As a software developer, I've always been interested in learning new tools and techniques to make accurate scale models of railroad equipment. I have learned how to use Inkscape to create 2D vector drawings to cut model parts from sheet styrene on a Cricut machine. For 3D work I learned how to use Sketchup to develop 3D CAD models that can be printed at Shapeways. Working from photos, plans and elevation drawings, I can design models that have every rivet on the prototype placed perfectly on a 3D printed model. There are some limitation due to the current state of the art of 3D printing, but with intelligent design, optimal 3D print orientation and some coats of a filling primer, great results can be achieved. Some designs may be best used as masters for resin casting.
So far, I have concentrated on designs for New Haven Railroad prototypes, mainly for things I or my fellow New Haven modelers haved wanted for years. Future projects I'm considering are 3D printed passenger car parts for the New Haven Meadow Lark/ Boston and Maine Shore Lark buffet solarium heavyweight Pullmans, or the New Haven 600-series coach sides.