HELP with external Drivers and computer water pump&fan



  • Good Morning
    I would appreciate if you could clarify a couple of questions I have about your Duet wifi and Duex boards.
    I need to use external drivers for 8 motors. Documentation says that I cannot connect the three pins to the controller side for this purpose. Could you explain me why not?
    Please note that I also have a duex5 board, but I can not use these drivers for this project, for other reasons.
    The motors I want to use have the integrated drivers.
    For this purpose, I would not mind to use the Duetwifi controllers for the 5 extruders. However I need a way to drive the other three motors for the axes which already have integrated drivers. Please note that I cannot use the LCD connector for the motors, since I need it for other purposes.
    Can I unconnect the pins (step / dir / cs) for each motor used on each axis in the 50-pin connection block and still use Duo / Duex safely?
    In addition, I need to connect a 12v and 30W water pump (Model D5 PWM9-38) and computer fans. The pump and the fan have four connectors as the following image:

    Where I can connect this pump and fan to duet wifi / duex?

    I would appreciate your help on the above.

    Thank you!



  • I don't have duex board but on my wifi main board I connected a 120mm 24v fan to one of the fan outputs (Fan 1). This is then connected in parallel to a buck converter to reduce voltage down to 12v for my water pump. The fan output seems quite happy to run both as long as current is below 2A.

    Both my water pump and fan have extra wires for monitoring/speed control I just didnt connect them to anything, just red and black, I can PWM the system if I want to but I have it set to just run at full power if hotend is over 45 deg C.


  • administrators

    @kradoq:

    I need to use external drivers for 8 motors. Documentation says that I cannot connect the three pins to the controller side for this purpose. Could you explain me why not?

    The test points for each of the internal drivers carry Step, Dir and CS. There is no separate Enable pin. I guess you could use just the Step and Dir pins, and leave your drivers permanently enabled, or use a GPIO pin to switch the Enables.

    @kradoq:

    Please note that I also have a duex5 board, but I can not use these drivers for this project, for other reasons.
    The motors I want to use have the integrated drivers.
    For this purpose, I would not mind to use the Duetwifi controllers for the 5 extruders. However I need a way to drive the other three motors for the axes which already have integrated drivers. Please note that I cannot use the LCD connector for the motors, since I need it for other purposes.

    Can I unconnect the pins (step / dir / cs) for each motor used on each axis in the 50-pin connection block and still use Duo / Duex safely?

    What you need is a DueX2 board, then you connect your 3 external drivers to the 3-pin headers near the unpopulated 3 drivers. With the DueX5 you face the same issue as on the main board, i.e. no Enable pins because they carry the CS signal instead.

    @kradoq:

    In addition, I need to connect a 12v and 30W water pump (Model D5 PWM9-38) and computer fans. The pump and the fan have four connectors as the following image:

    http://www.electronic-products-design.com/wp-content/uploads/pc_fan_4_pinout.png

    Where I can connect this pump and fan to duet wifi / duex?

    Connect the +12V and Gnd wires to V_FAN and Gnd respectively. You can pick these up from an always-on fan connector. Connect the control wire to the FAN- pin of one of the controlled fan outputs. You can leave the tacho wire unconnected, or connect it to PB6 on the expansion connector through a small signal diode (cathode to fan, anode to PB6). The purpose of the diode is to avoid feeding 12V intp PB6 if the ground connection breaks.

    HTH David



  • OK! I have understood..

    THANK YOU VERY MUCH


 

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