Monday, August 21, 2017

3d Printing in Model Railroading: The New Normal

Corey's D&RGW steel gondolas

A couple months ago, I shared my experiences selling 3d printed freight cars made in my garage. One of the first points in my talk was "you’re going to see lots more folks making kits this way in coming years."

And of course, we do see more folks making cars this way. Corey Bonsall recently told me about his drop-bottom-gondolas that he’s making on a Form 2 Printer. Corey’s model is the uncommon 42 and 46 foot GS gondola used by the Rio Grande and Utah Coal Route. It’s an uncommon prototype needed by D&RGW modelers. As I found with the Hart cars, gondolas are well-suited to 3d printing because of the complicated mechanisms and frames, need for inside-and-outside detail, smaller cross-section.

Corey is selling his models on eBay - $95 for a pair, which after my experiences seems like quite a decent price considering the labor involved.

Corey also detailed how he prints the models on the Formlabs discussion board. He made some different tradeoffs than I did. Corey 3d printed solid grab irons and steps rather than holes for wire grab irons. I'd gone with wire grab irons to match the resin models I've made; I love the detail, but I find drilling all the holes and placing the wires takes way too long. Corey's models shows quite acceptable detail, and also shows he added more detail than just a featureless bar. Corey also oriented the model for printing in a more clever way. He managed to tilt the model and add enough support structures to print the model in a single piece, with good detail inside and out. He widened the center channel for weight. Corey not only suggested usual lead weights, but pointed out that 3/16” tungsten cubes are pricey but available (about $6 / ounce as Pinewood Derby weights, but I assume there's cheaper sources. They're 1.7x the density of lead!)

These cars appear close to the SP’s G-50-9 series gondolas that Ulrich’s metal kits were based on. The Ulrich kits are still around, but like a lot of 1960’s models are getting scarcer. It would be neat to have another alternative for another of the SP’s iconic gondolas.

Meanwhile, I'm keeping my eyes peeled to see which other 3d printer owners decide to get into the model railroad manufacturing game.