Yes, I know this must be the thousandth thread about this topic, but unfortunately I just can’t get any further.
I have already tried all the solutions of other threads without any success.
I get the error “heater extruder not heating at expected rate” more or less at random.
I have already tried all the changes in the config file. Most recently I even set the min_extrude_temp to 0. The error still came back.
I have also already replaced the complete hotend. This includes the sensor and the thermistor to rule out a hardware error. What else can I do? I really don’t know.
The error starts in line 3940 of the log file. You can see the temperature jump of almost 100 degrees. How can that be?
I hope someone can offer me a simple solution here. It is enough for me to simply adjust the config file so that the printer runs. I never let it run on its own anyway.
More than likely a failing connection, maybe a frayed wire contacting the frame or metal housing.
A not fully broken wire, causing an intermittent break or grounding.
Movement of the connector wire causing an intermittent break or additional resistance.
Check these while on to see if you can cause the spike.
Also, you might look into these adjustments
[verify_heater extruder] #max_error: 120 #The maximum “cumulative temperature error” before raising an error. Smaller values result in stricter checking and larger values allow for more time before an error is reported. #Specifically, the temperature is inspected once a second and if it is close to the target temperature then an internal “error counter” is reset; otherwise, if the temperature is below the target range then the counter is increased by the amount the reported temperature differs from that range. Should the counter exceed this “max_error” then an error is raised. The default is 120.
check_gain_time: 50 #This controls heater verification during initial heating. Smaller values result in stricter checking and larger values allow for more time before an error is reported.
Specifically, during initial heating, as long as the heater increases in temperature within this time frame (specified in seconds) then the internal “error counter” is reset. The default is 20 seconds for extruders and 60 seconds for heater_bed. #hysteresis: 5 #The maximum temperature difference (in Celsius) to a target temperature that is considered in range of the target. This controls the max_error range check. It is rare to customize this value. The default is 5. #heating_gain: 2 #The minimum temperature (in Celsius) that the heater must increase by during the check_gain_time check. It is rare to customize this value. The default is 2.
To be more specific. I already had the problem with my old hotend. I suspected a hardware problem and ordered a new one. I also looked at this thoroughly before installing it. All cables looked ok and were not damaged or kinked.
Even now after several troubleshooting sessions everything still looks fine.
So the question is, where is Klipper reading this wrong value so suddenly?
I will try the parameters described by @NAPCAL. Maybe they will at least stop the shutdown.
From the laws of physics, such sharp temperature drops are impossible. When one experiences such drops, they are usually due to some hardware defects, typically around the thermistor.
I would not recommend playing with the heater’s settings. While you might be able to “hide” your issue and force Klipper to continue, it will not solve the problem and may create additional unwanted effects.
Sineos is right: such sharp temperature drops are impossible.
The 3D printer is a complicated machine with a lot of wires and parts. Maybe something has gone wrong with one of these components. It may not actually be the hotend thermistor but something else in the machine…
(sorry if I did or said something wrong here, I’m kinda new to this…)
@Sineos, I think my debugging advice got misunderstood. I was recommending making changes in the [verify_heater extruder] section temporarily to hold off the shutdown so the wiring fault could be found by watching the temperature graph and tracing it down. Then, after the repair has been confirmed, I would return the [verify_heater extruder] section to its default.
Indeed, I might have misunderstood the intention. This makes sense, of course. Thanks for clarifying, @NAPCAL. (Actually, I was already surprised to read such a comment from you )
@NAPCAL
your advice helped me a lot. Printer is running fine since i implemented these commands. Next step is to find the main reason for this error. But for now i’m fine with this solution.
Maybe after 5 years time has come for a new and bigger one.
Exactly, this should not be the case.
This is not, and in no way, a solution—it is merely a debugging advice and not a fix. You are experiencing an issue, and now it is just hidden, likely causing problems that could lead to catastrophic failures.
@vierringe, I fully agree with Sineos. Since the temperature reading doesn’t seem to show a drop below zero per the thermal graph, even though the klipy log does, it would be very difficult to get direct feedback from the log. You will need to use the temperature graph during the print head movement to find a common movement that triggers the quick temperature drop. This can lead you to the area of the fault.
The section [verify_heater extruder] is a safety feature that shuts down the printer to prevent the room where this printer is located from burning. So don’t leave the printer unwatched when printing.
Basically, it has detected an abnormal reading, so it doesn’t know if the hotend is heating beyond the safe operating boundary, so to be safe, it shuts down.
@NAPCAL, this is exactly the typical reaction when pointing users to such settings (at least from my experience):
Oh, the engine control indicator of my car is lit bright red.
Let’s put a nice smiley sticker on the light.
Voilà, I don’t see it anymore. Problem fixed.
This is also the difference between, e.g., Marlin and Klipper, which quite a few users do not appreciate:
Marlin:
“See, I have put a nice red light up. You may safely ignore it; it only has decorative purposes, and I won’t bother you with any pesky actions.”
Klipper:
“Here you have an ugly error message, and I’m not going to move a millimeter unless you fix this crap.”
)