3D Printing

Making masks and ear guards for healthcare workers.

 

Got a 3D printer yet?  We started using them at work years ago for fast prototyping.  They were expensive and very tempermental.  Prices have drastically plummeted as popularity increased.  The two I have at home are a Creality CR-10S, with a build volume of almost 12"x12"x16", and a Elegoo Mars resin printer.

They both have their pros/cons.  The CR-10S uses a spool of filament.  Looks very much like a spool of weed eater line.  It's about $20 per spool (1kg or 2.2 lbs.).  That's enough material for about 4 days of constant printing.  This is the printer I use for 95% of my projects.  I use PLA or PETG filament.  I avoid ABS, which requires a heated enclosure, has dangerous off-gassing, and is only slightly stronger than the other two materials.  PLA and PETG have almost no odor, and is safe to use indoors.

The Elegoo Mars is a resin printer.  It uses UV light to cure liquid resin in a vat.  There is a slight odor of the resin, and isn't recommended for indoor printing, though many do.  I use mine in the garage/workshop area.  Gloves should be worn when handling uncured resin.  The build volume is tiny by comparison, but the resolution is phenominal.  0.2mm layer height with the other printer, vs. 0.05mm layer height with the Mars.  If you want to print a highly detailed model, resin is the way to go.  If you want functional items, a filament type printer is probably a better choice.

Cost.  The Creality was about $450 when I bought it.  The Mars was $199 on sale.  I had the Creality for a couple of years before getting the Mars.  Very little I can't print with the combination of the two.

Where to get files.  The quick and easy way is to go to ThingiVerse, search for anything you desire, and download the files for FREE.  I believe their database now exceeds 2 million files.  That should keep you busy for a few lifetimes.  If you want to make your own custom stuff, a highly recommended CAD program is Fusion 360.  It's free to hobbyists, as long as you meet their criteria.  Details at this link.  There are also a series of free videos by Lars Christenson on YouTube showing you how to get started with this software, all they way to the most advanced projects.

 

Toy, or useful tool?  Well, that's up to you!

 

I'm sure everyone is now well aware of the pandemic outbreak, and the resulting lack of Pesonal Protective Equipment (PPE) for healthcare workers.  I have multiple family members locally that work in hospitals throughout the county.  I started offering 3D printed masks to them initially, then offered them to other healthcare workers via social media.

The free files, and details, are located here.

Ultimately, these didn't get put into use as the government stepped up and made purchasing PPE a priority.  But many were sent out as a backup.  Furthermore, this crisis is far from over, and the second wave is pending.

I have also supplied these to coworkers, and my former boss's daughter, who owns a Vet clinic.  PPE might be available for healthcare workers, but still difficult to source as Joe Public.  Please don't confuse a face cover with a face mask like this one.  Mine are using N95 equivalent filtration material.  Fabric DIY face covers are spit shields.  They provide NO protection to the person wearing it.  It's like trying to stop a mosquito with a chainlink fence.
The product that was in high demand was this mask strap.  Commonly called an "ear guard".  The surgical masks worn by heathcare workers loops around the ears.  They have been required to wear these masks all day long when around the public.  The elastic rubs on the backs of the ears and becomes quite painful and distracting.  These simple straps sit on the back of the head, bend with the contour of the head, and give the masks a place to hook.

These files are free to download here.
I stared sending these out in batches of 200 or more at a time.  I don't know how many I've made so far, but I keep reaching out on social media as I've met all the requests so far.

This design has been reviewed and approved for use in a clinical setting by the NIH (US National Institute of Health).  It can be cleaned with sanitizing sprays or wipes.  Details at the link above.
I made a shelving system for some of my radio scanners.  Very simple project that maximized space on my desk.  I uploaded the files and details to ThingiVerse at this link.
Like Earthboxes, but don't like the $50 price tag?  I designed my own parts to convert a standard 5 gallon bucket into an "Earth Bucket".  Pics and details uploaded to ThingiVerse.
So did my 3D version work as well as the store bought container garden?  How about an 8' tall tomato plant that refused to be contained in a cage?
The things I've designed, and shared, are located here on ThingiVerse These are just a few of the hundreds of things I've printed.

Need To Print BIG Stuff?

If you have the time and patience, there's virtually no limit to how large something can be 3D printed with even the hardware I have.  Someone online made a full sized Jabba The Hutt with a printer like mine.  The video series is located at this link.

At work, I was tasked with making an air plenum.  This project was sponsored by NIOSH.  The group was formerly known as The Bureau of Mines. 

Inside deeper mines, there are refuge chambers for miners to wait for help in case of an emergency.  Currently, they are using bottled oxygen (very dangerous), and air scrubber curtains to control CO2 buildup, but those are exothermic (get hot).   Imagine waiting 3 days for help in a box full of people, sweating so profusely it puddles on the floor.

Our goal was to add a cryogenic air supply to a refuge chambe inside a mine.  This would provide 96 hours of COLD - PURE breathing air.  To convert the liquid to a gas, it must go through a heat exchanger.  This is located inside the plenum, which uses a an air amplifier (venturi - no moving parts) to push warm air across the heat exchanger.  This warms the liquid and converts it into a breathable gas.  This gas feeds the air amplifier, which pushes the now cold air down a duct, into the chamber.  Absolutely amazing technology developed for the Space Program, now being applied to industry.

Anyway, back to my project.  The 16" square plenum needed to connect to a round duct.  My engineer designed the adapter flange, and split the file into 4 sections.  Each was 3D printed, then epoxy was used to bond the sections.
3 of 4 sections complete.
With the 4th section done, and glued, I put a strip of fiberglass cloth on the inside of each seam.  The inside and outside were coated with West Marine epoxy.  This makes the parts very tough, and waterproof.

This epoxy has almost no odor, cures quickly, and dries hard.  The junk at the big box stores stinks, takes a long time to cure, and is always a little tacky.  Once you use this stuff, there's no going back. 

It's available at the West Marine store, or can be purchased on Amazon: https://amzn.to/3dbqF6C
Here's the part attached to the plenum.
The first one I made was with a different color filament, but is identical otherwise.  The big gray box is the refuge chamber, and it's ready to connect to the orange air duct.
Once it passed all our lab testing, it was sent to NIOSH for testing inside an actual mine.  Here's a picture of the setup during the 96 hour test.  The glowing white tank under the air plenum collects the condensate from the heat exchanger, very similar to a home air conditioning system.  LED lighting was added so the waterline was visible.
The much smaller Elegoo Mars printer is ideal for models and other highly detailed small prints.  Can't get these details with a filament printer, and there are no visible layers lines.
Many of theses figures intended for resin printers are already sliced into manageable sized chunks.  I was able to get several of these parts on the build platform, but not all in a single print.


Here are the products I'm using:



Creality CR-10S 3D Printer
https://amzn.to/2YNUwwR

HATCHBOX PLA 3D Printer Filament (MANY colors available)
https://amzn.to/3etN68J

ELEGOO Mars Pro MSLA 3D Printer UV Photocuring LCD 3D Printer
https://amzn.to/2Bke6Zq

ANYCUBIC 3D Printer Resin (MANY colors available)
https://amzn.to/3fGedxc

As an Amazon Associate I earn from qualifying purchases.  Clicking these links doesn't increase your cost, but it does help pay for my website and YouTube channel.

 

 

 

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Last updated 06/18/20    All rights reserved.