Switching to Thermostatically controlled fan

JohnOCFII

Greetings.

I've read through some similar, recent threads, but since I want to avoid any temperature related hot-end clogs, I wanted to double check my understanding of the required configuration changes.

I've got a T3P3 Kossel Mini with DuetWifi. The initial setup shipped with an always-on fan for the hot-end. I'd like to switch that to be thermostatically controlled.

I've physically moved the hot-end fan from an "always-on" position to the PWM FAN1 position.
I've successfully tested the thermostatically controlled fan by entering M106 P1 T45 H1 in the DWC console, setting the hot-end temp to 60C and watching the fan come on as the temperature climbed above 45C, and watched the fan turn off as the hot-end temperature fell below 45C.

Where I am confused is what I need to change in my config.g. My current fan section is as follows. This is pretty much the template that came with the T3P3 Kossel Mini, with a few tweaks along the way.

[[language]]
; Fans
M106 P0 S0 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S0 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

Can I just replace the M106 P1 entry with:

[[language]]
M106 P1 T45 H1

```Or is there more to it than that?

For completeness, I've attached my current config.g file below.

Thanks,

John

[[language]]
; Configuration file for Duet WiFi (firmware version 1.19+) - updated 28 December 2017 - osh
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Thu May 25 2017 19:26:03 GMT-0500 (CDT)

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P2 ; Set firmware compatibility to look like Marlin

M665 R103.825 L215.0 B85.0 H247.640 X-0.115 Y-0.295 ; osh - testing KosselNozzle 8/25/2017
M666 X0.95 Y-0.67 Z-0.28 ; osh - testing KosselNozzle 8/25/2017

M208 Z-0.1 S1 ; Set minimum Z

; Endstops
M574 X2 Y2 Z2 S1 ; Define active high microswitches
M558 P1 X0 Y0 Z0 H6 F120 T2400 ; Set Z probe type to unmodulated, the axes used and the probe + travel speeds

; Tip: A larger trigger height in G31 moves you CLOSER to the bed
; G31 P500 X10.0 Y0 Z0.33 ; Set Z probe trigger value, offset and trigger height
G31 P500 X9.0 Y-5.0 Z0.20 ; Set Z probe trigger value, offset and trigger height ; osh - 8/25/2017
M557 R85 S20 ; Define mesh grid

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M350 X16 Y16 Z16 E16 I0 ; Configure microstepping without interpolation
M92 X80 Y80 Z80 E404 ; Set steps per mm - Titan extruder - osh 5/5/2017
M566 X1200 Y1200 Z1200 E1200 ; Set maximum instantaneous speed changes (mm/min)
M203 X18000 Y18000 Z18000 E1200 ; Set maximum speeds (mm/min)
M201 X1000 Y1000 Z1000 E1000 ; Set accelerations (mm/s^2)
M906 X1000 Y1000 Z1000 E800 I50 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Heaters
M143 H1 S285 ; Set maximum heater temperature to 285C
M305 P0 T100000 B3950 C0 R4700 H0 L0 ; Set thermistor + ADC parameters for heater 0
M305 P1 T100000 B4388 C0 R4700 H0 L0 ; Set thermistor + ADC parameters for heater 1
M570 H1 P120 T120 ;extend the heater fault timeout to 120 seconds
M307 H1 A569.6 C157.6 D4.7 B0 ; Measured PID for E0 = E3D V6 with 24V 40W cartridge

; Tools
M563 P0 D0 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

; Network
M550 PCharlotte3D ; Set machine name
M552 S1 ; Enable network
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Fans
M106 P0 S0 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S0 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Custom settings are not configured
M579 X1.005 Y0.998 ; adjust based on 100mm XY square - 5/28/2017 - osh

; Miscellaneous
T0 ; Select first tool

dc42

Yes, that one change is sufficient.

JohnOCFII

@dc42:

Yes, that one change is sufficient.

Thanks, David.

deckingman

In the later firmware versions there is a further refinement which may or may not be useful. You can now set a temperature range and the Duet will attempt to control the fan over that range using PWM. I've recently started using T60:140 instead of a fixed "T45" value. What this does is start the fan when the temperature reaches 60 deg C and ramps it up to full speed when the temperature reaches 140 deg C, maintaining full speed at any temperature above 140 deg C. I've found it knocks a few seconds off the warm up time but adds a few seconds to the cool down time, although the fan is quieter during that 140 to 60 degree cool down phase.

JohnOCFII

@deckingman:

You can now set a temperature range and the Duet will attempt to control the fan over that range using PWM. I've recently started using T60:140 instead of a fixed "T45" value. What this does is start the fan when the temperature reaches 60 deg C and ramps it up to full speed when the temperature reaches 140 deg C, maintaining full speed at any temperature above 140 deg C.

Very Interesting! I'll keep a note of that. I'm commissioning a new effector, new fans, new carriages and Haydn's Magball arms in my T3P3 Kossel Mini, so I'm already throwing a lot of change in at this time. If it all works properly, I will certainly consider that option.