12v fan for hotend help needed

StevenL · 30 Mar 2019, 03:24

OK. having an issue with getting 12v from Port 3 on the Duet5 for the new 12v Noctura Fan. This is an always on fan for the hotend.
According to this: https://www.instructables.com/id/Duex5-Use-Build-in-12v-Switching-Regulator-on-24v-/
But I dont have the PIN 1 shown in the instructable. I have the latest duet5 board which does not have spot 1.

I enter M106 P3 S1 and nothing happens.
obviously i'm missing something.

aidar · 30 Mar 2019, 07:06

I dont have Duex, but from pictures there seems to be another jumper located between middle endstop and termistor connectors. Ist this for selecting 12v ?

dc42 · 30 Mar 2019, 16:35

See https://duet3d.dozuki.com/Wiki/Duex_wiring_diagrams. On the latest DueX boards, the INT_12V_EN jumper has been moved to the middle left hand edge of the board in that diagram.

StevenL · 30 Mar 2019, 18:29

I did find the 12v enable pins on the left side. I placed a jumper on it and still nothing.
Not sure what I'm doing wrong. Would I be better off just using a DC-dc buck down converter (24v to 12v) off the original hotend fan pins ?

StevenL · 1 Apr 2019, 17:49

any ideas ?

dc42 · 2 Apr 2019, 10:24

Next to that jumper there is a 12V OUT connector. Do you measure 12V across its pins? Take great care not to short the pins together while you measure it.

StevenL · 3 Apr 2019, 16:39

This issue was I needed an S parameter. The 12v was enabled, but at a default 0 speed. so the fan was essentially off. I set M106 P8 S255 and the fan went on full.

bot · 4 Mar 2019, 16:56

@stevenl you had the S parameter in your original post... maybe S1 doesn't work as it should? Or were you accidentally commanding P3 when the fan was actually connected to P8?

StevenL · 4 Apr 2019, 14:42

S1 needs to be S255

bot · 4 Apr 2019, 14:50

S1 and S255 result in the exact same behaviour.