@infiniteloop Thanks for all of your suggestions and encouragement! I fixed the wiring and loaded up my spool of PETG, made the slicer print everything at 30mm/s and got this:

This looks much better to me. One side had a small section where the layers didn't bond very well, but overall it makes me happy! I didn't even calibrate the extruder! It needs some tuning still but at least its consistent! I need to find some better PLA. I'll probably throw what I have in the vacuum oven for a bit, but I think its probably a lost cause.

@infiniteloop This color and reflectivity made it hard to take pictures. In person in looks smoother than the pictures would indicate. It definitely does have some angled lines and texturing. Per @Phaedrux's advice I did take a video of it. I think I will start a new thread as you suggest since this isn't really about stringing or PLA anymore.

I'm also seriously thinking about cutting out a metal frame on my boss's laser to help with the rigidity. This printer was given to me and I think the age and the tab and slot melamine frame is close to its expiration.

Thanks to everyone who posted! I read them all even if I didn't reply directly.

@jens55 I think that separated when I pulled it off of the bed. I wasn't very gentle because I wanted to see how the layers stuck together. I definitely have some issues with the flatness of the glass bed which isn't helping that either.

@infiniteloop Thanks for all of your suggestions and encouragement! I fixed the wiring and loaded up my spool of PETG, made the slicer print everything at 30mm/s and got this:

This looks much better to me. One side had a small section where the layers didn't bond very well, but overall it makes me happy! I didn't even calibrate the extruder! It needs some tuning still but at least its consistent! I need to find some better PLA. I'll probably throw what I have in the vacuum oven for a bit, but I think its probably a lost cause.

@infiniteloop I tend to agree with you. I was watching it put down a first layer and the extrusion is inconsistent, some of it is obviously squeezing out past the nozzle making a wider track and bunching up and some of it is just barely stringing and not even bonding to the bed. I was trying to figure out if it was related to speed or just the extruder. This printer is not very rigid in my opinion, but slow speeds like you mentioned should be ok I would think? I tightened all the bolts holding the uprights to the base and the top a few weeks ago. The rounded off square print above was printed at 30mm/s at the fastest. The outer layer was only 15mm/s ( I missed that in the slicer settings, intending it to all be 30mm/s). I have also thought about moving the extruder from the top of the machine to about halfway down so I can use a shorter bowden tube. Its about 700mm right now. The frustrating thing is that this printer worked a few months ago before all of the upgrades (aside from stringing), but the stock PEEK heatsink in the hot end melted and destroyed the hot end. That was why I decided to upgrade everything. That might have been a mistake!

I have some older PETG and various other spools of PLA. The white PLA I'm using was fresh out of the bag a few weeks ago after I gave up on the older spool I was using. The new spool made no difference.

Last night I read that a partially clogged nozzle could possibly cause this. I have noticed that if I just extrude plastic at the max rate, about 6.5mm/s that it almost always curls back to the tip of the nozzle and it will also get really thick after a few seconds especially after the end of the plastic makes contact with the bed. I am running it really hard at that point, the extruder will start skipping at 6.7mm/s. While taking the nozzle out I broke the ground wire to the hot end fan. Now I need to find a way to release the broken pin so I can crimp on another one. Once the wire broke, I shut it off and walked away.

I then calibrated the extruder using the method Paedrux linked to above. I printed the object recommended with the recommended settings and had some weird results:

The brim was over extruding (?) and smearing on one corner and along one side, but the area where it was the thinnest due to my build plate not being flat (?) did not smear. Its definitely the thicker parts of the brim that had issues. On the walls there are adhesion issues/under extrusion that tended to get better as it printed. By the time it got to the seam it looked pretty good on the inner wall. The outer wall has the same look to it but it would start out looking good and get worse as it made its way closer to the seam. Both inner and outer walls were printing CCW except the first or second layer. I tried to get some light behind the print so you could see the patterns of gaps.

Thanks for all of the tips! I have Changed to 1/16 micro stepping, adjusted the max extruder speed to allow 45mm/s as called for in Cura (good catch Lo-Fi) and started running at 210C.

The calibration cube looks better in some respects especially the sidewalls. There is not nearly as much over extrusion and the layers look flat. The infill has gaps and does not appear to be extruding properly and the top 2 layers are way too light. You can also see the ripples in the outer wall from where the nozzle is getting bumped out of its path by dollops left from the ends of the infill lines. I'll include the G code that I used since I didn't save the slicer settings. The black mark is where I turned on Pressure advance at 0.5.
SRMAXV32_xyzCalibration_cube 210C.gcode

Next up is the stringing tests. The one on the left is pressure advance off and the one on the right is pressure advance at 0.5.

Current Config.G:

; Configuration file for Duet 3 Mini 5+ (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.10 on Mon Mar 21 2022 07:51:19 GMT-0500 (Central Daylight Time)

; General preferences
G90                                           ; send absolute coordinates...
M83                                           ; ...but relative extruder moves
M550 P"My Printer"                            ; set printer name
M665 R142.875 L288.08 B133.35 H335            ; 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 P0.0 S0                                  ; physical drive 0.0 goes forwards
M569 P0.1 S1                                  ; physical drive 0.1 goes forwards
M569 P0.2 S0                                  ; physical drive 0.2 goes forwards
M569 P0.3 S0                                  ; physical drive 0.3 goes forwards
M584 X0.0 Y0.1 Z0.2 E0.3                      ; set drive mapping
M350 X16 Y16 Z16 E16 I1                	      ; configure microstepping without interpolation
M92 X80.00 Y80.00 Z80.00 E94.4		          ; set steps per mm
M566 X1200.00 Y1200.00 Z1200.00 E2700.00      ; set maximum instantaneous speed changes (mm/min)
M203 X18000.00 Y18000.00 Z18000.00 E2700.00   ; set maximum speeds (mm/min)
M201 X1000.00 Y1000.00 Z1000.00 E1000.00      ; set accelerations (mm/s^2)
M906 X1200 Y1200 Z1200 E1900 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"io0.in"                          ; configure switch-type (e.g. microswitch) endstop for high end on X via pin io0.in
M574 Y2 S1 P"io1.in"                          ; configure switch-type (e.g. microswitch) endstop for high end on Y via pin io1.in
M574 Z2 S1 P"io2.in"                          ; configure switch-type (e.g. microswitch) endstop for high end on Z via pin io2.in

; Z-Probe
M558 P8 R0.4 C"io3.in+io3.out" H5 F1200 T6000 B1 ; set Z probe type to effector and the dive height + speeds, B1 turns off the bed heater during probing to stop the noise.
;M558 H30                                      ;*** Remove this line after delta calibration has been done and new delta parameters have been saved
G31 P100 X0 Y0 Z -0.3                           ; set Z probe trigger value, offset and trigger height
M557 R85 S20                                  ; define mesh grid

; Heaters
M308 S0 P"temp1" Y"thermistor" T100000 B4138  ; configure sensor 0 as thermistor on pin temp1
M950 H0 C"out0" T0                            ; create bed heater output on out0 and map it to sensor 0
M307 H0 B1 S1.00 F100                         ; enable bang-bang mode for the bed heater and set PWM limit
M140 H0                                       ; map heated bed to heater 0
M143 H0 S120                                  ; set temperature limit for heater 0 to 120C
M308 S1 P"temp0" Y"thermistor" T100000 B4138  ; configure sensor 1 as thermistor on pin temp0
M950 H1 C"out1" T1                            ; create nozzle heater output on out1 and map it to sensor 1
M307 H1 B0 S1.00                              ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280                                  ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"out3" Q500                          ; create fan 0 on pin out3 and set its frequency   LAYER
M106 P0 S1 H-1 B0.5                             ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"out4" Q500                          ; create fan 1 on pin out4 and set its frequency	HOT END
M106 P1 S1 H1 T40 B0.5                              ; set fan 1 value. Thermostatic control is turned off

; Tools
M563 P0 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

; Custom settings are not defined

; Miscellaneous
M501                                          ; load saved parameters from non-volatile memory

@engikeneer The popping was coming from the Extruder motor slipping. The PLA spool says its good for 180-220, so I can go 5 degrees lower. So far I just seem to make it worse. I've gone to 10mm retraction and that looks no different from 3.5mm but its a lot slower! I tried to print a calibration cube but all the retractions from the infill were bumping the hot end away from its path on the inner wall, and I could even hear it a little bit on the outer wall. I stopped that print and tried it with no retractions and it still looks awful. I'm beginning to think something else is wrong. I also bumped the extruder down to 1/64 micro stepping and turned up the current to 1.9A. the steps/mm should be 371 but I have it set to 375 to try to extrude slightly more because of gaps in the infill and first layer, may have been a bad move? This is getting frustrating, I don't know what to do next.

3.5mm Retract (default) 190C hot end temp:

Ugly Calibration Cube, No retraction:

; Configuration file for Duet 3 Mini 5+ (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.10 on Mon Mar 21 2022 07:51:19 GMT-0500 (Central Daylight Time)

; General preferences
G90                                           ; send absolute coordinates...
M83                                           ; ...but relative extruder moves
M550 P"My Printer"                            ; set printer name
M665 R142.875 L288.08 B133.35 H335            ; 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 P0.0 S0                                  ; physical drive 0.0 goes forwards
M569 P0.1 S1                                  ; physical drive 0.1 goes forwards
M569 P0.2 S0                                  ; physical drive 0.2 goes forwards
M569 P0.3 S0                                  ; physical drive 0.3 goes forwards
M584 X0.0 Y0.1 Z0.2 E0.3                      ; set drive mapping
M350 X128 Y128 Z128 E64 I1                   ; configure microstepping without interpolation
M92 X640.00 Y640.00 Z640.00 E375.00           ; set steps per mm
M566 X1200.00 Y1200.00 Z1200.00 E1200.00      ; set maximum instantaneous speed changes (mm/min)
M203 X18000.00 Y18000.00 Z18000.00 E1200.00   ; set maximum speeds (mm/min)
M201 X1000.00 Y1000.00 Z1000.00 E1000.00      ; set accelerations (mm/s^2)
M906 X1200 Y1200 Z1200 E1900 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"io0.in"                          ; configure switch-type (e.g. microswitch) endstop for high end on X via pin io0.in
M574 Y2 S1 P"io1.in"                          ; configure switch-type (e.g. microswitch) endstop for high end on Y via pin io1.in
M574 Z2 S1 P"io2.in"                          ; configure switch-type (e.g. microswitch) endstop for high end on Z via pin io2.in

; Z-Probe
M558 P8 R0.4 C"io3.in+io3.out" H5 F1200 T6000 B1 ; set Z probe type to effector and the dive height + speeds, B1 turns off the bed heater during probing to stop the noise.
;M558 H30                                      ;*** Remove this line after delta calibration has been done and new delta parameters have been saved
G31 P100 X0 Y0 Z -0.3                           ; set Z probe trigger value, offset and trigger height
M557 R85 S20                                  ; define mesh grid

; Heaters
M308 S0 P"temp1" Y"thermistor" T100000 B4138  ; configure sensor 0 as thermistor on pin temp1
M950 H0 C"out0" T0                            ; create bed heater output on out0 and map it to sensor 0
M307 H0 B1 S1.00 F100                         ; enable bang-bang mode for the bed heater and set PWM limit
M140 H0                                       ; map heated bed to heater 0
M143 H0 S120                                  ; set temperature limit for heater 0 to 120C
M308 S1 P"temp0" Y"thermistor" T100000 B4138  ; configure sensor 1 as thermistor on pin temp0
M950 H1 C"out1" T1                            ; create nozzle heater output on out1 and map it to sensor 1
M307 H1 B0 S1.00                              ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280                                  ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"out3" Q500                          ; create fan 0 on pin out3 and set its frequency   LAYER
M106 P0 S1 H-1 B0.5                             ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"out4" Q500                          ; create fan 1 on pin out4 and set its frequency	HOT END
M106 P1 S1 H1 T40 B0.5                              ; set fan 1 value. Thermostatic control is turned off

; Tools
M563 P0 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

; Custom settings are not defined

; Miscellaneous
M501                                          ; load saved parameters from non-volatile memory

@dc42 I think 190 wins, strings are finer, no boogers on the posts like the 185C and dimensionally it looks better. Also there was some under extrusion on 185 and the extruded popped a few times. I guess I need to slow it down and up the current or reduce the micro stepping if I want to run at 185.

@dc42 I'll try a lower temp. Thanks!

@phaedrux
config.g
SRMAXV32_four_square_cons 5mm.gcode