Boiler saddle

When I mated the boiler and the etched frame for the first time, they produced a dead short. Somehow, I had reversed the framigami pattern so the left side ended up on the top rather than on the bottom as planned. Fortunately I noticed before bringing any destructive electrons to the party. The situation remained […]

Yoke for 622

Once all six parts of each cylinder were soldered together, I really wondered if I would be able to add the yoke too. I wanted it soldered for strength, but feared turning the cylinder assemblies back into their constituent smithereens. I needn’t have worried. The hard part turned out to be holding the chassis in […]

Cylinder assembly

Getting the first cylinder right could have been luck. By the time I’d completed the second one, I think I knew what I was doing. So here, for future Rene, are the fixtures I came up with to get the cylinders together straight, with a minimum of fuss!

Cylinder parts and jig

When I tested the dry fit of the first cylinder parts, I still needed to get the guides straight. Little did I realize at the time how difficult that would be. I was even more surprised by how difficult it would be to hold the guides straight for soldering. I shouldn’t have been surprised. Indeed, […]

Once more unto the breach: oil cups

Thanks to comments from Rob and Richard, I re-examined my approach to the crosshead guide oil cups. Rob encouraged me to look again at the prototype while Richard suggested I think like a jeweller. So, despite my earlier capitulation, I launched back into battle with the oil cups. It took a few attempts. One was […]