G02/G03 Arc Issues

[zylantha]

I've started using the Arc Welder plugin for Cura and most results have been awesome, however I have had some strange behaviour printing this relatively simple model from Thingiverse:
https://www.thingiverse.com/thing:4649358

The one on the bottom was printed with Arc Welder enabled, and the one on the top with it disabled - otherwise all other settings are identical.

There is clearly a very distinct "tab" sticking out from the Arc Welder (i.e. G02/G03 enabled) print at a very particular point, which is definitely not there in the model. The tab that's printed isn't in Cura's "Preview", and I have imported the "Arc Welder" enabled GCODE into Simplify3D and I can't see the tab there either - everything looks fine, so while it certainly could be an issue in what Arc Welder outputs, the GCODE doesn't seeem to evidence it.

So far I can only conclude that there is some fault in Reprapfirmware's handling of the G02/G03 commands that's somehow creating this weird extra tab here, which as far as GCODE simulators can tell me shouldn't be there.

Happy to provide the respective GCODE files for closer examination.

Relevant config details:
Generated by: Cura_SteamEngine 4.11.0
Board: Duet 2 Maestro (2Maestro)
Firmware: RepRapFirmware for Duet 2 Maestro 3.3 (2021-06-15)
Printer: Ender 5 Plus

[PCR]

@zylantha Please post both gcodes

[zylantha]

@pcr

I can't see how to upload gcode to the forums but maybe these sharing links will work?

No ARC:
https://drive.google.com/file/d/1BpifPhJUYhkYpxqv4E8VMEdjSa1XMdIg/view?usp=sharing

With ARC:
https://drive.google.com/file/d/1BmFRK3AwKcSvsFkpU_evZFoFvfbI_kv1/view?usp=sharing

[PCR]

@zylantha are you using firmware retraction? and please post config.g

[zylantha]

@pcr Not using firmware retraction (I don't think Cura supports this?)

Here is my config.g:

; Configuration file for Duet Maestro (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.5 on Fri Oct 29 2021 22:45:49 GMT+1100 (Australian Eastern Daylight Time)

; General preferences
M575 P1 S1 B57600                             ; enable support for PanelDue
G90                                           ; send absolute coordinates...
M83                                           ; ...but relative extruder moves
M550 P"Ender 5 Plus"                          ; set printer name

; Network
M552 P0.0.0.0 S1                              ; enable network and acquire dynamic address via DHCP
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 S0                                    ; physical drive 1 goes backwards
M569 P2 S0                                    ; physical drive 2 goes backwards
M569 P3 S0                                    ; physical drive 3 goes backwards
M584 X0 Y1 Z2 E3                              ; set drive mapping
M350 X32 Y32 Z16 E16 I1                       ; configure microstepping with interpolation
M92 X160.00 Y160.00 Z800.00 E403.35           ; set steps per mm
M566 X1200.00 Y1200.00 Z24.00 E300.00         ; set maximum instantaneous speed changes (mm/min)
M203 X9000.00 Y9000.00 Z180.00 E6000.00       ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z100.00 E5000.00         ; set accelerations (mm/s^2)
M906 X700 Y920 Z920 E900 I50                  ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                       ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1                              ; set axis minima
M208 X355 Y360 Z400 S0                        ; set axis maxima

; Endstops
M574 X2 S1 P"xstop"                           ; configure switch-type (e.g. microswitch) endstop for high end on X via pin xstop
M574 Y2 S1 P"ystop"                           ; configure switch-type (e.g. microswitch) endstop for high end on Y via pin ystop
M574 Z1 S2                                    ; configure Z-probe endstop for low end on Z

; Z-Probe
M950 S0 C"zprobe.mod"                         ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe.in" H5 F120 T6000           ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-42.5 Y0 Z2.35                      ; set Z probe trigger value, offset and trigger height
M557 X15:305 Y15:335 S50                      ; define mesh grid

; Heaters
M308 S0 P"ctemp" Y"thermistor" T100000 B4092  ; configure sensor 0 as thermistor on pin ctemp
M950 H0 C"bedheat" T0                         ; create bed heater output on bedheat and map it to sensor 0
M307 H0 B0 S1.00                              ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                       ; map heated bed to heater 0
M143 H0 S150                                  ; set temperature limit for heater 0 to 150C
M308 S1 P"e0temp" Y"thermistor" T100000 B4092 ; 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
M143 H1 S275                                  ; set temperature limit for heater 1 to 275C

; Fans
M950 F0 C"fan0" Q500                          ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H-1                                ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"fan1" Q500                          ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H1 T45                             ; set fan 1 value. Thermostatic control is turned on
M950 F2 C"fan2" Q500                          ; create fan 2 on pin fan2 and set its frequency
M106 P2 S1 H1 T45                             ; set fan 2 value. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F0:2                            ; 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

; Custom settings
M106 P0 L0.6                                  ; Minimum 60% fan speed
M501

; Miscellaneous
M501                                          ; load saved parameters from non-volatile memory
T0                                            ; select first tool

[Phaedrux]

@zylantha said in G02/G03 Arc Issues:

Not using firmware retraction (I don't think Cura supports this?)

It does, but you must enable it in the Printer Settings plugin section.

[Phaedrux]

Can you show a better photo of the tab?

[zylantha]

@phaedrux How's this?

[Phaedrux]

Do you use coasting or wipe?

[zylantha]

@phaedrux No wipe, but I do use coasting. It's enabled with defaults - Coasting Volume 0.064 mm3, Minimum volume before coasting 0.8 mm3 and Coasting Speed 90%.

Should I try disabling it and see if the tab still appears?

[Phaedrux]

yes try disabling coasting/wiping/ etc

[zylantha]

@phaedrux No difference with coasting disabled - tab is still there.

[sebkritikel]

@zylantha I opened up the arc welder GCODE file in a few different parsers/previewers, and I’m not seeing anything that should generate that tab. It’s pretty weird!

I opened it up in Craftware (which doesn’t support G02/G03, but is still useful as a quick check) as well as a few online parsers that properly display G02/G03 segments.

[droftarts]

@zylantha I don't think ArcWelder is doing what you expect. The main outer circle hasn't been converted to arcs, looking at the gcode. Only the central hole, and the first and last segment of the exterior wall are G2 or G3. I think this glitch is happening on the corner of the larger part just after it prints the internal hole, rather than the part that slides in and out. Z=16 is about half way up, and this is the gcode for the perimeters of the larger part, at Z=16:

G1 F2400 X208.253 Y200.454 E0.01005
G1 X183.587 Y175.788 E1.39226
G2 X176.413 Y175.788 I-3.587 J-0.800 E0.52517 F2400
G1 X151.747 Y200.454 E1.39226
G1 X151.569 Y200.632 E0.01005
G3 X149.805 Y198.594 I16.998 J-16.495 E0.10398
G1 X147.682 Y195.591 E0.14678
G1 X147.29 Y194.962 E0.02958
G1 X145.466 Y191.607 E0.15242
G1 X145.21 Y191.065 E0.02392
G1 X143.738 Y187.39 E0.15801
G1 X143.579 Y186.911 E0.02014
G1 X142.529 Y183.027 E0.16058
G1 X142.456 Y182.669 E0.01458
G1 X141.84 Y178.511 E0.16777
G1 X141.823 Y178.305 E0.00825
G1 X141.693 Y173.976 E0.17286
G1 X141.699 Y173.815 E0.00643
G1 X142.087 Y169.428 E0.17578
G1 X142.989 Y165.072 E0.17755
G1 X144.418 Y160.772 E0.18085
G1 X146.275 Y156.805 E0.17482
G1 X146.364 Y156.641 E0.00745
G1 X148.596 Y153.039 E0.16913
G1 X148.769 Y152.794 E0.01197
G1 X151.328 Y149.577 E0.16407
G1 X151.653 Y149.216 E0.01939
G1 X154.452 Y146.439 E0.15737
G1 X154.896 Y146.048 E0.02361
G1 X157.898 Y143.697 E0.15219
G1 X158.525 Y143.264 E0.03041
G1 X161.665 Y141.354 E0.14669
G1 X162.46 Y140.931 E0.03594
G1 X165.364 Y139.599 E0.12752
G1 X194.636 Y139.599 E1.16831
G1 X197.54 Y140.931 E0.12752
G1 X198.335 Y141.354 E0.03594
G1 X201.475 Y143.264 E0.14669
G1 X202.102 Y143.697 E0.03041
G1 X205.104 Y146.048 E0.15219
G1 X205.548 Y146.439 E0.02361
G1 X208.347 Y149.216 E0.15737
G1 X208.672 Y149.577 E0.01939
G1 X211.231 Y152.794 E0.16407
G1 X211.404 Y153.039 E0.01197
G1 X213.621 Y156.615 E0.16793
G1 X213.73 Y156.816 E0.00913
G1 X215.575 Y160.756 E0.17364
G1 X215.594 Y160.804 E0.00206
G1 X217.011 Y165.072 E0.17949
G1 X217.913 Y169.428 E0.17755
G1 X218.301 Y173.819 E0.17594
G1 X218.306 Y173.966 E0.00587
G1 X218.177 Y178.305 E0.17326
G1 X218.16 Y178.511 E0.00825
G1 X217.544 Y182.669 E0.16777
G1 X217.471 Y183.027 E0.01458
G1 X216.421 Y186.911 E0.16058
G1 X216.262 Y187.39 E0.02014
G1 X214.79 Y191.065 E0.15801
G1 X214.534 Y191.607 E0.02392
G1 X212.71 Y194.962 E0.15242
G1 X212.318 Y195.591 E0.02958
G1 X210.195 Y198.594 E0.14678
G3 X208.431 Y200.632 I-50.893 J-42.268 E0.10398
G0 F12000 X208.45 Y201.329
G1 F2400 X183.062 Y175.942 E1.43298
G2 X176.938 Y175.942 I-3.062 J-0.943 E0.47752 F2400
G2 X151.550 Y201.329 I639980.875 J640031.472 E1.43298
G3 X149.416 Y198.876 I20.696 J-20.159 E0.12617
G1 X147.285 Y195.86 E0.14739
G3 X144.768 Y191.253 I55.554 J-33.342 E0.20962
G1 X143.286 Y187.553 E0.15908
G3 X143.117 Y187.037 I2.944 J-1.250 E0.02168
G2 X142.062 Y183.136 I-89.080 J21.998 E0.16129
G3 X141.343 Y178.324 I128.237 J-21.621 E0.19423
G1 X141.213 Y173.974 E0.1737
G1 X141.219 Y173.799 E0.00699
G1 X141.612 Y169.357 E0.17798
G1 X142.526 Y164.944 E0.17987
G1 X143.954 Y160.641 E0.18095
G1 X143.983 Y160.569 E0.0031
G1 X145.847 Y156.587 E0.17548
G1 X145.948 Y156.401 E0.00845
G1 X148.188 Y152.786 E0.16974
G1 X148.393 Y152.495 E0.01421
G1 X150.958 Y149.27 E0.16446
G1 X151.306 Y148.884 E0.02074
G1 X154.119 Y146.093 E0.15816
G1 X154.595 Y145.674 E0.02531
G1 X157.614 Y143.31 E0.15304
G1 X158.264 Y142.861 E0.03153
G1 X161.424 Y140.938 E0.14764
G1 X162.242 Y140.503 E0.03698
G1 X165.26 Y139.119 E0.13252
G1 X194.74 Y139.119 E1.17661
G1 X197.758 Y140.503 E0.13252
G1 X198.576 Y140.938 E0.03698
G1 X201.736 Y142.861 E0.14764
G1 X202.386 Y143.31 E0.03153
G1 X205.405 Y145.674 E0.15304
G1 X205.881 Y146.093 E0.02531
G1 X208.694 Y148.884 E0.15816
G1 X209.042 Y149.27 E0.02074
G1 X211.607 Y152.495 E0.16446
G1 X211.812 Y152.786 E0.01421
G1 X214.037 Y156.375 E0.16854
G1 X214.164 Y156.609 E0.01063
G1 X216.014 Y160.561 E0.17416
G1 X216.046 Y160.641 E0.00344
G1 X217.474 Y164.944 E0.18095
G1 X218.388 Y169.357 E0.17987
G2 X218.787 Y173.962 I151.528 J-10.809 E0.18449
G1 X218.657 Y178.324 E0.17417
G1 X218.636 Y178.572 E0.00993
G1 X218.018 Y182.744 E0.16833
G1 X217.938 Y183.136 E0.01597
G1 X216.877 Y187.062 E0.16232
G1 X216.714 Y187.553 E0.02065
G1 X215.232 Y191.253 E0.15908
G1 X214.961 Y191.827 E0.02533
G1 X213.128 Y195.199 E0.15318
G1 X212.715 Y195.86 E0.03111
G1 X210.584 Y198.876 E0.14739
G3 X208.895 Y200.834 I-18.222 J-14.011 E0.10324
G0 F2160 X208.45 Y201.329
G0 F12000 X208.469 Y202.026
G2 X182.498 Y176.056 I-669844.203 J669844.025 E1.46589 F2400
G2 X177.502 Y176.056 I-2.498 J-1.064 E0.42774
G2 X151.531 Y202.026 I669818.245 J669870.008 E1.46589
G2 X149.635 Y199.917 I-2855.646 J2565.332 E0.10955
G1 X149.035 Y199.168 E0.0383
G1 X146.887 Y196.129 E0.14853
G2 X146.454 Y195.435 I-11.406 J6.635 E0.03265
G1 X144.612 Y192.047 E0.15392
G1 X144.326 Y191.441 E0.02675
G1 X142.84 Y187.731 E0.15951
G3 X141.508 Y182.824 I72.291 J-22.257 E0.20301
G1 X140.888 Y178.633 E0.16909
G3 X140.739 Y173.784 I110.359 J-5.818 E0.19366
G1 X141.133 Y169.318 E0.17894
G1 X141.138 Y169.28 E0.00153
G1 X142.063 Y164.816 E0.18195
G1 X143.501 Y160.48 E0.18233
G1 X143.546 Y160.369 E0.00478
G1 X145.412 Y156.383 E0.17566
G1 X145.532 Y156.16 E0.01011
G1 X147.789 Y152.519 E0.17098
G1 X148.01 Y152.205 E0.01533
G1 X150.588 Y148.964 E0.16529
G1 X150.958 Y148.552 E0.0221
G1 X153.786 Y145.747 E0.15898
G1 X154.294 Y145.3 E0.02701
G1 X157.33 Y142.923 E0.15389
G1 X158.003 Y142.458 E0.03265
G1 X161.183 Y140.522 E0.14859
G1 X162.024 Y140.075 E0.03801
G1 X165.156 Y138.639 E0.13752
G1 X194.844 Y138.639 E1.18491
G1 X197.976 Y140.075 E0.13752
G1 X198.817 Y140.522 E0.03801
G1 X201.997 Y142.458 E0.14859
G1 X202.67 Y142.923 E0.03265
G1 X205.706 Y145.3 E0.15389
G1 X206.214 Y145.747 E0.02701
G1 X209.042 Y148.552 E0.15898
G1 X209.412 Y148.964 E0.0221
G1 X211.99 Y152.205 E0.16529
G1 X212.211 Y152.519 E0.01533
G1 X214.453 Y156.135 E0.16981
G1 X214.592 Y156.391 E0.01163
G1 X216.454 Y160.369 E0.1753
G1 X216.499 Y160.48 E0.00478
G1 X217.937 Y164.816 E0.18233
G1 X218.862 Y169.28 E0.18195
G1 X218.867 Y169.318 E0.00153
G1 X219.258 Y173.758 E0.1779
G3 X219.267 Y173.960 I-1.315 J0.160 E0.00807
G1 X219.137 Y178.346 E0.17513
G1 X219.112 Y178.633 E0.0115
G1 X218.492 Y182.824 E0.16909
G1 X218.406 Y183.242 E0.01703
G1 X217.336 Y187.203 E0.16376
G1 X217.16 Y187.731 E0.02221
G1 X215.674 Y191.441 E0.15951
G1 X215.388 Y192.047 E0.02675
G1 X213.546 Y195.435 E0.15392
G1 X213.113 Y196.129 E0.03265
G1 X210.965 Y199.168 E0.14853
G1 X210.365 Y199.917 E0.0383
G2 X208.469 Y202.026 I2853.750 J2567.441 E0.10955
G0 F12000 X208.488 Y202.723
;TYPE:WALL-OUTER
G1 F2400 X181.914 Y176.15 E1.49992
G2 X178.086 Y176.150 I-1.914 J-1.155 E0.37722 F2400
G1 X151.512 Y202.723 E1.49992
G1 X149.267 Y200.226 E0.13402
G1 X148.654 Y199.46 E0.03916
G1 X146.489 Y196.398 E0.14967
G1 X146.036 Y195.671 E0.03419
G1 X144.185 Y192.267 E0.15465
G1 X143.884 Y191.63 E0.02812
G1 X142.394 Y187.909 E0.15998
G1 X142.205 Y187.344 E0.02378
G1 X141.126 Y183.348 E0.1652
G1 X141.034 Y182.904 E0.0181
G1 X140.412 Y178.693 E0.16989
G1 X140.383 Y178.37 E0.01294
G1 X140.253 Y173.974 E0.17553
G1 X140.259 Y173.77 E0.00815
G1 X140.656 Y169.266 E0.18046
G1 X140.666 Y169.195 E0.00286
G1 X141.6 Y164.688 E0.18371
G1 X143.045 Y160.329 E0.18329
G1 X143.111 Y160.165 E0.00706
G1 X144.977 Y156.179 E0.17566
G1 X145.124 Y155.907 E0.01234
G1 X147.388 Y152.255 E0.1715
G1 X147.634 Y151.906 E0.01704
G1 X150.218 Y148.658 E0.16565
G1 X150.61 Y148.221 E0.02343
G1 X153.453 Y145.401 E0.15982
G1 X153.993 Y144.926 E0.0287
G1 X157.046 Y142.535 E0.15477
G1 X157.742 Y142.055 E0.03374
G1 X160.942 Y140.106 E0.14954
G1 X161.806 Y139.647 E0.03905
G1 X165.052 Y138.159 E0.14252
G1 X194.948 Y138.159 E1.19321
G1 X198.194 Y139.647 E0.14252
G1 X199.058 Y140.106 E0.03905
G1 X202.258 Y142.055 E0.14954
G1 X202.954 Y142.535 E0.03374
G1 X206.007 Y144.926 E0.15477
G1 X206.547 Y145.401 E0.0287
G1 X209.39 Y148.221 E0.15982
G1 X209.782 Y148.658 E0.02343
G1 X212.366 Y151.906 E0.16565
G1 X212.612 Y152.255 E0.01704
G1 X214.869 Y155.895 E0.17094
G1 X215.023 Y156.179 E0.01289
G1 X216.889 Y160.165 E0.17566
G1 X216.955 Y160.329 E0.00706
G1 X218.4 Y164.688 E0.18329
G1 X219.334 Y169.195 E0.18371
G1 X219.344 Y169.266 E0.00286
G1 X219.741 Y173.77 E0.18046
G1 X219.747 Y173.96 E0.00759
G1 X219.617 Y178.37 E0.17609
G1 X219.588 Y178.693 E0.01294
G1 X218.966 Y182.904 E0.16989
G1 X218.874 Y183.348 E0.0181
G1 X217.795 Y187.344 E0.1652
G1 X217.606 Y187.909 E0.02378
G1 X216.116 Y191.63 E0.15998
G1 X215.815 Y192.267 E0.02812
G1 X213.964 Y195.671 E0.15465
G1 X213.511 Y196.398 E0.03419
G1 X211.346 Y199.46 E0.14967
G1 X210.733 Y200.226 E0.03916
G1 X208.933 Y202.228 E0.10745
G0 F2160 X208.488 Y202.723
G0 F12000 X208.477 Y202.275
G0 X209.378 Y199.077

As you can see, it's mostly G1 moves around the perimeter. If you paste it into this gcode simulator https://nraynaud.github.io/webgcode/ you'll see that the G2 and G3 commands are only at the sharp corners (you can step through the moves and it highlights them on the preview). However, it does render correctly on this simulator.

Unfortunately I'm not set up with a printer today to test the gcode. I'll point @dc42 at this thread, as I'm sure there was a similar issue before RRF 3.3 that was fixed, but I can't find the thread.

Ian

[zylantha]

@droftarts I agree - Arc welder isn't smoothing the outside of the model, which is a separate problem (probably need to tweak a setting somewhere, but even so that tab really shouldn't be there according to the GCODE as interpreted by various apps.

I have a video of it printing, including where it did the tab - I might have to upload to Youtube to share though as it doesn't look like I can upload here to the forums?

[droftarts]

@zylantha yes, upload to YouTube and post a link. Can you run the Gcode I posted above, and video that? Helps with diagnosis if it can be shown in a small section of gcode. Can you also update your firmware to the latest 3.4beta6 to see if that makes a difference? You can always revert to 3.3 after testing.

Ian

[dc42]

@zylantha I've printed the first 3 layers, and I didn't see the tab. So maybe this is already fixed in the 3.4beta series firmware. The print is slow so I didn't let it run for longer.

If after upgrading to 3.4beta6 you still have this problem, please provide a cut-down version of this print that still exhibits the problem, e.g. with 0 or 1 bottom solid layers and low infill. Preferably centre it on X0 Y0 because all my printers have X0 Y0 at bed centre.

[zylantha]

Thanks @dc42, I have reprinted the exact same GCODE on 3.4.0beta6 and the tab didn't appear - so looks like this bug is fixed in this latest beta firmware.

[dc42]

@zylantha thanks for confirming.