This is sort of an adjunct and update to the thread I'd started last week, Realistic 3D printed tracks for Plarail Advance, which generated some interest in using the parametric track modeller for 'regular size' Plarail rolling stock. As I'd previously been focused on Advance and being new to the hobby, the challenges of developing tracks suitable for the big cars proved to be complex, although the main hurdle was developing multi-colour parts that can be printed on non-AMS printers (i.e. 3D printers that print from a single colour filament reel at a time with the user needing to pause and swap reels for varying layer colours etc). Away from the printing technicalities, understanding how regular Plarail tracks and trains work together has proven to be interesting.
For Advance, the approach was simple as it was essentially just modelling typical model railway rails and sleepers sitting atop a trackbed. However, for regular size the sleepers and track bed need to be on the same plane to roll smoothly. Separately printing such parts on a basic single filament fed printer while maintaining top surface (z height) accuracy was not entirely straight forward and evolved into a 'hybrid' design of sleepers that slot through an upper trackbed part, which itself then sits atop a bottom trackbed base. The idea being if the sleepers and adjacent trackbed have been printed from the same offset then they should be as close as possible to having a level top surface and the tolerance between them and the underlying bed would to some degree absorb vibrations.
For the aesthetic, I briefly considered how the Real Class trains are depicted with grey plastic track and extension of the sleepers, implying the outer edge as the rail. However, in my opinion it is better for the inner rails to be represented with the crown and web of traditional rails and the outer edge rail to perhaps be incorporated into guard rails, third rails or embankments... or even deleted altogether. Japanese metro commuter trains are somewhat known for their narrow gauge any way and I have a penchant for the Yamanote line cars.
I try not to get hung up on scale, the absence of a consistent Plarail scale is part of the charm, however I somewhat arbitrarily picked 1/76 as the starting point (further explanation with tables can be found in my 3D printable file page on the Maker World toward the bottom of the Description).
And then despite all of what I just said, testing today was with the Shinkansen which throws all those scale parameters out the door
While I have printed multi-colour test parts with an AMS unit printer, in which the trackbed and sleeper top surface is essentially perfectly smooth and each track segment is a unified solid part; the following photos are from this evenings test with non-AMS enabled parts. For me the most fascinating discovery was that the outer rail, at least in this simple loop with 215mm radius curves, was redundant. There were no derailments with this 4 car E5.
For Advance, the approach was simple as it was essentially just modelling typical model railway rails and sleepers sitting atop a trackbed. However, for regular size the sleepers and track bed need to be on the same plane to roll smoothly. Separately printing such parts on a basic single filament fed printer while maintaining top surface (z height) accuracy was not entirely straight forward and evolved into a 'hybrid' design of sleepers that slot through an upper trackbed part, which itself then sits atop a bottom trackbed base. The idea being if the sleepers and adjacent trackbed have been printed from the same offset then they should be as close as possible to having a level top surface and the tolerance between them and the underlying bed would to some degree absorb vibrations.
For the aesthetic, I briefly considered how the Real Class trains are depicted with grey plastic track and extension of the sleepers, implying the outer edge as the rail. However, in my opinion it is better for the inner rails to be represented with the crown and web of traditional rails and the outer edge rail to perhaps be incorporated into guard rails, third rails or embankments... or even deleted altogether. Japanese metro commuter trains are somewhat known for their narrow gauge any way and I have a penchant for the Yamanote line cars.
I try not to get hung up on scale, the absence of a consistent Plarail scale is part of the charm, however I somewhat arbitrarily picked 1/76 as the starting point (further explanation with tables can be found in my 3D printable file page on the Maker World toward the bottom of the Description).
And then despite all of what I just said, testing today was with the Shinkansen which throws all those scale parameters out the door
While I have printed multi-colour test parts with an AMS unit printer, in which the trackbed and sleeper top surface is essentially perfectly smooth and each track segment is a unified solid part; the following photos are from this evenings test with non-AMS enabled parts. For me the most fascinating discovery was that the outer rail, at least in this simple loop with 215mm radius curves, was redundant. There were no derailments with this 4 car E5.
![[-]](https://www.blueplastictracks.org/images/collapse.png)
