The Buzz Is Back

As Eishindo inches closer to releasing track switches, there's a nice buzz developing over at Taking T Gauge. The discussion involves quite a range of issues, from the size and geometry of the switches to the design and function of the points. I truly hope that Eishindo is checking in, because the ideas being kicked around carry quite a bit of merit.

What size switches should be made? Quite some time ago Eishindo released a photograph of a prototype switch (below) evidently made for show only; close examination suggests that it was not functional—nor could it be made to be given its design. It appears that it may have been fabricated using Rapid Prototyping, and its geometry was almost certainly based on a merging of straight and curved track sections (the same technique I used to make my own functional switch).



This "modular" approach would make it very easy to integrate the switches into plans using their sectional track. However, the angle of such a switch is acute, making it impractical to build things such as yards or even a simple crossover. An arguably better approach, though, would be to follow the lead of Micro-Trains (Z scale) and others, providing a longer switch with a matching curved track section to bring a diverging route parallel to the main. Not only is appearance vastly improved, but so are the planning options—even with a single switch size. Images and videos of functional prototypes from Eishindo (as seen below) suggest they may be headed in this direction, but of course this is no guarantee.



Now to the points themselves. As I've learned, switch geometry in T gauge is pretty gruesome owing to the extremely coarse "standards" involved. Tolerances are enormous and sloppy almost certainly due to manufacturing limitations—the products would not be as economical as they are with tighter tolerances; not to mention the limitations imposed by physics involved, particularly the extremely low masses of the trains (at times I'm surprised T Gauge trains run at all—kudos to Eishindo for making it possible and affordable).

Here are some numbers to consider. Likely due to manufacturing limitations, track gauge varies as much as 10%, from 3.0 to 3.3 millimeters—that scales out to 135 mm, or over 5 inches! This forces wheels to adopt wide treads and narrow gauge. Wheel treads are around 0.55 mm, or a scale 248 mm, nearly 10 inches. Wheel gauge hovers around 2.8 mm, and varies as much if not more than the track. With an inside flange-to-flange dimension of roughly 2.25 mm, one can determine a nominal flangeway of about 0.4 mm. However, numbers on paper do not always translate into something functional, and based on direct experience, this number is way off. My switch (shown below in situ) did not work reliably until the flangeways were spread to a whopping 0.7 mm! That's a scale 315 mm, or over a foot! With rail already measuring 0.6 mm wide, a pair of guardrails will then be separated in the middle by a little more than the width of a rail. That's quite absurd-looking!



There's been much discussion on the design of the points. Should there be one point or two? Where and how should it/they pivot? A number of remarks suggest that an unorthodox design would be unwelcome due to unrealistic appearance. However, even though I built my switch following traditional prototype practice (two independently-pivoting points and a full frog with guardrails), I can't say that it's necessarily the ultimate in realism—if for no other reason than its rail measures a scale foot wide and four feet tall! It was also a significant challenge to make operational, given the fine adjustments needed for its many parts.

After considerable thought, and in spite of the praise I've received for my efforts, I've come to the conclusion that Eishindo would do best to employ an old tinplate design, which utilizes one moving part that comprises both points as well as movable frog guardrails that close on the frog point. Although its aesthetics are not as desirable as a more traditional design, I believe it would prove to be far more robust and reliable—not to mention much easier to manufacture. Guardrails are eliminated, and the path through the length of the switch is smooth and seamless, making it more than accommodating to a tremendous variation in wheel tolerances.



Of course, it's obvious that such discussions will have little or no influence on what Eishindo actually does, particularly since R&D is evidently already well along. Regardless, it does demonstrate one fact that must not be underestimated in its significance: there is quite a bit of serious interest in T Gauge.

Postscript: Rumor has it Eishindo has already released their turnouts, rendering the entire discussion moot. Now, if they could just keep their website up-to-date...