Bed leveling on DuetWifi+Duex5 using 4 independent Z motors



  • I have been using 3 independent Z motors on my CoreXY (HyperCue Evo) machine... Currently, the bed is configured as:
    Left Front - Stepper Motor with Lead Screw (Z0)
    Left Rear - Linear Bar with Bearings/Bushings
    Right Front - Stepper Motor with Lead Screw (Z1)
    Right Rear - Linear Bar with Bearings/Bushings
    Middle Rear - Stepper Motor with Lead Screw (Z2)

    and I am thinking of experimenting of adding a 4th independent Z motor... so I can get rid of the Linear Bar with Bearings and just mounting the 4 Stepper Motors with Lead Screw at each corner alone - would this be correct? or do I still need linear bars with bearings/bushings? Please advice, Thanks!



  • Hi the Linear rails/bars are provide the Stability an accuracy and the Screws provide the movement/motion of the system. No screw is that accurate that you dont have an possibly x/y movement of the table.



  • Thanks! What would you recommend?

    Adding 2 linear bars+bearing/bushings in the middle?
    Left Front - Stepper Motor with Lead Screw (Z0)
    Left Middle - Linear Bar with Bearings/Bushings
    Left Rear - Stepper Motor with Lead Screw (Z1)
    Right Front - Stepper Motor with Lead Screw (Z2)
    Right Middle - Linear Bar with Bearings/Bushings
    Right Rear - Stepper Motor with Lead Screw (Z3)

    Or Go extreme with 4 Linear Bars with Bearling Busings
    Left Front - Stepper Motor with Lead Screw (Z0)
    Left Middle - Linear Bar with Bearings/Bushings
    Left Rear - Stepper Motor with Lead Screw (Z1)
    Right Front - Stepper Motor with Lead Screw (Z2)
    Right Middle - Linear Bar with Bearings/Bushings
    Right Rear - Stepper Motor with Lead Screw (Z3)

    Rear Middle Left - Linear Bar with Bearings/Bushings
    Rear Middle Right - - Linear Bar with Bearings/Bushings

    Or putting Linear Bars with Bearings/Bushings next to each leadscrew Mounts?

    Or putting the linear bars with Bearing/Bushings on the extreme corners and putting the leadscrew mounts next to each linear bar mounts?

    What would be the best? (sorry being very wordy...)



  • or go with 6? 4 on the sides and 2 in the rear?


  • administrators

    I haven't built a CoreXY machine, but the most common configuration seems to be:

    • Linear rails left middle and right middle
    • Leadscrews front left, front right, and rear middle

    Getting 2 linear rails exactly parallel to each other is difficult enough, 3 or 4 would be worse.


 

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