Welcome! Log In Create A New Profile

Advanced

Only turn on extruder cooling fan when temperature is above xx degrees

Posted by danededane 
Forum List Message List New Topic
danededane
Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 02:52AM
Hello ,

I've been looking at the following in marlin configuration_adv.h:

#define E0_AUTO_FAN_PIN -1
#define EXTRUDER_AUTO_FAN_TEMPERATURE 50
#define EXTRUDER_AUTO_FAN_SPEED 255 // 255 == full speed

My board is "lgt kit v1.0"



But as far as I understand I cannot control fan 2 and 3 because they are directly 24V and ground connected. Right?

So my question is, do I have other options? can I use other pins on the board to act like D7 (FAN1 Parts cooling fan)?
Reply Quote
Dust
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 04:55AM
Correct you cannot used those always on fans.

Yes you could use D7, to turn on an external mosfet to drive the fan.

Edited 1 time(s). Last edit at 05/07/2022 04:56AM by Dust.
Reply Quote
danededane
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 04:59AM
Hi Dust ,

But D7 is used for parts cooling . Other options ? .
Reply Quote
Dust
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 05:19AM
Not according to that diagram, D7 is up top, D9 is the cooling fan.
Reply Quote
danededane
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 05:31AM
Oh sorry , my bad !

But I'm using D7 for my newly installed 3DTouch confused smiley
Reply Quote
Dust
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 05:47AM
So use another pin that isnt in use.

D4, D5, D6 or D11
Reply Quote
danededane
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 05:51AM
Lets say I would use D11

Should I then just write:
#define E0_AUTO_FAN_PIN D11

or

#define E0_AUTO_FAN_PIN 11

??
Reply Quote
Dust
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 06:12AM
#define E0_AUTO_FAN_PIN 11
Reply Quote
danededane
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 06:44AM
That seems to be working .

But I'm only getting around 5V between the D11 and the ground pin next to. Can that be true?

Right now my parts cooling are running like on this drawing:
[imgur.com]
Reply Quote
Dust
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 07:45AM
D11 is a io pin. it is 5v It is also low current, so you don't use it to control a 5v fan either.

This is why you need the external mosfet

The IO pin turns on the mosfet The mofet provide the 12v or 24 to the fan

Edited 1 time(s). Last edit at 05/07/2022 07:56AM by Dust.
Reply Quote
danededane
Re: Only turn on extruder cooling fan when temperature is above xx degrees
May 07, 2022 11:27AM
Thanks alot for the answers @Dust!

I think I get it now :-)
Reply Quote
Newer Topic Older Topic
Sorry, only registered users may post in this forum.

Click here to login