Hornby announce 3D Scanning for ultimate accuracy

3D Scanning of Adams Radial

The Warley Model Rail Exhibition promises to be an exciting show for the model rail enthusiast again this year. The Hornby team are delighted to be able to exhibit the models they have been working on. Visitors to the three day show will be able to examine the decorated samples (samples made from the new tooling and then decorated by hand) of the Drummond 700, K1, and J15. There will also be running samples (undecorated samples from the new tool) of the D16 and the Crosti Boiler 9F. Hornby will also be revealing a rapid prototype model which is a highly detailed 3D printed version of the newly announced King Class.




The quest for ultimate accuracy reaches unprecedented levels this year as the Hornby team have been utilising 3D scanning of real locos in preservation. LIDAR scanning uses laser light to accurately map the surface of an object in three dimensions, resulting in a high-definition 3D computer image of the object. This image can then be fed into the Hornby CAD system, enabling us to produce incredibly detailed models directly mapped from a vehicle, rather than recreating the shape from other sources such as blueprints or photographs.

The laser scanner is placed around the asset in as many as 40-50 positions, from both the ground and a raised platform such as a scissor lift, in order to get the best coverage. The scanner rotates, sweeping the area with a laser, which is constantly taking measurements throughout the scan. As many as 5 million points are mapped in each sweep, producing a 3D image with detail as small as a fraction of a millimetre.

The next step is to align all of the separate scans, then clean out all unwanted material, such as the surrounding area, people and any errors cause by reflective and refractive surfaces such as glass and mirrors. Finally, this point cloud is then converted into a solid polygonal mesh object, ready for us to use as a template for the Hornby CAD system.

The British Rail Class 71 Electric Locomotive is a Bo-Bo configuration engine built for service on Southern Region’s Kent Coast Main Line at the British Rail Doncaster works between 1958 and 1960. The Class 71 was only able to work over the third rail power system in service, which ultimately limited its operational scope for passenger and freight work. Despite this restriction, the engines worked high profile routes, notably the Night Ferry and the Golden Arrow.

The Adams Radial was designed by William Adams and introduced in 1882 for service on the London and South Western Railway (LSWR). Originally rostered for suburban traffic, the class was soon displaced to the countryside by Dugald Drummond’s M7 class. Most of the class was scrapped around the end of the First World War. One has survived and can be found on the Bluebell Railway, which is the locomotive scanned by Hornby.

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