New Duet installation/conversion using Wanhao interface board

starbuck

Howdy, I'm in the process of converting a Monoprice Maker Ultimate (Wanhao Duplicator 6) from it's busted Wanhao board into a new Duet Ethernet.

I want to use the ribbon cable/wiring that already goes up from underneath the printer to the hotend. I took the wiring out and probed it with a multimeter.

Here are some pictures I took of the wiring I'm referring to: https://photos.app.goo.gl/so91uxHR1HgP6nRA8 and I made a quick diagram of the wiring as I understand it on the Wanhao interface board. I've also added comments to each picture.

I found these resources already with details about the old board. https://3dprint.wiki/reprap/wanhao/duplicator6/major_components/motherboard and https://docs.google.com/spreadsheets/d/1XX6I6iNZCkVIueA0zD95mo8jjTG3_VZ3gDfGH6G9hfs/edit#gid=237340617 which was a great starting point for me.

After probing the pins, I labeled them with masking tape and found something interesting and here's where my question actually begins.

How does the Duet expect things to be wired? Specifically the T0 heater, the PWM fan and the always-on fan.

The pins/cables I have available are

24V(+) (4 of these)
T0 heater (-) (4 of these)
PWM (-)
Fan (-) (always on)

My problem is that all 4 of the 24V lines are connected (shorted?) to each other so if I plug in T0 heater and the Fan(+) then it might cause the heater to be always on or something. I believe that Wanhao's board uses different logic to power on the fans and the T0 heater than Duet wants.

Should I be able to connect a 24V and a PWM (-), a 24V and the Fan (-) and the 24V and the heater and plug them all into the Duet with no issues?

Let me know if I can make anything clearer or answer any questions about this. Thanks in advance!

dc42

It's OK to use a common wire to provide +24V to the extruder heater and both fans, because the Duet switches the negative side of the heater and fans. Take it from the extruder heater terminal block, because that one is rated at 6A or more, whereas the fan output pins are only rated at around 3A.

Caution, very old Duets have the E0- and VIN pins of the terminal block labelled the wrong way round on the underside of the board. Similarly for E1- and VIN. The VIN pins of those connectors are the ones that are connected together by a trace on the underside of the board.

starbuck

Thanks @dc42! I'll try to update with the results after I'm done wiring everything.