Time to share. When my basement is more clean I'll make a video. The build volume is 610 x 610 x 760mm.
-Fully enclosed by means of window shrink wrap over lightweight doors. With the basement around 50F and the build plate at 55C, the internal temperature stabilizes at 70C with no additional heating, "Space blanket" covering on build plate and downward-facing top surface of printer help reduce radiative heat loss.
-It's meant mainly for production work. I have both single- and four-extruder toolheads which mount via a kinematic quick-change end effector. No screwing and unscrewing, and the height registration really is repeatable. Spring-loaded latches hold the toolheads in place (no screws). The quad-toolhead subdivides the HBP into 12"x12" squares for 4x parallel printing. I've only made test prints with that toolhead so far, but it works.
-HEPA filtered exhaust fan.
-I used guide tube intended for 3mm filament even though I run 1.75mm filament. The tube paths are so long that the narrower guide tubes gave carbon-filled filaments too much resistance. This works just fine though, and the filament seems much less likely to break within the guide tube.
-The HBP has 5 zones: 4 12" square silicone heater pads, and a nichrome wire permieter wire, to counteract the temperature gradient at the edge. The Duet moderates each zone very nicely. The heaters are plugged into AC, which would draw over 3kW with everything on. To avoid such large surges and let it plug into a 15A breaker, a Variac is used to reduce the peak power to a more sane 1kW.
-A large (14") Raspberry Pi-powered touchscreen provides access to Duet Web Control.
-All the white plastic parts in the pictures were self-printed. The control panel is in two pieces.
-Because I really don't want to burn my house down (this runs often when I'm not home):
- 8 smoke sensors, any one of which will turn off a master relay. The arduino-powered logic for that is powered separately. Each toolhead has a smoke sensor next to each extruder, and there are others peppered around the electronics, and over the big Variac.
- A separate, off the shelf HAVEN automatic fire extinguisher, which activates on its own if the temperature gets to 135F.