I'm never quite sure where to post these, whether here in the 3D printing forum, or on a regular forum concerning detailing. My approach to 3D printing and model railroading is to use it as a source for items I can't regularly, easily or cheaply get elsewhere, and most of my stuff ends up a hybrid of "standard" modeling techniques and items I design and print myself.
Anyway, a while back I happened to pick up a pair of Williams CNJ "GP7s" (since CNJ GP7s never had dynamic brake blisters, and these did) at auction for $60, and with an extreme lack of O scale CNJ decals available anywhere, not having to do a lot of painting and decaling made it a no-brainer. After popping off the dynamic brake blisters, I figured with a bit of modification, they'd serve me well.
I came up with a short list of items I'd need. Obviously, the long nose needed to have cabinets for the lighting equipment, the horns needed moved to the roof. Real exhaust stacks were needed (and not the oversized junk molded in to the dynamic brake blister), and with NJ environmental laws, they'd need spark arrestors. A bell for the short nose, correct CNJ marker lights, a smoke deflector for the cab roof (I've seen them with none, 1 or 2, but decided I'd go with 1) and some steam generator related roof detail would cover most of it, I can later add more MU stuff and drop steps if I so desire, but it'll noticeably BE a CNJ GP7.
While I was at it, I wondered how hard it would be to replace the molded on roof fan/grills with actual ones. Not that hard, it turned out. Now, I didn't go whole hog and make them to spin (though that wouldn't be terribly hard, as I did the fan shrouds and fans in 2 pieces, and the fans could be easily modified, but that was more than I'm currently looking to do, as I don't have a motor for them), but they should look nicer than the molded on ones.
To this I'll add lift rings and 18" drop grab irons sourced through regular channels, touch up the paint, and either modify the shell to fit on a Lionel chassis (as I have a donor GP9 with TMCC and railsounds sitting around), or upgrade it with an ERR TMCC board and railsounds, depending on which turns out easier to do.
Here's where it stands at the moment, still need to drill for the lift rings and grab irons, and touch up the paint. The classification lights can have an LED mounted in them (front currently open), and the sides drilled out if I desire..
