HIVE - Core ONE Internal Carbon / HEPA FIlter

HIVE Filter – "High Efficiency Internal VOC Eliminator" for the Core ONE / +

Internal HEPA + Activated Carbon Filtration for the Prusa Core One, designed to scrub chamber air without dumping heat!

The HIVE Filter recirculates filtered air back into the chamber instead of exhausting it out of the machine, preserving chamber temperature while continuously reducing VOCs and particulates. This is especially useful for ABS, ASA, PC, PA and other materials sensitive to temperature changes.

Inspired by designs like the Bento Box and Nevermore, HIVE was built from scratch to tightly integrate with the Core ONE, maintain inner chamber volume, and improve temperature uniformity. Warm air is drawn directly from the active print area, passed through dual HEPA filtration and a multi-stage carbon bed, then redistributed evenly near the bottom of the chamber.

The goal:
Cleaner air, higher chamber temps, and more consistent temperatures top to bottom.

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Featured in this video:

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Want to Build It Easier?

If you’d be interested in a laser-cut, powder-coated steel side panel to improve sealing, rigidity, and overall fit, let me know. I’m currently gauging interest and may also offer hardware kits (fans, magnets, inserts, screws, & a buck converter PCB) to avoid buying bulk quantities for a single build.

Leave a comment or email [email protected] if interested.

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Design Goals

• Internal air scrubbing without exhausting chamber heat

• Multi-pass filtration for improved VOC reduction

• Minimal impact on usable chamber volume

• Even temperature distribution during high-temp prints

• Fully reversible, no firmware or base hardware modification

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Key Features

• Dual robot vacuum–style HEPA filters (intake)

• Large multi-stage activated carbon canister

• Dual 40 mm PWM fans

  • 4028 recommended

  • 4020 supported with included spacer

• Curved internal ducting for even air distribution

• Magnetically retained components to reduce rattling and leaks

• Uses the existing Prusa chamber filtration fan port

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Hardware Required (Affiliate Links)

• Prusa Core One / Core One L: https://mrly.link/coreone

• 2× Robot vacuum HEPA filters: https://amzn.to/3NoefjG

• Activated carbon pellets: https://amzn.to/3ZiDGFT

• 2× 40 mm 4-wire PWM fans

  • 4028 preferred: https://amzn.to/49Jwmbl

  • 4020 supported with spacer

• 37× M3 Voron heat-set inserts: https://amzn.to/49FSxPt

• 37× M3×8 mm screws: https://amzn.to/4qrNglF

• 8× M3×35 mm screws: https://amzn.to/45Yy3jM

• 23× 6×3 mm magnets: https://amzn.to/4pKOs2E

• 12 V buck converter (for 12 V fans): https://amzn.to/4pGw9LP

• 4-pin JST-XH fan splitter (optional but recommended): https://collabs.shop/l0fyz7

• 4 Wire Molex Clik-Mate Jumper Cable (Buddy Board Connection): https://www.digikey.com/en/products/detail/molex/0151350406/6830170

• ASA / ABS filament recommended (PETG untested): https://mrly.link/prusament

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Files Included

• Main Body (multi-piece, Core One printable)

• Main Body (single-piece, 300 mm+ bed)

• Carbon vessel components

• Printable side panel mounting plates

• Solid side panel DXF (for laser cutting - 1.5mm steel recommended)

• 9 mm fan spacer (for 4020 fans)

Note:
The video shows a laser-cut steel side panel. This upload focuses on the fully printable Core One version. Interest in pre-made steel panels is being evaluated.

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Print Parameters

Main Body Parameters:

• 3 Perimeters

• 10% Support Cubic Infill (saves material)

• 6 Top Layers / 4 Bottom

• Brim Recommended (large surface areas want to warp)

• NO Supports Required

• ABS/ASA Recommended (PETG may work but is untested for fitment.)

Filter Body Parts, Connectors, & Fan Mounts:

• 3 Perimeters

• 30% Adaptive Cubic Infill

• 5 Top / 4 Bottom Layers

• Brim Recommended

• NO Supports Required

• ABS/ASA Recommended (PETG may work but is untested for fitment.)

Filter Grates (Pre-Setup 3MF Files Included & Recommended):

• Split Parts to Objects (each grate is 2 parts laid together)

• Slice Grates with 0/0 Top/Bottom Layers (IMPORTANT)

• 2 Walls for Grates

• 30% Triangles Infill (IMPORTANT, to allow airflow but trap carbon pellets)

• Slice Handle Supports with 4/3 Top/Bottom Layers

• WARNING: G-code Conflict error will pop up & parts will print ugly as they overlap, but they should print fine anyway.

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Assembly Overview (Short Version)

1. Install heat-set inserts where indicated.

2. Glue magnets into all mating pockets (verify polarity).

3. Assemble the main body (skip if printing single-piece).

4. Install multi-piece connectors with M3×8 screws.

5. Mount fans to the fan bracket (use spacer for 4020 fans).

6. Attach fan bracket to the main body.

7. Assemble the carbon vessel and fill in stages with carbon pellets.

8. Secure vessel top flange.

9. Install HEPA filters into the HEPA housing.

10. Attach printable side panel plates.

11. Remove the stock left side panel and retain push pins.

12. Wire fans to the Prusa filtration fan port
    (buck converter required for 12 V fans).

13. Mount the HIVE assembly using the original push pins.

14. Insert carbon vessel, attach HEPA housing and honeycomb grille.

15. Enable Chamber Filtration in the printer menu.

NOTE: Proper photo instructions are pending and should be available shortly, for now please feel free to ask for clarification on any steps that are unclear.

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Notes & Warnings

• No firmware modification required, this uses the default Prusa Chamber Fitler g-code!

• PWM fans are required (2- or 3-wire fans would run at full speed continually.)

• VOC reduction verified by smell testing only. (Further testing is pending!)

• Chamber temperature increased and equalized noticeably.

• Use at your own discretion when printing high-VOC materials.

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Support My Work

If you find this useful, consider supporting what I do: http://www.MandicReally.com/links