I have been working on the right hand cylinder and motion today and can call it a success, though there were a couple of steep learning curves to be overcome along the way.
I have been considering coupling the piston movement to the valve movement, basically having the connecting rod drive the valve spindle to and fro, But I have decided against it as this project is not supposed to get in the way of the big picture!
With the three driving axles moving smoothly, the next task was to build up the cylinder, fit the slide bars and the valve linkage and add the crosshead/connecting rod to see if it all works.
First photo:
Ignore the lack of one slide bar, it will be added later! The various components relevant to moving rods, etc. come first, forget the cylinder wrap and the draincocks, they come later. The valve linkage is already installed and it moves freely, but the actual installation needed quite a lot of thought and also nimble fingers (which I don't have) so took all morning to figure out. Next the crosshead and slide bars. I fitted the lower one and then placed the crosshead on top, checking for interference, knowing there would be! Two problems arose, both sorted now. The first was the front driver crankpin, it needed filing back. The second was the sandbox. That was simply removed so that white metal could be sliced and filed away. It has yet to be fitted back but that won't be a problem.
Before moving on, take a look at the piston and valve rods. It would be easy to install a connection between the two that would use the wheel motion/connecting rod to flick the valve linkage to and fro.
Second Photo:
This shows the valve linkage from above. The pivot uses a brass screw and
two* nuts, the one at the top resembling the real thing on Drysllwyn Castle, see
post 20. The interior will hardly be visible so a blob of solder was left as insurance. (* I just checked, two, not three nuts, so edited!)
Photos 3 and 4:
Back to the slide bars. This proved to be easier than anticipated though it is not yet complete - additional fillets are required on the motion bracket to add strength. The front axle crankpin nut clears the crosshead, having been filed down and a dab of solder applied to the retaining nut.
I am hoping to complete the left hand side more quickly and then it will be adding the cylinder wraps and draincocks. I might then take a break because I have a DCC chip to install in another locomotive and I keep talking about scenery for Penmaenpool.