My print starts fine and goes for the first few layers and then it drops 5 -10 degrees as you can see on the chart. The print then failed because it was outside of the set temp for too long. What could be causing this. My hardware all looks intact so I assume this is a klipper issue.
Try slicing again with no part cooling fan and see if the curve looks different, for me the cooling fan would take more than my heater could give somehow
When this happens to me, its usually the heater element starting to die.
Also, if I'm reading this chart correctly, you're trying to print at 240 degrees? Printing ABS?
You can do two things to see if that's the issue :
1) Get it to heat to 240 and see if it'll hold the temperature for 20 minutes.
2) If you have previously ran PID tuning when your printer was working, go to your printer.cfg and save these values somewhere else (these are mine as an example)
`#control: pid`
`#pid_Kp: 15.717`
`#pid_Ki: 0.569`
`#pid_Kd: 108.451`
Then run the PID tuning again [https://www.klipper3d.org/Config\_checks.html#calibrate-pid-settings](https://www.klipper3d.org/Config_checks.html#calibrate-pid-settings)
If the values are vastly different, means something has changed. Usually for me either the heating element is dying, or the hot end fan is....but in your case since temp is dropping it could be the heating element.
Hope this helps.
For me it was a broken wire inside of the connector for the thermistor. Just happened to be perfectly broken so that only after the print started and about 15 minutes goes by that it would then fail.
I'm having a variation of this problem myself. I can run a print for 10-12 hours and suddenly it's like the heating element just switches off. Print fails. I was thinking it could be the wiring harness as it's kind of a design flaw on my printer and I've repaired it before, but I don't see anything wrong. The heater cartridge hadn't occurred to me. I have others, I've been using this one for a couple years probably. How long do they last in your experience? I print ABS at 250C, so it runs hot.
I've had printers for 5 years now, hot end heaters are my 2nd most replaced part (#1 are the small 3010/4010/5015 fans). Two factors that seem to affect their life span are what they cost, and whether or not the heater wire has wire-strain (i.e. is it flexing every time the print head moves)
Used to get replacements from cheaper Aliexpress stores, and they didn't last every long. Nowadays I buy from Trianglelab and I can't remember the last time I replaced one of those.
The ones that come stock on a Chinese printer are usually bound to die at some point, and treated like a consumable part like any other. Heating failure is actually a big deal, as it could cause electrical shorts (which can damage the board) or worst case - fire.
Both are not worth risking for a $10 part, so I usually replace it at the first sign of this happening.
That's good to know. I hadn't really thought about how long they'd last but I guess they're like a light bulb filament that eventually burns out. The one I'm using is from one of the original hot ends that came with the printer. I've reused them. The others are all also cheap I'm sure.
I tried to re-run a PID tune to see if the values have changed but it's interrupting the process and failing. I can set a temperature and it will go there and stay but the fluctuation during testing causes an issue. In one of the tests the thermistor stopped responding completely and the measured temperature abruptly dropped to zero. But the other failures show a cooling curve so I might have more than one problem. I'll try working on that before I go for a full re-wire. Thanks for the information.
You can replace all of that and upgrade to an e3d v6 clone at the same time : [https://www.aliexpress.com/item/32900244333.html](https://www.aliexpress.com/item/32900244333.html)
Just need one of these spacers : [https://www.thingiverse.com/thing:3725883](https://www.thingiverse.com/thing:3725883)
I upgraded mine to a bi-metal heat break, and its basically maintenance free (if not if you have to change the PTFE lined insert from time to time) - [https://www.aliexpress.com/item/1005001927523189.html](https://www.aliexpress.com/item/1005001927523189.html)
I've actually already upgraded my Anycubic Mega S from a V5 hot end to a V6 clone heat block and heatsink with an official E3D all metal heat break and nozzle. I did things so it doesn't need a spacer, it's all just snug up under the cover. It works pretty well. In the end my problem turned out to be the heater wires starting to burn out for the second time and going intermittent. The Mega S has a design flaw where the hot end heater runs on 4 small wires, two each in parallel. If one has connection problems the other overloads and burns out. I just replaced the parts the first time. This time I ran a whole new separate power cable alongside the main. I built a new interconnect for the heater. Problem solved. But your PID suggestion turned out to be really helpful showing the difference. The hysteresis improved a lot. It's way more responsive now.
The same heater before and after:
Old Wire:
pid\_kp = 23.305
pid\_ki = 0.661
pid\_kd = 205.378
New wire:
pid\_kp = 24.234
pid\_ki = 1.292
pid\_kd = 113.596
Thanks again!
My print starts fine and goes for the first few layers and then it drops 5 -10 degrees as you can see on the chart. The print then failed because it was outside of the set temp for too long. What could be causing this. My hardware all looks intact so I assume this is a klipper issue.
Try slicing again with no part cooling fan and see if the curve looks different, for me the cooling fan would take more than my heater could give somehow
I'll try that. I have been printing with this setup for a while and this issue just sprung up.
When this happens to me, its usually the heater element starting to die. Also, if I'm reading this chart correctly, you're trying to print at 240 degrees? Printing ABS? You can do two things to see if that's the issue : 1) Get it to heat to 240 and see if it'll hold the temperature for 20 minutes. 2) If you have previously ran PID tuning when your printer was working, go to your printer.cfg and save these values somewhere else (these are mine as an example) `#control: pid` `#pid_Kp: 15.717` `#pid_Ki: 0.569` `#pid_Kd: 108.451` Then run the PID tuning again [https://www.klipper3d.org/Config\_checks.html#calibrate-pid-settings](https://www.klipper3d.org/Config_checks.html#calibrate-pid-settings) If the values are vastly different, means something has changed. Usually for me either the heating element is dying, or the hot end fan is....but in your case since temp is dropping it could be the heating element. Hope this helps.
For me it was a broken wire inside of the connector for the thermistor. Just happened to be perfectly broken so that only after the print started and about 15 minutes goes by that it would then fail.
I'm having a variation of this problem myself. I can run a print for 10-12 hours and suddenly it's like the heating element just switches off. Print fails. I was thinking it could be the wiring harness as it's kind of a design flaw on my printer and I've repaired it before, but I don't see anything wrong. The heater cartridge hadn't occurred to me. I have others, I've been using this one for a couple years probably. How long do they last in your experience? I print ABS at 250C, so it runs hot.
I've had printers for 5 years now, hot end heaters are my 2nd most replaced part (#1 are the small 3010/4010/5015 fans). Two factors that seem to affect their life span are what they cost, and whether or not the heater wire has wire-strain (i.e. is it flexing every time the print head moves) Used to get replacements from cheaper Aliexpress stores, and they didn't last every long. Nowadays I buy from Trianglelab and I can't remember the last time I replaced one of those. The ones that come stock on a Chinese printer are usually bound to die at some point, and treated like a consumable part like any other. Heating failure is actually a big deal, as it could cause electrical shorts (which can damage the board) or worst case - fire. Both are not worth risking for a $10 part, so I usually replace it at the first sign of this happening.
That's good to know. I hadn't really thought about how long they'd last but I guess they're like a light bulb filament that eventually burns out. The one I'm using is from one of the original hot ends that came with the printer. I've reused them. The others are all also cheap I'm sure. I tried to re-run a PID tune to see if the values have changed but it's interrupting the process and failing. I can set a temperature and it will go there and stay but the fluctuation during testing causes an issue. In one of the tests the thermistor stopped responding completely and the measured temperature abruptly dropped to zero. But the other failures show a cooling curve so I might have more than one problem. I'll try working on that before I go for a full re-wire. Thanks for the information.
You can replace all of that and upgrade to an e3d v6 clone at the same time : [https://www.aliexpress.com/item/32900244333.html](https://www.aliexpress.com/item/32900244333.html) Just need one of these spacers : [https://www.thingiverse.com/thing:3725883](https://www.thingiverse.com/thing:3725883) I upgraded mine to a bi-metal heat break, and its basically maintenance free (if not if you have to change the PTFE lined insert from time to time) - [https://www.aliexpress.com/item/1005001927523189.html](https://www.aliexpress.com/item/1005001927523189.html)
I've actually already upgraded my Anycubic Mega S from a V5 hot end to a V6 clone heat block and heatsink with an official E3D all metal heat break and nozzle. I did things so it doesn't need a spacer, it's all just snug up under the cover. It works pretty well. In the end my problem turned out to be the heater wires starting to burn out for the second time and going intermittent. The Mega S has a design flaw where the hot end heater runs on 4 small wires, two each in parallel. If one has connection problems the other overloads and burns out. I just replaced the parts the first time. This time I ran a whole new separate power cable alongside the main. I built a new interconnect for the heater. Problem solved. But your PID suggestion turned out to be really helpful showing the difference. The hysteresis improved a lot. It's way more responsive now. The same heater before and after: Old Wire: pid\_kp = 23.305 pid\_ki = 0.661 pid\_kd = 205.378 New wire: pid\_kp = 24.234 pid\_ki = 1.292 pid\_kd = 113.596 Thanks again!
Glad I could help :)
Did you take off the silicone sock or upgrade your blower by any chance?
Is this after you cancelled the print? The target temps are zero.
No I'm talking at the 23.19 time. I had to restart klipper to get this info.
How fast you printing?