Poor man's automated chamber top vent  

Poor man's automated chamber top vent

Now that firmware 6.3.3 no longer insists on waiting for the "Set the vent correctly!" prompt, but lets it time out after a minute, it finally makes sense to automate the vent switching. I opted for a cheap-and-cheerful solution: Attach little tabs to the inside of the vent slider and to the Nextruder, and let the Nextruder push the slider in the right direction via a bit of custom startup G-Code. 

Here's my current setup: The slider part replaces the middle nut on the slider's mounting screw. The Nextruder part attaches via two of the lid screws -- you will need to replace the standard M3*25 screws with M3*30. Conveniently, my Core One kit came with two spares.

I had originally planned to move the tab on the slider further forward, such that it sits below the metal frame, well in the non-printable area. But that made it inconvenient to remove and replace the lid; hence the tab now sits just at the edge of the slider. The Nextruder part is designed to stay clear of the slider during normal printing. It will only start to brush against the slider tab when moved to Y=-5 mm, and fully engages at Y = -7 mm.  

I'm attaching the STL files. I printed them in PETG, in the orientation shown below. The tab on the Nextruder provides enough flex to safe-guard against accidents, but more than enough force to move the slider.

The G-Code below goes into the Startup G-Code section in PrusaSlicer. I placed it just after the homing command (G28). If you decide to install this in your printer, please double-check the positions (by carefully moving the Nextruder manually via the front panel).

; ------------------------------------------
; Automatic vent control via Nextruder
; jm 9.6.25

G1 Y0 F6000 ; go to safe position
{if filament_type[initial_tool] =~ /.*(PLA|PETG).*/}
  ; Open vent
  G1 X85
  G1 Y-7
  G1 X100 F1000
  G1 X85 F6000
{else}
  ; Close vent
  G1 X115
  G1 Y-7
  G1 X100 F1000
  G1 X115 F6000
{endif}
G1 Y0 ; go to safe position
; ------------------------------------------