Parametric WW2 7.5x20 Mud & Snow Tire

An OpenSCAD model of a US Army 7.5x20 mud and snow tire. This tire was used on 2.5 ton trucks.

The default scale is 1/48. Setting the ScaleFactor variable to another scale is all that's needed to generate a given scale:

ScaleFactor72 = 0.0138;
ScaleFactor48 = 0.02083;
ScaleFactor35 = 0.02857;

ScaleFactor = ScaleFactor48;