The online magazine on the history and operation of vintage scale model trains in American OO gauge

Thursday, December 22, 2016

Building Modern Diesels in American OO, Part III: Results

 It took a while but it is great to finally see finished results of big projects.

And here we are, the three “modern” (1970s-80s) era Diesel locomotives are done, two approximations of the original SD-40 prototypes and also an approximation of a GE U23B. Both types are a bit (gasp) freelanced due to the parts sources and not wanting to go extremely heroic in the kitbash job, but even with the compromises they are I think pretty effective models.

Size wise they are correct in all major dimensions and the Shapeways 3D printed cabs were key items to make them work visually next to for example a Kemtron GP7 (not to mention looking correct next to freight cars!). About those cabs, I have mixed feelings. On one hand, they are to scale and are better than any cab I would have scratchbuilt or kitbashed. On the other hand, the surfaces are not all smooth. The roof area of the SD cab is very smooth, for example, but the sides have “lines” of horizontal texture. I could have attempted to sand it off but at the same time felt that might be risky and likely to cause new problems. So I left the cabs as they were.

The cabs drove the paint scheme as well. In my general article on 3D printed parts I note that the FUD material requires special cleaning and acrylic paint. I figured I was best to paint the plastic parts with the standard red I have used for years on Orient Diesels and to paint the cab a contrasting yellow for a modern scheme. That decision worked out pretty well I think.

In part II I was getting to final details. Mostly the handrails are the original ones associated with the donor models. On the SD40s I split the end handrails and added chains, a fun detail to add. Another big final thing was getting them running. Both of the SDs are powered, one drive being not in as good a shape as the other it turned out. I had to replace four of the six main gears on the axles associated with the wheels, they had split. I have had to do this before, it is a design flaw of these old Athearn drives. I don’t think it is noticeable really that the trucks are HO scale, they disappear visually under the model.

The U23B is unpowered. I had a couple options on trucks but decided to use what were originally unpowered trucks off the early type of Mantua/TYCO GP20, with new wheels. I like the look, and they are OO scale wheelbase with correct size wheels so no compromises there. I did go in and add a light wash of black paint in the screens and grids and may add more weathering. One other thing I may change are the fuel tanks. They are constructed from GP20 tanks and are not really the correct shape (as they are EMD tanks). I expect to be tweaking this and the other two models for some time.

A final detail worth mentioning, I used the coupler mounts original to the SD drives, so even with underset shank couplers they are low. The rear coupler on the U23B is also mounted low to match, which is why it is the trailing unit in the photos, the front coupler is the correct height.

I am enjoying running all three together. They will pull anything I put behind them (some of the Johann built modern cars I have are quite heavy) and it has been fun to get out his TOFC models again as well. Finally I have correct engines to pull those cars!

It has been a great project and it will be interesting to see what additional worlds 3D printing opens up in American OO. But as for me I think with these Diesels done I will change directions a bit and focus on some older school restoration projects.

UPDATE: This photo is a bonus photo, showing the completed OO U23B with a comparable Athearn HO U30C body. The OO model is a pretty effective conversion.

Return to Part I of series

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