Step 1: The Problem
The flag pole seated in a metal bracket, which seated on the axle between the hub and the frame of the trailer. The metal bracket lasted about two months before it got squished and bent and loose.
Step 2: The Solution
The rapid prototyper we have is a Stratasys Prodigy Plus; an FDM 3D printer. The Prodigy Plus seems to have been discontinued, of the current lineup it's probably closest to the FDM 200mc.
The Prodigy Plus takes CAD models as input and prints the parts out of ABS plastic. The resolution is a bit better than 0.010 inches in all three dimensions, though structures of that size are very weak. It prints about 1 cubic inch per hour, depending on settings & geometry. Overhanging geometries are supported by printing a light-weight, water-soluble scaffolding (the prototyper's CAM software adds this automatically).