Updated v.2: Fans, Hotend and Thermistor wiring!

A project log for μ3D: RatRig V-Core 3 EVA wiring over RJ45

A daughter board that mounts on a 3D printer hotend assembly to enable all wiring over RJ45

Alexander WilliamsAlexander Williams 10/06/2021 at 05:280 Comments

In the previous log entry, I mentioned that I added support for wiring the hotend heater and thermistor.

This time, I also added two (2) more JST-VH connectors at the top of the PCB, for a high-current parts fan (aka layer fan). For each connector, one pin is GND and the other is PWR.

This is cool because it automatically adds support for a hardware PWM fan as well (3 wires), which is typically a useful feature for parts fans. To use a PWM fan, you simply need to wire the PWM signal to PIN 8 on the left "Parts Fan JST-XH" connector, and then PWR/GND on the middle "Parts Fan JST-VH" connectors.

Alternatively, it can also be used to wire a third fan, where each FAN connector only supports PWR+GND without a PWM signal.

I've also changed the orientation of the lower JST-VH connectors to allow for nicer/straight traces, and I changed the labels on the pins to avoid confusion with the RJ45 pins.

Overall I kind of like this design since it's much more flexible and provides various different wiring options for lots of components.