Trying to tune extruder. What might I be missing



  • Hi Everyone,

    You may have seen me ask a couple of questions on the Facebook groups but for this type of question, I think this forum is better.
    Let me see how short and clear I can make this.

    I am trying to print this Sword. Specifically, I am trying to print the test print.

    For some reason, I have always suffered when printing parts like this as I get huge blobs at the end of the move leaving blobs.

    I believe my extruder speed, accel and jerk speed were set extremely high. Creating very high pressure. At least that is what I think is happening.

    I am using a E3D Titan with a E3D V6 all metal 0.4mm. Bowden trying to print PLA

    I am using Cura 4.4 as my slicer. Previous versions of Cura were producing same effects.

    I believe all of the following items will help me successfully print this model

    • Line width (for the test model seems that 0.45 is best as this removes gaps between walls)
    • Retraction (1.8 @ 50mms but have tried 6.5 @30ms)
    • Coasting (would like to avoid if possible)
    • Extruder acceleration (Really not sure what is best. Have tried 1000, 3000)
    • Extruder jerk (have tried 40, 250, 600)
    • Pressure advance (0.1 seems to have little effect 0.5 and 0.6 seem close to helping)
      *Outer wall wipe (default is 0.1. Doesn't appear to make much difference)

    my Z Seam is all in line

    I'm really not sure what starting values I should work with and then what order I can start to increase what in order to get the best results. I know the model can be printed and I have to believe it can be printed on my setup

    Here are my test prints. You can see the blobs at the wall start-stop points



  • For some reason, I cannot upload any images so here is a pic of my printer and the prints I have been churning out
    Pictures



  • Can you post your config.g file?

    How long is your bowden tube?

    Getting a good print for this is going to be a matter of getting your retraction and pressure advanced tuned.

    Disable coast and wipe in the slicer. Focus on pressure advance instead.

    Extruder acceleration and jerk will need to be high. Set 3000 for both. This will allow pressure advance to work best and will allow for quick retractions.

    Even your Z axis speeds may be too low. You want to reduce the pause at layer change to reduce the blob.

    Next you will need to tune your retraction. I prefer to do this with a test model that has two cylinders a few inches apart. Use firmware retraction (cura has a hidden checkbox for it) and then start with retraction very low and increase it every few layers until things start to look good. For retraction speed, aim for 60mm/s. We want the retraction distance to be as short as possible but still remove stringing, and we want i to complete as quickly as possible to minimize oozing.

    Then when your retraction is dialed in you can start to introduce pressure advance. If 0.6 seems close to helping, start there. You may need even more yet.



  • This is my original config.g before I started playing around. I have noticed if i use lower acc and jerk the extruder is a lot quieter, which would be good but will give your idea a try.

    Bowden is about 30cm long

    ; Configuration file for Duet WiFi (firmware version 1.20 or newer)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool on Sun Jan 14 2018 17:24:59 GMT+0000 (GMT Standard Time)

    ; General preferences
    M111 S0 ; Debugging off
    G21 ; Work in millimetres
    G90 ; Send absolute coordinates...
    M83 ; ...but relative extruder moves
    M555 P1 ; Set firmware compatibility to look like RepRapFirmare
    ; Automatic saving after power loss is not enabled

    M665 L245 R110 H190 B80 X0 Y0 Z0
    M666 X0 Y0 Z0 A0 B0
    M208 Z0 S1 ; Set minimum Z
    ;M579 X0.984 Y0.984 ; X Y Corrections

    ; Endstops
    M574 X2 Y2 Z2 S0 ; Set active low endstops

    M558 P8 I1 R0.9 A30 F200 T4000 S0.03 X0 Y0 Z-0.1 H3
    G31 X0 Y0 Z-0.05 P250

    ;https://www.duet3d.com/forum/thread.php?id=2769
    ;https://duet3d.dozuki.com/Wiki/Gcode#Section_G31_Set_or_Report_Current_Probe_status
    ;The Z value is the Z height when the probe is triggered. Not an offset.

    M557 R80 S20 ; Define mesh grid

    M572 D0 S0.1 ; pressure advance

    ; Drives
    M569 P0 S1 ; Drive 0 goes forward
    M569 P1 S1 ; Drive 1 goes forward
    M569 P2 S1 ; Drive 2 goes forward
    M569 P3 S1 ; Drive 3 goes forward
    M92 X100 Y100 Z100 E398 ; Set steps per mm
    ;M350 X64 Y64 Z64 E64 ; Configure microstepping without interpolation
    M350 X16 Y16 Z16 E16 I1 ; Configure microstepping without interpolation

    M566 X900 Y900 Z900 E3000 ; Set maximum instantaneous speed changes (mm/min) was 1200
    M203 X18000 Y18000 Z18000 E3000 ; Set maximum speeds (mm/min) was 18000
    M201 X1500 Y1500 Z1500 E1500 ; Set accelerations (mm/s^2) was 1000
    M906 X1600 Y1600 Z1600 E1300 I10 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Heaters
    M301 H0 S1.00 P10 I0.1 D200 T0.4 W180 B30 ; Use PID on bed heater (may require further tuning)
    M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280 ; Set temperature limit for heater 1 to 280C

    ; Tools
    M563 P0 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

    ; Network
    M550 PMicroMake D1 ; Set machine name
    M552 S1 ; Enable network
    ;M587 S"DOG NET" P"bu33l1ghtyear" ; 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

    ; Fans
    M106 P0 S0 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
    M106 P2 S1 I0 F500 H T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; Custom settings are not configured
    M501



  • @buzzby said in Trying to tune extruder. What might I be missing:

    M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1

    B4138 is the default and almost certainly wrong for your thermistor.
    With that you would be printing at the wrong temperature.



  • @Veti How would i find the correct value. Both the bed and hotend report the same temp when cold and it seems to match with the expected room temp.



  • The problem is that even if it's accurate at room temp, it's very likely going to diverge at high temps since the curves won't match.

    You'd need to do some experimental testing and some math to figure out the values for your thermistor.

    https://www.electronics-tutorials.ws/io/thermistors.html

    Or you'd need to figure out what brand/type it is and find some information about it from the manufacturer or from other users of the same printer maybe?

    Or if you had a known accurate way of measuring high temperatures you could compare the temp of the hotend when set to something like 200c to what your measuring device says.

    Or, you could replace it with a quality thermistor with known values, or a PT100 sensor, or a PT1000 sensor, or a type-k thermocouple, which don't require defined values to get accurate results from.

    And finally, the old school way of figuring it out would be to lower your temp until the material just barely extrudes, for PLA that would likely be around 160-170c and then increase the temp until it starts to show signs of overheating. Then you can set your print temps in between there and use a temp tower test print to help find the sweet spot temp. Then you can just set your temps based on those results regardless of what the actual number is.

    But based on your problem description, I don't think your temps are really that far off. Doing a temp tower would be a good idea anyway just to try and find the sweet spot. It may help with blobbing/oosing/stringing a bit.



  • What is the layer height that you are printing with.. it can so happen that the extruder is pushing more that what is coming out and pressure is building up in the extruder.

    Also check your layer change and retraction settings in the slicer. probably layer height change is taking a long time.

    you can also read through the gcode that is generated and check for unwanted codes or change in feedrate.



  • if its a original e3d its a semitec 104-gt2. the configurator has those values if you click on the beta value.



  • @georgepaul using a 0.15 layer hight with an initial of 0.2. I am NOT retracting at layer change but do have retraction turned on.



  • @Veti said in Trying to tune extruder. What might I be missing:

    if its a original e3d its a semitec 104-gt2. the configurator has those values if you click on the beta value.

    How to I find the beta values in the configurator. Or more simple (for me) what would the M305 look like for an E3D V6

    This ?
    M305 P0 T100000 B4725 C7.06e-8 R4700



  • yes those are the correct values.

    in the configurator you click on the input field where it says by default 4138.



  • The journey continues,

    Redid the heater tuning.

    I have redone the stringing test after flipping Cura to use firmware tuning. Current setting is

    M207 S2 F3600 Z0.075

    Then I pushed the pressure advance. I ended up at 0.7. Any higher and the wall quality suffers and get streaking

    M572 D0 S0.7

    I once again then descend into madness trying to print this sword test print model the above dont make the print work but it is better.

    I have tried using coasting in cura as 0.128, 0.192, 0.256 and 0.512.
    None of these produce a print that separates so have stuck with 0.512.

    Tried adjusting the coasting speed but could see no difference at all.

    Tried lowering the overall print speed from 60 to 50, 40, 30, 20 all produce the same results.

    I am not sure what might be next other than starting to increase the values on the X Y Z Acceleration and jerk.

    Any more suggestions?

    Here is a full config.g dump

    ; Configuration file for Duet WiFi (firmware version 1.20 or newer)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool on Sun Jan 14 2018 17:24:59 GMT+0000 (GMT Standard Time)
    
    ; General preferences
    M111 S0                                   ; Debugging off
    G21                                       ; Work in millimetres
    G90                                       ; Send absolute coordinates...
    M83                                       ; ...but relative extruder moves
    M555 P1 				; Set firmware compatibility to look like RepRapFirmare
    ; Automatic saving after power loss is not enabled
    
    M665 L245 R110 H190 B80 X0 Y0 Z0
    M666 X0 Y0 Z0 A0 B0
    M208 Z0 S1                                ; Set minimum Z
    ;M579 X0.984 Y0.984	; X Y Corrections
    
    ; Endstops
    M574 X2 Y2 Z2 S0                          ; Set active low endstops
    
    M558 P8 I1 R0.9 A30 F200 T4000 S0.03 X0 Y0 Z-0.1 H3
    G31 X0 Y0 Z-0.05 P250
    
    ;https://www.duet3d.com/forum/thread.php?id=2769
    ;https://duet3d.dozuki.com/Wiki/Gcode#Section_G31_Set_or_Report_Current_Probe_status
    ;The Z value is the Z height when the probe is triggered. Not an offset.
    
    M557 R80 S20                              	; Define mesh grid
    
    M572 D0 S0.7 					; pressure advance
    M207 S2 F3600 Z0.075				; Retract Settings for G10/11
    
    ; Drives
    M569 P0 S1                                ; Drive 0 goes forward
    M569 P1 S1                                ; Drive 1 goes forward
    M569 P2 S1                                ; Drive 2 goes forward
    M569 P3 S1                                ; Drive 3 goes forward
    M92 X100 Y100 Z100 E398           	  ; Set steps per mm
    ;M350 X64 Y64 Z64 E64                    ; Configure microstepping without interpolation
    M350 X16 Y16 Z16 E16 I1                   ; Configure microstepping without interpolation
    
    M566 X900 Y900 Z900 E3000              ; Set maximum instantaneous speed changes (mm/min) was 1200
    M203 X18000 Y18000 Z18000 E3000           ; Set maximum speeds (mm/min) was 18000
    M201 X1500 Y1500 Z1500 E3000              ; Set accelerations (mm/s^2) was 1000
    M906 X1600 Y1600 Z1600 E1300 I10           ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30                                   ; Set idle timeout
    
    ; Heaters
    M301 H0 S1.00 P10 I0.1 D200 T0.4 W180 B30 ; Use PID on bed heater (may require further tuning)
    M305 P0 T100000 B3950 C0 R4700            ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120                              ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4725 C7.06e-8 R4700      ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280                              ; Set temperature limit for heater 1 to 280C
    
    ; Tools
    M563 P0 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
    
    ; Network
    M550 PMicroMake D1                        ; Set machine name
    M552 S1                                   ; Enable network
    M586 P0 S1                                ; Enable HTTP
    M586 P1 S0                                ; Disable FTP
    M586 P2 S0                                ; Disable Telnet
    
    ; Fans
    M106 P0 S0 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
    M106 P2 S1 I0 F500 H T45                  ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on
    
    ; Custom settings are not configured
    M501
    


  • @buzzby said in Trying to tune extruder. What might I be missing:

    I have tried using coasting in cura as 0.128, 0.192, 0.256 and 0.512.

    Coasting and pressure advance do not play well together. Better to use pressure advance by itself.


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