FANnyPack Zero2Sixty

For reasons I'll never understand, the parts you can get in the Australian wet tropics are never what everyone else can get. I don't know, maybe it's the crocodiles.

For this reason, and because of where I have my filament spool, I needed to use a 6015 fan in order to vent hot dry air from my Voron 0's electronics enclosure and replace it with the hot wet air from my study.

While I did happen to completely redraw in CAD, this I was copying the style and ideas behind 3DPandMe's FANnyPack Zero. The design was completely generated in OnShape, and is mostly parametric (for different fan sizes), but due to issues with the grille pattern replication, I've not included the parametric version.

The fan is set up to exhaust from the electronics enclosure, with fresh air being drawn up from through the skirts. This leads to good cooling for both the MCU and the Host (be aware that my boards are mounted in such a way as the majority of heatsink fins are parallel to the airflow). This fan completely replaces the teeny tiny circulation fan that was specified. My boards do not go above 50degC anymore, and usually only hover in the 44-48degC range.

I've included an SVG (generated in Easel) and a .pdf for the fan cut out. One cable entry is for setting up in an exhaust configuration and the other is for supply. If you don't have access to a CNC or Laser, simply print out the .pdf (or 3D print a template) and use a rotary tool, or if you have a large printer, I've included some .stl for back panels as well. 

The .pdf contains a positioning guide to assist your setup.

You want to position the right hand edge of the fan no closer than 40mm to the right hand edge of the back panel (avoids the stepper on that side). The left hand edge no closer than 105mm to left hand edge of the back panel (avoids the spool). You want the fan as high as possible, about 10mm from the top of the panel is good (maximises cooling coverage).

Print the fan shroud at 0.2mm layer height using normal Voron settings, face down.

Cut the hole out of your existing back panel, or a new one. Pictured is the wooden test board I used because acrylic is expensive and difficult to obtain where I live (much like 80mm fans and 1515 aluminium extrusions). The pattern is rotated 30 degrees from the picture to match the skirt pattern.

Install the fan using m3 x 25mm BHCS through the shroud, then fan, then panel (any other order will give weird results). Add an M3 washer and an M3 nut on the threaded ends to hold everything in place. Don't overtighten it, but don't be too shy.

Remove the old electronics cooling fan and plug your new 6015 one in. Do not put the back panel on until you've modified the code. No cooling is bad, even at idle.

Find the code in your printer.cfg file and change it out for this hot snippet:

[temperature_fan system_fan]
pin: gpio20 # the fan control pin (must be a mosfet or a pwm fan)
control: watermark # the type of hysteresis we are using
max_delta: 3.0 # fan turns on/off at 3° over/under target_temp
sensor_type: temperature_host # same as a temp_sensor you want to use
min_temp: 0
max_temp: 100 # just the valid temperature ranges
target_temp: 45.0 # the target temperature for the fan

Slightly modified from the code supplied by r/DopeBoogie in this Reddit conversation: https://www.reddit.com/r/klippers/comments/wwuewg/configuring_a_fan/

I've set mine at 45degC as that's about 2 degrees above idle for me, and I'm reading the host because the MCU rarely gets warmer than the host in my experience.

Then, once all that's done, replace the back panel.

Make sure you test it at idle for a bit to check it's all working before starting a 3 day print! This setup works for me, if your setup is different, please comment so others can make informed choices!