4 pin 5V fan on 3 Mini

richardmckenna

Hi, I have a 4 pin 5V fan I would like to use as a hot end fan on the on 3 Mini. Just want to check how to wire it.

I'm supplying EXT 5V anyway to power LEDs.

If I use OUT 3 to control the fan, can I connect as follows

Fan Black to OUT3 - GND
Fan Yellow to OUT3 - out3.tach
Fan Blue to OUT3 - out3-

Can I just connect Fan Red to 5V PWM - 5V_EXT ?

Thanks

dc42

@richardmckenna yes that should work.

richardmckenna

@dc42 Perfect thanks

richardmckenna

@dc42 ok not quite working. If I config like:

M950 F1 C"out3" Q25000
M106 P1 C"Fan" S0 H-1

Also tried inverting the pin with, which I think you are supposed to do with 4 wire PWM fans

M950 F1 C"!out3" Q25000
M106 P1 C"Fan" S0 H-1

Calling M106 P1 S1 and M106 P1 S0 doesn't do anything.

If I disconnect the Blue PWN wire the fan operates at 100% as it should (according to it's datasheet) so it's getting power.

richardmckenna

ok I have got somewhere, connecting as above I could not get it to work.

So I'm now connected:

Fan Red (+) - VFD-5V_EXT
Fan Black (-) - VFD-GND
Fan Blue (PWM) - VFD-out6_buff
Fan Yellow (FOO) - OUT3-out3.tach

and in the config I have:

M950 F1 C"vfd+out3" Q25000