I started threading the motor components. I've only done the six holes that connect nozzle shell to the nozzle ring, so I have a long way to go. It's exciting that those 12 holes line up so well, though. The nozzle design consists of two main pieces. The purpose is to reduce the amount of heat transfer from the throat region to the composite motor casing. The two pieces are separated by a extremely high temp. gasket. In addition to that, the shell flange has a slightly smaller diameter than the ring so that there is no direct metal to metal contact between the two pieces.