PLA cooling fans no longer working with new FW

(code17_SW) #1

I’ve installed the latest FW from Github (21June15) and am no longer able to turn on the cooling fans with M106. Is anyone else having this issue?

Imported from wikidot

(Arthur Wolf) #2

How old was your config file ? The syntax for switch gcodes changed ( a long time ago )

(Wolfmanjm) #3

Yes you need to fix your config, certain defaults have changed recently. Use a recent config file and check the wiki.

(Warlord007_SW) #4

same problem here

M106 and M107 no longer work with the new FW

when turning the Printer on the PLA cooling fans start up and you cant control them.
Here are my fans config

  1. Switch module for fan control (Part cooling Fan) true # M106 # M107 # 2.4 # pwm # pwm output settable with S parameter in the input_on_comand 255 # set max pwm for the pin default is 255

switch.misc.enable true #
switch.misc.input_on_command M42 #
switch.misc.input_off_command M43 #
switch.misc.output_pin 2.6 #
switch.misc.output_type digital # just an on or off pin

  1. automatically toggle a switch at a specified temperature. Different ones of these may be defined to monitor different temperatures and switch different swithxes
  2. useful to turn on a fan or water pump to cool the hotend

temperatureswitch.hotend.enable true #
temperatureswitch.hotend.designator T # first character of the temperature control designator to use as the temperature sensor to monitor
temperatureswitch.hotend.switch misc # select which switch to use, matches the name of the defined switch
temperatureswitch.hotend.threshold_temp 60.0 # temperature to turn on (if rising) or off the switch
temperatureswitch.hotend.heatup_poll 15 # poll heatup at 15 sec intervals
temperatureswitch.hotend.cooldown_poll 60 # poll cooldown at 60 sec intervals

(Arthur Wolf) #5

Ok that looks like the right syntax.

Would you mind starting again from the latest firmware, and latest configuration file, only change what you need for the fans to work, and test again ?

(Warlord007_SW) #6

hi arthurwolf

i have put firmware on from 29th aug.
tested and firmware worked ok
then put on the new config and only changed the fan controls that was all

the board would not boot with this config (red light thats all)

But the dam fan was still running without the board even powering up correctly.

Please fix this

(Arthur Wolf) #7

Alright so : the fans are not broken in firmware. If they had been broken since the beginning of july, I would have literally gotten hundreds of emails about it ( lots of people use Smoothie, and use fans, and have my email … ). But I only got your single forum post about it.

Can you tell me : 

  • In which mosfet exactly did you plug your fan ?
  • What is your fan’s voltage and current ?
  • Did you install a diode across the mosfet ?

The board not booting up also hints at a separate problem from the fan problem.
Please tell me if using the latest firmware, and latest unedited configuration file, the board boots or not.


(Warlord007_SW) #8

Hi arthurwolf

I did not start this thread, so either code17 had another issue, or something strange is happening.

I did what you asked in your previous post and installed the new firmware.
You then asked me to put a new config on and ONLY change the fan settings, i did this and that is why the board would not boot as many setting in the config would be wrong for my setup.
with my original config and the fan settings posted above, the board works fine, apart from the pla fan being on all the time.

my hotend fan is on pins 2.6 and this works with temp sence (60deg)
my pla fan is on pins 2.4
its a 12v 0.10A fan
there is no diode across the mosfet, never has been and the fan worked fine until the mid-end of july when i upgraded the firmware

(Wolfmanjm) #9

if the fan comes on when you power up then you have a blown mosfet. Bigger fans need that flyback diode. This does not appear to be a firmware issue.

(Arthur Wolf) #10

As wolfmanjm said, it is very likely your mosfet blew up due to lack of protection.

Please see the 3D printer documentation at, in particular the section about fans.