hi everyone, I hope you're doing as well
as can be given everything that's going on.
As we've all heard, in the wake of the
Cova 19 outbreak there's been a
worldwide shortage of some critical
medical supplies. The n95 respirator mask
is one of the items that's in extremely
short supply right now. It's been
identified as one of the only disposable
respirators that's effective in helping
to block the transmission of the virus.
After some research we were able to find
a few DIY 3d printed N95 substitutes
in PPE communities that claim to offer
some protection when no N95 is available.
One design that stood out was from
Copper3d.com. We'll leave a link in the
description. The design is open sourced,
it's simple, the print is relatively fast
and easy, the product is reusable and
can be shipped in a flat-pack. Copper3d.com says that this
design is only intended to be a
prototype and not a final product.
They're currently taking notes from
members of the community making
improvements to their designs and from
what I understand, they're going to be
releasing a version 2 very soon.  Now, a
bit of a disclaimer here. We're not
medical professionals so we can't speak
to the efficacy of these devices.
Copper3D claims that this mask design is
only viable if it's printed using PLActive
- which is their proprietary brand of
antimicrobial PLA 3d printer filament.
Once again, the idea here is that these
devices are a LAST RESORT MEASURE ONLY
...to be used when no N95 or equivalent is
available. The thinking is that some form of
protection is better than nothing at all.
when using these devices people should
by no means feel invulnerable to the
obvious risks and should continue to act
responsibly, practice good hygiene social
distancing and
continue to attempt to limit exposure as
much as possible. Now with all that said,
let's dive in.  Here's Copper3D.com/HackThePandemic
on this page you'll find the most recent
design of the Copper3D mask and some
print and assembly instructions.
There's no CAD data here, it's just STL
files but they're good to go so if
that's the way you want to run, you just
download the files and drop them into
your favorite 3d printer software.
Here we see we're using simplify3D and the stuff just goes in and it prints great
We can see that the largest component of
this print (which is the main body of the
mask) fits easily on the bed of the
makeup gear m2 and there's a lot of room
to spare. The m2 is a pretty standard bed
size so you shouldn't have any problems
with build size on this. This is an unmodded print
of the original Copper3d design. After a
few tests we noticed a couple of issues
that were pretty easily solvable with a
little bit of time in CAD which we'll
get into in a minute.
Here we can just see some issues with
the cap. There was some printing failures
due to long spans and some rigidity
issues in the walls of the port. There
are some failures in the threading etc.
We're using SolidWorks for all of our
CAD work on this.  So basically what we
did was just bring in the STL file of
the original design and trace it out,
then we modified our SolidWorks model. The first issue that we noticed on our
test prints was that it was incredibly
hard to breathe through one port.  The
second problem was some rigidity issues
in the port walls.  If you heat it up and
cooled it down a few times when you were forming it to your face, we noticed that
the port would start to warp and this
would affect the threading and the
overall fit and seal of the cap. Now our
solve for this was a redesign of the cap
and thread assembly. We found that once
we thickened those port walls and
carefully redesigned the tolerances on
the thread, we were getting a much more
confident fit with the screw cap.  The
print was able to withstand a lot more
heating and cooling cycles without failure
in the port areas. For our tests we were
using a regular PLA based 3d printer
filament which is not recommended for
final printing of these these devices.
Again in Copper3D's documentation, they
suggest you use PLActive. as with many
things these days PLActive is in pretty
short supply and high demand. You can
find suppliers that will source a for
you but currently the wait times are
pretty long. We found a lot of
information out there that suggests that
other fda-approved antimicrobial
materials could be used in place of PLActive if
it can't be sourced. We managed to find
something called PUREMENT which does have
an FDA approval, it is antimicrobial
and it's PLA based filament. We'll be
moving on the Purement while we wait for
our shipment of PLActive to arrive.
One of our 3d printing suppliers suggested that we try an antimicrobial PET-G
filament. PET-G is interesting because
right out of the box it's food-safe. It's
also more pliable and less brittle than
PLA. It's more heat resistant and
resistant to chemicals. These 3d printed
masks require sterilization after a
certain amount of use. That involves
submerging the printed components in an
alcohol bath. Apparently a PET-G based
material will hold up much better during
the cleaning cycles to alcohol than PLA
base material would. One of two methods
can be used to form the mask to the user
when it's ready to go.
The first is submerging the mask in a
hot water bath. The temperature should be
between 60 and 70 degrees Celsius. When the mask comes to a threshold
temperature of the consistency
transforms to something that resembles
a wet lasagna noodle.
We opted for the second method, which is
applying heat to localized areas of the
mask body. This can be done with a
hairdryer or a low power heat gun. The
process in both cases is a little bit
time-consuming but relatively simple. The
first step is to fold the side flaps
back along the ribs on the nose section
to roughly match the users face.
The second step is to heat up the bottom
flap so that the connection point acts
as a bit of a hinge. The idea here is to
match the transition angle and the
contours of the chin and the jaw.
This involves tucking the side edges of
the bottom flap into the upper section
of the mask. Now it's time to move on to
the second phase which is creating a
seal. This involves re-heating the outer
edge of the mask starting at the throat
and working our way up around the
perimeter towards the nose. It's
important to be careful here because
prolonged exposure to the heated plastic
could give you a bit of a burn which
experienced a couple of times in my
experiments.
Once the mask has been properly fitted
to the users face you're going to find some
pretty large gaps where the panels have
been folded and tucked. Mainly in the
chin area and the nose area. There's
plenty of suggestions out there on how
to seal this up. What we found works best
is to just run a raw piece of filament
of the same material along the gap and
weld the seam shut using a small
soldering iron.
not pictured here was the additional
seal that we added. We suggest running a
bead of silicone along the bridge of the
nose in the bottom of the jaw these are
areas that we found were the most prone
to leakage. The original documentation in
the community have offered plenty of
suggestions on what to use to fill the
ports for filtration material. The most
popular option seems to be the 3d
printed antimicrobial PLActic disc which
is included in the STL files, sandwiched
between one layer of cotton padding and
one layer of non-woven polypropylene. the
cotton padding can be sourced from any
regular makeup removal pad and cut down
to size, and the non-woven polypropylene
can be sourced from a reusable grocery
bag. Another option that was provided was actually to cut down an N95 mask and
load the ports with one layer of N95
material. In this configuration, one N95
mask could potentially be used for
several reloads of one reusable mask or
it could be used to load several masks
at the same time.
As always, if you have any questions
regarding anything in this video please
comment and we'll respond to you as soon
as possible.
We're lucky we live in a time where
we're surrounded by technology that can
help us endure and limit the severity of
situations like this. Please be
responsible and follow the guidelines
set out by your government and the WHO.
This virus has staggering implications
if left to spread without intervention
Individuals can have a dramatic
influence on the severity of the outcome
of the crisis. Please do everything you
can to distance yourself from others.
We'll come out of this and connect on the
other side. In the meantime those of us
with loved ones at high risk are
counting on you.
