Stepper setup & DEFAULT_AXIS_STEPS_PER_UNIT

Discussion in 'Calibration, Help, and Troubleshooting' started by rvator, Feb 20, 2017.

  1. rvator

    rvator Active Member

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    I am building a BigBox Dual Hybrid Titan from scratch and have some uncertainties concerning stepper setup.

    I have the following situation:

    X/Y - Axis 0.9° /step (400 steps/rev)
    Z - Axis 1.8 °/step (200steps/rev) / Z- Leadscrew pitch 8mm
    E0/E1 1.8° /step (200 steps/rev) & Titan Extruders

    At the moment I came to following results:

    microsteps DEFAULT_AXIS_STEPS_PER_UNIT
    X-Axis 16 160
    Y-Axis 8 180
    Z-Axis 16 400

    Titan Extruders 16 417.5

    Can anyone confirm my results?

    Firmware:
    To set the corresponding values I downloaded the "Marlin-Hybrid-Dual" firmware source code. Now I am wondering, why there are only values for one extruder (E0 / 417.5) defined.

    #define DEFAULT_AXIS_STEPS_PER_UNIT {160,180,1600,417.5} // default steps per unit for Titan BigBox

    I think, the Z-value of 1600 is for the old 2mm leadscrew pitch.

    Regards,
    Franz
     
  2. Ephemeris

    Ephemeris Well-Known Member

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    X - With your 0.9° motor providing 400 steps/rev driving a 20 tooth GT2
    and using 16x microstepping, 160 is what I'd expect
    16/(1/400*20*2) = 160 microsteps/mm

    Y - With your 0.9° motor providing 400 steps/rev driving a 16T GT2 pulley
    that belt drives a 36T on the Y drive shaft which has 20T pulleys that
    drive the Y carriages I expect
    8/(1/400*16/36*20*2) = 180 microsteps/mm

    Z - If you're using the 2 mm pitch, 8 mm lead (4 start) leadscrews 400 is correct with your 1.8° motor and 16x microstepping

    For the Titan the ratio depends on things like filament squishiness and you really have to measure it and see. However your numbers look about right. (I'm using 408 right now)

    Most importantly, my hat is off to you for doing it from scratch!!! Very impressive :)
     
    #2 Ephemeris, Feb 20, 2017
    Last edited: Feb 20, 2017
  3. rvator

    rvator Active Member

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    Hello Ephemeris,

    thank you, now I have more confidence in my setup.

    But I still wonder, why there is only one parateter for the extruders in the dual software.
    #define DEFAULT_AXIS_STEPS_PER_UNIT {160,180,1600,417.5} // default steps per unit for Titan BigBox

    Thank you for your complimnet. I underestimated the work a little before beginning, but now I am comming to the end.

    At the moment I am struggling wit a ERR MINTEMP Message at power up, but I have to do some investigations, before I can ask seriuos questions.

    Franz

    BigBOX_FM.jpg
     
    mike01hu likes this.

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