Covid Mask - Makeup Pads - Carbon Filter
This is an easy print and a durable reusable mask that uses cheap round cotton makeup pads and if you want activated carbon between pads you can get at the pet store. Credit goes to mottleyfoo at https://3dprint.nih.gov/users/mottleyfoo and https://3dprint.nih.gov/discover/3dpx-013545
I tried printing a lot of different masks and I found that this one is solid and easy to print. The filters are cheap and easy to change. Use ABS at 100% fill. I put a rubber edging on mine you can find on Amazon but not needed. The receptacle is like a removable cartridge so you can have several for a quick change out.
There are also adjustable buckles for 1/4 inch elastic straps you can print with it.
The only issue I have printing this is the inside threads on the receptacle tend to have some stringing on them when I print on my Da Vinci 1.0a. I found that I can trim them off with an exacto knife and they still thread fine.