Leapfrog Creatr HS two steppers on y axis



  • Hi there
    I'm planning to upgrade a Leapfrog Creatr HS to Duet 2 Ethernet version.
    This printer has two stepper motors on the Y axis. Is it possible to connect the Y two steppers in parallel to one of the outputs on the Duet 2, so I can use both of the extruder outputs for the printer's two extruders?
    Anyone who has experience of converting a Leapfrog - please get in touch if you can offer any help/advice as I'm a beginner to Duet.
    Thanks for your help, Peter


  • Moderator

    @Peter_3D Yes, you can wire two motors in parallel (or series, which is usually better) and connect them to one motor driver output. It will depend on how much current your stepper motors are rated for, because if wired in parallel you need to double the current going to them, which will be limited by the stepper drivers on the Duet. eg if you have 2x 1.6A motors on Y, we'd normally recommend setting the current to 80% for a single motor, so 1.3A, which would then need to be doubled to 2.6A if motors are wired in parallel. The drivers on the Duet 2 Ethernet are limited to 2.4A, and require extra cooling if run at this current.

    Alternatively, wiring your motors in series means you just set the current as for one motor. There is also a motor driver (Z) on the board that has two motor pinouts, so you can connect your two Y motors to that (assuming you don't want them for 2x Z motors), remap the drivers with M584. These pins are wired in series, so again, the motor current setting would be as for one motor.

    Ian



  • Thanks Ian. If I were to go with the "in series" option, connecting the two Y axis steppers to the Z axis driver with two sockets, how would I deal with configuring voltage for the two motors in series? Would the voltage at the output of the driver need to be doubled? Thanks, Peter



  • @Peter_3D said in Leapfrog Creatr HS two steppers on y axis:

    how would I deal with configuring voltage for the two motors in series?

    you can work out the emf at the speed you want and just make sure you have enough Vin. nothing to configure.
    https://www.reprapfirmware.org/ has a calculator for the emf



  • @bearer Thank you. By Vin, do you mean the power supply voltage to the board (eg 12v or 24v)?
    Thanks, Peter



  • @Peter_3D said in Leapfrog Creatr HS two steppers on y axis:

    By Vin, do you mean the power supply voltage to the board (eg 12v or 24v)?

    yes, it can be anything between 10 and 24-ish volts, but 12 and 24 are most common.

    you can use 24v even if your emf calc only say 6v or whatever. but if you have more emf than supply voltage you'll be limited by the speed you can achieve.



  • @bearer Thanks for your help


  • Moderator

    @Peter_3D said in Leapfrog Creatr HS two steppers on y axis:

    Thanks Ian. If I were to go with the "in series" option, connecting the two Y axis steppers to the Z axis driver with two sockets, how would I deal with configuring voltage for the two motors in series? Would the voltage at the output of the driver need to be doubled? Thanks, Peter

    The stepper driver deals with the voltage, all you can do is set the current. It's better to be running on 24V than 12V, generally. For more information on choosing and configuring stepper motors, see https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors

    Ian


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