OO enthusiast Jack Bartman got things rolling with Shapeways, working with a designer who had previously worked up a SW7 and a SD9 in N scale. He produced for Jack OO versions of both, and I purchased one of the SW7 models. The listing may be found here.
This one I purchased is in what they describe as the “White Strong & Flexible White nylon plastic with a matte finish and slight grainy feel.” I would say that wording, now that I have the model, is marketing at its best and worst. The material has more the feel of a dense Styrofoam than plastic, and it is actually porous! It a type of Nylon, it is flexible but holds the shape well, and has a very grainy, powdery feel -- especially when it first arrived, and I had not blown the excess powder off. The price was right, it is cheaper for a big model such as this, but I will never get this material again, the FUD material is the one to use for model railroad applications.
The AHM SW1 is oversized for HO (more here) but really only about 1/80 scale, and the difference shows. The AHM S-2 works a bit better as an OO model, as does the Fleischmann Baldwin, but the new SW7 model has left me rethinking my switcher fleet to be sure. Probably some more extensive kit bashes are in my future….
I am also planning at this point to paint this model black and be very minimal on the decals. It is a trick we can use to our advantage, the model has low detail and the details are a little rough due to the material choice, black will help hide this fact. Also, with this material you pretty much have to use acrylic paint and I will likely brush paint it, something I have not done on a model of this size in years. Shapeways has a guide to painting this material on their website.
The cab listing is here.
This one I purchased is in what they describe as the “Frosted Ultra Detail Matte translucent plastic that showcases fine and intricate details.” While my heart sank a little when I saw the SW7 material, this FUD material really excited me. It has the feel in your hands of being a resin casting, a solid feeling (it is actually an acrylic polymer material), and certainly will build up into an outstanding model. Whew!
Pierre Bourassa built up this big GE engine from scratch. The Shapeways cab is to scale, matches the size of the GE cab, and really will make the models I have underway look sharp.
Painting the FUD material also has some special challenges. There are a quite a few discussions of this topic online. The central problem is there is a waxy film on the FUD material that has to be removed, and even then you are still looking at using Acrylic paints (because apparently enamel paints won’t dry properly on this material). A solvent marketed as Bestine (use in a well ventilated area!) seems to be commonly recommended to clean FUD parts, and I gather that a 5-10 minute soaking will remove the wax residue and leave the part with a white, opaque finish ready for painting. If you have the equipment an ultrasonic cleaner does a great job too.
For those curious, I am told that a Shapeways designer only makes $3-4 per sale on a part the size of that cab. They are basically individuals designing models to fit their hobby interests and clearly are not getting rich on this, so if contacted they may not be very willing to do a complicated design specifically for you. But again, if it is an existing model that is already listed, they may be willing to help as they can probably bang out the OO version in literally a matter of minutes.
A final note is that end Shapeways price relates to the material you choose for the model and the size of the model. Large models will be quite expensive in the FUD material, but parts such as a cab more reasonable. For more Shapeways OO models search 1:76 or OO in their website, with 1:76 providing more relevant results.