Fine Tuning - Need your opinion



  • Hi all,
    I am currently setting up a Titan Aero Direct Drive on my delta printer. I printed a 20mm cube in vase mode to calibrate the extruder and it was fine. I printed a calibration cube and I modified the acceleration, jerk and pressure advance values. The dimensions on the x,y and z sides are 19.91mm, 19.89mm and 20.06mm. Here are the pictures:





    I need your opinion on how to tune it further and get better prints: Here is my configuration file. My autocalibration is consistently between .015 to .020 mm. I get a good first layer.

    ; Configuration file for Duet WiFi (firmware version 1.17)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool on Thu Jun 01 2017 14:36:55 GMT+0200 (W. Europe Daylight Time)

    ; General preferences
    M111 S0 ; Debugging off
    G21 ; Work in millimetres
    G90 ; Send absolute coordinates…
    M83 ; ...but relative extruder moves
    M555 P2 ; Set firmware compatibility to look like Marlin

    ;*** The homed height is deliberately set too high in the following - you will adjust it during calibration.
    M665 R170.013 L360.31 H460.932 B100.00 X-0.760 Y-0.883 Z0; Set delta radius, diagonal rod length, printable radius and homed height
    M666 X0.68 Y-0.26 Z-0.42 A0.00 B0.00; Put your endstop adjustments here, or let auto calibration find them
    M208 Z0 S1 ; Set minimum Z

    ; Endstops
    M574 X2 Y2 Z2 S0 ; Define active high microswitches
    M558 P5 F300 X0 Y0 Z0 I1 H3 T2400 ; Set Z probe type to unmodulated, the axes for which it is used and the probe + travel speeds
    G31 P10 X0 Y0 Z-0.42 ; Set Z probe trigger value, offset and trigger height original 0.558 changed to 0.45 and back to 0.55
    M557 R50 S10 ; Define mesh grid

    ; Drives
    M569 P0 S0 ; Drive 0 goes forwards
    M569 P1 S0 ; Drive 1 goes forwards
    M569 P2 S0 ; Drive 2 goes forwards
    M569 P3 S0 ; Drive 3 goes forwards
    M350 X16 Y16 Z16 E16 I0 ; Configure microstepping without interpolation
    M92 X160 Y160 Z160 E785 ; Set steps per mm
    M566 X500 Y500 Z500 E800 ; Set maximum instantaneous speed changes (mm/min) original 1200 for all
    M203 X6000 Y6000 Z6000 E800 ; Set maximum speeds (mm/min) original 6000 and 800
    M201 X600 Y600 Z600 E500 ; Set accelerations (mm/s^2) original 600 and 500
    M906 X1400 Y1400 Z1400 E1000 I60 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ;Pressure Advance
    M572 D0 S0.1

    ; Heaters
    M143 S285 ; Set maximum heater temperature to 285C
    M305 P0 T100000 B3950 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M305 P1 T100000 B4388 C0 R4700 ; Set thermistor + ADC parameters for heater 1
    M307 H1 A303.2 C140.1 D3.5 B0

    ; 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

    ; Network
    M550 PSM3D ; 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 T20 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P2 S1 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off

    ; Custom settings are not configured

    ; Miscellaneous

    T0 ; Select first tool

    My observations are:
    I see some over extrusion in some places.
    Blobbing on corners which I have reduced a bit by using pressure advance
    I tried reducing jerk and acceleration but did not improve anything

    Previously, I used Titan direct drive (not aero). I had better prints. Now, I am trying to tune the settings. The print seems very average but I want to have as good as possible. so, I need your suggestions to try. Your help is much appreciated.

    Cheers,
    Vasan


  • administrators

    1. To avoid over extrusion, assuming you have calibrated your extruder steps/mm correctly, just reduce the extrusion factor a little either in the slicer settings or in DWC or PanelDue. When you have found the optimum value, write it on that reel of filament.

    2. Change: M350 X16 Y16 Z16 E16 I0 ; Configure microstepping without interpolation

    to: M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation

    Or perhaps use x32 or x16 microstepping instead, however x16 with interpolation should be good enough.

    3. Your last photo shows more moire than I expect from a delta with 0.9deg motors. This may be caused by excessive friction in one of the carriages or one or more of the joints. That could also account for the imperfect layer registration.

    4. What layer height are you using? Your full step Z distance is 0.1mm, so a layer height of 0.2mm should be a good choice.

    HTH David



  • Thanks David for your help!

    1. Sure I will play with the extrusion multiplication factor
    2. Can you please explain or refer to a link about what this interpolation does and why it matters here?
    3. I will lubricate the linear rails and check this theory.
    4. I am currently using 0.2mm layer height

    Do you think the acceleration and jerk settings are fine? I am using a Titan Aero Direct Drive. I feel that layer registration might be affected if I choose too high an acceleration and low jerk values. It will be great to know your opinion.

    Thanks again and Regards,
    Vasan


  • administrators

    2. Interpolation is a feature whereby the stepper driver splits each 1/16 microstep into 16 x 1/256 microsteps. This gives smoother and especially quieter motion.

    4. The acceleration and jerk settings I use on my delta are 3000 and 600. You may need to use lower values because of the increased mass on the effector. I don't see any artefacts in your print (e.g. ringing) that suggest your values are too high.



  • Thanks again David for the explanations. I will try with 1000 and 200 for acceleration and jerk to see what happens!

    Best Regards,
    Vasan


 

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