DIY Self Driving 1/48 Scale Narrow Gauge Battery Locomotive Learns to Shuttle on Its Own

Diorama111, a DIY maker from Japan, has spent many hours squeezing motors, lights, and controllers into models that no larger than a matchbox. His latest project is a 1/48 model narrow-gauge battery locomotive on 9 mm track that has its own power, lighting, and enough onboard electronics to perform a short shuttle without the need for a remote.

A custom plastic chassis conceals a coreless motor, which is mounted to a central shaft and coupled to a couple of worm gears that mesh with spur gears on both axles. Running both wheels at the same time results in a much smoother crawl, as opposed to one axle just “hitching along” through its side rods, as it would if only one set of wheels were being driven. A 3.0V supercapacitor, a tiny DC-DC step-up converter, a custom control board, and an infrared receiver are mounted on top of this drivetrain, all coupled by thin magnet wire to fit on a deck that would essentially disappear within a genuine cab.

The paint job is simple and industrial-style: bright blue with dark gray accents and a prominent red stripe. A 1/48 Tamiya military person was resculpted and recast so he could sit in the driver’s seat wearing a blue uniform and a yellow hardhat. That small bloke even turns to face the direction of the train, and the white headlights and red taillights alternate when the engine travels in the opposite direction.

Autonomy on this layout is a master class in brilliance. Photoreflectors along the track identify the run’s end points. Nearby infrared LEDs communicate with the locomotive’s receiver, allowing the loop on the track to instruct the controller on board, in this example, “hey, time to stop.” Fortunately, most of the smarts are in the engine rather than tangled up under the bench; after all, who wants a large mess of wires?

If you prefer manual control, an infrared remote (the OE13KIR remote is mentioned in the build notes) can step in and take over as needed. You may also provide the rails with 6-7V, and the supercapacitor and boost converter will keep the electronics stable. The autonomous shuttle is the true showpiece, as you can see this small battery locomotive flawlessly operating the line from end to finish.

Diorama111 has already experimented with fitting electronics into tight spots, such as 1/150 trains with supercapacitors under the cab and tiny automobiles following wires beneath a roadway. This time, they’ve gone bigger, using a 1/48 size battery loco, which finally allows for a driver figure that can turn his head and a routine that doesn’t just whack into a bumper and hope. If you have a layout that likes to ‘breathe on its own’ and you are captivated by it, then this little blue engine has it all in one small package.
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