Heater Temperature Excursion
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@Phaedrux said in Heater Temperature Excursion:
How is your wiring for the thermistors ran?
The graph in your first photo is clearly signal noise. It thinks the temp is dropping and increases power to maintain temp, but then it gets a real reading and sees the temp is actually hotter than expected and triggers the fault.
I would be inclined to replace the thermistor and wiring entirely.
Thanks for the tip @Phaedrux, in my delta I have 3 wiring harnesses (one in each tower) and the hotend thermistor was running along side the hot end fan for a long distance.
I moved the fan to a different harness and was able to print without errors again, though the noise was significantly higher in the bed thermistor for some reason. (does not go through that harness at all).
I can't really understand why this issue suddenly popped up, and I can't say that I feel like I solved it since the temperature readings for the bed were so noisy in the beginning (but became completely smooth after the bed was up to temp).
Is there perhaps a way to filter transients in the temperature probe? (I meam physically, like a ferrite or a capacitor)
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@Leav said in Heater Temperature Excursion:
Is there perhaps a way to filter transients in the temperature probe? (I meam physically, like a ferrite or a capacitor)
Not sure about that.
Twisted pair and/or shielded cable can help avoid picking up noise. A PT100 in 4 wire mode is a good choice in this situation as it is designed to reject noise.
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@Leav For heatbed this looks like a noise, but honestly... 50*C drop for about 60 seconds? That is not a noise. That looks like poor connection to heater.
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@BoA said in Heater Temperature Excursion:
That looks like poor connection to heater.
If it was actually losing connection it would show open circuit and temp would shoot to 2000c to trigger fault.
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@Phaedrux It would show open circuit in case of problem with thermistor, but on second pic it looks like bad connection to heater.
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Hi,
I'm bringing up this old thread since I am still chasing heater faults...
This happened ~3 hours into a print, after the following changes to the system:
- Changed heater cartridge (new)
- Changed to thermistor in cartridge form factor
- Added silicone sock (even though there is no
- Tuned the new heater configuration
Unfortunately I was not near the printer at the time so the temperature graph was lost to the sands of time, but it was and is smooth when I look at it now.
Are there any ideas or suggestions for other things to look for that could cause this? quite annoying to have what looks to be a solid setup interrupted by inexplicable random hiccups like this.
Looking at M122 response, I found this line:
... === Platform === Slowest loop: 581.48ms; fastest: 0.12ms ... === Network === Slowest loop: 581.68ms; fastest: 0.00ms WiFi signal strength -72dBm, reconnections 0, sleep mode modemThat looks like a suspiciously long loop time to me, and could also perhaps explain minor hiccups/stuttering i've been noticing in the delta motion?
The correlation to the network loop time is too close to be coincidental...
Is this abnormal?
I added the Signal strength since atheory has already been brewing in my head that:
Weak signal -> Network Lags -> CPU lags -> heater control loop losing control -> temperature excursion...What do you think?
Thanks for your time and ideas!
Full M122:
M122 === Diagnostics === RepRapFirmware for Duet 2 WiFi/Ethernet version 3.1.1 running on Duet WiFi 1.02 or later Board ID: 0JD0M-9K662-MGPSS-6J1FD-3S46N-TVU6Y Used output buffers: 3 of 24 (18 max) === RTOS === Static ram: 27980 Dynamic ram: 93124 of which 48 recycled Exception stack ram used: 592 Never used ram: 9328 Tasks: NETWORK(ready,308) HEAT(blocked,768) MAIN(running,1732) IDLE(ready,80) Owned mutexes: WiFi(NETWORK) === Platform === Last reset 06:06:23 ago, cause: software Last software reset at 2020-10-10 13:09, reason: User, spinning module GCodes, available RAM 9424 bytes (slot 2) Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0441f000 BFAR 0xe000ed38 SP 0xffffffff Task MAIN Error status: 0 MCU temperature: min 29.3, current 38.1, max 43.7 Supply voltage: min 23.7, current 24.1, max 24.3, under voltage events: 0, over voltage events: 0, power good: yes Driver 0: standstill, SG min/max 2/423 Driver 1: standstill, SG min/max 13/423 Driver 2: standstill, SG min/max 41/408 Driver 3: standstill, SG min/max not available Driver 4: standstill, SG min/max not available Date/time: 2020-10-10 19:16:18 Cache data hit count 4294967295 Slowest loop: 581.48ms; fastest: 0.12ms I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0 === Storage === Free file entries: 10 SD card 0 detected, interface speed: 20.0MBytes/sec SD card longest read time 2.9ms, write time 62.5ms, max retries 0 === Move === Hiccups: 0(0), FreeDm: 169, MinFreeDm: 137, MaxWait: 6600918ms Bed compensation in use: mesh, comp offset 0.000 === MainDDARing === Scheduled moves: 2, completed moves: 2, StepErrors: 0, LaErrors: 0, Underruns: 0, 0 CDDA state: -1 === AuxDDARing === Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0 CDDA state: -1 === Heat === Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1 -1 -1 Heater 0 is on, I-accum = 0.0 === GCodes === Segments left: 0 Movement lock held by null HTTP is idle in state(s) 0 Telnet is idle in state(s) 0 File is idle in state(s) 0 USB is idle in state(s) 0 Aux is idle in state(s) 0 Trigger is idle in state(s) 0 Queue is idle in state(s) 0 Daemon is idle in state(s) 0 Autopause is idle in state(s) 0 Code queue is empty. === Network === Slowest loop: 581.68ms; fastest: 0.00ms Responder states: HTTP(2) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0), 0 sessions HTTP sessions: 1 of 8 - WiFi - Network state is active WiFi module is connected to access point Failed messages: pending 0, notready 0, noresp 0 WiFi firmware version 1.23 WiFi MAC address 24:62:ab:15:71:64 WiFi Vcc 3.39, reset reason Unknown WiFi flash size 4194304, free heap 22440 WiFi IP address 192.168.1.6 WiFi signal strength -72dBm, reconnections 0, sleep mode modem Socket states: 0 4 0 0 0 0 0 0 -
When do you see stutters in motion? Can you post your full config.g? Your M122 doesn't indicate any actual hiccup interruptions, but maybe it was gathered after a reboot?
I think this is still an issue of thermistor interference/noise.
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@Phaedrux Config files below.
Regarding wiring issue... it could be, I do understand that wiring issues can be tricky to replicate, but for the record I did try to heat up the extruder and jiggle the wires to see if I can create any noise, and no dice.
Config.g
; Configuration file for Duet WiFi (firmware version 3) ; executed by the firmware on start-up ; ; generated by RepRapFirmware Configuration Tool v3.1.4 on Sun Jul 19 2020 22:30:32 GMT+0300 (Israel Daylight Time) ; General preferences G90 ; send absolute coordinates... M83 ; ...but relative extruder moves M550 P"Goliath" ; set printer name M665 R172.66 L511.07 B150 H329.8 ; Set delta radius, diagonal rod length, printable radius and homed height M666 X0 Y0 Z0 ; put your endstop adjustments here, or let auto calibration find them ; Network M552 S1 ; enable network M586 P0 S1 ; enable HTTP M586 P1 S0 ; disable FTP M586 P2 S0 ; disable Telnet ; Drives M569 P0 S0 ; physical drive 0 goes backwards M569 P1 S1 ; physical drive 1 goes forwards M569 P2 S0 ; physical drive 2 goes backwards M569 P3 S1 ; physical drive 3 goes forwards M584 X0 Y1 Z2 E3 ; set drive mapping M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation M92 X100.00 Y100.00 Z100.00 E137.82 ; set steps per mm (E is 430 for bondtech, 137.82 for creality) M566 X600.00 Y600.00 Z600.00 E1200.00 ; set maximum instantaneous speed changes (mm/min) (was [x,y,z]=1200) M203 X9000.00 Y9000.00 Z9000.00 E1200.00 ; set maximum speeds (mm/min) (was [x,y,z]=18000) M201 X500.00 Y500.00 Z500.00 E1000.00 ; set accelerations (mm/s^2) (was [x,y,z]=1000) M906 X1000 Y1000 Z1000 E1500 I30 ; set motor currents (mA) and motor idle factor in per cent M84 S30 ; Set idle timeout ; Axis Limits M208 Z0 S1 ; set minimum Z ; Endstops M574 X2 S1 P"!xstop" ; configure active-high endstop for high end on X via pin !xstop M574 Y2 S1 P"!ystop" ; configure active-high endstop for high end on Y via pin !ystop M574 Z2 S1 P"!zstop" ; configure active-high endstop for high end on Z via pin !zstop ; Z-Probe M558 P5 C"!zprobe.in" H5 F250 T6000 ;A3 S0.01 ; set Z probe type to switch and the dive height + speeds (was 120mm/sec) G31 P500 X30.31 Y17.5 Z2.44 ; set Z probe trigger value, offset and trigger height (z probe is at a circle with radius 35mm from extruder) M557 R160 S20 ;Set probing radius to 160mm with a probe spacing of 20mm ; Heaters M308 S0 P"bedtemp" Y"thermistor" T100000 B4725 C7.060000e-8 ; configure sensor 0 as thermistor on pin bedtemp M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0 M307 H0 B1 S1.00 ; enable bang-bang mode for the bed heater and set PWM limit M140 H0 ; map heated bed to heater 0 M143 H0 S135 ; set temperature limit for heater 0 to 135C M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.060000e-8 ; configure sensor 1 as thermistor on pin e0temp M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1 M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit M308 S2 P"e1temp" Y"thermistor" T100000 B4725 C7.060000e-8 ; configure sensor 2 as thermistor on pin e1temp (chamber thermistor) ; Fans M950 F0 C"fan0" Q100 ; create fan 0 on pin fan0 and set its frequency M106 P0 X1 H1 T45 ; set fan H1 (was 0.25) value. Thermostatic control is turned on ; Tools M563 P0 S"Extruder0" D0 H1 F0 ; define tool 0 G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C ; Lighting M950 P0 C"e1heat" ; create output port 0 attached to heater 1\ M42 P0 S0.1 ; Turn on Case light 10% ; Load Custom settings M501Config-override.g
; config-override.g file generated in response to M500 at 2020-10-08 22:54 ; This is a system-generated file - do not edit ; Delta parameters M665 L511.070:511.070:511.070 R173.652 H337.845 B160.0 X0.728 Y1.338 Z0.000 M666 X-1.091 Y-0.667 Z1.759 A0.00 B0.00 ; Heater model parameters M307 H0 A340.0 C200.0 D5.5 S1.00 V0.0 B1 M307 H1 A561.3 C290.3 D4.1 S1.00 V24.0 B0 ; Workplace coordinates G10 L2 P1 X0.00 Y0.00 Z0.00 G10 L2 P2 X0.00 Y0.00 Z0.00 G10 L2 P3 X0.00 Y0.00 Z0.00 G10 L2 P4 X0.00 Y0.00 Z0.00 G10 L2 P5 X0.00 Y0.00 Z0.00 G10 L2 P6 X0.00 Y0.00 Z0.00 G10 L2 P7 X0.00 Y0.00 Z0.00 G10 L2 P8 X0.00 Y0.00 Z0.00 G10 L2 P9 X0.00 Y0.00 Z0.00 -
@Leav said in Heater Temperature Excursion:
I did try to heat up the extruder and jiggle the wires to see if I can create any noise, and no dice.
Is this a direct drive extruder setup? As in, do the motor wires run along with the heater and thermistor and fan wiring?
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@Phaedrux
it looks like a delta.please post a picture of the printer
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@Phaedrux said in Heater Temperature Excursion:
When do you see stutters in motion?
Forgot to answer this. Usually during long sweeping curves I will see the printer pause for a fraction of a second and continue.
I thought perhaps the CPU is getting overloaded...
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When you notice it doing that check the m122 for hiccups. Though that's usually only when using microsteps higher than 16 which you are not. Curves with small segments could do it. What slicer do you use? s3d has been known to do that.
Low e jerk and pressure advance could be another possibility.
Do you use mesh compensation? Low z jerk can sometimes cause stutters in xy but you've got a delta so all jerk is the same on xyz so I don't think that's what's going on here.
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@Phaedrux said in Heater Temperature Excursion:
When you notice it doing that check the m122 for hiccups. Though that's usually only when using microsteps higher than 16 which you are not. Curves with small segments could do it. What slicer do you use? s3d has been known to do that.
I use PrusaSlicer, will do the M122 when I notice the hiccups.
Low e jerk and pressure advance could be another possibility.
Interesting, I don't use pressure advance but I can see why the low E jerk could cause that.
Do you use mesh compensation? Low z jerk can sometimes cause stutters in xy but you've got a delta so all jerk is the same on xyz so I don't think that's what's going on here.
Yes I'm definitely a mesh user. I see how that could cause issues for cartesian users, but I agree probably unrelated for me on a delta.
If I may re-ask the question from a few posts ago: what do you make of the "slowest loop" statistic? Is that not concerning?
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Unsure of the slowest loop stat. @dc42 would have to comment.
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I hope this isn't bad form, but it seems this question slipped by so I'm tagging @dc42 again...
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@Leav said in Heater Temperature Excursion:
I hope this isn't bad form, but it seems this question slipped by so I'm tagging @dc42 again...
No that's fine. Keeps us from forgetting. Thanks for giving it a couple days.
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Still chasing this, and I've worked on a few things since I last posted:
- New Thermistor (cartridge style, to rule out issues with wires shorting in the heater block)
- New heater cartridge
- Successfully replaced wifi module with esp-07s - Signal went from ~-70dbm to ~-55dbm
Started a five hour print, temperature graph was smooth, minus a few blips which seemed to indicate that the heating process gets "stuck" (??) either in "on" or "off" mode for a second, and the then recovers:
I let it be, thinking this is a minor issue, but after a few hours the excursion hit again:
I was able to resume the print (thanks for such a robust recovery mechanism!), and there was still a bit of noise:
But now it is very smooth (minor blip still shows up):
Does anyone have any clue what could cause this? I feel like this is some sort of random behavior that gets introduced and suddenly vanishes, making debugging very frustrating...
Here is a copy of the M122 response after the recovery:
M122 === Diagnostics === RepRapFirmware for Duet 2 WiFi/Ethernet version 3.1.1 running on Duet WiFi 1.02 or later Board ID: 0JD0M-9K662-MGPSS-6J1FD-3S46N-TVU6Y Used output buffers: 3 of 24 (11 max) === RTOS === Static ram: 27980 Dynamic ram: 93124 of which 48 recycled Exception stack ram used: 576 Never used ram: 9344 Tasks: NETWORK(ready,268) HEAT(blocked,792) MAIN(running,1732) IDLE(ready,80) Owned mutexes: WiFi(NETWORK) === Platform === Last reset 04:52:37 ago, cause: power up Last software reset at 2020-10-16 16:27, reason: User, spinning module GCodes, available RAM 9376 bytes (slot 0) Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0441f000 BFAR 0xe000ed38 SP 0xffffffff Task MAIN Error status: 0 MCU temperature: min 22.3, current 36.8, max 43.8 Supply voltage: min 23.7, current 24.0, max 24.3, under voltage events: 0, over voltage events: 0, power good: yes Driver 0: ok, SG min/max 42/430 Driver 1: ok, SG min/max 78/423 Driver 2: ok, SG min/max 0/416 Driver 3: ok, SG min/max not available Driver 4: standstill, SG min/max not available Date/time: 2020-10-17 12:48:30 Cache data hit count 4294967295 Slowest loop: 275.25ms; fastest: 0.12ms I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0 === Storage === Free file entries: 9 SD card 0 detected, interface speed: 20.0MBytes/sec SD card longest read time 2.9ms, write time 63.4ms, max retries 0 === Move === Hiccups: 0(0), FreeDm: 161, MinFreeDm: 137, MaxWait: 455270ms Bed compensation in use: mesh, comp offset 0.000 === MainDDARing === Scheduled moves: 215624, completed moves: 215603, StepErrors: 0, LaErrors: 0, Underruns: 0, 0 CDDA state: 3 === AuxDDARing === Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0 CDDA state: -1 === Heat === Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1 -1 -1 Heater 0 is on, I-accum = 0.0 Heater 1 is on, I-accum = 0.4 === GCodes === Segments left: 1 Movement lock held by null HTTP is idle in state(s) 0 Telnet is idle in state(s) 0 File is doing "G1 X-5.074 Y-103.468 E29.61163" in state(s) 0 USB is idle in state(s) 0 Aux is idle in state(s) 0 Trigger is idle in state(s) 0 Queue is idle in state(s) 0 Daemon is idle in state(s) 0 Autopause is idle in state(s) 0 Code queue is empty. === Network === Slowest loop: 275.44ms; fastest: 0.00ms Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0), 0 sessions HTTP sessions: 1 of 8 - WiFi - Network state is active WiFi module is connected to access point Failed messages: pending 0, notready 0, noresp 0 WiFi firmware version 1.23 WiFi MAC address 48:3f:da:45:74:de WiFi Vcc 3.38, reset reason Unknown WiFi flash size 4194304, free heap 24504 WiFi IP address 192.168.1.6 WiFi signal strength -55dBm, reconnections 0, sleep mode modem Socket states: 4 0 0 0 0 0 0 0 -
Given that on both the negative and positive small excursion you show, the leading edge is 'instantaneous', followed by a real ramp to compensate, it looks like a thermistor issue. The actual temperature cannot change that fast. After a sudden change in the thermistor+wiring resistance, the heater initiates a real ramp + overshoot to compensate. There has to be a loose connection in the thermistor wiring somewhere, I think.
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This has been suggested before, but I'm willing to give it a try again.
I'll expose the electronics bay and jiggle everything around while holding at ~250c.
Will report back.
