Extruder temperature is going crazy.

If I leave the extruder heater at let say 250 celsius for 30 minutes is pretty stable. During the print is reaching insane high peaks. I've not been using the printer so much lately but last time there were no issue at all. Now I cannot complete even the firstlayer_test print which is a 25 minutes print. What's happening?
No description
42 Replies
TheTik
TheTik4mo ago
Have you run a PID_CALIBRATE ?
Moophlo
Moophlo4mo ago
yes few minutes ago and without any issue
TheTik
TheTik4mo ago
those spikes actually seem too steep to be real thermistor might be going bad at those temps? and mis-reporting, causing the heater to turn on when it shouldn't be?
Moophlo
Moophlo4mo ago
maybe but how to fix. I've a genuine phaetus the one from the basic vcore standard kit is not supposed to fail after less than 50 hours print
Moophlo
Moophlo4mo ago
here the logs, don't know if it can help
TheTik
TheTik4mo ago
replace would be the fix and/or diagnostic step Actually, triple check the thermistor wiring too Does the PID_Calibrate show the same spikes?
Moophlo
Moophlo4mo ago
zero perfect
blacksmithforlife
Are you using the MAX31865 chip? I and others have had issue with that causing the PT1000 thermistor to read +/- 3℃
TheTik
TheTik4mo ago
So it only does it under heating AND motion, further suggesting its a wiring issue
Moophlo
Moophlo4mo ago
again i can leave the printer unattended at 240 celsius the temperature doesn't make a move, is a perfect flat line
TheTik
TheTik4mo ago
The spikes are bigger than that
Moophlo
Moophlo4mo ago
speaking of spikes of +160°
blacksmithforlife
yeah that sounds like a wiring issue if it is only happening while it is moving
Moophlo
Moophlo4mo ago
Write g-code response
Traceback (most recent call last):
File "/home/pi/klipper/klippy/gcode.py", line 459, in _respond_raw
os.write(self.fd, (msg+"\n").encode())
BlockingIOError: [Errno 11] Resource temporarily unavailable
Stats 6316.2: gcodein=0 mcu: mcu_awake=0.000 mcu_task_avg=0.000000 mcu_task_stddev=0.000000 bytes_write=3195 bytes_read=6745 bytes_retransmit=9 bytes_invalid=0 send_seq=268 receive_seq=268 retransmit_seq=2 srtt=0.001 rttvar=0.000 rto=0.025 ready_bytes=0 upcoming_bytes=0 freq=179979189 Octopus: temp=0.0 raspberry_pi: temp=51.5 heater_bed: target=0 temp=0.0 pwm=0.000 sysload=0.71 cputime=381.499 memavail=434864 print_time=0.000 buffer_time=0.000 print_stall=0 extruder: target=0 temp=0.0 pwm=0.000
Write g-code response
Traceback (most recent call last):
File "/home/pi/klipper/klippy/gcode.py", line 459, in _respond_raw
os.write(self.fd, (msg+"\n").encode())
BlockingIOError: [Errno 11] Resource temporarily unavailable
Stats 6316.2: gcodein=0 mcu: mcu_awake=0.000 mcu_task_avg=0.000000 mcu_task_stddev=0.000000 bytes_write=3195 bytes_read=6745 bytes_retransmit=9 bytes_invalid=0 send_seq=268 receive_seq=268 retransmit_seq=2 srtt=0.001 rttvar=0.000 rto=0.025 ready_bytes=0 upcoming_bytes=0 freq=179979189 Octopus: temp=0.0 raspberry_pi: temp=51.5 heater_bed: target=0 temp=0.0 pwm=0.000 sysload=0.71 cputime=381.499 memavail=434864 print_time=0.000 buffer_time=0.000 print_stall=0 extruder: target=0 temp=0.0 pwm=0.000
this is on the logs
blacksmithforlife
BlockingIOError: [Errno 11] Resource temporarily unavailable
what kind of SD card do you have and how old is it?
Moophlo
Moophlo4mo ago
on the raspberry you mean?
blacksmithforlife
yes
Moophlo
Moophlo4mo ago
is pretty new like 128GB
blacksmithforlife
what brand?
Moophlo
Moophlo4mo ago
I've to check for brand and model but high performance
blacksmithforlife
I trust the logs when it says it is having trouble writing to disk
Moophlo
Moophlo4mo ago
SanDisk 256GB Extreme Pro mmm
blacksmithforlife
yeah that should be a good card. Maybe it got damaged if you are seeing a lot of that in the logs
Moophlo
Moophlo4mo ago
Raspberry Pi Diagnostics - version 0.13
Sun Apr 21 22:22:22 2024

Test : SD Card Speed Test
Run 1
prepare-file;0;0;19793;38
seq-write;0;0;19464;38
rand-4k-write;0;0;2938;734
rand-4k-read;6829;1707;0;0
Sequential write speed 19464 KB/sec (target 10000) - PASS
Random write speed 734 IOPS (target 500) - PASS
Random read speed 1707 IOPS (target 1500) - PASS
Test PASS
Raspberry Pi Diagnostics - version 0.13
Sun Apr 21 22:22:22 2024

Test : SD Card Speed Test
Run 1
prepare-file;0;0;19793;38
seq-write;0;0;19464;38
rand-4k-write;0;0;2938;734
rand-4k-read;6829;1707;0;0
Sequential write speed 19464 KB/sec (target 10000) - PASS
Random write speed 734 IOPS (target 500) - PASS
Random read speed 1707 IOPS (target 1500) - PASS
Test PASS
I'm trying an fsck let see with no print running:
Moophlo
Moophlo4mo ago
No description
TheTik
TheTik4mo ago
thats pretty steady with no movement
Moophlo
Moophlo4mo ago
meanwhle I'm running a benchmark:
Moophlo
Moophlo4mo ago
No description
Moophlo
Moophlo4mo ago
No description
Moophlo
Moophlo4mo ago
40 minutes without a single spike
Moophlo
Moophlo4mo ago
can this be the cause?
No description
TheTik
TheTik4mo ago
Yeah, undervolting things wil result in unpredictable behavior. And a thermistor is just a resistor, so if you're trying to measure voltage drop...
Moophlo
Moophlo4mo ago
updates: changed RPI 3b+ with RPI 4 update2: the rPI is not powered anymore with GPIO, but has a separate power supply at 3A system load is under 0.5
Moophlo
Moophlo4mo ago
No description
Moophlo
Moophlo4mo ago
No description
Moophlo
Moophlo4mo ago
with some luck maybe I'll be able to complete firstlayer_test print but still it doesn't look good at all
Moophlo
Moophlo4mo ago
No description
Moophlo
Moophlo4mo ago
why? why? why? 😢 why the last 9 minutes of the print were stable? It was a wiring issue
TheTik
TheTik4mo ago
Tada! Glad you found it 😎
galile0
galile03mo ago
Hi, would you care to elaborate on what the wiring issue was? I am experiencing similar issue on my VC3.1 with Rapido PT1000. Might be in the same spot, considering it seems to be the same setup
Moophlo
Moophlo3mo ago
Most likely it was a cold soldering I put the temperature high and than with the hand I bended spot by spot all the wiring group from the hotend to the frame And found out that touching in a specific point the temperature was sky rocketing So as I'm a moron and I didn't want to disassemble and redo properly the junction I just put there ten zip ties at half a centimetre one from the other very very tight and the problem never showed again
galile0
galile03mo ago
Okay, thanks ill go bend some wires then