Deactivate heater fault detection possible?

CR3D

At the moment we are building a printer in which we preheat the filament chamber with a heater to preheat the filament.

We are currently using Bang Bang Mode. However, it is not easy to do a good tuning with the Chamber.


;Chamber Temp
M308 S3 P"e2temp" Y"thermistor" A"Chamber"T100000 B4725 C7.06e-8 ; Case temp 100k semtek
M950 H3 C"duex.e2heat" T3                           ; create chamber heater output on e1heat and map it to sensor 3
M307 H3 B1 S1.00                               ; enable bang-bang mode for the chamber heater and set PWM limit
M141 P0 H3                                      ; map chamber to heater 3
M143 H3 S70                                  ; set temperature limit for heater 3 to 70C

Is it possible to completely deactivate the heater fault detection for this heater?

We have taken many safety precautions. The heater also has a bi-metal temperature switch which disconnects the voltage if it gets too hot.

Thank you in Advance

Regards Christian from CR-3D

Phaedrux

Which fault specifically are you triggering?

You can make some adjustments to the heater fault detection with M570, this may help. Disabling fault detection entirely would require firmware modification, but I don't think it's something Duet would make available.

https://duet3d.dozuki.com/Wiki/Gcode?revisionid=HEAD#Section_M570_Configure_heater_fault_detection

Tuning a chamber is possible though, so maybe we can work through that route rather than trying to disable a safety feature?

CR3D

@phaedrux

Yes, of course I understand that and that's why I write that we have taken safety precautions.

I have already made the adjustments with M570. It worked so far.

But I'll give an example ... The chamber heats up and maintains the temperature. The fan heater switches itself off and on again. Then the door is thrown open and the Chamber Temp drops drastically as fresh air comes in. And you have a heater fault very quickly.

what I wanted to ask is that you can define the switch-on and switch-off points for bang-bang. It currently switches off and on at every 2 ° C deviation. A larger area would also be sufficient for the filament chamber.

o_lampe

@cr3d said in Deactivate heater fault detection possible?:

Then the door is thrown open and the Chamber Temp drops drastically as fresh air comes in. And you have a heater fault very quickly.

A workaround could be, having a switch at the door to trigger a macro. The macro would temporary switch off the heater and no error would occur. But it might take a few seconds before the macro is activated. An indicator LED triggered by the same macro would help.

The deluxe version would be a pushbutton at the door that activates a solenoid to unlock the door. (after the heater is off)

Phaedrux

Take a look at these threads for ideas on using a door trigger to alter behaviour using conditional gcode.

https://forum.duet3d.com/search?term=door&in=titles&matchWords=all&sortBy=topic.lastposttime&sortDirection=desc&showAs=posts