NexGen3D: 120mm Activated Carbon Filter System

Please Note: Fan should be installed to pull air through the filter and exhaust out towards the back, this gives you the max performance of both the fan and the filter, and will stop crap from building up on the fans.

Update: I have installed 2 of these inside my K1C, they fit perfectly on either side, and you can fit one at the back on the left side, I used a buck converter with the Artic Max fans and performance is excellent, you can as I have done, do a combo of Hepa filter and dense activated carbon filter, best of both worlds and both are quite high flow, which is my main issue with other filter types, also simple filter medium change is great feature.

I have designed a nice simple easy to build and easy to maintain air filter system, mainly designed for the inside of your printer, but most certainly can be used elsewhere.

Print consists of three parts, the main body, lid and option mounting bracket, the bracket has a number of mounting hole options, I have added some that will align with 2020 extrusion as well.

For the fan, you can use many options, there is a massive range of 120x25mm fans available, if you go for a 12v fan, you can either limit your PWM to 50% or if you dont have that kind of control, you can use a buck converter, or opt for a 24v fan, GDSTime make a good dual ball bearing 24v 120mm fan, myself, I highly recommend the new 12v Artic 120mm Max Fan these are dam awesome and are very cheap to buy, considering they can run up to 3300rpm, they are quite hefty as well, but these are 12v only, if you need a quality 24v then the Noctua Commercial PPC fan but these will cost more than double the Artic Max.

Stuff you will:

• 1 x 3D Printer :)
• 2 x M3 threaded inserts (For the lid)
• 2 x M3 x 8 to 12mm BHS or SHS (For the lid)
• 1 x 120mm x 25mm Fan (Your choice here)
• 4 x Standard self tapping fan counter sunk screws (Standard ones used for PC's, the Artic Max come with these)
• Filter Medium: Activated Carbon Filter Sheet 5mm Thick (Buy 1m x 1m sheets of this, and cut up to size)
• Option Hepa Filter with activated carbon foam (You will need to peel one of the white layers off as they are too restrictive otherwise)

For the mount, its up to you on the length of the bolts required, but the holes are designed to take button head M3 bolts, optionally, you can just stick it down with VHT tape.

You can print form what ever you like, probably go for PETG or better if its going inside your printer for obvious reasons, if its just being used around the office or outside your printers, then PLA will be fine.

I recommend cutting the filter medium to 120mm x 130mm, then load it like a toaster, I made this to be super simple to swap the filter, even for the laziest of us, its like loading a pop tart, doesn't get any easier, you can play around with other filter medium if you like, I did test vacuum cleaner Hepa filters, but the white Dacron layer is a little too restrictive for an axial fan, if you peel a layer off, then they work okay, but the Activated carbon sheets I linked to are the best bang for your buck, you can also find these on Amazon, just make sure they 6mm thick or less.

For Klipper, I have added my CleanAir config file to help get you started if you would like to automate the air filter, this is the same config I use on all my other filter systems.

If I find any issues with the design, I will update the model as I go, as these will be my main filter system moving forwards as they are cheap and easy to build and maintain.

Large printers like the K1 Max and similar, use at least 2 of these, for smaller machines, 1 should be sufficient.