The drops especially are way too steep for this to be a PID tune. There’s too much thermal mass to loose that kind of temperature basically instantly.
Lots of wandering around? PID tune seems like a good starting point, especially if something on the printer changed. Defying the laws of physics? Something else is going on.
That’s worrying then. He can see the wires broken but it still has enough connectivity to keep chugging.
On the plus side if the thermistor broke enough that it would keep pumping heat into the system then thermal runaway protection should trigger at least.
This is basically spot on. It’s not full open, but it’s close. This is the first print I’ve noticed it on. It wasn’t a long print, so I figured I would let it go and see what happened. If Klipper loses it for too long it will go into thermal shutdown. Ask me how I know :(
There’s no way the hot end’s temperature is changing that much and that rapidly in such a small time period. Rapid 1-2 °C fluctuations? Sure. This is significantly bigger than that.
I think I need more coffee. Does the chart show where the thermistor failed?
I’m kind of worried that it’s not obvious and if it happened to me I’d miss it.
Or is it that it doesn’t show? And, if so, that’s worrying since thermal runaway protection may not trigger properly.
+1. No idea what’s supposed to lead to this conclusion. I’d say that’s a bad PID tune.
The drops especially are way too steep for this to be a PID tune. There’s too much thermal mass to loose that kind of temperature basically instantly.
Lots of wandering around? PID tune seems like a good starting point, especially if something on the printer changed. Defying the laws of physics? Something else is going on.
The short timeframe and variations that are way to high even for a mediocrely tuned PID
That’s worrying then. He can see the wires broken but it still has enough connectivity to keep chugging.
On the plus side if the thermistor broke enough that it would keep pumping heat into the system then thermal runaway protection should trigger at least.
This is basically spot on. It’s not full open, but it’s close. This is the first print I’ve noticed it on. It wasn’t a long print, so I figured I would let it go and see what happened. If Klipper loses it for too long it will go into thermal shutdown. Ask me how I know :(
If you got used to looking at your graph and saw those dropouts, you start looking for a physical problem.
There’s no way the hot end’s temperature is changing that much and that rapidly in such a small time period. Rapid 1-2 °C fluctuations? Sure. This is significantly bigger than that.
Ahh. I see that now. Not cycling like it normally would.