Z Scale 80' Fluted-Side 10-6 Sleeping Car (ATSF)
This is a model of an 80' 10 roomette-6 bedroom passenger sleeping car with fluted sides inspired by what the Santa Fe railroad used on some of their Chief passenger trains. The trucks/couplers I suggest for this model are Micro-Trains #959 or 959-A (aluminum).
I print my models on a filament (FDM) printer. That's what they're designed to be printed on. For weight and strength the roof should be printed at 100% infill. The body can be printed from 50% to 75% infill for weight. Print both pieces flat-side down and no supports will be needed.