March 12th update: After seeing my pictures of the original when placed inside the fan, it looked like the sides were maybe a bit short so I made a longer version. It is in the raw model files and there is a second print profile to choose if you want to try the longer one to ensure more coverage. I've also added photos of my attempt at science (let's be real, it's more low brow “stience”) to show the changes in air flow when using it.

And of course, thanks to everyone that has downloaded/made it! I really hope it has been helpful and would love to hear if it worked for you.

--------------------

Ahem…Cue the Infomercial voice…

Are you tired of having all your flat prints lift in a corner(s)?

Have you been intentionally arranging things on the plate to keep them away from the back left side?

Have you been reading all the advice to “just turn off the AUX fan setting altogether for PLA” but that makes you worry that next time you go and print something with actual overhangs you will forget about it and then screw it up?

Did you think turning the AUX fan down or off midprint would help, only to find it going full blast again after switching to the next filament for multicolour prints?

Is the AMS unit sitting on top of your printer preventing you from “going topless” and opening only the door sucks too?

If you have finally had enough of the AUX fan acting like an invisible, unkillable Terminator whose only purpose is to crush your dreams… then i have an invention for you!

Seriously though, this thing works.

I have remixed the very neat Auxillary Fan Diffuser by HDZ3DWORK. The diffuser is a wonderful design and it is great to keep in for everyday printing but I found it did not solve the lifting when printing flat coasters/signs the way I was hoping. I tried printing a full solid version of the original diffuser but it fits quite tightly in there and I found myself terrified that not allowing any air was gonna burnout a fan motor or something so I figured I'd just modify it.

FYI: Adding a brim does work too but removing them was not always flawless and can still cause damage to the bottom- which matters on facedown, flat prints especially. We have been and will continue to up the plate temperature (usually just to 60 for PLA on a P1S) as that seems to improve first layer adhesion regardless, but lifting had just become an inevitable reality. So.. like Frank Costanza creating Festivus, I just knew “there has to be a better way!?”. The changes I made are listed below. I alternate between the original diffuser and this one depending what is printing instead of doing an all out ban on the AUX fan in the PLA filament settings.

1. Made a wider, solid front to block air going directly towards the plate.
2. Added length to the “arms” that go inside so there is a gap between the back of the blocker and the fan. 
3. Cut out a large portion of the “arms” in the middle and opened up both ends to allow for free flow. With the added length of the arms you can pull out, push in or tilt it to slightly adjust the air. The majority of the air goes out the middle and travels up or down.

Please try it if you are having the same issues and let me know if it helps!