The AG1LE RCH wagon

The Railway Clearing House (RCH) was set up in 1842, initially to apportion receipts for goods and passengers passing between individual railway companies. The RCH naturally provided a forum in which the companies could discuss joint operations. One particular difficulty was the interworking of wagons for which there were no accepted standards.

By the time of the grouping in 1923, the familar standard wagon design had been fully developed. You can read more about the background, and look at a set of drawings here.

The material on this page forms a parameterised 3D model of the RCH wagon with measurements taken from those drawings. All modelling is specified at life size. Scaling and bloating parameters may be used to generate models at any desired scale.

The model

The model is implemented using the OpenSCAD scripting tools. Versions for other 3D scripting tools will appear in due course. If you are not familiar with this kind of tool, you might like to look at this tutorial.

The model comes as a small set of assemblies, designed to be individually printed. The goal is to minimise the use of supports, and to allow the wheelsets to be inserted without having to try and bend the axle guards out of the way. This approach also allows one to mix and match body types, subframes and wheelsets. I provide separate STL files for the body, the floor and chassis, the sole bars and the wheelsets; by working with the OpenSCAD source file you can extract different sub-assemblies.

My test prints have used a Cetus 3D MK2. I print the elements upside down, using a 0.2mm nozzle at the smallest layer height and slowest speed. Apart from the wheelsets, no support structures are needed and I recommend that you switch them off if you are using the Cetus proprietary slicer. I do use a raft.

Print times at these settings are long: 52 hours for the body, for instance, but the results are (to my eye) suprisingly good. Of course, you can get a much faster print if you use a bigger nozzle or thicker layer height.

Copyright and licensing

I retain the copyright of the model's source code, but I have licensed this model's intellectual property under the Zero Clause BSD license. You can read about this kind of licensing here - what it means in practice is that you are free to use the model but you must not remove the license notice or my copyright notice.

Present state of development

The most recent release is V1.00 dated 9 January 2020.

The first body type (side doors with wooden stanchions) is completed. All internal platework is modelled, and bolt heads, nuts and countersunk screws are individually represented taking of the account size variations on the diagrams. Further body types (end doors, bottom doors, metal stanchions, coke rails and perhaps a van) will follow.

A timber underframe and floor are complete up to, but not including, the metalwork (gusset plates, bolts and so on). No buffers or draw gear have been modelled so far.

The sole bars and axle boxes are crude maquettes, and are not meant to accurately represent the real thing but they do allow a running model to be constructed. The axle boxes are designed for use with 5mm sintered bronze oil-filled bearings that provide free running with either printed, or turned-metal wheelsets.

Source files

AG1LE OpenSCAD models make use of a set of utility constants, functions and modules that reside in ag1leLib.scad: you will need both of these files to build your own STL models.

Ready built STL files for 1:32 Gauge One

Ready built STL files for 10mm Gauge One

Support

Questions, error reports, requests for new variants, reports of successful or otherwise prints from your favourite machine and so on are all welcome.

You can email me (Adrian Johnstone) directly or try the Gauge One 3D Circle forum at https://groups.io/g/GaugeOne3DCircle.

Pages managed by Adrian Johnstone, last updated 9 January 2020