8.23 Kiddie Train Ride

It all started when I received an email from a modeling friend in the UK. He was beginning a new N Scale layout that was to feature an amusement ride, and he wanted to pick my brain about T Gauge. I replied that I'd been out of the scale since 2013, and forwarded a few links to some key resources.

Then I sat thinking for a bit. My friend had unknowingly planted a seed. Granted, it was a tiny one: I only had a 3" x 6" space for a loop of track, which made for some darned tight curves! That would automatically eliminate any rolling stock with two trucks—T Gauge trucks don't swivel nearly enough to handle 1.5" radius curves. (Trivia: T Gauge track in N Scale is almost exactly 18-inch gauge.)

After making a paper template of the space for the loop, I began bending flex. I'd wanted the loop to be a single piece of flex, but I found it nearly impossible to achieve the right shape in one shot. After three tries, I extracted the two best pieces, and joined them together using T Gauge rail joiners.

After soldering the joiners and attaching feeder wires, I installed the loop of track on the layout permanently with CA. Then I painted the track, which completed the easy part. The really, really tough part would be making a functional locomotive. The advantage I had was that it didn't have to look like anything real, much less anything at 1:450. As for a mechanism, I'd leverage a chance discovery: the threads of a 2-56 screw mesh surprisingly well with the gears on T Gauge drive wheels; this would allow me to engineer a relatively simple worm reduction drive.

Proof of Concept Model

Many hours were spent staring at a box of tiny parts, holding gears and wheels up next to one another, scribbling sketches on paper, and pretending to build the mechanism in my mind dozens of times. When I'd rehearsed the plan enough times, I got to work. First, I made a pair of spacer blocks precisely the width of the motor out of PC board material. Into each of these I drilled a dimple to make bearings for the ends of a "worm" made from a 2-56 screw: I chucked the screw into a drill and tapered the ends to points with files. Then, I drilled and tapped a nylon gear scavenged from a micro servo, threaded it onto the worm, and bonded it in place with CA.

Next came the side frames, which I made from extra-thin PC Board. I assembled the side frames onto the spacers with CA, with the worm positioned between the spacers such that it spun smoothly. I press-fit the motor down into place until its pinion gear engaged the gear mounted on the worm, then bonded the motor permanently in place with CA. I quick tested the motor to be sure it ran smoothly before continuing.

After cutting down the drive axle bearings, I soldered them to the sides of the chassis, then installed the wheelsets. Moment of truth time: will it run? It ran... sort of. Noisy and stuttering, it almost hopped down the track like a jackrabbit. But it did run. Which means this proof of concept model can be improved, and so I placed an order with a company in the UK for a slew of spare parts to make a better version.

The size looked good with the loco placed on the layout.

Change of Plans

T Gauge has historically had performance issues, and considering the effort I've put into the project so far, I felt the ROI wasn't going to be worth it. That's when I was reminded by a new Railwire member about Teeny Trains, a magnetically-propelled novelty toy (I used to own one back when they were first introduced). As it happens, at $38 their cheapest product was appealing, and it was also comparable in size to the original loop of track I'd made. That the magnetic track looked hokey was no issue at all—kiddie rides rarely look realistic. The only drawback I could see was the inability to control speed, and I was willing to trade that for reliable operation.

And so on 13 October 2020 I placed an order for an off-the-shelf solution to this little scene. I had to move the brewery office back a fraction of an inch, but that was trivial. Above, the loop of T Gauge track has been removed, the brewery office relocated, and the space to be occupied by the Teeny Train marked out.

The Teeny Train set arrived on 19 October 2020. The whole thing is built on a single piece of thin PC board (above), which was perfect: all I had to do was create a relief on the layout for the components mounted to the bottom of the board. (The grey circles in the corners of the board are where foam rubber feet were attached, which I removed.)

Then I rendered artwork for better-looking track by drawing ties and rails over a gravel texture background (above). After printing the art on shipping label stock (which I chose because it has an opaque layer), I sprayed it with several coats of clear flat sealant, per a fellow Railwire member's recommendation. Then I applied it to the PC board (below).

Installation took a few minutes. I just had to create a relief for the components and a slot for the power connector (below left). After that, the unit neatly dropped into place (below right) on 20 October 2020.

The next challenge will be to turn the goofy-looking Teeny Trains taxis and/or buses (below) into the kiddie ride rolling stock.

Reference

This beastie became the prototype for the kiddie ride rolling stock. Knowing just what I was after, a fellow Railwire member found it for me in a YouTube video.

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