Realistic parametric train track rail and trackbed

A customisable parametric train track, rail and trackbed modelling tool written in OpenSCAD!  

LATEST UPDATE:  March 10th, 2025

• A ‘unified’ model format compatible with AMS printer setups has been finalised and example .3mf added to the file repository.
• An updated OpenSCAD script demonstrating these changes (v2.4) has also been added.  See below for further information.

Say goodbye to those boring old blue plastic tracks and hello to detailed multi-coloured and realistic rails for your favourite engines to roll on.  The concept began as an alternative to the classic Tomy Plarail tracks which can look out of place next to the quality of the regular trains and “Plarail Advance” system (a near N scale product that runs side by side on blue plastic tracks).

The customisation options however allow compatability beyond the traditional scale - possibilities would include true N scale, “Thomas” minis and more.

Traditional dovetail socket and joints options can be turned on/off, rail and trackbed profiles fully customised and even magnet cavities added to give a clean realistic appearance.

Note:  In order to use the fuzzy modifier part on the segment follow these steps:

1. From the customiser, export the trackbed only
2. Export the fuzzy contour part only (disable other parts from the customiser)
3. In Bambu Studio, import both .stl files together (choose ‘Yes’ to import as one object with multiple parts)
4. Find the plate in the ‘Objects’ section within the menu on the left side
5. Right click on the fuzzy modifier part and select ‘Change type’
6. Make it a modifier
7. Click the ‘Others’ tab below and change Fuzzy Skin to ‘Contour’
8. Voila - the trackbed edges will print realistic and fuzzy!

UPDATE:  March 4th, 2025

A finalised version of a ‘unified’ track plus trackbed format, compatible with full size Plarail trains has been added.  Alongside the updated customiser default values, the option for either ‘cylindrical’ or ‘cube’ magnet cavity cutouts has been added.  A short segment straight with cylindrical magnet cutouts is provided in the updated .3mf (v2.4).  As the dovetail and socket joint ends can be enabled or disabled, the possibility of connecting chains of magnetically joined segments between pre-existing blue plastic track is possible - offering a cleaner look to the overall track.  By overlapping the cavity with the trackbed end and press fitting the magnets, a relatively strong bond is possible.

Testing with long rolling stock comprising numerous cars typically demonstrates a redundancy of the outer ‘guard rails’, although best placement of transitions is still being determined.

UPDATE:  March 4th, 2025

A finalised version of the ‘hybrid’ format customiser is essentially complete and will be uploaded to the file list here soon (likely designated v2.20) - the values seem to work well but I still need to clean up the code and would like to model and print straights to add as part examples.  This was also the first test of full size Plarail train on a track without outer ‘guard rails’ - a 4 car E5 Shinkansen is used in the demonstration.  The curve radius is Plarail standard 215mm and there were no issues with derailment in this test loop.

UPDATE:  March 1st, 2025

In order to achieve maximum compatibility across printer setups (i.e. with or without AMS capability), options for separately printing rails and trackbed have been explored.  The latest adaptation is a ‘hybrid’ form, which combines the horizontal slice with the through trackbed cutout for rails.  

A hybrid format enables the main trackbed, inner trackbed edges, rails and internal trackbed between sleepers to be differentially printed.  Testing continues…

UPDATE:  Feb 27th, 2025

A print profile including a 215mm curve radius and 107.5mm straight segment compatible with Regular Size Plarail has been added.  In the previous update, two options for generating ‘flat surface’ sleeper beds were added - a horizontal dovetail slicer and cut-through-trackbed sleepers.  

The customiser horizontal dovetail slicer has so far proven more favourable due to:
Solid construction as two parts that seamlessly slide together

Near perfectly flat sleeper/trackbed interface with ‘Top surface’ ironing set in Bambu Studio.

The trade off is model colourisation is somewhat more tedious as it is not based on layer height alone (the rail support is marginally extended to paint bucket fill all sleepers at once but still adds an extra step) and filament changes are required (a total of six if using four colours and printing by object, including both the trackbed and rails segments).

UPDATE:  Feb 26th, 2025

The template track compatible with regular sized Plarail trains (not the smaller Plarail Advance) has been updated more closely reflect what I consider to be a good ‘full size’ Plarail “world scale” as well as providing options for printing multi-colour parts with smooth trackbed and sleeper top surface.  

‘Blue Plastic Track’ Scale

These values are only a suggestion and fairly arbitrary.  While there is no consistent regular size Plarail scale, my preference is to work backwards from a scale human figure and favour aesthetic over strict numbers.  

The model trains themselves have no fixed scale and don't really reflect the significant differences between real world commuter and Shinkansen rolling stock as well as track gauge.  In this update I have focused on the commuter E231-500 as a reference and used approximate sizes based on limited research.

From the table above we can see the broad range of scales employed to unify the overall size of the product, however the car width, door height and gauge are relatively closely aligned.  Arbitrarily picking 1:76 as a scale for the template, I generate the following values:

Sleeper depth is non-contributory in this instance as, for the regular size Plarail, we want a smooth surface and it will be buried within the trackbed.  I have not added a specific sleeper spacing option to the OpenSCAD script so sleeper spacing is also arbitrary.  Typical spacing would be 600-700mm between centers (350-450mm gaps) and in 215mm segments I have used a sleeper count of 26 (note that each end sleeper is half width as I incorporated an algorithm to ensure track segments end on sleepers in order to avoid gaps).

Compatibility with ‘regular size’ Plarail rolling stock

My initial focus was on side by side 8.2mm gauge tracks compatible with Plarail Advance (close to N scale at ~1:150) however the plan was to develop a template compatible with the regular size Plarail trains too!  The obvious hurdle being - the regular size trains don't employ typical self-centering conical wheels but instead straddle the center rails and require a relatively smooth surface to roll on.  To overcome this I've added two main options to the customiser:

1. A horizontal dovetail slicer (which functions much like the one in Bambu Studio BUT will follow the curve radius for curved segments.
2. Parameters for fine control over sleeper height and Z-offself, allowing for ‘through trackbed’ parts which can be printed seperately and slotted on top of one another.

…Full documentation is still in progress and will follow shortly!