Version 4 was the first attempt at the current PolyNC design ethos. The design was unusual to say the least. It also did not use the 8020 aluminum extrusion and was slated to be a much smaller machine.
This version was at best a skeleton that caused justification for one thing: The electronics based on the L6470 Stepper motor driver would appear too expensive if used with such a small machine. This was one of the pivotal moments that influenced the desire to “go big or go home”.
This version envisioned a ceramic mono piece extruder, which drove the filament via a gear in the engorged section midway up. The extruder was actually supposed to be two (2) difference ceramics which were composited together. At the bottom a ceramic that provided heat in exchange for electrical power, and above that a ceramic that insulated from that heat.
It goes without saying that the concept was poorly conceived, as there was no way such a structure could be produced with limited access to machinery; if it were at all possible to build in the first place.