Marcus Wolschon

Why do you use a 2 part mold anyway? Since the upper side is flat, you could have used a very trivial one part mold with an open top and nothing could possibly go wrong.

Try sealing the mold with something easy to remove, so it doesn't leak. (e.g. a leftover drop of silicone from another casting some hours earlier)

I tried subtracting a cleaned up 3D scan of my face. But it wurned out that it's MUCH easier to heat up the mart "Contouer" with a filter assembly attached (so the thread doesn't warp out of shape) and a gasket and push it to your face to have it perfectly conform to your face.

What has been updated on the small silicone mold?

"Filter Body" should not be perfectly symmetrical but link with a freature of with the "Mask Shroud". So it doesn't turn freely with no way to hold it when trying to thread on "Filter Ring".

I'm printing with nGen for years and it never, ever delaminated. From week long printed masters in 40 and 20 micron layers to super fast stand-ins in 0.6mm to strong and never leaking mother molds in 0.3. It's more well tempered in it's temperature range then even PLA. Sterilization over here happens by bathing the parts. Heating would damage the straps at the very least. I'm using the project as a starting point to experiment with subtracting a 3D scan of a face from the mask with and without a silicone seal. It worked well in the past for custom fit electrooculography rigs and now I'm looking, if it can be set up as an automated pipeline for many faces.

"@Marcus Wolschon see the print settings on the Project Home page. https://wiki.rivercitylabs.space/covid-19/3d-printed-masks#required-print-settings" Ah, damn. "Filament: PETG" I just removed the PETG from my printer because after 2 days of trying I still can't get that damn stringing under control. Already got back to nGen and will never, ever return to PET-G. 255°C is the very upper limit of the PET-G sold by Colorfabb and would made the stringing even worse.

This seems to list the standard threads. https://gasmaskandrespirator.fandom.com/wiki/Thread:11144 NATO is "STANAG 4155" 40mm, 1/7”=3,63mm

Looks like most gas mask filters use a 40mm thread. The difference to 68x3mm or 62x4mm should be large enough, so an adapter to a standard size that others are also using is possible.

First print failed because "Mask Size Contour Large" seems to be a vase print and the walls don't come out anywhere near air tight. Since I have no model to modify for thicker walls, I'm improvising and trying again with my 1.0mm nozzle but this time 150% flow rate. I may have to file done some parts later, so that it still fits.

Could you please not only publish the exported STL meshes but also the original project files? Thank you. Does the filter attachment use any standard filter thread/bajonett? If so, wich one? You have "Filter Attachment Short *". Is there also a "Filter Attachment Long"?