BentoBox 2x 5015 radial fans HEPA/Carbon filter

HEPA/Carbon filter box for the Bambu Lab X1C 3D Printer. Kudos to the previous designers, for the great idea to have a modular filter box. The original used 40x10mm axial fans and exhausted at the top. The version I worked off of was a re-mix using 5015 radial fans and exhausted at the bottom. Links at bottom.

Parts List:

(2) 5015 radial fans (0.1A @ 24vDC or 2.2watts, 6000rpm)
(16) M3x8 socket head screws
(8) 6mm dia x 3mm thick disc magnets
(1) 80x40x15mm HEPA filter
(55g/2oz) 4mm dia cylindrical activated carbon pellets
(1pair) JST-SCY connector male/female, 15cm leads (or your 2 wire connector pair)
(8cm) 2mm heat shrink tubing
(15cm) clear packing tape

Design notes:

Printed at 0.24 layer height, 3 perimeters, 15% infill. Weight in ABS was 220g, which is down from 246g from previous version (10% less).

Prints without supports (top cover and fan vent models print upside down).

Changed the "magnet to magnet" connection to "magnet to M3x8 screw" everywhere, so you don't have to worry about polarity of the magnets. Observing polarity is even more frustrating if you have several units for a farm (where mixing up parts could be disastrous, repel etc). Lock-up is weaker now but still fine for the job. As before, using 6mm dia x 3mm thick disc magnets and M3x8 socket head screws, no threaded inserts.

Added a tongue and groove type seal between the pressured parts (fan vent to HEPA, HEPA to Carbon). This helps keep the air from blowing out between the parts. Also added alignment pegs and holes, to help keep wear off of the tongue when re-assembling.

I eliminated some height by moving the electronics bay from above to behind the fans (I added this height to the Carbon box). The electronics/wiring bay is now 12.8mm tall x 95mm wide x 52.5mm deep. However, I avoid electronics and directly wire to run the fans full time at 24vDC (they are very quiet). I also widened the slot for the fans (15.6mm from 15.0mm), because the original was very tight, which made the fans difficult to slide in and get fully into place (my flow is adjusted correctly). Now there is just enough pressure to keep the fans in place, but not so much as could warp the flimsy fan chassis. If your fans are too loose, just add layers of tape on the back of the fans (also do this if a fan is noisy from vibration). Wire exit options are on left and right sides.

The HEPA filter housing is a nice press fit for the current 80x40x15mm filters sourced off Amazon. $10usd/10 pack.

I kept the external dimension the same as before (170x110x56mm), but was able to increase the volume of the carbon box to 300cc (previously 250cc). Grate spacing is still 3mm, so I'm using 4mm dia carbon pellets. A full box is about 55g or 2oz of carbon. $27usd/6lbs.

I changed the bottom vent duct to blow diagonally across the floor and better distribute the exhaust air. Also changed the "L" locating cutout on the bottom; made it more narrow (1.8mm from 2.0mm) which took out alot of "slop" in the fit, and holds more firmly in place now. Removed the 2mm gap to the wall (since wire options are on either side, no need to route wires behind). Preserved the small gap on the left side of box, for wire to exit (tape it down flat to the fan box and use the light gauge fan wire here).

Assembly Notes:

I encourage everyone to wire it up to the internal 24vDC power supply; it's literally just screws. Good instructions online for removing the PS, link below. There is an empty screw down terminal pair on the PS that the 15cm JST male was perfect to route into the chamber without having to extend it (make sure to route it out the open bottom of the PS cover). Tape it down to be clear of the Z threaded rod, and on the floor of the chamber. When replacing back cover, if having problems getting the second flange around the adjuster in place, just push straight down on it with a flat screwdriver.

Placing fans into the fan box, may need some fiddling to get their exhausts aligned with the outlets, and the impellers centered on the intakes. Took 10 seconds.

Be careful no to overtighten screws; I had a couple of units strip one of the "fan vent to fan box" screws which have a shallow engagement depth, but it didn't seem to affect the part fitment. A wisp of superglue in the fan box hole would fix. I did find some screws difficult to start with a wrench (the ones in filter housing), but I used a screwgun honestly. if using a wrench, you may have to ream some holes with a Phillips screwdriver.

To install magnets, no glue is needed (6.1mm dia hole). Install by placing on the end of a flat screwdriver and hammering, being careful to not strike the "tongue" in the part.

Be careful of the pull tab on the filter, laying outward and getting caught between the mating parts. Cut it off; you can easily push filter out from below.

Thanks again to the original creator ThruTheFrame, and re-mix creators RISCie and BC.

ORIGINAL MODELS LINKS

Original Design, Thrutheframe
https://www.printables.com/model/272525-bambu-lab-x1c-bentobox-air-filter

Re-Mix Design 1, RISCie
https://www.printables.com/model/334301-2x-5015-bambu-lab-x1c-bentobox-air-filter

Re-Mix Design 2, BC
https://www.printables.com/model/338763-bentobox-2x5015-blowing-down

Bambu PS replacement
https://wiki.bambulab.com/en/x1/maintenance/replace-power-module

PARTS LINKS

5015 24v radial fans
https://www.amazon.com/AEDIKO-Cooling-Printer-Bearing-50x50x15mm/dp/B09NND6682/ref=sr_1_2?crid=20T50G5DVKT4I&keywords=5015%2Bblower%2Bfan%2B24v%2Baediko&qid=1675403857&sprefix=5015%2Bblower%2Bfan%2B24v%2Baediko%2Caps%2C98&sr=8-2&th=1

HEPA filters, 80x40x15mm
https://www.amazon.com/Electropan-Filter-Replacement-Robotic-Cleaner/dp/B0782T7L6P/ref=sr_1_2?crid=1XCUVJ7XWBEUJ&keywords=10pcs+hepa+filters+ilife&qid=1675403985&sprefix=10pcs+helpa+filters+ilife%2Caps%2C87&sr=8-2

Carbon pellets 4mm, 6lb bag
https://www.amazon.com/AQUAPAPA-Activated-Charcoal-Pellets-Aquarium/dp/B01F1QZTQC/ref=sr_1_2?crid=HPJX0NVNI3X9&keywords=aquapapa+6+lbs+carbon&qid=1675404050&sprefix=aquapapa+6+lbs+carbon%2Caps%2C89&sr=8-2

Magnets 6mm dia 3mm thick 100pcs
https://www.amazon.com/TRYMAG-Refrigerator-Multi-Use-Cylinder-Whiteboard/dp/B09MRN2X7L/ref=sr_1_1_sspa?keywords=6x3mm+magnets&qid=1675404122&sprefix=6x3mm+%2Caps%2C83&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExRUE2R1BFUzE5WlY0JmVuY3J5cHRlZElkPUEwODUxMTgxU1ozSUJXMzdIOFc1JmVuY3J5cHRlZEFkSWQ9QTAwODE3NzcySTc2Vks5RkdYV0lLJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==