Cotton Belt EV Caboose 41

The previous post covered the other "test" caboose I built when I began developing the concept of a 3D printed modular caboose kit. The prototype for this model was the inspiration for the whole caboose project. Like some standard cupola cabooses of Norfolk & Western and Great Northern, Cotton Belt's extended vision cabooses had the cupola side windows placed at the corners. Although it is possible to modify an Atlas caboose to represent this unique variation, I decided instead to try my hand at 3D printing a replacement cupola.

With the memory of kitbashes of a Frisco extended vision caboose:

...and one of Mopac's distinctive extended vision cabooses fresh in my mind:

...it wasn't long before I decided to print a new roof, ends and sides to save myself the trouble of cutting up the Atlas model. And so began - innocently enough - what has become a quest to be able to model nearly any version of the International Car Company's extended vision caboose.

Since the process was described in the previous post, I will let the photos do the talking here for the most part.

This was the first cupola I designed for this caboose. It has an opaque, white appearance that is the result of washing it in isopropyl alcohol to remove the waxy residue that's part of the printing process. Unfortunately, the alcohol also had the effect of distorting and shrinking the part. I also discovered that the alcohol made the part brittle at the same time I discovered the shrinkage. When I tried to fit the cupola to the modified Atlas body it split the cuopla. I printed another version of this cupola design and that's what you see on the model. 

After experiencing an alignment issue between the cupola and the printed body (which occurred because I didn't include any keys or tabs so the interior would remain clean for detailing), I revised the early higher cupola design to eliminate the sidewall extensions originally designed for the Atlas body and incorporated the additional body height into the sides. This design change means the higher cupola cannot be easily modeled using the Atlas caboose without modifying the body to include the side extensions, but it really isn't a difficult problem to solve for the motivated modeler. I couldn't see why my design needed to suffer to accomodate the Atlas body when I had no intention of using it for future builds. This change was carried out through all affected models in my product line. If you look closely, you can see the area underneath the cupola where I had to use Bondo to fill in the misaligned areas between the cupola side extensions and the sides.

I painted this model with a brown paint mixture I tried to match to an Athearn Genesis caboose. I started with Model Master Rust and mixed in some burnt umber and burnt sienna until I was satisfied/gave up. The orange ends were much easier: they are Model Master Go Mango. The window frames were painted the same as on the Santa Fe caboose. 

Just as with the Santa Fe model, I'm happy with this one. I would like to see the printing process get a little better and cheaper, but in the end I got much more than I had hoped for when I originally dreamed up the idea of printing rather than kitbashing this model's cupola. 

Highball!