diff options
| -rw-r--r-- | config/example.cfg | 13 | ||||
| -rw-r--r-- | klippy/extras/fan.py | 4 |
2 files changed, 17 insertions, 0 deletions
diff --git a/config/example.cfg b/config/example.cfg index ed33b3d6..f0c6f2c9 100644 --- a/config/example.cfg +++ b/config/example.cfg @@ -259,6 +259,19 @@ pin: ar9 #kick_start_time: 0.100 # Time (in seconds) to run the fan at full speed when first enabling # it (helps get the fan spinning). The default is 0.100 seconds. +#off_below: 0.0 +# The minimum input speed which will power the fan (expressed as a +# value from 0.0 to 1.0). When a speed lower than off_below is +# requested the fan will instead be turned off. This setting may be +# used to prevent fan stalls and to ensure kick starts are +# effective. The default is 0.0. +# +# This setting should be recalibrated whenever max_power is adjusted. +# To calibrate this setting, start with off_below set to 0.0 and the +# fan spinning. Gradually lower the fan speed to determine the lowest +# input speed which reliably drives the fan without stalls. Set +# off_below to the duty cycle corresponding to this value (for +# example, 12% -> 0.12) or slightly higher. # Micro-controller information. [mcu] diff --git a/klippy/extras/fan.py b/klippy/extras/fan.py index 5f72a780..f11a9e86 100644 --- a/klippy/extras/fan.py +++ b/klippy/extras/fan.py @@ -16,6 +16,8 @@ class PrinterFan: self.max_power = config.getfloat('max_power', 1., above=0., maxval=1.) self.kick_start_time = config.getfloat('kick_start_time', 0.1, minval=0.) + self.off_below = config.getfloat( + 'off_below', default=0., minval=0., maxval=1.) ppins = printer.lookup_object('pins') self.mcu_fan = ppins.setup_pin('pwm', config.get('pin')) self.mcu_fan.setup_max_duration(0.) @@ -29,6 +31,8 @@ class PrinterFan: def handle_request_restart(self, print_time): self.set_speed(print_time, 0.) def set_speed(self, print_time, value): + if value < self.off_below: + value = 0. value = max(0., min(self.max_power, value * self.max_power)) if value == self.last_fan_value: return |