Update 2025-11-17: Now a PI controller (proportional + integral) instead of just proportional Update 2025-11-22: M141 macro & auto-stop after a print has finished Update 2025-11-23: bugfixes to CHAMBER_CONFIG, updated tuning values I think we are all frustrated with the exhaust_fan! It is loud, …

Works great for me. Printing PETG enclosed with 50 c max on the chamber. Thank you

I have updated start print macro and printer.cfg, now it does throttle nicely when I sent M141 commands. But I get errors when using M191: [image] Also it seems to send M191 commands when starting a print, cancelling the print with an error. Not sure where that command comes from, I did not see M…

Typo on my part, try replacing the M141 & M191 macros with this. I made the following changes: Fixed the min/max bug If the print bed isn’t already on, turn it on OrcaSlicer sends its chamber “Activate temperature control” command before the Starting gcode, so it’ll never actually begin the print…

Thanks for the help, it is working again :slight_smile:

Regarding chamber temperatures, I’d also like to cite @Fabio 's experience that PETG clogs at 55°C , which is considerably less than @Liberty4Ever 's 61°C that I initially quoted. This further corroborates the chamber heater suggested 50°C for PETG.

Bugfix: Incorrect RPM The reported exhaust_fan RPM was bogus and reporting slower values when set above 35% because the poll interval was incorrect. [fan_generic exhaust_fan] pin: PB0 tachometer_pin: PB1 tachometer_ppr: 1 tachometer_poll_interval: 0.0019 #was 0.0046 cycle_time: 0.05 #was 0.01 max_p…

@Rooroo4u I’m not sure I follow all the changes you’re making. Photos or links would be helpful. I’m reluctant to make hardware changes since, while they may be quieter, the replacements may not provide adequate cooling. Assuming they are powerful enough, my software changes above should work, alth…

I’ve updated the M141 & M191 macros above with logic for stirring the air with the fans if they’re not already set.

i’ve got a strange problem I’ve tried this before with a set temperature of 35° with PETG just for testing and it worked perfectly now after tinkerin a bit with my zero i started another print with a target of 45° and now the auxiliary fan immediatly startet running at 100% which is quite counterp…

Since fan2 / aux fan / rear curtain fan is an inlet, I haven’t utilized it in my macros. In fact, there doesn’t seem to any real control loop on it at all, thermostat or otherwise. Its just set statically by the slicer, generally by the filament’s cooling section Auxiliary Fan Settings

PID Controlled Exhaust Fan (Quiet!)

Sovol Zero

rpcyan November 22, 2025, 9:59pm 2

bump for major update.

Let me know how this works for you!

2 Likes

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PID Controlled Exhaust Fan (Quiet!)

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