We should have the masters for the D450 tractor next week. For interest I am posting a few pictures created during the manufacturing process:
1 - We design the model in the Catia CAD program, shown below:
Pale grey parts are resin, dark grey is cast metal and yellow parts are etched brass.
2 - The master parts are created using stereo lithography (SLA), where a laser forms the parts in a tank of resin. These two pictures show two planned builds.
The beauty of this method is that we can design the model once then produce masters in whatever scale is required. With the ground equipment we normally do it in 1:144, 1:72, 1:48 and 1:32.
I will add some photos when the masters arrive.