Quote Originally Posted by David Manley View Post
I've made a load of 3D models of 1/300 and 1/600 WW2 costal forces craft which I was putting up for free on some of the Facebook naval groups. I've stoped doing that now as one of my friends said things like that were likely to put him out of business.

Model railways I think are a bit harder to manage in 3D modelling, at least as far as locomotives are concerned. But I have seen some lovely 3D printed carriage, wagon and loco bodies so I agree it is a matter of time.
Main barrier for modern American types is the chassis; EMD and GE each have standard "building block" components that stack onto different frames to build up different models. Even the old "Covered Wagons" of the '50s, the hard part is the cab and nose compound-curves, everything behind the cab door is basically a slab of sheet material. OTOH, a California company 3d-printed a fully functional Colt .45 out of Inconel a few years ago and they still haven't stressed it to breaking in test-fire yet, so... it's a matter of time, and realistic expectations about what can be done as a single piece vs what needs to be done as separately fabricated components with a human assembler.