My modelling workbench chair is one of those cheap office chairs, with a gas strut providing the lifting mechanism. I've got a sinking feeling that the gas strut has a leak...

I rediscovered a couple of old projects (while looking for bits for another project), the NER Class H (later Y7) and the AEC shunter. Cue some faffing about curing intermittent pickup issues, and a short while later, the H is running happily up and down the test track on a 9v battery (video below). Nice and slow and smooth, too.

The AEC is a different story, the chassis sort-of works, but has nowhere near enough traction, being 2-wheel drive. The body is already very heavy, so I can't add more weight to help it. This means a chassis redesign to make it 4wd, not too hard, but will take time.