Retreat to known ground

I’ve put the debacle of the micro connectors and missed resistor behind me, and as I said, I’ve decided to revert to connectors I know and trust. These are harvested from an IC socket, and are quite robust, but also big. Okay, big is relative in our world: I often tell people that a lot […]

A bad week for electronics

You’d think that if your father had a doctorate in electrical engineering, at least a little wizardry might have rubbed off! Nope, he kept it all to himself, apparently. The story starts with the Hall effect sensor, which the ESU decoder wants to synchronize the exhaust sound. Countless YouTube videos make this gizmo look trivial, […]

622’s tender cable

I struggled a little bit with whether to simply extend the leads from the tender-mounted decoder so that they could connect with the locomotive, or whether to create a cable with connectors on both ends. In the end, I decided on a cable, rather than having to deal with an obscene length of wires hanging […]

Tender coupling

622’s tender coupling is a sandwich of phosphor bronze and styrene. The two layers of bronze carry track power from the two sides of the engine to the two sides of the tender through a mind-bending arrangement of layers and folds. Seriously, it is such a puzzle that I wasn’t certain I would have the […]

Tender coupling tests

I recall a story about a cab ride where the engine backed around a tight corner, and the writer had act quickly to avoid losing their thumb between the cab and the tender. Photos of 622 and her sisters confirm the tender should be startlingly close to the cab. However, it would be a bit […]

Tender lowered

Arguably, I should have built a whole new end beam, but replacing only the visible portion of the draft gear saved me from positioning eight bolts in two perfectly-aligned squares. It was a bit of a pyrrhic victory, however: assembling the shambles of shims and the mammoth metal plate that support the repositioned coupler and […]

Slow modelling to the rescue

I’ve decided that the tender was indeed too high, making the 3D-printed body bolsters and end beam superfluous. Having rediscovered that photo of 624 wrecked at St Polycarpe, I know the body bolsters were the wrong shape anyway, so no great loss there. The end beam, however, needs reconfiguration to keep the coupler at the […]

Tender chassis

The tender chassis went together quite quickly with all the 3D printed parts. Upon reflection and further measurement, the rear coupler was .01” too high. I shaved the bolsters down, and then everything looked pretty good – apart from the temporary coarse-scale wheels! The trucks are Kadee HTC caboose trucks, which are a reasonable facsimile. […]

Locomotive coupling level?

I just got the tender up onto its temporary wheels and checked the coupler height at each end. The rear looks okay, but the front is perhaps .010” too high. I’m wondering if a slight joggle in this coupling is okay, or will that have a tendency to lift the tender?

Motor and light connections

One thing I’ve learned in my short career as a locomotive builder is that I take my engines apart a lot. It won’t do to have soldered connections holding the boiler where the lights are to the chassis where the wheel rotation sensor is and to the motor. Fortunately, it seems like the 1mm headers […]