After 19 hours of printing: Printing paused:heater fault

c310

David, can it be something with my board or firmware (fault detection algorithm) ??
i replaced heat cartridge again... and system was printing fine for a day or two. yesterday as a sudden heater fault again.
i pulled it from outlet and decided to try next morning... results are very strange... very.

my steps:

i switched system on and
almost immediately connected via web interface.
almost immediately i faced "temperature excursion exceeded 15.0C"

in wiki this error residing in "maintaining temperature" section. but in my case it was only heating up for few seconds.

config.g related
M563 P0 D0 H1 F0
G10 P0 S200 R180
M570 S120 H1 P10 T15
M305 P1 X200

@dc42, how that can take place???? how does duet board detect failure???
is there something i can test on the board?

dc42

If you got that heating fault message after you reconnected DWC to the Duet after the Duet had already reported a heating fault, then that message is probably a duplicate of an earlier one.

If you restarted the Duet after that heating fault, then I suspect you have both temperature setting and tool selection commands in config.g. I see that you have G10 P0 S200 R180 in config.g. Do you have a T0 command in config.g as well? If so, do you really mean to heat up the extruder as soon as the printer is turned on?

c310

yes, T0 is there.

and i keep printer off when not printing, and i found it convenient to heat up head immediately.

by the way, is there similar command to heat up bed?

i still got the same error after ~30 sec after power on....
"Error: Heating fault on heater 1, temperature excursion exceeded 15.0°C"

so what is your verdict over my machine?

dc42

I never expected anyone to put a heating command in config.g so I haven't tested it or thought through the potential complications.

c310

i removed G10 from config.g now printer starts without error.

after print starts .... some time later temperature very slowly goes down.

could it be some power issues? i have ordered new heaters, but afraid that would not help .

dc42

Yes it could be power issues. Check the VIN voltage display in Due Web Control. Also check that the screws in the terminal blocks that the heaters are connected to and the screws in the VIN terminal block are still tight.

c310

what kind of AWG will be suitable for 1m cable and 50W heater?

dc42

Is the heater 12V or 24V?

c310

now it is 12v, after upgrade will be 24

dc42

A 12V 50W heater draws about 4.2A and a 24V 50W heater draws 2.1A. There are tables online giving maximum recommended current for different wire gauges.

c310

well, my cable is 0.75 sq.mm. that is more than enough for 4 amps and 1 m... will test other cable, but do not think it will help.