Check hotend FAN RPM

[PetrKroupa]

Hello,
I have hotend fan conected to 1LC tool board. It is noctua 3 wire fan. I configure tacho input and see around 4000 rpm. No problem. Is there way to pause/stop print when fan is stoped/slow down to some rpm? Or run some macro when this happend...
Many thanks.

[cosmowave]

@petrkroupa You can check the rpm in daemon.g

[tecno]

Why bother with more than 2 wires and full speed as you need the air flow.

My noctua starts at 45°C

[PetrKroupa]

@tecno - Mine also starts at 45 degrees. Basically, you're right. That is, provided that everything works. The moment the fan is broken or blocked by some dirt, you have a problem. I wouldn't start dealing with it until it happened to me. For example, PRŮŠA checks both fans.

[cosmowave]

@petrkroupa like i said.
Create the deamon.g file in sys folder. Check there your rpm from object model.
Note: deamon.g will run every 10sec, so your check can be delayed 10sec. But i think, this should not be a problem...

[PetrKroupa]

@cosmowave - OK, thanks. I will try.

[PetrKroupa]

@cosmowave - I can not find "fans" or RPM in objects. Do you please have some link with right sintax. Many thanks.

[cosmowave]

@petrkroupa I think the rpm is somewhere in the "sensors"
i'm not at the machine now...

[dc42]

@cosmowave said in Check hotend FAN RPM:

Note: deamon.g will run every 10sec, so your check can be delayed 10sec. But i think, this should not be a problem...

If you want it to run more frequently, use a while-loop in daemon.g - but include a G4 delay command (e.g. G4 S2 to delay two seconds) within the loop, to prevent it using too much CPU time.

[PetrKroupa]

I tried to find the right object but I was not successful. Please send where to look. Thanks

[dc42]

@petrkroupa it's fans[N].rpm where N is the fan number.

[PetrKroupa]

@dc42 - Many thanks! I will put here whole code when it works.

[PetrKroupa]

It can definitely be improved a lot, but it is enough for the basic function. Thanks to everyone for the help.

daemon.g

G4 S1

if heat.heaters[1].current > 55	&&	heat.heaters[1].current < 1000	; hotend temp more than 55c ?
		; hotend temp more than 55c ?, termostacic fan set to 45c (fan have time to start spin)

	if fans[1].rpm < 500.0 				; hotend fan spining faster than 500rpm?
	
		M150 R128						; Neopixel red!
		M104 S0							; set hotend temp to 0c
		M291 P"Hotend fan error!!!"  S1
		M98 P"pause.g"					; run pause.g
		
	else
		;M150 U128						; Neopixel green
		
else
	
	;M150 U128							; Neopixel green
	
G4 S1