Custom Projects and Kitbashes

The Ballad of The N Scale General Electric 25 Tonner (Or: How I Learned to Build a Critter) –

This is a slightly convoluted story. A member of (and others) going by the handle “Randgust” has put a lot of time into perfecting N scale critters. He has built quite a few and runs a side-operation selling kits for various otherwise unavailable N scale locomotives ( At any rate, I found his various threads covering the trials and tribulations of building an N scale 25 Tonner pretty interesting from an engineering/problem solving standpoint (here is a Youtube video of his GE in action: Now, I’m not going to lie… I like critters a lot. Although I haven’t actually seen a 25 Tonner in person, I have been around plenty of other small switchers and I really like the contrast they present against a background of North American railroad equipment, which is always very large. I got to thinking that it was time for me to start looking into a critter project.

You may remember that I had built an Alco S4 from a Shapeways print sometime ago. I tend to poke around Shapeways on a regular basis looking for new N scale items. One day, I think in December or January of this year, I discovered a little Nn3 narrow gauge GE 25 Tonner meant as a static item or flatcar load ( I thought, “Heck, if this thing is hollow I can use it as a shell and just build a mechanism for it!” I contacted the designer and he confirmed that it was a hollow shell with fixed narrow gauge axles. That was all I needed to know, I placed an order for two of those little boogers (assuming I would damage one during the conversion process) and began my patient wait for UPS to arrive.


What arrived, about two weeks later, was a pair of pretty well detailed little critter shells. Even though they appeared to have already been cleaned, I dropped them in Bestine overnight just to be sure they were ready for primer.

As you can see, the only work I initially planned for was the removal of the narrow gauge axles, I figure I could drop what was left on a basic mechanism and move forward from there… boy was I wrong.

I slapped some paint on one shell and went to work measuring dimensions out, seemed this shell was a bit smaller than the Kato 11-105 Power Chassis components I was planning on utilizing. Some days of thought went past along with consulting with Randgust himself (via about details of his 25 Tonner build.
It turned out that I was going to need to re-dimension some things and make some changes to the Kato truck/gearbox which forms the heart of this 25 Tonner.


What I came up with was using the side frames from the 25 Tonner shell to hold the end-axle electrical pickups in place with the remainder of the chassis built up from .20 styrene sheet (the same material used by Randgust on his build).

After getting the axles and electrical pickup tweaked to a point where the locomotive would actually run, albeit rather poorly, I began ballasting the garbage out of the chassis and shell. Once ballasted it, the little critter ran a great deal better. Some Atlas/Accumate couplers, and a snazzier paint job later, I think I have something of a winner.



I need to add some details and handrails, but I basically have a decent little N scale critter at this point. It runs very well forward and acceptably backward (although I may be able to improve that with a transistor throttle). There are a few mechanical woes that plague the drive train, like a dislocated rear axle, but those only appear if the locomotive is run at high speed. It even operates through Atlas Snap switched with non-powered frogs, that isn’t bad for 4-wheel pickup/drive, so I am at least coming close to the standard set by Randgust and his 25 Tonner!

I even tried it in operations but the Cheap-O 1980’s Bachmann trainset powerpack I am currently using is just too limited for precise control. Hopefully things will improve once I retrieve my Tech II from storage or pick up a new throttle at the local hobby shop.
I hope this post serves to inspire some creativity in the same way I was inspired, there are a lot of great projects out there in the 3D printing world for N scalers with a little imagination. Take some time to browse Shapeways, or any other kit site, find something you could use on your layout and make it happen. Don’t ignore a potential project just because there is no commercial chassis available, part of what makes this a hobby is making what you can’t buy.


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5 responses to “Custom Projects and Kitbashes”

  1. Jonathan Caswell says :


  2. Jonathan Caswell says :

    Reblogged this on By the Mighty Mumford and commented:

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  4. bumthum says :

    Sure, when I get the opportunity I’ll do a post on the subject of the hows and whys of my blog.

    In the meantime:

    – Pick a subject which interests you and don’t worry about whether others will enjoy it. With over 6 billion people on Earth, there are likely to be at least a few people who share your interests and won’t care that you aren’t making an effort to “focus group” your content. Think about it… how many people are really interested in collecting 1960s-1980s era B&M N scale equipment? Fortunately I have enough interest in full-scale railroading to broaden the appeal of my blog.

    – I try to use a photo whenever possible to illustrate my topic because it saves on trying to explain things which are much more obvious in a picture.

    – Finally, for now, keep posts as short as possible. This isn’t high school English Comp. where you do what you can to “fluff” a paper to reach the teacher’s minimum length requirements. Say what you have to say to get your thoughts out and leave it at that. If someone wants more information they will ask, it’s better than running the risk of boring people with stuff they really don’t need to read to get your point.

    I hope this helps a little. As I said, when I get time, I will do a full post about this topic.

  5. Jonathan Caswell says :

    Reblogged this on By the Mighty Mumford and commented:

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