Hey guys I have these Tomytec Railcars The Railway Collection Nagano Electric Railway Series 8500 (3-Car Set) (Model Train) Tomytec 224075 Railway Collection|Electric Car N Scale|1/150 I am making a circular subway system, and I am about to install the track. I'm noticing my left over 19'' radius track is too large for the amount of subway stations I want. I haven't even bought my power chassis yet, nor less better metal trucks. The other day, I set up a circle with my friends 12'' radius track, and pushed my railcars in a circle, they did ok. I'm thinking about getting 12'' radius for my circle, do you think its too small? I'm not planning to run trains high speed or anything, but would be fun to be capable of it. Do you think the tomytec power chassis can handle the small radius? My Bachmann HHP-8 Can! Thanks! Will
Apart from Shinkansen (bullet trains) and some steam almost anything from Tomix/TomyTec should run on 9 3/4" (this is common to all Japanese brands due to limited space on Japanese layouts). A lot of Tomix/TomyTec rolling stock is designed for even smaller radius curves (their latest version of the DE10 road switcher can pass 4" curves, even 4" s-curves!). I believe the TM-08 power unit can go as low as the 177mm Tomix minicurve track (7"), but the safer radius is Kato's larger 8" radius track. Of course how small a curve it can physically negotiate vs how it looks is a different concern. For a 20m EMU like this I think you should stop at 11" for any visible track as long as you have the space, this will prevent the overhang from becoming too obvious (when you start seeing the outer rail peek out from under the car the radius is getting ridiculous).
The Tomytec power truck chassis has the great advantage that the universal pivot is designed right at the center of the truck. Not only will it take rather absurd curves, it doesn't hang up doing it. In this respect it is better than the Kato design.
Yep. All non-Shinkansen Japanese stock will do a 9 3/4" radius s-curve with no tangent in the middle.
Speed should not be a problem (certainly not if you run anywhere near prototypical speeds). You can easily run bullet train models around 11" curves (scaled up those are 146' industrial curves, the real thing needs 2 miles) faster then prototype speed without derailment. The laws of physics don't 'scale' to models, which is why they can stop on a dime and rip around tight corners without derailing, yet a tiny bread crumb can cause one to jump the tracks. With a few special exceptions (like getting an older heavy locomotive and running it at full throttle into a grade change going into a curve) your derailment risks are unrelated to speed or curvature. Poor grade transitions, uneven track joints, poor track work in general (like out of gauge flex track) and coupler tension (where the loco is pulling on one end, the back of the train is too heavy to move fast enough, and something in the middle gets pulled off the tracks like a tug of war) are the main problems. And Atlas track isn't a problem (unless it's code 55, I've never really looked if the TomyTec wheels are pizza cutter). Just be more careful laying it, unlike Kato or Tomix sectional track it requires a bit more attention to keep all the joints smooth and level.
I can confirm I run my Tomytec railcars on Kato 216mm (8 9/16") radius curves on my small Japanese layout, they do this with no problems whatsoever.
