This model is designed from drawings published in "Historic Carriage Drawings, Vol 3, Non passenger coaching stock" by Peter Tatlow
It's the 'Blue Book' (ISBN 1-8998 16-09-7). Also consulted were, photographs available on-line from many sources supplemented by viewing vans where I could.

The version contributed here is a plain 'non sensing' van.
An alternative version has also been made with one axle fitted with a rotation sensor. This is intended for future locomotive remote control systems where the van will house RC equipment linked to the loco via control rods (this was the original impetus to create this van).

The model is presented and documented as a top level assembly and 4 sub assemblies i.e. W frame and wheel assembly, Under fame assembly, Body assembly and Roof assembly.

All parts have been FDM printed except for axle tubes, ball races, springs for coupling hooks and to emulate brake hoses, coupling hook retaining pins and drawing pins for buffer heads. These items are generally not CAD modelled. Modelers may of course choose to purchase some commercial items if preferred.
Brake links and rods were made from 1mm florists plastic coated steel wire (usually green) in my model they are painted black.