E3D V6 nozzle with Ormerod 2.

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dc42

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Traumflug

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derek5a
BUT It mentions that the command doesn't work with any firmware?

Perhaps, because it's an entirely pointless command. Temperature is controlled all the time, so before temperature gets even close, heaters are already turned off.

It needs quite some imagination to construct a case where such a temperature is reached and the firmware manages to avoid damage. If the firmware works, it doesn't get there and if the firmware doesn't work, it's unlikely it can heal its self. Instead of writing such code it's better to make sure the existing code is reliable.

My main business is safety critical software. Where the software is necessarily complex (as it is for a 3D printer), and the safety-critical functions (controlling temperature in this case) are coupled with other functions (which is the case here because both are done in the main loop, and other things may delay repetition of the main loop), it is good practice to have independent and much simpler code to monitor safety. So RepRapFirmware checks the thermistor readings against lower and upper limits every time it reads them. It reads one thermistor every other tick interrupt, so on a Duet that's each thermistor every 14ms. If the tick interrupt fails, the hardware watchdog will reset the machine, turning off all the heaters.

So in the context of RepRapFirmware, M143 is not a pointless command, because it would be used to set the safety limit in the config.g file. The current fixed limit of 300C is a reasonable limit for most users, but not for this particular one. The limit is also the maximum temperature that we allow the user to set. I don't know whether in Teacup you guard against a user sending M104 S2250 when he meant M104 S250, but in RepRapFirmware we do.

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derek5a
Any idea how long away that is likely to be?

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derek5a
It tends to through up an error because it didn't reach temp in 150secs. So i'm having to heat up the hot end in stages... But other than that no issues.