jig. I decided on making an adjustable one which will take all sizes of engines. So far, I've only loctited the wheels and crank pins in place, but I will be pinning them. I painted the wheels at this time because it's easier than when on the axles and the lathe makes a turntable. However, I'm now not so sure, as it was so easy to scratch the wheels on the central locator when taking it out of the jig and then I had to retouch. The bogie wheels now look all wrong being left unpainted, so I've painted them to match. I won't be fitting to the frames just yet, as these haven't been finished as a lot more holes will need to be drilled as for example, the bolt holes for the cylinders, and it's much easier to drill when flat.
Having glued them all together comes the moment of truth; is the back-to-back dimension accurate. I was within 12 thou on all axles which is good enough. They should pass through the points without derailing.