Z Scale 40' Pre-War Steel Boxcar
This is a model of a pre-war American steel-sided boxcar, similar to the AAR boxcar design of the 1930s. The trucks/couplers I use for this are Micro-Trains #954 (Bettendorf Black).
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. I print the body at 75% infill for weight. Print both pieces flat-side down and no supports will be needed.