Before mounting the drivers on their half-axles, I had to clean up their backs. This is a touchy task due to the Proto:87 flanges, which disappear in a heartbeat and a string of expletives if you’re not paying attention. The best approach was to face only up to the portion of the wheel formed by the form tool. This was accomplished by eye, or erm, by Optivisor.
I only managed to make one wheel and axle an interference fit, and so, I wound up soldering them. This operation required an alarming amount of Carr’s green-label flux due to the time required to heat the metal.