Print stuttering around curves, LaErrors

NitroFreak

I´ve now captured it on video so that it´s easy to see.
100mm circle, 2 perimeters, no infill, Z seam always at the front.
I dropped the Z axis steps back to x16 and 800 steps /mm. Yes i did use Z hop but i can´t imagine how that would affect a mid layer line.

https://youtu.be/IbhTUJ972cE

It is really weird because i used to be able to print at 250mm/sec no problem.
https://www.youtube.com/watch?v=o-Qg3nTha1A

After that I didnt really change anything apart from some tpre, tfree and tpost files. But this is all single extrusion.
Here is another M122 after the circle

M122
=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 2.03 running on Duet WiFi 1.02 or later
Board ID: 08DGM-917NK-F23T0-6J9DJ-3S86S-TWBWD
Used output buffers: 3 of 24 (16 max)
=== RTOS ===
Static ram: 25680
Dynamic ram: 94004 of which 0 recycled
Exception stack ram used: 476
Never used ram: 10912
Tasks: NETWORK(ready,648) HEAT(blocked,1172) MAIN(running,3748) IDLE(ready,160)
Owned mutexes:
=== Platform ===
Last reset 00:29:05 ago, cause: software
Last software reset at 2020-04-27 10:32, reason: User, spinning module GCodes, available RAM 11076 bytes (slot 3)
Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0441f000 BFAR 0xe000ed38 SP 0xffffffff Task 0x4e49414d
Error status: 0
Free file entries: 10
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest block write time: 0.0ms, max retries 0
MCU temperature: min 36.7, current 38.2, max 40.0
Supply voltage: min 24.3, current 24.6, max 24.8, under voltage events: 0, over voltage events: 0, power good: yes
Driver 0: standstill, SG min/max 0/1023
Driver 1: standstill, SG min/max 0/1023
Driver 2: standstill, SG min/max 0/249
Driver 3: standstill, SG min/max 0/1023
Driver 4: standstill, SG min/max not available
Date/time: 2020-04-27 11:02:02
Cache data hit count 4294967295
Slowest loop: 43.29ms; fastest: 0.08ms
I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
=== Move ===
Hiccups: 1415, FreeDm: 169, MinFreeDm: 134, MaxWait: 32660ms
Bed compensation in use: none, comp offset 0.000
=== DDARing ===
Scheduled moves: 6, completed moves: 6, StepErrors: 0, LaErrors: 0, Underruns: 0, 0
=== Heat ===
Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1
Heater 0 is on, I-accum = 0.3
Heater 1 is on, I-accum = 0.4
=== GCodes ===
Segments left: 0
Stack records: 1 allocated, 0 in use
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
serial is idle in state(s) 0
aux is idle in state(s) 0
daemon is idle in state(s) 0
queue is idle in state(s) 0
autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 202.38ms; fastest: 0.08ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0) Telnet(0)
HTTP sessions: 1 of 8

WiFi -
Network state is running
WiFi module is connected to access point
Failed messages: pending 0, notready 0, noresp 1
WiFi firmware version 1.23
WiFi MAC address b4:e6:2d:52:f6:45
WiFi Vcc 3.34, reset reason Turned on by main processor
WiFi flash size 4194304, free heap 25032
WiFi IP address 192.168.0.93
WiFi signal strength -58dBm, reconnections 0, sleep mode modem
Socket states: 0 0 0 0 0 0 0 0

And here is my config.g

; Configuration file for Duet WiFi (firmware version 1.21)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v2 on Sun Feb 03 2019 22:30:32 GMT+0100 (Central European Standard Time)

; General preferences
G90                                             ; Send absolute coordinates...
M83                                             ; ...but relative extruder moves

; Network
M550 P"ARPEG"                                   ; Set machine name
M552 S1                                         ; Enable network
M587 S"KDG-4F519" P"ApbjYbr9nQu7"               ; Configure access point. You can delete this line once connected
M586 P0 S1                                      ; Enable HTTP
M586 P1 S0                                      ; Disable FTP
M586 P2 S0                                      ; Disable Telnet

; Drives
M569 P0 S1                                      ; Drive 0 goes forwards (X1)
M569 P1 S1                                      ; Drive 1 goes forwards (X2)
M569 P2 S0                                      ; Drive 2 goes backwards (Z)
M569 P3 S1                                      ; Drive 3 goes forwards extruder
M569 P4 S1                                      ; Drive 4 goes backwards extruder 2
M569 P5 S0 T8:8:8:8                             ; Drive 5 minimum step pulse timing 3 microseconds (JMC servo minimum 2.5 microseconds)
M584 X0:1 Y5 Z2 E3:4                            ; Apply custom drive mapping
M350 Y1 Z16 ;E16:16I0                           ; Configure microstepping without interpolation
M350 X16:16 I1      E16:16 I1                   ; Configure microstepping with interpolation
M92 X88.89 Y360.00 Z800.00 E411:430            ; Set steps per mm, mk8 extruder 94.3
M566 X1000.00 Y1000.00 Z200.00 E1500.00:1500.00     ; Set maximum instantaneous speed changes (mm/min)
M203 X24000.00 Y24000.00 Z2000.00 E4200.00:4200.00 ; Set maximum speeds (mm/min)
M201 X5000.00 Y5000.00 Z700.00 E2000.00:1000.00  ; Set accelerations (mm/s^2)
M906 X1600.00 Y800.00 Z1100.00 E1100.00:1200.00 I30 ; Set motor currents (mA) and motor idle factor in per cent
M593 F24.5                                      ; Dynamic Acceleration Adjustment at 24.5 Hertz
M572 D0 S0.02                                   ; Pressure advance 
M84 S30                                         ; Set idle timeout
;M207 S0.2 F1800 Z0.8

; Axis Limits
M208 X5 Y5 Z0 S1                                ; Set axis minima
M208 X215 Y255 Z280 S0                          ; Set axis maxima

; Endstops
M574 X1 Y1 Z1 S1                                ; Set active high endstops

; Z-Probe
M558 P0 H5 F120 T6000                           ; Disable Z probe but set dive height, probe speed and travel speed
M557 X20:170 Y20:195 S20                        ; Define mesh grid

; Heaters
M307 H6 A-1 C-1 D-1                             ; Disables heater 6 output as heater output and configures it as General I/O port
M307 H7 A-1 C-1 D-1                             ; Disables heater 7 output as heater output and configures it as General I/O port
M570 H0 P10 T40                                 ; Lets the chamber deviate a max of 40C for max 10sec from its set temp (to not raise a fault when opening oven door)
;M140 H-1                                       ; Tell the firmware there is no bed heater
M307 H0 B0 A188.1 C188.1 D3.5 S1.00             ; Disable bang-bang mode for the bed heater and set PWM limit (G=188.1, tc=275.7, td=-1.6)
M305 P0 T100000 B4138 R4700 S"Chamber"          ; Set thermistor + ADC parameters for heater 0
M143 H0 S240                                    ; Set temperature limit for heater 0 to 240C
M305 P1 X200    S"Model"                                ; Configure thermocouple for heater 1
M143 H1 S430                                    ; Set temperature limit for heater 1 to 430C
;M305 P2 T100000 B4138 R4700 S"Support"           ; Configure Thermistor + ADC parameters for heater 2
;M143 H2 S320                                    ; Set temperature limit for heater 2 to 290°C    
M305 P2 X201    S"Support"                               ; Configure thermocouple for heater 2
M143 H2 S430                                   ; Set temperature limit for heater 2 to 430C
M307 H1 A225.2 C128.7 D4.1 V24.5 S1.0 B0        ; Set PID parameters for Extruder Heater 1 model: gain 952.0, time constant 389.2, dead time 5.2, max PWM 0.30, calibration voltage 24.3, mode PID, inverted no, frequency default
M307 H2 A225.2 C128.7 D4.1 V24.5 S1.0 B0        ; set preliminary PID for support extruder
                                                ; 12V Hotend autotune 390° while 212° chamber Heater 1 model: gain 495.4, time constant 164.7, dead time 2.9, max PWM 0.50, calibration voltage 23.1, 
                                                ; 24V CTC Heater 1 model: gain 225.2, time constant 128.7, dead time 3.4, max PWM 1.00, calibration voltage 24.5
;M307 H2 A468.7 C131.8 D4.3 V24.5 S0.3 B0         ; Heater 2 model: gain 468.7, time constant 131.8, dead time 4.3, max PWM 0.30, calibration voltage 24.5, (12v heizpatrone im alu block)

; Fans
M106 P0 S0.3 I0 F500 H-1                        ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T45                       ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 S"Model" D0 H1                          ; 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
M563 P1 S"Support" D1 H2                        ; Define tool 1
G10 P1 X24.93 Y1.18 Z-1.2                       ; Set tool 1 axis offsets
G10 P1 R0 S0                                    ; Set initial tool 1 active and standby temperatures to 0C

; Automatic saving after power loss is not enabled

; Custom settings are not configured

; Miscellaneous
T0                                              ; Select first tool

NitroFreak

I remember, when i did the 250mm/s test, that it started to judder and slow down randomly at around 280mm/s.
What can cause the processor to overload like that with just 60mm/s?

deckingman

@NitroFreak Your video is very reminiscent of problems I had when pressure advance was first introduced. Although, that was with multiple extruders feeding a mixing hot and with much higher PA values than you are using. Still, I wonder if it might be worth disabling PA just to see if it makes any difference or not?

Phaedrux

@NitroFreak said in Print stuttering around curves, LaErrors:

I dropped the Z axis steps back to x16 and 800 steps /mm. Yes i did use Z hop but i can´t imagine how that would affect a mid layer line.

No I don't think that would cause mid layer issues, but skipping steps on a z hop is a recipe for inaccurate layer heights.

Charlie

@NitroFreak I love that channel! Your values are all a little higher than mine so I may want to change mine. But more importantly, I agree that I thought the 32 bit system should solve this issue. Is there any way to know if its an issue due to extensive mesh facets? I have no hiccups or underruns, and I thought that was where you would see the issue, but I must be mistaken.

Phaedrux

Do you have another SD card to test with?

Charlie

@Phaedrux Yes, I do have another SD card to test with. I will disable Pressure Advance in the config.g file (I only disabled it mid-print before) and report my findings. My duet is unfortunately buried deep in the printer case (hindsight 20/20, lol) so it may take some time to remove and reinstall the SD.

Phaedrux

@Charlie said in Print stuttering around curves, LaErrors:

M566 X480.00 Y480.00 Z30.00 E10000.00 ; Set maximum instantaneous speed changes (mm/min)

The other thing that occurs to me is low Z jerk value and using mesh compensation. I notice your Z jerk is very very low.

Phaedrux

I tried a saved gcode that was showing the slow down/pauses and it's still doing it, though I didn't have any LAErrors. Just some underruns. At least in the first few layers.

Scheduled moves: 8454, completed moves: 8416, StepErrors: 0, LaErrors: 0, Underruns: 15, 0

I resliced the model and printed it again, this time no stutters. The only difference was the Cura build version. The update notes between the two versions says

20200424 - Upstream changes + fix 2 upstream regressions (skirt line print ordering and polygon simplification).

20200328 - Upstream changes + smooth support area outlines to reduce line count (complex outlines will now slice and print faster, gcode size is reduced).

Maybe the polygon simplification is the difference here?

brisma

Try with Cura 4.5.0, the new official version 4.6.0 seems bugged.

dc42

Underruns are usually caused by one of the following:

Printing over USB instead of from SD card (most hosts can't supply GCodes fast enough consistently)
SD card issues. Make sure the SD card is formatted with a high cluster size, preferably 64kb. Also confirm that you are using the built-in SD card of the Duet, because external SD cards use a slower interface.
Long sequences of very short movements in the GCode. Not usually a problem with modern slicers, but has been in the past especially with Simplify3D.

If you have any small print files that consistent give rise to lookahead errors, please share them.

NitroFreak

@dc42 said in Print stuttering around curves, LaErrors:

SD card issues. Make sure the SD card is formatted with a high cluster size, preferably 64kb. Also confirm that you are using the built-in SD card of the Duet, because external SD cards use a slower interface.

Do you mean the SD card that is in the slot directly on the duet?
I usually use the upload function over DWC, does that put it at the correct location?

NitroFreak

I just sliced the same 100mm circle with cura 4.5 and it works well without stuttering up to 135mm/s, after that the same thing happens.
BUT i used to be able to do it at 250mm/sec.
How is it possible that the code grips the throat of the duet so hard? Especially with the increased maximum resolition and deviation?
Can an external 360 steps/mm stepper really strain the duet so hard?

This is the latest M122 with Cura 4.5 and a print speed of between 60 and 180mm/s for the 100mm circle.
How can i reduce the 971000 hiccups?

M122
=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 2.03 running on Duet WiFi 1.02 or later
Board ID: 08DGM-917NK-F23T0-6J9DJ-3S86S-TWBWD
Used output buffers: 1 of 24 (8 max)
=== RTOS ===
Static ram: 25680
Dynamic ram: 94004 of which 0 recycled
Exception stack ram used: 444
Never used ram: 10944
Tasks: NETWORK(ready,652) HEAT(blocked,1172) MAIN(running,3748) IDLE(ready,160)
Owned mutexes:
=== Platform ===
Last reset 00:26:33 ago, cause: power up
Last software reset at 2020-04-27 10:32, reason: User, spinning module GCodes, available RAM 11076 bytes (slot 3)
Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0441f000 BFAR 0xe000ed38 SP 0xffffffff Task 0x4e49414d
Error status: 16
Free file entries: 10
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest block write time: 393.1ms, max retries 0
MCU temperature: min 26.7, current 40.0, max 42.4
Supply voltage: min 24.3, current 24.6, max 24.8, under voltage events: 0, over voltage events: 0, power good: yes
Driver 0: standstill, SG min/max 0/464
Driver 1: standstill, SG min/max 0/1023
Driver 2: standstill, SG min/max 0/243
Driver 3: standstill, SG min/max 0/1023
Driver 4: standstill, SG min/max not available
Date/time: 2020-04-28 16:22:48
Cache data hit count 4294967295
Slowest loop: 161.60ms; fastest: 0.07ms
I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
=== Move ===
Hiccups: 971463, FreeDm: 169, MinFreeDm: 106, MaxWait: 397961ms
Bed compensation in use: none, comp offset 0.000
=== DDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0
=== Heat ===
Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1
Heater 0 is on, I-accum = 0.3
Heater 1 is on, I-accum = 0.4
=== GCodes ===
Segments left: 0
Stack records: 1 allocated, 0 in use
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
serial is idle in state(s) 0
aux is idle in state(s) 0
daemon is idle in state(s) 0
queue is idle in state(s) 0
autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 394.79ms; fastest: 0.00ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0) Telnet(0)
HTTP sessions: 1 of 8

WiFi -
Network state is running
WiFi module is connected to access point
Failed messages: pending 0, notready 0, noresp 0
WiFi firmware version 1.23
WiFi MAC address b4:e6:2d:52:f6:45
WiFi Vcc 3.35, reset reason Turned on by main processor
WiFi flash size 4194304, free heap 23328
WiFi IP address 192.168.0.93
WiFi signal strength -63dBm, reconnections 0, sleep mode modem
Socket states: 0 0 0 0 0 0 0 0

bot

@NitroFreak this is likely because about a year and a few months ago, a change was made to RRF to eliminate the fallback to double/quad stepping when the step pulse generator gets overwhelmed. IE, hiccups are more common now because the system is always running at the set microstepping mode.

Have you configured any axes to be higher than 16x microstepping?

Edit: I see now from your first post that you seem to have 16x enabled on all axes, which should be fine. But, these high speeds are inducing the hiccups. See if you can get away with running 8x microstepping on your x/y axes. (by get away with, I mean if the noise bothers you too much or not)

dc42

@NitroFreak said in Print stuttering around curves, LaErrors:

@dc42 said in Print stuttering around curves, LaErrors:

SD card issues. Make sure the SD card is formatted with a high cluster size, preferably 64kb. Also confirm that you are using the built-in SD card of the Duet, because external SD cards use a slower interface.

Do you mean the SD card that is in the slot directly on the duet?
I usually use the upload function over DWC, does that put it at the correct location?

Yes it does, unless you change to SD card 1 in Duet Web Control.

dc42

@NitroFreak said in Print stuttering around curves, LaErrors:

Hiccups: 971463, FreeDm: 169, MinFreeDm: 106, MaxWait: 397961ms

Something isn't right, because if you are using x16 microstepping on all drivers, you should be getting no hiccups, or at most just a few. Please send M350 after printing the 100mm circle and check that it still reports x16 microstepping.

Charlie

As an update, I was able to eliminate the stuttering (the banding is likely an issue for another day, lol) by re slicing in Cura 4.5 (Cura 4.6 was where I was having the issues).

Settings are:
No wall overlap compensation
Max resolution: 2.333 mm
Max travel resolution: 0.8 mm
Max deviation: 0.05 mm

x16 Microstepping with interpolation

Still had Look Ahead Errors (forgot to copy the M122) but MaxWait was 0 ms.

bot

Interesting. Can you inspect the gcode manually and see a vast difference? Are the segment lengths much different?

NitroFreak

@dc42 said in Print stuttering around curves, LaErrors:

@NitroFreak said in Print stuttering around curves, LaErrors:

Hiccups: 971463, FreeDm: 169, MinFreeDm: 106, MaxWait: 397961ms

Something isn't right, because if you are using x16 microstepping on all drivers, you should be getting no hiccups, or at most just a few. Please send M350 after printing the 100mm circle and check that it still reports x16 microstepping.

Yes it is,

M350
Microstepping - X:16(on), Y:16, Z:16, E:16(on):16(on)

But, it reports Y as x16 microstepping while it shouldn´t, i have configured Y as x1 microstepping due to the external drive. But the scale at which Y drives is still correct. so I don´t know?

bot

@NitroFreak Ah, I was looking at Charlie's config.g not yours.

The way you write your M350 statement is a bit odd. you comment out the I0 in the first statement. Try refining it into two clear statements like this:

M350 Y1 Z16 ;E16:16I0 ; Configure microstepping without interpolation
M350 X16:16 I1 E16:16 I1 ; Configure microstepping with interpolation

M350 Y1 Z16 I0
M350 X16 E16 I1