I've finally (after about 8 months) finished the pair of 3D printed, Kato chassis powered, ex military diesels: the CWR produced Hunslet left) and the Narrow-Planet Baguley Drewry (right). Both are relatively straightforward but tasks like fitting couplings, painting, glazing, and weathering have been completed in occasional modelling sessions.
Fitting the couplings to the Baguley was easy enough, with a slot cut into the buffer block for the Microtrains draft block and plenty left for the screw. There's plenty of space inside for some lead which helps tame the sprightly Kato chassis. Glazing was a little fiddly but templates in the instructions helped with cutting out, the brass etched frames were painted separately and fitted afterwards to hide any join - however I couldn't help getting spots of superglue on the paint, which had to be hidden by a little "dirt".
The Hunslet had no space for the couplings even after I cut a square hole in the buffer beam due to the chassis fitting flush inside, so I made up a mounting block using plasticard stuck to the face of the bufferbeam. Such blocks were common on NG locos and it holds and disguises the coupler draft box, providing something solid for the screw too. 3D printed glazing was provided, it's a little milky with some faint layering visible (and sanding it would make it worse!) but I used it anyway - it's convenient and looks OK. Here you can see I've also finished painting and weathering a couple of RNAD wagons too.
The Hunslet's party trick is the working headlights. The headlight openings were glazed with a drop of Micro Krystal Klear, and the micro SMLED's stuck behind them. The PCB was pushed into the bonnet so the contacts touch the Kato chassis when fitted. The lights work really well, the circuit suggested by my friend Harry does the job of keeping the LED's lit at a constant brightness and reasonably flicker-free, and I think I've got the brightness about right. The circuit meant less space for lead, but I still squeezed a little in around it and it runs fine.
Both locos have been weathered using a little dry-brushing, a dirty wash, and some powders (which may get toned down a little), the idea is to capture locos working in preservation service on maintenance trains - generally clean bodies but with some track and exhaust dirt. They could both do with a driver (and the Baguley could use a representation of an interior) but otherwise they are ready for service. Despite my reservations about 3D printing, I am very pleased with the end results.