PID Autotune and may Thermal Runaways.
Hi guys,
i have upgraded to e3d V6 Lite reasonably, made successful parts and - of course - did PID Autotune.
Right now i am printing PLA @220/60 and i had my third Thermal Runaway Error.
Did PID Autotune again. Same thing. Is there anything in Marlin (the fresh RC) to tweak?
The Hotend has its sock on wich helped a lot a while ago.
Any ideas would be appreciated.
oliver
Marlin3DprinterTool has a “one-button” solution for AutoTune of PID. The graph of the temperature is scaled to be ± 20C on the current temp. It should be visible if there is somthing wrong with the thermistor connection and/ör heter cartridge.
Doesn’t appear to be thermal runaway. It looks instead like a faulty connection to the thermistor. The downward spikes, and corresponding ‘recovery’ which occurs at a rate much faster than your hotend heats up suggests the temperature readings aren’t reliable.
I would check for failing connectors, ensure the thermistor is secured in the heater block, and finally try to determine if the wires to the thermistor are failing.
Was the printhead moving or stationary over the 25 minute period shown in the image?
Thank you for your answers! The Printhead was moving. Delta Printer. I did not found any loose screws or broken cables. I have decided to reassemble the printhead for no reason. Did PID Autotune and: It worked so war. Looking good!
How i have to get that stupid Bon Jovi song out of my head again. 
Noise in the signal with the printhead moving does still point toward cable failure. The best analogy I can think of, would be to ask if you’ve ever had a pair of headphones slowly stop working.
One day they’re fine. Another day, one ear occasionally clicks or produces short bursts of static. Eventually that ear stops working all together.
Looking for this kind of failure with a multimeter is non trivial until the cable completely fails. I’ll admit, this is speculation by someone who has even seen your machine or cables involved, but that’s how I interpret the graph you shared.
Best of luck! 
@jesse_dean good point! i will check this tomorrow.
I second a cable or connection issue, those spikes are pretty gnarly. Good luck!
