I wanted some O Scale 1930s era tractor-trailers for my layout so I designed, printed and assembled my own custom ones!
I decided to focus on the 1930s, my favorite automobile era. I designed a truck based on the 1937 GMC CoE, the very first of the cab-over-engine style semis, in Fusion 360.
I printed out several trucks and trailers in sturdy ABS filament. They're very easy to print although the trailers suck up a lot of material.
To give the trucks a classic 1930s dimestore toy look, I added rubber O-ring tires to the models. I mostly settled on simple paint schemes based on what I found in period truck advertisements such as this. The hubs are also 3D printed and the axles are made from steel escutcheon pins pressed in to sections of rubber tubing.
For trailers, I started off designing a car hauler. This doesn't match a specific historic setup but it is closely based on a period toy by the Auburn Rubber Toy Company. I've added some vintage rubber-molded sedans from the Sun Rubber company as a load.
I also designed a streamlined Fruehauf trailer. This is directly based on the Fruehauf Warehousemans Van from the late 1930s.
Keep on trucking everybody!