stl of face mask

[jfeig]

I was given a file for a safety mask from a medical friend to make them some masks.  I am a 72 yo retiree with nothing to do.  The file is a .STL file with over 100,000 facets.  As a non-expert I would like to modify the mask by adding and modifying some of its features.  

I am stuck with my failed attempts to convert to a solid in "FORM" mode.

attached is a ZIP file of the 2 components.

My small cities public safety department will also be grateful as they are washable and the filter is made with a HEPPA furnace filter material. 

Thank you

[jfeig]

Yes, this file would be perfect for posting to the Fusion 360 samples of projects.

[laughingcreek]

Unless you have the quads version of this mesh, I wouldn't bother trying to convert it to a brep.  if the modifications are simple, it can probably be done with mesh mixer.

this model would also be fairly easy to remodel in fusion, using the base mesh as a reference.  Can you detail what needs to be modified?  wouldn't be surprised if someone here ends up doing it for you.

[TrippyLighting]

@laughingcreek you got that right 😉

@jfeig If you've never worked with T-Splines (Forms) then that's a tall order. I re-created this using splines, lofts, and surfaces. With some gentle tucking and pulling on the spline points, this can be adapted easily.

[jfeig]

Peter a 1000 thanks for the assistance.

[cmoher3]

I think it's great to see a lot of people pursuing this and I was too until I stumbled upon the requirements of the actual filter material. I'll refer you to a pretty basic overview of the challenges of a DIY , making presumably N95 grade masks for healthcare workers.

https://www.forbes.com/sites/brucelee/2020/03/29/making-an-n95-mask-for-covid-19-coronavirus-what-yo...

I think face shields are probably a lot less demanding, or if you see my other post, making equipment for the sterilization and rejuvenation of the standard polypropylene N95 (3M) mask. They were supposed to be disposable but as we all must know by now, the Sh!+ Storm we all seem to be in is causing them to be used beyond their designed duty cycle.

I have far more in depth papers on the filter fabric and it's very high tech manufacture, if you want them.

[Anonymous]

Dang, im a day late and a dollar short reading this post. I am a medical and aerospace engineer who specializes in materials and micro biology.

The last few years i have tested masks that have been 3d printed and they all work very well against viruses. 
The material used for the filter medium is actually extremely easy to come by. a basic 3M 1500 advanced alergen furnace filter is made from melt blown electro statically charged polypropylene. same stuff as a N95 mask. 

Here is what most people do not know. 
1. when a mask says 0.3 microns 95% efficient, that does NOT mean thats the smallest particle size it will capture. 0.3 is actually the HARDEST to capture because it floats linearly and almost streamline with the pressure gradient. Anything larger than 0.3 is super easy to catch due to it being heavier and more massive. Things below 0.3, such as 0.125 microns are easy to catch as well due to a particle physics behavior known as Brownian motion. The 0.125 sized particles bounce off of other gasses in the surrounding area and since the material is statically charged, they stick right to it.  however, this is not how a virus works at all. we do not nor can not breathe out a naked virus. Viruses require a living host in order to replicate since they are non living things. They require the host cells organs, energy supply, food etc in order to replicate. The smallest host cell size that will allow replication is between 0.4 and 0.5 microns in size. these are very large cells and when we breathe out these 0.5 micron size cells, we call them aerosols. 

the actual testing my group has done with the american chemical society shows that even a standard single layer pillow case non static charge will capture 96% of particles larger than 0.3 microns. My entire thesis is on this stuff and i started long before covid haha.

anyway, to bad im late to the party to give this information.

[Anonymous]

i know this is a long shot, but any way you could show a short video of how you made the lofted section? i know its using the spline tools and loft tools with rails, but i want to see the wireframe section before the loft to see how its setup:)

thanks

[TrippyLighting]

One of my posts above had the Fusion 360 model attached.

Once you have downloaded it, you can go step by step through the timeline and see how it was constructed.
If that does not answer your question, I'll make a screencast.

Very interesting and informative post BTW. Thanks!

[Anonymous]

To be honest, you dont know how scared i was to post that. I do this for a living, and the last year has been so stressful from what people have called me haha. I am usually really good at not personalizing things, but after a while, peoples comments and name calling toward me does end up hurting, i am human haha. 

I do not have 360 because my laptop can not run it at all. I used to have 360 about 5 months ago on another machine, and i do not have that anymore.
a screencast would be great. That way, when i do get access to 360 again, hopefully soon, i can try it out. The base of the mask i can make, its the lofted piece that im wondering how you did, i have a few ideas of how you did, but those could be over complicated haha

[jfeig]

To everyone who replied I want to give credit to the original designer of the "Montana Mask" that was the starting point of the uploaded design.

I am a senior citizen with no prior CADCAM experience, I enlisted someone else with more experience to convert the original file to a solid. I taught myself @ age 68 by watching Lars Christensen.  When I went to college it was all pencil, paper, and a slide rule.  After one year I changed my major to accounting.

I trimmed the front nose of the mask to reduce the amount of material needed for 3-D printing on a Creality S-4 printer. I printed about 60 masks, most were given away, 4 at a time.  The idea of the 3M furnace filters was my idea as I had 4 filters in my basement.  18 months ago, when I took on the challenge, none of the quality filters were available.  I have used the masks with one or 2 layers of filter material.

[jfeig]

Yes, the file was uploaded to the Fusion 360 gallery.

A modification of the design that is not in the file is the addition of adhesive backed foam, 1/4" x 1/4", that I purchased at the local ACE Hardware store and attached to the inside face of the mask for a better seal to the face of the person wearing the mask.

[TrippyLighting]

I'll have to defer this to the weekend.

Oddly enough, when I try to open this file on my Windows computer at work Fusion 360 crashes repeatedly.

It opens fine in macOS.

When I looked at the file myself and went through the timeline I could not recall why I made certain decisions so I'll have to take a closer look at it again.

Should I get distracted, and not post a screencast until you have access to Fusion 360 again, feel free to tag me here.

[TheCADWhisperer]

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@TrippyLighting wrote:

Oddly enough, when I try to open this file on my Windows computer at work Fusion 360 crashes repeatedly.

It was a little slow to open on my Windows machine, but once opened it was fine.

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@TrippyLighting wrote:

When I looked at the file myself and went through the timeline I could not recall why I made certain decisions so I'll have to take a closer look at it again.

---

You've either gotten wiser since then... or ...gone the other way...   😄

[Anonymous]

ok, thanks:) it will be a while till i get F360. need a machine that can run it haha. My basic school laptop can not

[Anonymous]

ok, i have f360 installed, but sine im so new, im not sure how to see the time line, or what that even is, to see how you made the mask. I do have the file loaded:)

[TrippyLighting]

The timeline is the collection of icons on the bottom. Those icons indicate features and most of those can be edited to change parameters.

The browser tree contains objects. Sketches bodies etc. If you start with a sketch, it is an object but it also shows up in the timeline as a feature. 

You can drag the timeline marker back and move it forward with the arrows to the left of the timeline. If you observe the browser you'll see objects appearing that are created by the features in the timeline. That will provide you with an overall understanding of what sequence of steps was taken to create the objects in the browser.

For a more detailed look, you can then right-click on a feature in the timeline and edit it so see what parameters were used to crate it.

That screencast I promised is still on my todo list and I'll see that I create it over the weekend.

In the meantime I'd encourage you to go complete one of the courses here.

[Anonymous]

awesome thank you. I am a huge sketchup pro user and have made masks in it a few times. Back in the day, 3 years ago, i did my CSWP, but cant remember any of it since i never used it. F360 looks interesting to me. I will still use sketchup pro but thinking of using f360 as well. Tahnks for the link, i will look at the course. 

i will also browse through the timeline and see how it all works:)

[jfeig]

The time line should be there. If not you can turn it on to see what I did.