Two Stepper Drivers from Single Output Pins



  • Hello,
    I want to drive two Y motors with external drivers. Since both the Y motors should follow the same command and at the same time, I connected E2_Enable, E2_Step, E2, Dir to the two Stepper Drivers to run Two different Motors. But with this connection, the motor does not move.

    If I connect it to the single Stepper drivers, the motor moves perfectly.

    Now, is it possible that I connect E2 and E3 to stepper drivers respectively, and mention that in the config file to make both motors move at the same time?


  • administrators

    Two external drivers to one step/dir/enable pin should work however it may be that an element of electrical incompatibility means one works and two don't.

    Configure an axis using two driver channels use M584:

    https://duet3d.com/wiki/G-code#M584:_Set_drive_mapping



  • Configure an axis using two driver channels use M584:

    I don't get this. Is this mean that I connect two stepper drivers to two different sets of Enable, Direction and Step of the expansion board, and add a command to run both the motors at the same time?


  • administrators

    Are they stepstick-type drivers, or large external driver modules with opto isolated inputs? If the latter, then given that those are usually intended for 5V drive and they only get 3.3V if you drive them directly from the expansion connector, it's quite likely that when you drive 2 of them form a single set of pins, the drive voltage drops too much. In which case, do as Tony says. Your interpretation of what he meant is correct.


 

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