I solved it, didnt read enough... The Duex5 inverts the signal depending on how you name the pin in firmware...
The spam bot wont let me change the first post anymore I guess

"Sometimes a pin has multiple names.

Example:

"exp.heater3"
"exp.8"
"duex.e2_heat"
"duex.pwm1"
These four all refer to the heater3 pin, either on the expansion connector (where it is pin #8 of 50) or on the heater output terminal block of a DueX2 or DueX5. However, there is a difference. The DueX boards buffer and invert the signal. Therefore, when you use one of the forms prefixed with duex the firmware knows it has to invert the signal, but it doesn't invert it if you use one of the other forms. In contrast, when you referred to logical pin 3 in previous versions of RRF, the firmware always inverted the signal - so if you were driving a servo or BLTouch from this pin you would have needed to use the I1 parameter in your M280 command."

Ok, I think I see the issue now. I tuned the hotends and retried printing again and had heater faults. It seemed to primarily happen in the dock.

At some point I realized that the the fans are cooling the nozzle (it does have a silicone sock) and that this cooling effect must be amplified but the air getting redirected in the dock which is causing the heater fault.

So now I am wondering:
First should I tune the heater with the print fans running?

Second, I can turn the fan off before it docks, but how do I turn it on? I could hard code the macro to always turn it on but I would like it to turn on only when needed.

I could probably put this in the slicer manually but I dont see an option to so it automatically in the slicer (prusa slicer) anyone have thoughts on that?

Thanks!

Thanks for the replies! I was thinking about doing something along those lines. I guess I will have to make a temporary harness, I have an idea on how to do that without too much grief, then I will have something I can move from tool to tool as necessary. Also Thanks @dc42 for pointing out the M122 command I very likely would have missed that.

If I still have an issue after this tuning method, is there something i can do to get some sort of fault diagnostic message on what is causing the heater fault?

I just started getting a second tool working on my tool changer. I have a duet 6HC with a 3HC expansion.
I am using two Hemeras with pt1000 sensors.

I have had a lot of good prints using 1 tool. I just added a second tool and I seem to get random tool faults, I have no idea what the fault is there are no temperature spikes on the graph and nothing I seem to do will actually log any information about what is causing heater fault.

Side note it appears there is no way tune a tool heater attached to a 3hc board I am wondering if this has something to do with the fault as I don't k ow what to do to get tuning parameters.

@ChrisP That does get me closer to what I am going for, I will try it out later, thanks.

@dc42 said in Bed minimum heating time.:

M143

I think this is the solution I am looking for but I am not sure how you implement it. Right now I am only displaying the second sensor attached the the aluminum and waiting for them to match visually.

So I have this in my config:

	; Main Board
	M308 S0 P"0.temp0" Y"thermistor" T100000 B3950 A"Bed"		; Silicone Pad
	M308 S5 P"0.temp1" Y"thermistor" T10850 B2900 A"BedT"		; Thermal Lug

	M950 H0 C"0.out0" T0						; Bed.  H = Heater 0, C is output for heater itself, T = Temperature 

	;*** Max Temp ***
	; Main Board
	M143 H0 S130								; Set maximum temperature for bed to 130C

sensor (defined above)

So I would rather make the heater using the Thermal lug attached to the aluminum, but I am not sure how you use the center sensor to limit how hot the pad can get while heating the plate. You cant assign both senors to the heater can you?

This might be where virtual heaters come into play but I understand those even less.

@jens55 That type of thing sounds great, but where and how do you run a loop of code like that?

@jens55 The only thing I am afraid of is say I want to run abs at 110, I have magnets that will die at 150 so I have thermal cutoff fuses to prevent that. I am unsure how hot the center could get before the edge warms up. I know 30-40c quite a ways off but I just wanted some sort of protection from getting too hot in the center.

There is substantial lag at the edge, when it goes to 60 I think at one point I think have around 15-20C of separation. I haven't spent the time to really gauge it yet so I am not 100% sure what the max separation is.

@Phaedrux That is definitely a work around, if I don't want to use the edge sensor. Just wanted to have something a little more complete if possible. Especially if I am running back to back prints and don't a 5 min delay every time I go to print. Yes of course I could turn the delay on and off... until I forget then its a pain.

But for the time being I do something similar to what your suggesting.

I have a middle sensor on a silicone pad and a sensor on the edge of the bed a lot like this post:

https://forum.duet3d.com/topic/2098/multiple-combined-thermistors-for-a-single-tool-heatbed/3

So the idea is I set one of the sensors as a virtual heater. The part I am unclear on is what I do with the virtual heater once its created.

For the sake of argument lets say the center heats to 60 in 1 min and the edge heats to 60 in 5 min.
What I would like is to heat the bed based on the edge value to ensure the bed is fully at temp but I don't want the center to get hotter then say 5 degrees or so past 60 to prevent a massive overshoot and protect the thermal fuse

In summery, If I heat using the edge sensor, but make a virtual heater in the center, how do I set the virtual heater to be a cop to prevent overtemp? Is this possible?

I am using:
Board: Duet 3 MB6HC (MB6HC)
DSF Version: 1.2.4.0
Firmware: RepRapFirmware for Duet 3 MB6HC v0.6 or 1.0 3.0 (2020-01-03b3)

I solved it, didnt read enough... The Duex5 inverts the signal depending on how you name the pin in firmware...
The spam bot wont let me change the first post anymore I guess

"Sometimes a pin has multiple names.

Example:

"exp.heater3"
"exp.8"
"duex.e2_heat"
"duex.pwm1"
These four all refer to the heater3 pin, either on the expansion connector (where it is pin #8 of 50) or on the heater output terminal block of a DueX2 or DueX5. However, there is a difference. The DueX boards buffer and invert the signal. Therefore, when you use one of the forms prefixed with duex the firmware knows it has to invert the signal, but it doesn't invert it if you use one of the other forms. In contrast, when you referred to logical pin 3 in previous versions of RRF, the firmware always inverted the signal - so if you were driving a servo or BLTouch from this pin you would have needed to use the I1 parameter in your M280 command."