3 Wire Fan

[kingstar]

I'm working on a Nevermore Mini, which uses a 4028 server type fan. This fan type has 3 wires. Looking at the pinout of Octopus, I believe I can use J40 for this fan type. It appears J38 is used to set the voltage. I would just need to configure it to use PB7 to drive the PWM signal and make sure the wires connect to the proper pins? Anyone have experience doing this and have a configuration example?

 

 

[claudermilk]

You could try, PB7 is intended to be for the bed sensor probe, but doesn't work correctly for that on the Octopus. Maybe it will work for this application.

[kingstar]

I just found in Ellis' guide a section for using a 3 wire fan for the hotend. It looks like I don't actually need to hookup all 3 wires as the 3rd wire is just the tachometer. I'll try to see if I can get that working, otherwise, I'll just hook up the two wires.

[sandman50]

Yes. the 3rd wire is the tachometer. Not needed if you don't want to use it.