3D Printing PPE

[Tony Brookes]

see https://www.3dcrowd.uk 

I saw this earlier today on Twitter, and I think it’s legit. Anyone with a 3d printer can help, or others can volunteer or just send some funds.

Tony

[Bernard(Home)]

I have signed up to this. Anyone interested and I can point them at the relevant sites and files. The procedure is attached and it looks like they are only accepting PETG and PLA parts. I need to check what I have as I am currently using TPU.

Bernard

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[Bernard(Home)]

I printed the attached yesterday as test prints. The material is TPU and they appear to be quite useable, although the 3dcrowd procedure says that the material is not preferred. The material is very flexible but plenty strong enough to support a mask. I would think it is ideal from a wearable perspective as it will conform to the head shape.  I am going to canvass some friends and acquaintances in the health industry to see what they see of the situation.

Video: https://youtu.be/Pn1MUPIIK20

I have considered several possibilities while these were printing off. One is to make what I can and drop them directly in to RDH. I don't have any plastic sheet or elasticated bands though. Throughput will be pathetically low and so may well be of no real benefit. A second option is to obtain some PETG and that is possible although it is looking scarce on Amazon. Prusa are making it available so I might get some from there. I am doing some test prints with some PETG that I have.

Any input from other members will be gratefully appreciated. Even if it is words of encouragement or advice on likely outcome. Also if anyone has any interface with the NHS, there may be other ways that a group of makers could assist. I think we all want to help, but maybe we feel that we could not make any real difference. If there is a way of finding out from the inside, maybe we could help.

Thanks to Tony for posting the initial link.

Bernard

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[Al Johnson]

I lack materials, printer and contacts so probably can't be much help, and
I'll avoid uninformed speculation. I hope you can get some first hand
information as to whether or not it's useful, or what might be better.

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[Bernard(Home)]

Thanks Al, that is no problem. I am doing some experiments with the
material I have and I think I might be able to make some parts. It will
be interesting to see what can be acheived.

Hopefully see you soon once the coast clears.

Bernard

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[Bernard(Home)]

3D printing update

There has been a massive response to this nationally from the maker
community so I thought I would update on my own thoughts and experience
so far.

Firstly the emphasis appears to be quantity and distribution. There are
many thousands of makers using their printers to make a handful of masks
apiece. They are being accumulated at hubs and then distributed in
quantity. The idea is that each maker produces a batch of 10 and then
sends them off.  Most of the chat on the forum is around the
distribution process. There is also a substantial chat about the
manufacture process and it seems that quite a few makers are
experiencing difficulties with the print process.

From my own experience, I produced a frame using TPU which is a
flexible material that I have had most success with. There are two parts
to the print, the first is the head frame and the second part holds and
shapes the visor at the lower edge. The print itself was successful. The
head frame looks fine. The lower piece is ok but has some thin sections.
I then tried to print using some PETG which appears to be the preferred
material. In the past, I have not  had success with PETG. The printer I
have is quite basic and the prints tend to come out fragile despite
several attempts at tweaking settings. At that time I gave up as I found
other materials easier and more reliable to print with. The latest
attempts were no better and the lower piece in particular is fragile and
can be broken quite easily.

The alternative preferred material is PLA and this is a material I have
had some success with. I have done some test pieces and they have come
out successfully. The frame is a time consuming print and the risk of
failing part way through is enough to mean that throughput is low.

As far as the design is concerned I can see several limitations that
make me feel that the masks will not really be reliable to use. If this
is correct, it will be a great shame because the effort will only have a
limited impact. I see two primary issues. Firstly the clear flexible
shield fits on to lugs on the head frame and, secondly, there is a
friction fit to the lower edge. I think that the visors will self
release from the headband and the lower brace will come off.

I am trying to find out if the official NHS supply channels are reacting
yet. I suspect that individual hospital buyers are clutching at anything
and everything they can get their hands on. An outlet offering free
supply is bound to be heavily subscribed with very little evaluation of
quality. I fear that there will be a lot of scrap once the NHS can
obtain officially approved PPE. I may be wrong, I am certainly not in
the know. What is clear is that there is plenty of enthusiasm to produce.

Bernard

[Al Johnson]

It sounds like it would be worthwhile to:
a) get some feedback on the performance of the design so improvements can
be made
b) someone skilled in design for 3d printing optimising the design for
reliability and speed of printing, possibly with different optimisations for
different sorts of printer
Are those sorts of thing going on?

I don't suppose anyone is including the material recycling markers in the
prints? Perhaps adding that would be a good job for the slicer since IIRC the
material is usually specified at that stage? PLA can be composted in
industrial settings (home composting doesn't usually reach the temperature
required). There's a recently announced enzymatic process for breaking PET
down into feedstock, although quite a lot already ends up as fabric or
insulation. It'll probably be a few years before that one makes it from lab to
plant though. I don't think I've seen anything about recycling TPU.

[Bernard(Home)]

Thanks for the response! All good thoughts. There are several facemask
designs around and the one for this initiative is from Prusa themselves.
Main criteria was to make it on a standard Prusa i3 bed plate. I would
be very surprised if any user feedback has been incorporated. You are
right that there is no recycling information included. I can't see them
having an extended lifecycle, used or not, so there will be plenty of
scrap to get rid of.

The sentiment of producing items like this in quantity for a good cause
is laudable. Unfortunately it is also a way of rapidly converting raw
material into scrap that then needs to be recycled.

Cheers
Bernard