Comment on Biqu B1 SKR V1.4 mainboard to SKR MINI E3 V3?

• UncleStewart@sh.itjust.works ⁨3⁩ ⁨weeks⁩ ago

  Here comes the fun part.
  The Biqu B1 has all it’s wires to the hotend via a USB-C cable. All wires from the motherboard goes to a card in the back of the printer, and fom there is a USB-C to a card in the hotend. This card splits up to TH0, CNCFAN, CNCAN1, FAN2 and HE0. Even power to the nozzle heater goes in the USB-C.

  On the old SKR v1.4, the wire labeled DCIN were connected to FAN1 (GND - 12/24v), and FAN0 were connected to FAN0 (2.3 - 12/24v).
  On the new SKR MINI V3 the DCIN wire is connected to FAN1 (12/24v - PC7), and FAN0 wire to FAN0 (12/24v - PC6).
  The wire DCIN is not from PSU, but gives power to the card in the hotend.

  In the printer.cfg all of fan-stuff are commented out, and the only thing is:

  [fan_generic hotend_fan] #use for testing of hotend fan pin: PC7
  pin: PC7
  
  [fan] #part fan pin: PC6
  Pin: PC6
  

  This gives me sliders in Klipper for PC6 and PC7, and I can set FAN1 to 100%.

  This should in (my) theory give power to the card in the hotend. But when i slide FAN0 in Klipper nothing happens with the fans.

  When i disconnect the wires to the nozzle heater from the motherboard i now have about 24 volts on those wires, and this happens without heating the heater.

  The reason for me starting this project was that one day i just got error message when heating the nozzle. First i bought a new heater, thermistor and the block they are mounted in. This did not help. So, now the motherboard is replaced and I’ve added a Raspberry PI with Klipper to the setup, and still no joy.

  source

  • B0rax@feddit.org ⁨3⁩ ⁨weeks⁩ ago

    Ok, let’s look into it. (you can also send me your printer.cfg if you want) The Mini e3 v3 has the following switchable outputs:

    • HB - PC9
    • E0 - PC8
    • FAN0 - PC6
    • FAN1 - PC7
    • FAN2 - PB15

    Keep in mind that they all switch ground only. 24V is always there.

    You can use all of them for whatever you want, Klipper is very flexible here. HB is your heated bed, no questions here. E0 should be connected to your Hotted board HE0. I don’t know which of the fans on your board does what, you may need to connect them all and see which one does what (I guess your hotend does not have 3 fans). in the end you want [hotend_fan] to be the one calling the hotend (not the part!). the [fan] will be controlled by the slicer (overhangs, bridges and so on).

    DCIN on your board should ideally be connected directly to the PSU, you do not want it to be switched.

    don’t worry, we will get you back printing.

    source