Thanks, both of you. I will fill out the form, and will also look for that floating option. I just started another print, and will look at this shortly.
Edit: Yes, this works. Thanks.
Edited by brianmichalkI filled out the form on behalf of the doctor who sent me this request, so it's a little off in places, because I am not a medical professional.
I need to enlist the help of someone with a late copy of Autodesk to make some minor modifications to the design. Where is the best place to ask this?
Before printing hundreds, print one and carefully test if it really fits and closes well. Cover the front opening (filter opening) with your flat hand, and try breathing: it should be *absolutely impossible* to inhale, and your body should immediately go into panick-mode.
However, if you can still inhale with the front opening closed, it leaks sideways, and would not protect well and cause a false sense of security.
I have seen too many dust masks (like for painting) that did not work at all.
The real gas masks we used in the chemical industry were a lot bigger, and they had to be from very flexible rubber to close all gaps around mouth, nose, and chin. Yes, the masks you see in war- and horror films, with huge filters and creepy glasses. :-)
So I do have some doubt about the effectiveness of anything that is less soft and less big than those old real gas masks...
I have printed a handful now, and the mask will stay on my face with no leakage if a sheet of paper is covering the filter. I trust that the doc who designed it knows what he's doing as far as the face model is concerned.
I just finished a session with James Youmatz from Autodesk. Awesome guy. We walked through the modifications, and removed the collisions for a nested print. I'm going to run a test print, and if it works, I'll put these files on Github.
I assume you solved the editing, else I have the latest Inventor release so just shout if you need help. Have also possibility to run basic CFD.
Regarding the comment on effectiveness, if you can hold it in place by inhaling it should be good enough. That's how we test scuba masks and other.
The masks mentioned are designed to keep really nasty stuff out that can kill you in just one breath.
I have many hours training in said masks and failing the inhale test or not keeping your filter dry would result in a very unpleasant experience when your in a building filled with military grade tear gas. 🤮
Thanks for the offer. I am testing now. The hospital has the first five masks, and I'm awaiting feedback.
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The feedback on the mask is that it fits the men, but not the women. Where would I find a collection of 3D point clouds to use in this design? I think I'm going to need to make three sizes.
Scans might be available from the hospital you have contact with.
This is an awesome idea. Just asked the hospital. If I can get the scans, how hard is it to make the new design? In Solidworks I can replace parts. Can this be done in Autodesk? Replace one STL with another?
I'm navigating the Fusion download now. Trying to find the system requirements. Can I run it in a VM?
17 hours ago, AndersK said:I assume you solved the editing, else I have the latest Inventor release so just shout if you need help. Have also possibility to run basic CFD.
Regarding the comment on effectiveness, if you can hold it in place by inhaling it should be good enough. That's how we test scuba masks and other.
The masks mentioned are designed to keep really nasty stuff out that can kill you in just one breath.
I have many hours training in said masks and failing the inhale test or not keeping your filter dry would result in a very unpleasant experience when your in a building filled with military grade tear gas. 🤮
Hoi Anders,
Do you also have data on *how long* a mask can be weared? Ours were chemical gas masks with filters depending on the industrial chemicals. As soon as the active stuff (e.g. active carbon) in the filter would run out, the filter had to be replaced. This was usually not very long: 30 min ... 1 hour, or so, depending on the filter, the gas concentration and the invironment. But that was 35 years ago, and products and rules may have changed a lot since then.
I am particularly wondering on how long a medical mask can be weared before bacteria start to grow wildly? Their reproduction time is usually around 20 min, if I remember well. So, after 2 hours, you have 64x more bacteria than in the beginning, if they can reproduce in the filter.
Also, I think a good mask should have two filters, both equipped with a one-way valve. One filter for incoming air, so others don't infect you. And the other filter for air you breathe out, so you don't infect others. If both flows go via one filter, and they all accumulate and start to grow, it might make matters worse in both directions. You inhale back your own bacteria, and you blow-out the ones accumulated from outside. Similar to blowing-out a dirty filter with compressed air. Then the filter is like carrying around your own legionella incubator. Sort of tropical CO2-enriched green-house, moist, warm.
Also, a lot of medical filters do not stop (dry) viruses and bacteria, but they are designed to stop and absorb water droplets. This greatly reduces the risk of infection, but it still might cause a false sense of security, where people take greater and unnecessary risks. Home-made filters might work or not, very unpredictable. But if they are worn for days and days, without refreshing, then it might be much safer to put dirty socks over your nose...?
I believe medical personnel should wear masks in these times, but they should take a fresh one for each patient, and even then replace it every 30 minutes or so...
If worn incorrectly, filters might only work by means of the placebo-effect? People who are more confident and positive are less likely to get sick, compared to people who believe they will get sick?
But this is just my view, based on common sense. I don't have scientific data to prove or disprove it.
As you say lifespan of a filter greatly depend on exposure and media. Low exposure to gas and particles and proper maintenance and they will last for years.
Medical is another thing, short use only then sterilise and replace filter media if not disposable.
Edited by AndersK
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Hi Brian, thank you for your message and trying to help others!
If you need more print capacity you could check this map and see if there already is a 3D printer hub near you, or you could fill out this form and we can see if we can help you find one (or help printing).
I think you can not have the model float in Cura. You would need to export them like that from your CAD tool. @maht?
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