Dankdryer

Some engineering filaments specify drying at temperatures up to 140C. Standard filament dryers can't approach this temperature (most peak at 70--80C). How to construct one that can handle it?

We need materials and electronics which can operate in such an environment. Ideally, we'll keep most of the electronics out of the heated chamber, but it'll likely be quite warm immediately outside as well. This seems possible for everything but our sensors, which must necessarily be within the chamber. We'll need a thermostat, and might want a humidity sensor. We'll also have a load cell to weigh the spool/chamber, and thus let us know how much water has been evaporated. I haven't been able to find a humidity sensor rated above 100C, so that's a nonstarter. We'll want to put the thermostat on lengths of wire.

We'll drive the ceramic heating element via AC, as it wants significant wattage.

Filament-wise, the hot chamber, heat shield, and central column will be printed in Bambu PAHT-CF, while the bottom chamber will be printed in Polymaker polycarbonate.

Hotbox

• LM35 thermostat (up to 150C)
• 110V 230C 3.03" x 2.44" ceramic heating element (230C)
• Chamber material: Bambu PAHT-CF (225C)
• 150C NC thermocouple
• Noctua NF-A8 80mm 12V fan

The hotbox mates to the croom via four corners using M5x40mm screws. It has a 80mm fan for exhaust opposite the heater. This is not 80x80mm² (6400mm²) of exhaust, but rather π40² (~5026.5mm²), since the fan is circular. We thus want ~5026.5mm² of vents in the floor. The heater is wired to the AC and to the thermocouple, which will open (killing the circuit) if the chamber reaches 150C.

Outside of chamber

• Motor: Geartisan 12V DC 5RPM motor
• Load cell: HX711 + 5kg axial load cell
• MCU: ESP32-S3-WROOM
• AC -> DC 12V adapter
• LMS2596 buck converter
• TB6612FNG motor controller
• Chamber material: Polymaker polycarbonate clear (260C)