Because official testing is still in progress, we are submitting this to be included by the NIH 3D Print Exchange for "Community Use". Therefore, please read and understand our current stance about this as of 4/12/20 at the time this is written and until further notice:

"This device is a general purpose face mask intended for use in the community and is not suitable for use by a healthcare professional or in a healthcare facility or environment, as described in FDA Guidance Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency, Section V B. This device has not been tested to assess the out-gassing limits of the material or their corresponding health effects."

Because official testing is still in progress, we are submitting this to be included by the NIH 3D Print Exchange for "Community Use". Therefore, please read and understand our current stance about this as of 4/12/20 at the time this is written and until further notice:

"This device is a general purpose face mask intended for use in the community and is not suitable for use by a healthcare professional or in a healthcare facility or environment, as described in FDA Guidance Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency, Section V B. This device has not been tested to assess the out-gassing limits of the material or their corresponding health effects."

VERSION 2 FILE REPACK IS LAUNCHED 4/12/20:
-Now 4 sizes instead of 6, and renamed: Large Wide, Large Narrow (most people so far), Small Wide, Small Narrow
-Masks all fit the same filter box
-Increased depth for better nose fit
-Grill is thinner for faster print with less waste
-Filter box redesigned
-All masks have 2 elastic strap attachment points and they are lower to fit different different rubber edge liners, tubing, etc
-Press-and-glue square to hold first 2 layers of filtrete in place to increase speed of installation and minimize glue usage
-fusion360 .fd3 files finally provided as masks were remade for me by Everett W. in Nevada, HUGE thanks to this incredible designer
-attachment loop if you want to add another elastic attachment site to the nose of my original mask design using a 3D pen

Youtube original tutorial at:https://youtu.be/ySOCNycv-aA

Youtube "COVID Pandemic Mask Post-production: Molding, Sanding, Sealing and Upgrades" [[[COMING SOON]]]

Version 2 can be printed with 3 on a plate on an Ender 3 (220 x 220 plate) as seen in the photo. It's 7h16m for 3 Large Narrow masks using 0.3 mm layers with a 0.4 mm nozzle at 60 mm/s.

If for some reason you want access to the files from version 1, they will remain accessable here:https://drive.google.com/drive/folders/1He3TSlDc5UCXDhZF0_TLeBUN2oqIc1jD?usp=sharing

I'm a doctor who loves 3D printing. We have a nationwide PPE shortage as a result of COVID19. I'm ready to distribute this optimized design for free for in-house printing in hospitals and elsewhere. My hospital is buying printers and will be expanding fast. You may use these designs and please share with everyone. You may not sell for profit but may accept donations to cover the costs of the supplies.

I've calculated average cost per mask+filter to be $1.94
$0.97 PLA + $0.12 3M filter + $0.31 MERV 13 filter + $0.25 glue + $0.29 tourniquet or elastic.
Additional Costs with processing and upgrades: Suggested upgrades include spraying 1 - 2 layers on the outside of the mask with clear acrylic ($0.08 per mask), adding window/door foam to the edge ($0.40), and adding a thin layer of silicone around the box-mask junction - just enough to seal it, but still be pulled apart if filter change is desired ($0.03). Additional cost = $0.51; TOTAL = $2.45
In these approximate calculations, I am not including cost of supplies such as sand paper, garbage bags, gloves, organic fume respirator, and wear and tear on machines.

If you wear this OVER a surgical mask for comfort and to filter the air an additional time in case any virus gets through cracks or micropores despite sealing the plastic, this would add another $0.58. Here in the hospital we have a few doctors experimenting with a layer of Halyard H600 between the mask and their face. One even put velcro to hold this layer along the inside of the mask. That stuff is featured in my other video, theoretically pushing this mask up to filtration numbers >99% though physics lab tests are pending. See other project:
https://www.youtube.com/watch?v=xVYypLYEo_0
https://www.thingiverse.com/thing:4262131

Disclaimer:
There are no guarantees about the efficacy of any home made masks. Use at your own risk. Get creative, stay safe. These are okay to use per CDC ONLY if you run out of other approved masks. Though the goal is to reach and exceed n95 level of filtration, this has not yet been confirmed. Testing is in progress will be updated with any findings. These are a last resort mask, considered equivalent to a scarf. You have to be the one to choose what you wear and I am not responsible for any negative outcomes if you choose to use this. The video and info here are for educational use only.

Collaborations and Thank You's
-Everett from Nevada - this guy helped me do at least 8 revisions of the mask. He is an incredibly talented 3D designer and offered to help me extensively without compensation, just to help us all make a difference in this fight against coronavirus. I had asked for help on youtube and he responded. I couldn't have done it without him. He is to thank for most of the improvements listed at the top. THANK YOU,

-This is a remix of Kvatthro's thing #4222563, in that I started with some of his early files and modified them many times to get to where the designs are today. Kvatthro and I are finally connected and are friends. We video chat about design ideas frequently and share designs and concepts from across the world with each other. He is an incredible guy with a dedicated team in Slovenia. Please see his newest concept to use a ventilator circuit filter that provides over 99.99% filtration, holds pressure at 5 bar without leaks, and provides good saturation. The filter can be changed every 24 hours of use, and are affordable and accessible to hospitals.https://www.thingiverse.com/thing:4242653

-Thanks "Igor & Pascal" - from France comes a second strap loop model, now used as both attachment points

-Please see the remixes - there is a gasket that can be printed from TPU though I have not tried, thanks mrdanielphelan

-The idea for the square to hold the filter in place with minimal glue was sparked by Dr. Premkumar as well as the press-fit piece remix made by TheLastDunedain, thanks.

-ABA-PGT with input from DaVinci and Medtronic for designing and injection molding the new filter box for us. - Bob Hazelton, the speed at which we are making these wouldn't be possible without you. Thank you!!

Donations through GoFundMe: gf.me/u/xsqhra

Links to some of the news coverage:
https://www.wfsb.com/news/local-doctor-using-d-printer-to-print-masks-for-medical/article_de3a805a-72c6-11ea-887e-db303591745e.html

https://www.nbcconnecticut.com/news/local/doctor-3d-printing-face-masks-for-health-care-workers/2246501/

https://www.theday.com/article/20200327/NWS01/200329496

Future plans: flange edges out around face, experiment with dual nozzle printers for TPU material against face while keeping the rest rigid, make the filter box have tabs so the filter retaining square pops in tight without need for any glue at all, and seek NIH approval for community use as is and medical use with added one layer of halyard h600 between mask and face for >n99. Will also upload mask-fit paper templates asap when complete, made for us by Dr. Sean London.