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In my never-ending quest to model unique and interesting locomotives in O Scale, I have finally finished my latest 3D printed creation-- the Union Pacific's City-series E2 diesel engine. The E2 is a second-generation diesel streamliner, possessing the distinctive aesthetic of UP's M10000 series without the first generation's articulated limitations.

00 Finished locomotive

This project started off life as an ordinary MTH Railking New York Central E8 diesel set that I picked up online. The set had some damage and missing parts, but after making repairs I had a good, working, Protosound 2.0 command-equipped frame to build on top of. After comparing the frame's dimensions to my current list of things I want to make, I figured that the E2 would be a good fit.

01 Donor engine frame

The next and longest part of the project was designing the new locomotive body. I made a scale drawing of the donor frame in Fusion 360 and then designed a new shell to fit on top and around it. After many late evenings rendering in Fusion, I had a complete A unit body, divided into 2 pieces and optimized to fit my Qidi XPLUS filament printer.

EMC E2 diesel A unit

After about 4 days of nonstop printing, I had both body sections fabricated in sturdy ABS plastic. The body fit was very close and even uses the donor engine's original mounting hardware.

02 A unit body shell

The next step was to design a front pilot and new truck sideframes for the E2's 6-wheel trucks. This took a couple of revisions to get right, but by modifying and reprinting the parts I was able to dial everything in.

03 Pilot and sideframes added

Once I was happy with the fit and finish of the A-unit, I branched off my Fusion drawings to create a B-unit. This was followed by another several days of printing as I generated the second set.

EMC E2 diesel B unit

After settling on the City of San Francisco's 1941 paint scheme, I spent several days applying a 3-color paint scheme, taping off between coats and doing the necessary touchup with Q-tips to clean up the occasional splatter or run. I used Rustoleum 2x primer-paint aerosol, as I usually do.


With the paint and stripes applied, it was time for decals. I could not find any suitable UP streamliner decals in O Scale, but I was able to find a set of City of San Francisco decals in HO scale offered by Microscale. This was a compromise but I made the best of it.

04 Paint and Decals

Decals were followed by hand-formed grabirons made with 0.050" wire. After a final application of Rustoleum Matte Clear, I cut some clear plastic and fitted the entire locomotive with windows. I even figured out a way to make illuminated number boards by using the strategically positioned slots I designed into the shell.

05 A and B unit

Although the original MTH lamps are well positioned to illuminate the cab and the locomotive marker lights, they're too short to reach the E2's high headlight. I spliced a white LED onto the front headlight bracket to address this.

06 Added LED Headlight

After bolting everything back together, it was finally time for the track! Here's a view from the rear.

08 view of b unit

And here's the E2's rounded nose, ready to take off for the West Coast!

09 Headlight aglow

Check out how it moves these period passenger cars on my layout!


Images (12)
  • 00 Finished locomotive
  • 01 Donor engine frame
  • 02 A unit body shell
  • 03 Pilot and sideframes added
  • 04 Paint and Decals
  • 05 A and B unit
  • 06 Added LED Headlight
  • 07 body sections being painted
  • 08 view of b unit
  • 09 Headlight aglow
  • EMC E2 diesel A unit
  • EMC E2 diesel B unit
Original Post

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Thank you everyone for the kind words! I did work really hard on this one and I'm very proud of how it came out.

@Norton posted:

Very, very impressive. Did you create the file or is there one there out there already?


I always make my own digital models since it gives me a reason to work on my drafting skills. I'm a compulsive tinkerer so having the original source files lets me make improvements or modifications whenever I need them.

In case you're curious, here's a view of the underside of the A unit model in Fusion 360. I've highlighted one of the 2D sketches that I used to shape the inside of the nose so you can see some of what goes into the 3D render process.

EMC E2 diesel on mthrk e8 underside


Images (1)
  • EMC E2 diesel on mthrk e8 underside

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