Torturing a 3HC past 100°C, it's still alive!

Hugsy

Hi,

Just a feedback on my experience with a few 3HCs running on a 6HC. Currently, they're running in a heated chamber with a weak cooling solution, got a MCU temperature readout of 107,8°C yesterday and just above 100°C today.
Funny thing is at some point they started to giving out driver "over temperature shutdown" without any "over temperature warning" so they might be in warning mode all the time, I just don't know.

But geez, these things can cook! ^^

infiniteloop

@Hugsy

got a MCU temperature readout of 107,8°C

Thank you for the test. Please let us know when the board is fully cooked.

dc42

@Hugsy thanks for the feedback.

The microcontrollers on Duets are rated at either 85C or 105C depending on what we can get. The LEDs are rated at 85C. Other components are normally 105C or more.

If you overheat the LEDs, the effect is that their brightness will fade more quickly than normal. Running the MCU over its rated temperature may or may not cause it to misbehave.

Hugsy

@dc42 On some boards I observed that some commands were misinterpreted, when we sent an extrusion command we sometimes saw a retraction. On some rare occasions the F speed was completely wrong and the extrusions were too fast (scary fast actually).
This was extremely random though so we added some cooling just to be sure.
This is on 3HC v1.01

dc42

@Hugsy said in Torturing a 3HC past 100°C, it's still alive!:

On some boards I observed that some commands were misinterpreted, when we sent an extrusion command we sometimes saw a retraction

Which firmware were you running? That is a known issue with 3.5.0-beta.3 on some machines.

Hugsy

@dc42 We were running either a custom 3.2 or 3.3 at the time, now we are on a custom 3.4.5 and have 0 issues apart from the missing driver overtemp warning.

dc42

@Hugsy I would expect you to get one overtemp warning from each driver as the chamber and drivers heat up. Only new warnings get reported, so you wont get another one unless you cool the chamber and heat it up again, or do something else that cancels the first overtemp warning.

Hugsy

@dc42 That's also what I expected but looking at the logs I don't see any warning.
Thank you for the insights on the warnings.