Solved Common +3.3V and GND for multiple Duet MFMs

[themelle]

Hi there,

my search in the forum was not really successful so I'd just ask my simple question:

Recently I've added three more extruder drives to my printer and now I'd like to add three more MFMs to the existing one MFM I used up until now.
The existing MFM is wired to E0_STOP on a Duet2Wifi. It has +3.3V and GND supplied through the corresponding pins on E0_STOP connector.
To keep wiring simple I would like to use +3.3V and GND from E0_STOP for the other three MFMs as well, and only wire the signal line from the MFMs to the respective connectors on the Duet board. Would this be possible? Or does every MFM need separate +3.3V and GND lines?

Thanks in advance,
Andreas

[jay_s_uk]

@themelle that should be fine

[dc42]

@themelle that should be fine as long as the ground wire isn't especially thin.

[themelle]

@jay_s_uk Thanks for your quick response!

@dc42 Thank you for confirming @jay_s_uk
To play it safe: what would be "especially thin" for the common ground wire in terms of AWG (or mm^2)?

[dc42]

@themelle 22awg should be OK.

[themelle]

@dc42 Thanks again, so I should be safe as it is - great

[themelle]

@dc42 @jay_s_uk

Just as a quick feedback: I can confirm that running 4 Duet Magnetic Filament Monitors on common wires for +3.3V and GND coming from E0stop on a Duet2 Wifi does indeed work like a charm.

Thanks again and Happy Easter everyone!

[dc42]

@themelle thanks for confirming.