Hi guys,

I did some testing this morning.
in fact, what I see as a problem here is the remaining heat on the heater. It can be very hot when I stop heating with it.
I need the fan to continue running for a few seconds once the heater is off to cool it down.
I was so sure to have this kind of feature in the firmware, that i didn't check at all. This is the behavior I see as optimal:

-> heater ON -> Turn fan ON
-> Heater OFF -> Let fan ON for a delay then turn OFF

It seems simple, but I can't seem to find a way to implement this. If anybody knows how to do this, then I would love to hear it. I see the solution with the thermistor can do this, but I thought it might be simpler to have it straight from the firmware.

thank you and have a nice day

@dc42
Yes I can do this. I was more looking for a straight ON FAN when heating, but this seems safe enough.
When I hooked it up to another output, I had problems with PWM.
I'll test it and see what it does.

thank you!

@phaedrux I could put it straight on the heater, but then I got 2 heaters...
I don't love this solution, but it's a good backup.

thank you for your help

Hello,

i just installed my Duet2 ethernet (V1.04a) on my 3D printer here and I have faced a little difficulty here. Firmware version is 2.01

I have a chamber heater with fans for spreading the heat around. The fans are on a separated connection.
So right now I plugged my heater in heater E6 connection and my fan on E3 fan connection (on the DUEX 5 board).
My problem is that I can't find a way to start the fan as soon as the heater is turned on. I could use a thermostatic control, but the thermistor is quite far away from the heater and i'm pretty sure I'll burn some stuff before getting a temperature rise to start the fan. Is there a way to start the fan on at full power as soon as I start the heater without having it on all the time?
I don't want to simply have the fan controlled by separate G-code because there is too much risk of someone forgetting to turn it on.

thank you and have a nice day