While ASA is a fantastic material for outdoor use and high-heat applications, it requires more care than printing with PLA or PETG.
Why External Venting is Essential
Even if you are using a high-end enclosed printer like a Bambu Lab or equipped with internal carbon filters, it is always better to vent to the outside.
- Filter Saturation: Carbon filters have a limited lifespan and lose effectiveness over time without obvious signs of failure.
- Ultrafine Particles (UFPs): While carbon is great at scrubbing Volatile Organic Compounds (VOCs), it doesn’t always catch 100% of the microscopic particles generated during the melting process.
- Styrene Content: ASA is chemically similar to ABS; it produces that distinct “plastic smell” which is a direct indicator of styrene gas.
Pro-Tip: If you can smell the print, you are inhaling VOCs. An enclosure keeps the heat in for better part strength, but a dedicated vent hose to a window is the gold standard for respiratory safety.
Machine end G-code
This opens the top vent and run the exhaust fan to cool the chamber quickly after printing
;===== ASA COOLING & VENTING MODE =====
M1002 gcode_claim_action : 66 ; Claim UI action for "Finishing"
M104 S0 ; Turn off hotend heater
M140 S0 ; Turn off bed heater
; Set Air Duct to Cooling Mode (This opens the top vent and rear flaps)
M145 P0 ; P0 = Cooling Mode (Vents Open)
; P1 = Heating Mode (Vents Closed)
; Maximize Fans to clear fumes and drop chamber temp
M106 P2 S255 ; Auxiliary Fan 100% (Circulate air)
M106 P3 S255 ; Chamber/Exhaust Fan 100% (Vent VOCs)
G4 S300 ; Dwell for 300 seconds (5 Minutes)
M106 P2 S0 ; Turn off Auxiliary Fan
M106 P3 S0 ; Turn off Chamber Fan
M400 ; Final sync
;===== ASA COOLING & VENTING MODE =====