After buying a Bento Box with the “upgraded” fans, and being very underwhelmed by the amount of air it moves, I decided the best solution is to just get rid of the air.
I picked up:
4" Variable Speed Duct Fan:
https://amzn.to/3zgVHKX
Back draft damper:
https://amzn.to/3RJn9av
Ducting:
https://amzn.to/4cGTPJR
The back draft damper has a return spring which really fought the low-power fan. So, I cut the spring out and glued in some damper blade limiters, so they don’t get stuck facing up, or flip over to one side:
I bought a flange to connect the duct to my ceiling, but it was a piece of garbage. So, I designed a new flange to help connect the fan directly to the damper. (forgot to take a picture).
I also made a 210mm extension that I glued into the damper outlet. This made the fan, damper, extension, and flange all a single assembly to attach onto the ceiling. The goal here was to avoid going into the attic. I also used some exposed triangular infill as a mesh filter for the outlet of the extension. This keeps any insulation from coming back down:
The last piece is a custom manifold that attaches magnetically to the back of the machine and pulls through the existing outlet. Now, I can also take out the carbon filter and the filter door to reduce restriction a lot. With those gone, even the stock fan can move quite a bit of air out of the printer. But, obviously I can now kick on the duct fan for a boost with nasty materials.
