Implementing heating error panics?
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Hi guys,
Im nearly done with my printer setup! One thing I would like to consider is the way the printer responds to heating errors (to prevent a fire). The way I see it there are three main concerns:
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Temperature rising when not instructed to.
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Temperature not rising when instructed.
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Temperature dropping in a print.
Case 1 seems to be the most critical and would indicate some kind of always on failure (perhaps a mosfet failure) - this is a serious issue as the duet cant turn off the heater which would lead to a prompt fire (or machine damage). I dont know how common this is but ideally I’d like the duet to activate a digital I/O which will in turn kill the mains power (basically printer suicide) and stop any kind of further heating.
Cases 2 and 3 seem to suggest a heating cartridge failure or that the thermistor or heater carriage has become detached from the print head. and so is less critical than the first can can be resolved by simply pausing the print and turning heaters off.
How would I implement this with the duet? Is there a way to modify its panic behaviour to include the digital signal out?
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See this thread:
https://forum.duet3d.com/topic/3156/how-should-the-firmware-respond-to-a-heater-fault/17
There are heater fault actions recently implemented, but we are waiting on clarification on their behaviour as release notes and wiki don't agree.