CORE XY HEVO how much for acceleration and speed ?

  • Hi !
    I have build a corexy Hypercube Evo with 1.8° 1.68A steppers motors, dual Z, BLTOUCH.

    The default configuration from the configurator seems very low:
    M566 X600 Y600 Z18 E300 ; Set maximum instantaneous speed changes (mm/min)
    M203 X6000 Y6000 Z400 E6000 ; Set maximum speeds (mm/min)
    M201 X1500 Y1500 Z100 E10000 ; Set accelerations (mm/s^2)

    How proceed to tune each values ?
    What is the maximum instantaneous speed changes vs the maximum speed ?

    Have you some typical values for a corexy ?


  • it depends on your own requirements for the print.

    with higher speeds and jerk settings you will most likely see or increase ringing in your prints.
    also the noise of the printer will increase with higher speeds.

    there will not be a definite answer for max Settings as each hypercube is custom build and therefore will behave different.

    so print something like a benchy. then increase the speed and compare the results.

  • @pipersw Those values look reasonable to start with, with the exception of the instantaneous speed change for the extruder which I would set to 3000 rather than 300.

  • Moderator

    @pipersw said in CORE XY HEVO how much for acceleration and speed ?:

    What is the maximum instantaneous speed changes vs the maximum speed ?

    The maximum speed should be set to your maximum reliable travel speed, that way increasing the speed factor slider won't effect your travel moves and lead to lost steps. You can get an idea for your maximum acceleration and top speed using these calculators if you know your motor characteristics. > EMF calculator

    You can also use M204 P and T to set independent acceleration values for print and travel moves. For travel you can set it to close to what you get from the max acceleration calculator. For print moves it will depend on many other factors.

    Instantaneous speed change is Jerk. It's the speed to which the print head will slow down before doing a direction change. 600-1200-1500 range is what I use on my corexy, but it's going to depend a lot on your frame rigidity, print head mass, and print speed. I also use the slicer to alter the jerk for internal features versus external features. Lower jerk on the outside usually reduces ringing vibrations.

    Have you some typical values for a corexy ?

    Those defaults are a good starting point. Double them and halve them and note the difference.

  • Thanks for the links, it's help me.

    I have set for starting point:

    M566 X600 Y600 Z30 E3000 ; Set maximum instantaneous speed changes (mm/min)
    M203 X15000 Y15000 Z1500 E6000 ; Set maximum speeds (mm/min)
    M201 X3000 Y3000 Z100 E10000 ; Set accelerations (mm/s^2)

  • @pipersw, I have a printer similar to yours, 300x300, with 0.9deg X/Y, 1.9 mm ID 660mm Capricorn bowden tube and two Z motors.

    M566 X600 Y600 Z100 E3000 ; Set maximum instantaneous speed changes (mm/min) (Jerk)
    M201 X600 Y600 Z30 E8000 ; Set maximum accelerations (mm/s^2)
    M203 X15000 Y15000 Z3000 E15000 ; Set maximum speeds (mm/min)

    I also use pressure advance because it improves the print quality. I get best printing results with:
    M572 D0 S0.5 ; set K-factor (from calibration script)

    But I typically dial it down for quieter printing
    M572 D0 S0.3 ; set K-factor

    I am using a dual drive BondTech clone which has very good grip on the filament and can move fast with no slip.

    The printer uses stall detection to home the X/Y so no need for those X/Y limit switches and a BLTouch for Z homing and mesh bed leveling. It also uses Gates GT2 belts that IMO are better than the stock Chinese ones.

    I am not an expert by any mean but thanks to advice I get here and many hours of tweaking (RepRap firmware makes it much easier with those gcode configuration files) I am getting results which I like.

  • This is what I use and have tuned over the years:

    # speeds, accelerations, jerk and moves
    JERK_NORMAL=([X]=12 [Y]=12 [Z]=5 [E]=10) # max instantaneous speed changes (mm/s)
    JERK_HOMING=([X]=0 [Y]=0 [Z]=0 [E]=0 ) # max instantaneous speed changes (mm/s)
    ACCEL_NORMAL=([X]=2500 [Y]=2500 [Z]=100 [E]=9000 [PRINT]=2500 [TRAVEL]=2500) # (mm/s^2)
    ACCEL_HOMING=([X]=500 [Y]=500 [Z]=50 [E]=250 [PRINT]=500 [TRAVEL]=500) # (mm/s^2)
    MAXSPEEDS=([X]=150 [Y]=150 [Z]=30 [E]=30) # max speeds (mm/s)
    XY_SPEEDS=([SLOW]=20 [FAST]=150 [HOMING]=80) # speed for X or Y movements
    Z_SPEEDS=([SLOW]=3 [MEDIUM]=8 [FAST]=20) # speed for Z movements
    E_SPEEDS=([SLOW]=10 [FAST]=30) # speed for E movements

    These are variables in the tool I wrote to parse and export a config for me, but you can see the values that matter there.

    BTW the tool is here if you want to play (works in linux or windows/cygwin).

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