Bed Fans Macro

This repository contains a Klipper macro configuration for controlling bed fans during 3D printing. The macros dynamically adjust fan speeds based on the bed's temperature and the chamber's temperature, ensuring optimal cooling and heating conditions.

Features

• Dynamic Fan Control: Adjusts fan speed based on bed temperature and chamber temperature.
• Heating and Cooling Thresholds: Fans are enabled or disabled depending on configurable temperature thresholds.
• Fast and Slow Fan Speeds: Uses different fan speeds for rapid cooling and steady-state conditions.
• Integration with Bed Temperature Commands: Overrides standard M140 and M190 G-code commands to include fan control logic.
• Delayed G-code Execution: Periodically checks and adjusts fan speeds during heating and cooling cycles.

Configuration Variables

The macro uses the following configurable variables defined in the _BEDFANVARS macro:

• variable_heating_threshold: If bed temp target is above this threshold, fans will be enabled.
• variable_cooling_threshold: While bed is cooling down, if temp is above this threshold, fans will be controlled.
• variable_cooling_delta: Fast fan speed will be used for cooling until within delta of chamber temp
• variable_fast: Fan speed used for printing and initial cooling.
• variable_slow: Fan speed used while bed is heating and while within cooling delta.
• variable_fan: Name of the fan to control.
• variable_chamber_sensor: Name of the temperature sensor to monitor while cooling.

How It Works

1. Heating: The fans are set to slow speed while heating until the bed reaches the heating threshold, the fans will then switch to fast speed.
2. Cooling: When the bed's temperature is above the cooling threshold, the fans are controlled based on the difference between the bed and chamber temperatures. Fast speed is used for rapid cooling, and slow speed is used for steady-state cooling.
3. Idle: When the bed's temperature is below the cooling threshold or matches the chamber temperature, the fans are turned off.

Usage

1. Copy the bedfans.cfg file into your Klipper configuration directory.
2. Adjust the variables in the _BEDFANVARS macro to match your setup.
3. Add [include bedfans.cfg] to your printer.cfg.

Credit

This implementation is based on Ellis' Bed Fans Implementation.