Witch polaritiy is switched?

[Milan R]

Hello,

I have my 3D printer up and running, but I want to redo the wiring to get rid of some wires to the tool head.

I'd like to use a single wire for all ground and voltage supplies when possible. (Maybe excluding the heater becuase of wire sizes)

But for the fans and heater, one of the wires is switched, and I couldn't find out which side is switched. I guess they all share a common ground, but I wanted to be sure.

As a bonus, can someone tell me why the BL Touch has 2 voltage and 2 ground cables? Can I just short these together to not run single wires for every one of these cables?

Thank you and best regards,
Milan

[dc42]

@Milan-R like all other 3D printer boards for which I have details, Duets switch the ground side of heater and fan outputs. Therefore you can use a common positive voltage supply to heaters and fans if they all need the same voltage.

You can normally use a common ground wire for the two BLTouch ground wires. This might not work if the wires between the BLTouch and the controller board are very long.

You cannot share a ground wire between a thermistor or PT1000 sensor with anything else except another thermistor or PT1000.

When using a Duet 3 series main board, you can greatly reduce the number of wires to the tool head by using a tool board.

[Milan R]

@dc42 Thank you.

I use a Duet2 but still that healps a lot.