Reoccuring Lines and even gaps in print.



  • Hi, Can anyone please tell me what this is causing?

    I recently fixed my Z axis Leadscrews and installed antibacklash nuts, Because I thought this was the problem.

    Now I'm starting to think its an extruded problem, but it makes no sense because normally under extrusion happens randomly when the printer decides when it feels under exstrudy. but this seems not random it is reoccurring every 8 layers or so.

    0_1552404371960_file-1.jpeg



  • https://forum.duet3d.com/topic/5909/guide-for-posting-requests-for-help

    Could use some more information.

    Is your bed heater running in bang-bang mode?



  • For convenience, I will paste my Config file. 😉

    ; Configuration file for Duet WiFi (firmware version 1.21)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool on Wed Aug 29 2018 23:11:26 GMT+0200 (Midden-Europese zomertijd)

    ; General preferences
    G90 ; Send absolute coordinates...
    M83 ; ...but relative extruder moves
    M555 P1 ; Set firmware compatibility to look like RepRapFirmare
    ;M572 D0 S0.6 ; Pressure advance

    ; Network
    M550 POptimus Prime ; Set machine name
    M552 S1 ; Enable network
    M586 P0 S1 ; Enable HTTP
    M586 P1 S0 ; Disable FTP
    M586 P2 S0 ; Disable Telnet

    ; Drives
    M569 P0 S1 ; Drive 0 X goes forwards
    M569 P1 S1 ; Drive 1 Y goes forwards
    M569 P2 S0 ; Drive 2 1Z goes forwards
    M569 P3 S1 ; Drive 3 E0 goes forwards
    M569 P4 S0 ; Drive 4 2Z
    M584 X0 Y1 Z2:4 U4 E3 P3 ; Driver remapping
    M671 X-31:330 Y0:0 S1.0
    M350 X16 Y16 Z16:16 U16 E16 I1 ; Configure microstepping with interpolation
    M92 X80 Y80 Z400:400 E97.2 U400 ; Set steps per mm
    M566 X400 Y400 Z200:200 U200 E800 ; Set maximum instantaneous speed changes (mm/min)
    M203 X4000 Y4000 Z1000:1000 U1000 E8000 ; Set maximum speeds (mm/min)
    M201 X600 Y600 Z400:400 U400 E800 ; Set accelerations (mm/s^2)
    M906 X800 Y800 Z800:800 U800 I0 ; Set motor currents (mA) and motor idle factor in per cent
    M906 E1000 I50
    M84 S20 ; Set idle timeout

    ; Axis Limits
    M208 X0 Y0 Z0 S1 ; Set axis minima
    M208 X300 Y300 Z400 S0 ; Set axis maxima

    ; Endstops
    M574 X1 Y1 S1 ; Set active high endstops
    M574 Z1 S2 ; Define Z to use Probe. Home to Min

    ; Z-Probe
    M558 P9 H20 F300 T4000 X0 Y0 Z1 ; Disable Z probe but set dive height, probe speed and travel speed
    M557 X20:280 Y20:280 S20 ; Define mesh grid
    G31 P25 X-39 Y0 Z1.15 ; Z probe trigger value, offset in relation to nozzle. And trigger height adjustment

    ;BL-Touch / Heaters
    M307 H0 B0 S1.00 ; Disable bang-bang mode for the bed heater and set PWM limit
    M307 H1 A247.4, C85.3, D2.6 S1 ; Set Pid Tuning for Hotend
    M305 P0 T100000 B4088 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M143 H0 S90 ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4088 C0 R4700 ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280 ; Set temperature limit for heater 1 to 280C
    M307 H3 A-1 C-1 D-1 ; Disable the 3th Heater to free up PWM channel

    ; 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 T50 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; Tools
    M563 P0 D0 H1 ; Define tool 0
    G10 P0 X0 Y-7 Z0 ; Set tool 0 axis offsets
    G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

    ; Automatic saving after power loss is not enabled

    ; Custom settings are not configured


  • administrators

    What is the pitch of the banding, what is the pitch of your leadscrews, and what layer height are you using?



  • Can you describe your printer a bit more? The Z axis arrangement in particular? What are the lead screws? Maybe post a picture?

    M566 X400 Y400 Z200:200 U200 E800 ; Set maximum instantaneous speed changes (mm/min)
    M203 X4000 Y4000 Z1000:1000 U1000 E8000 ; Set maximum speeds (mm/min)
    M201 X600 Y600 Z400:400 U400 E800 ; Set accelerations (mm/s^2)

    The speed, jerk, and acceleration settings for the Z axis are a little high.

    If you run the Z axis up and down do you notice any hesitation or binding? Does it sound smooth and consistent, or is there whine and wobble? If you touch a finger to the Z axis while it's in motion do you feel smooth motion, or pulses and vibration?

    What does the temperature graph look like in the DWC? Have you done a PID tuning of the heaters?



  • Have you calibrated steps?



    • The printer is a little bit modified, original it was a CR10S.

    • I use the ordinary lead screws that come with the CR10S, 8mm. (already replaced the original ones with better ones)(The old were not straight).

    • I have done PID Tuning, Temperature is rock solid.

    • I have literally no idea if the speed or jerk settings are oke

    • Layer height is always 0.2 or 0.15

    • Dual Z-axis moves pretty smooth, I have installed anti-backlash nuts.

    • See photo for the arrangement.

    0_1552410965886_file-2.jpeg

    Question, can anyone scan through my printer config file for any weird settings? I have the CR10S.



  • I think that it has something to do with the extruder.
    The Z rods are nearly perfect. I double checked it multiple times.



  • @nelisgast said in Reoccuring Lines and even gaps in print.:

    Layer height is always 0.2 or 0.15

    With Tr8*8 lead screws and 1.8 degree motors 0.15 would be a non-multiple of your step length of 0.04. Use 0.12 or 0.16 instead. 0.2 is also ok.

    Based on the calculator here: https://www.prusaprinters.org/calculator/#optimallayer

    Reduce your Z axis jerk to M566 Z30
    Reduce your Z axis max speed to M203 Z500
    Reduce your Z axis acceleration to M201 Z60



  • Your extruder does have a very low steps per mm, but I don't think it would have this kind of a result of bulges along the Z axis.

    You can easily test using a higher extruder microstepping by adding another M350 line right below your current lines so that it looks like this

    M350 X16 Y16 Z16:16 U16 E16 I1 ; Configure microstepping with interpolation
    M92 X80 Y80 Z400:400 E97.2 U400 ; Set steps per mm
    M350 E64 ; boosted microstepping for extruder
    

    Since the steps per mm are already set for x16 microsteps, the second microstep command will automatically recalculate for you.



  • Thanks, I'm trying the new settings now.

    I'll keep you guys updated 😉


 

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