Model Railway Incline Trackbed + Piers PARAMETRIC

A system for raising and supporting model railway track that is completely adjustable and parametric. The system consists of track support platforms (trackbeds) and associated risers (supports / piers) to alter the level of the track, create an incline, or to support it at one level. As this is parametric many variations and track sizes are possible. The test designs and defaults are for n-gauge and straight and curved inclines are supported in any combination. The design supports other gauges.

Elements

The following elements are available:

1. Straight trackbed (17mm to 310mm)
2. Curved trackbed (7.5 to 120 degrees, radius 140mm to 510mm)
3. on-ramps
4. off-ramps
5. Track Supports and Risers in multiple styles (low to high, with interlocks for the trackbeds) enabling inclines and ramps.
6. Mid section supports for creating spirals and multi layer tracks (not yet fully tested)

The trackbed sections are interlocked with subtle dovetails and wedges to provide vertical support between sections and resistance to twisting and horizontal separation. The pieces are completely interchangeable allowing any geometry and set of curves and straights to be combined. The on-off ramps can be added to curved or straight parts. Both the curves and straights are completely customisable.

You can find pre-made profiles for HO at this link:

https://makerworld.com/en/models/2876804-ho-scale-railway-trackbed-piers-customisable#profileId-3212444

Assembly

Should be pretty self explanatory for anyone into model railways as the parts are interlocking and can only be combined in the right ways. 

Track types supported

The default settings are for Fleischmann Piccolo tracks in n-gauge (Spur-n) but any size can be created. For now I have limited the sizes to N and HO type geometries and sizes but if you contact me with requirements I can adjust the design and provide new files. For larger scales I intend to add more support structures under the track platform (trackbed) to enhance strength.

Here are some typical track specifications. Trackbed width of 18mm seems to work.

Printing

I print in PLA for strength and dimensional accuracy. The parts are set for tight interference fit as they are assumed to be part of a permanent layout. Of course this can be adjusted in the parameters for tighter and looser fits. No supports are required and parts are orientated to print flat on the bed.

License

Licensed only for personal use. 

Not licensed for commercial use of any kind. If you are a ‘not for profit’ club intending large scale usage please contact me to discuss if you need a license. If you are a ‘model village’ or other commercial operation you need a commercial license.

If you'd like a commercial license please contact me. 

Design Notes

This is the first release for people to use (but I have done 4 pre-releases and tested the parts in different ways to optimise the design). I learnt a lot about 2D and 3D geometry and OpenSCAD in working out how to parameterise everything so the parts are inter-changable, the dovetails automatically end up in the right place and parts are pretty much infinitely adjustable :-). The parametric code outputs at the plate center and you can use auto arrange to distribute depending on your machine and the part sizes you make. I have a P1S + AMS and typically it can print four (4) first radius curved parts at a time.  The design is intended to minimise filament usage while being sufficiently strong. 

Of course, with a parametric model it is possible to create combinations that have errors, particularly in the notches where the risers engage the trackbed and in the height combos for the risers. Eventually I will add more error trapping but for now I want feedback from the community on what works and what needs improvement before investing that time. I am using the stable OpenSCAD version 2021.01 for maximum compatibility.  I tried AI ‘vibe coding’ but I ended up coding 90% by hand as the AI could not get the geometries right to add and subtract components. 

I was inspired to design this as I wanted to make a track spiral and saw that a designer had hand designed a nice one and the community was using scaling to alter for different gauges, which does not work well for curves. A user in that chat requested a parametric version so here it is. 

Ideas for Backlog (dates TBD, not in any particular priority)

1. adjustments based on feedback from the community
2. properly curved on/off ramps (for now it uses a straight ramp on a curve, as extruding a curved/rotated wedge in a parametric manner requires some thought and interesting geometry work)
3. error checking and tolerance work (as variable reassignment is no supported in OpenScad, requiring interim variables)
4. error trapping on the risers/supports 
5. more error trapping on the roadbeds
6. passing parameters between the roadbeds and the risers
7. strengthening members for larger geometries
8. enhancements to make spirals easier
9. coded in track geometries for specific models
10. double track enhancements
11. surface textures
12. more decorative items
13. adjustable tolerances
14. ….