Using Duet 3Mainboard with external stepper drivers


  • administrators

    @mpentenr said in Using Duet 3Mainboard with external stepper drivers:

    @dc42 Are there any news on this topic ?

    Not yet. Now that we have the prototype Tool Board, there are two ways we could support external drivers without needing a new main board:

    1. Do a version of the EXP3HC board with outputs for 3 or just possibly 4 external stepper drivers instead of on-board drivers. This would probably be best for those who are actually using external drivers, not step-servo motors. But we don't expect many people to need external drivers with Duet 3.

    2. Do a version of the Tool Board that has a single set of step/dir/enable outputs, to drive a single external driver or step-servo drive. I think this might be better for those using step-servo motors with built-in controllers.



  • @dc42 said in Using Duet 3Mainboard with external stepper drivers:

    @mpentenr said in Using Duet 3Mainboard with external stepper drivers:

    @dc42 Are there any news on this topic ?

    Not yet. Now that we have the prototype Tool Board, there are two ways we could support external drivers without needing a new main board:

    1. Do a version of the EXP3HC board with outputs for 3 or just possibly 4 external stepper drivers instead of on-board drivers. This would probably be best for those who are actually using external drivers, not step-servo motors. But we don't expect many people to need external drivers with Duet 3.

    That would be my favorite, because of my 2pt100(bed) and 3K-Type Thermocouple (Pellet Extruder) which I cant connect to the tool board or is it possible to use thermo connectors on one board and step/dir/ena on another board for one "axis/extruder"? I also would need 2 of these boards, because of the 3 (X/Y/Z)axis with external drivers and up to 3 external drivers for the (pellet)extruders.

    1. Do a version of the Tool Board that has a single set of step/dir/enable outputs, to drive a single external driver or step-servo drive. I think this might be better for those using step-servo motors with built-in controllers.

    Please take into account, that the Vin for example for my pellet extruder is 48V, when designing the driverless Tool Board with step/dir/ena output.

    Thanks
    Marc Pentenrieder


  • administrators

    @mpentenr, what motors and drivers do you plan to use on that machine? Although we don't support as much as 48V at present, we are considering making variations of main and/or expansion boards that support up to about 54V. The TMC5160 drivers can take 60V, it's just the voltage regulators we use that limit us to around 35V.



  • @dc42 Hi, on the 3 axis I am using 1KW 380V Servo Motors and on the pellet extruder, I am using the following:
    Motor Driver: https://us.nanotec.com/products/1768-c5-e-2-09-motor-controllerdrive-for-canopen-or-usb/

    Stepper motor: https://us.nanotec.com/products/574-st8918m6708-a/


  • administrators

    Thanks. Are you using the encoder input on the stepper driver for the pellet extruder? What is the maximum rotation speed needed by the pellet extruder motor? Have you established that you really do need 48V to drive it?



  • @dc42 said in Using Duet 3Mainboard with external stepper drivers:

    Thanks. Are you using the encoder input on the stepper driver for the pellet extruder? What is the maximum rotation speed needed by the pellet extruder motor?

    No, I am not using the encoder input (at the moment, perhaps I need to).
    The max rotational speed will be around 500 rpm, because of an 10:1 gearbox on the stepper, so up to 50 rpm at the pelletextruderspindle



  • @mpentenr said in Using Duet 3Mainboard with external stepper drivers:

    @dc42 said in Using Duet 3Mainboard with external stepper drivers:

    Thanks. Are you using the encoder input on the stepper driver for the pellet extruder? What is the maximum rotation speed needed by the pellet extruder motor?

    No, I am not using the encoder input (at the moment, perhaps I need to).
    The max rotational speed will be arounf 500 rpm, because of an 10:1 gearbox on the stepper, so up to 50 rpm at the pelletextruderspindle

    At the moment the pellet extruder is highly experimental, so I don't know the exact values. Time and experiments will show 😉



  • @mpentenr said in Using Duet 3Mainboard with external stepper drivers:

    @dc42 Are there any news on this topic ?

    Hi dc42, are there any news on driverless duet3 or addon boards for driving motors with external drivers ?!


  • administrators

    @mpentenr said in Using Duet 3Mainboard with external stepper drivers:

    @mpentenr said in Using Duet 3Mainboard with external stepper drivers:

    @dc42 Are there any news on this topic ?
    

    Hi dc42, are there any news on driverless duet3 or addon boards for driving motors with external drivers ?!

    We have a few tool board prototypes modified to drive a single external driver at 5V signals levels. We will turn this into a production item. We still need to lay it out on a PCB, but that shouldn't take long, because the design is based on our Tool Board.

    We haven't yet made a decision on whether to make a driverless version of the main board.



  • DC42,
    I would be interested in a driver-less version as well. Don't get me wrong, those 5160's are nice but I already have $200 invested in my hobby CNC's external drivers and when / if I make the switch from the UC100 to the Duet , I will also be getting a Duet wifi for my 3d printer. The thought of spending $400 + on the upgrade while shelving $400 in parts with no use is a real bummer. And I get that an $800 hit is nothing for most, but for a guy just trying to learn a new hobby....

    Kyle


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