Chamber Temperature Control in OrcaSlicer: M141/M191 Guide
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Chamber temperature control in OrcaSlicer

OrcaSlicer’s chamber temperature control preheats an active chamber heater to a target temperature using M141 and M191, before your print starts. This page walks through where the setting lives, what each command does, and gives you a target calculator for common materials.

Commands: M141 / M191 Setting level: Printer + Filament Requires: Active chamber heater

What chamber temperature control does

It’s active heating, not passive heat-soak — OrcaSlicer tells the printer to reach a target chamber temperature and wait.

If your printer has an active chamber heater (not just heat that builds up naturally from the bed and hotend), OrcaSlicer can drive it directly. When enabled, OrcaSlicer inserts an M191 command near the start of the G-code — before the machine start G-code runs — so the chamber reaches its target temperature before printing begins, rather than warping up slowly during the first layers.

This matters most for materials prone to warping: ABS, ASA, PC, and nylon all print more reliably with a stable warm chamber — the kind of setup most enclosed 3D printers compatible with OrcaSlicer are built for. Low-temperature filaments like PLA are the opposite case — see the warning further down.

Where the setting lives

Two toggles have to agree — one on the filament, one on the printer.

Filament Settings

Filament Settings → Activate temperature control
  • Tells OrcaSlicer this filament profile wants active chamber heating

Printer Settings

Printer Settings → Basic Information → Support control chamber temperature
  • Variable: support_chamber_temp_control
  • Advanced mode setting — see the interface guide if the menu layout looks different
Both switches have to be on. OrcaSlicer only inserts the M191 command when the filament’s “Activate temperature control” and the printer’s “Support control chamber temperature” are both checked. Miss either one and nothing gets emitted.

Enabling it, step by step

  1. Open Filament Settings

    Enable Activate temperature control for the material profile you’re using.

  2. Open Printer Settings

    Enable Support control chamber temperature under Basic Information (Advanced mode). New to setting up a profile? Start with printer selection.

  3. Set the chamber temperature target

    Enter the target for this filament — see the calculator below for common starting points.

  4. Slice and check the G-code

    Confirm an M191 command appears near the top of the file, before the machine start G-code.

  5. Verify firmware support

    M141/M191 only do something if your printer’s firmware — or a Klipper macro — actually drives a chamber heater. Once it’s working, it’s worth re-running your calibration guide tests, since chamber temperature changes flow behavior enough to shift your tuned values.

M141 vs. M191, explained

CommandBehavior
M141 S{temp}Sets the chamber heater target — does not wait for it to be reached before continuing.
M191 S{temp}Sets the chamber heater target and pauses the print start until that temperature is reached.

OrcaSlicer also exposes two variables you can use directly in your own Machine G-code, if you’d rather control the exact placement yourself:

M191 S{chamber_temperature[0]} // first filament’s chamber temp M191 S{overall_chamber_temperature} // highest chamber temp across all filaments used

overall_chamber_temperature matters most on multi-material prints — if you’re pausing to change filament mid-print between materials with different chamber targets, OrcaSlicer uses the highest value across all of them rather than switching targets partway through.

This is useful if your printer doesn’t support M141/M191 directly, or if you want to handle heat-soaking manually inside a print-start macro instead — see our guide on generating G-code from STL files if you’re new to editing Machine G-code directly.

Chamber temperature target calculator

Pick a material for a commonly used starting range, then generate the exact M191 command. Always check your specific filament brand’s recommendation too — these vary.

M191 S0

No active heating needed — PLA can clog the nozzle if the chamber runs too warm.

Setting it up with Klipper

Klipper needs a heater defined and two macros to translate M141/M191 into its own heater commands.

[heater_generic chamber_heater] heater_pin: PB10 max_power: 1.0 sensor_type: NTC 100K MGB18-104F39050L32 sensor_pin: PA1 control: pid pid_Kp: 63.418 pid_Ki: 0.960 pid_Kd: 1244.716 min_temp: 0 max_temp: 70 [gcode_macro M141] gcode: SET_HEATER_TEMPERATURE HEATER=chamber_heater TARGET={params.S|default(0)} [gcode_macro M191] gcode: {% set s = params.S|float %} {% if s == 0 %} M117 Chamber heating cancelled {% else %} SET_HEATER_TEMPERATURE HEATER=chamber_heater TARGET={s} TEMPERATURE_WAIT SENSOR=”heater_generic chamber_heater” MINIMUM={s-1} MAXIMUM={s+1} M117 Chamber at target temperature {% endif %}

Change the pin names and PID values to match your actual hardware and sensor before using this. If your printer heats the chamber partly with the bed, you can also uncomment a line like M140 S100 inside the M191 macro to assist heating.

If the machine has an auxiliary fan, OrcaSlicer will automatically turn it on during the heating period to help circulate air — no separate setting needed for that part. See the auxiliary fan guide if you want to control it manually too.

Chamber heat vs. warping vs. filtration

Does chamber temperature actually reduce warping?

Yes, for high-temperature materials — a warm, stable chamber for ABS, ASA, PC, and nylon reduces the thermal shock that causes layers to pull apart at the corners, and can improve interlayer bonding strength.

Is it safe to just max out the chamber temperature?

No. Push it too high and you risk softening lower layers, and for PLA specifically, an overly warm chamber can lead to nozzle clogging.

Does chamber heat affect air filtration?

Yes — a higher chamber temperature reduces the efficiency of air filtration for materials like ABS and ASA. If you’re running both, treat them as one combined setup rather than two settings tuned separately. See the air filtration guide for the exhaust side of this trade-off.

Don’t apply a high chamber target to PLA. Low-temperature filaments like PLA can clog the nozzle if the surrounding chamber gets too warm — this is one setting where “more heat, better print” doesn’t hold.

Questions people ask about this

Does OrcaSlicer support chamber temperature control?

Yes, through the M141/M191 commands — but only if your printer has an active heater and both the filament and printer toggles covered above are turned on.

Why is my chamber temperature not working in OrcaSlicer?

Almost always one of the two toggles being off, missing firmware/macro support, or a heater that isn’t actually configured in your printer’s firmware — see the troubleshooting checklist above for each case.

What chamber temperature should I use for ABS?

A commonly used starting range is 40–60°C — see the calculator above, and adjust based on your specific ABS brand’s recommendation and how much warping you’re seeing.

M191 vs M140, what’s the difference?

They control different heaters entirely — M140 sets the bed temperature, M191 sets and waits on the chamber temperature. They’re not interchangeable, though some Klipper macros use both together to assist chamber heating with the bed.

How do I set up a chamber heater in Klipper for OrcaSlicer?

Define a [heater_generic] section for the heater, then add M141 and M191 gcode_macros that call it — the full example is in the Klipper section above.

Can I use chamber temperature control without a physical heater?

Not for active heating — M141/M191 need a real heater to drive. Without one, your only option is passive heat-soak from the bed and hotend, which OrcaSlicer doesn’t actively control.

Troubleshooting

  • M191 isn’t showing up in the G-code

    Check both toggles: Activate temperature control on the filament, and Support control chamber temperature on the printer. Both are required. Also confirm you’re on a current OrcaSlicer version — if the slicer is misbehaving more broadly, see Orca Slicer not working.

  • Print starts before the chamber reaches temperature

    Confirm you’re using M191 (waits) rather than M141 (doesn’t wait) — or that your Klipper macro actually includes a TEMPERATURE_WAIT step.

  • Chamber never reaches the target

    This is a firmware/hardware issue at that point — check the heater’s max power, PID tuning, and that the sensor is reading correctly, not the OrcaSlicer setting. If OrcaSlicer itself is crashing or misbehaving separately, see fixing an Access Violation error.

  • “Heater chamber_heater not configured” error in Klipper

    The M141/M191 macros are trying to call a heater section that doesn’t exist yet. Double-check the [heater_generic chamber_heater] block is actually present in your printer.cfg and the name matches exactly what the macros reference — a typo or a missing include file is the usual cause.

  • M191 times out and the print aborts

    Klipper’s TEMPERATURE_WAIT has no built-in timeout by default, but some custom macros add one. If yours does and the chamber is slow to heat, either raise the timeout or reduce the target — a chamber heater sized for a small enclosure can take a long time to hit 60°C+ targets in a large one.

  • Chamber overshoots the target and oscillates

    This points to poor PID tuning on the chamber heater rather than an OrcaSlicer setting. Run a PID calibration routine against the chamber heater specifically — the values in the Klipper example above are printer-specific and won’t transfer cleanly to different heater wattages or enclosure volumes.

  • Chamber temperature reading looks wrong or jumps erratically

    Usually a thermistor placement or wiring issue — a sensor mounted too close to the heater element reads hot while the rest of the chamber is still cold, and a loose connection shows up as sudden spikes or drops. Check the physical mounting before assuming it’s a firmware bug.

  • Chamber can’t hold temperature with the door or lid open

    Not a bug — an open enclosure loses heat faster than most chamber heaters can compensate for. If you need the door open for a specific step, expect the target to drift until it’s closed again; some setups pause heating entirely if a door sensor is wired in.

  • Bed and chamber heaters seem to compete for power

    On printers where both draw from the same power supply or mainboard rail, running both at high power simultaneously can trip a fuse or brown out the board. Check your printer’s rated power budget before pushing both bed and chamber temperature high at once.

  • Different filaments in one print show different chamber behavior

    Expected — see overall_chamber_temperature above. OrcaSlicer picks the highest target across all filaments used rather than switching mid-print, so a PLA+ABS combo print will heat-soak to the ABS target for the whole job.

Frequently asked questions

What commands does OrcaSlicer use for chamber temperature?

M141 sets the chamber heater target without waiting; M191 sets the target and waits until it’s reached before continuing.

Where do I turn on chamber temperature control in OrcaSlicer?

Enable Activate temperature control in the Filament tab, and Support control chamber temperature in Printer Settings (Advanced mode).

Does OrcaSlicer need a physical chamber heater?

Yes — for active heating via M141/M191 to do anything, the printer needs an actual heater and firmware or macro support for those commands.

Is a higher chamber temperature always better?

No. It helps high-temperature materials like ABS, ASA, PC, and nylon resist warping, but low-temperature filaments like PLA can have nozzle-clogging issues if the chamber gets too warm.

Does chamber heating affect air filtration?

Yes. A higher chamber temperature reduces the efficiency of air filtration for materials like ABS and ASA, so the two settings should be balanced together, not tuned in isolation.

Can I set chamber temperature manually without M141/M191?

Yes, using chamber temperature variables like {chamber_temperature[0]} or {overall_chamber_temperature} in your own Machine G-code, useful if your printer doesn’t support M141/M191 natively.

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