Filter Column

Filter Column uses a 4028 fan (must be a powerful one) with stackable round (80mm diameter, 50mm height) boxes (or pipes), pulls air from the top through the stacking boxes to the bottom. Carbon pellets or HEPA paper can be added to each box with a sieve freely.

Each box has an inner diameter 80mm, it's designed for the V-core 3.1, which has up to 100mm space in the rear.  A 500mm Z height needs around 9 boxes, to separate air flow and avoid pushing air onto bed.

The sieve needs zero top and bottom layers. You can choose the filling pattern. 15% - 20% Gyroid should work for 4mm pellets, it may be better than Honeycomb.

Do not store each box full of carbon filter, 20% - 30% full should be good, or even with alternative empty boxes. You can rotate and/or shuffle boxes in a cycle to even out the carbon saturation.

I have tried 2 printed versions for adding HEPA papers: two plates for flat paper and two plates for pleated paper. The pleated one is recommended as it has much less pressure drop. Alternatively, there are some rounded HEPA modules online, which can be inserted on the top a column tightly.

The 4028 base can be printed up-side-down w/o support. It's designed for a 3030 frame. I only checked the space for V-Core 3.1 500mm. You may need a different one.

There is an optional ring to fix the tall column at the up side, just insert it into the 3030 frame and rotate 90 degree.

BOM: 8 M3 heat inserts, 4x35mm M3 screws, 4x8mm M3 screws

About the vane: some online sources say it's better to separate the carbon to small area, it could help to balance the carbon usage, avoid air choosing an easy path. But I do not feel necessary (as the path is so long here), just provide it.

If you need different dimensions, let me know and I can think about generating a new one.

Tested with ABS for hours – my son (more sensitive nose) said he couldn't smell anything about it while playing in the same room.