I have 12V fans and I'm old and I don't want to learn about buck converters and I don't wanna open the door to change the fan speed.

All credit where credit is due:

Immaculate Air Filter for K2 Plus

Ubigene's original Immaculate Air Filter for K2 Plus is an extremely awesome design, so I just did a little remix of one tiny part of it so that I could use a 12VDC wireless PWM controller from OwlTree:

https://www.amazon.com/dp/B0GKGJKFTY

To control three Noctua fans:

https://www.amazon.com/dp/B00KF7MVI2

https://www.amazon.com/dp/B0C2CGBSZT

I drilled a hole in the back plate of the printer, by the existing power cable socket. Some day I'll probably put a grommet in the hole, but for now I just carefully snaked the USB-C power cable through the hole and into the main printer cavity.

A note about the retainer for the PWM controller: if it's loose, add some painter's tape to it. I measured and guessed at a tolerance based on some new filament so it's not perfect, but I printed the whole thing in PETG and it's good enough for me.

So this little guy fits just snug enough to not fall out while I'm swinging the entire assembly into place:

Also if you use stainless mesh for your prefilters you can just use a soldering iron to melt it into the plastic and not worry about glue.

OwlTree Plate for Immaculate Air Filter

Original