Engineering and Covid-19

I’m going to take a break from trying to build cat trees for a bit to talk about how flexible the world will need you to be. Sometimes, you have to be prepared for your whole life to switch around and your focus devoted to a new topic. My current day job is to make sure life safety systems work correctly and will do what they need to the instant something happens. I knew things were going to get bad, and at sometime I was going to have to switch concentrations even if it would be in my off time.

After a few months of saving, I finally bought my first 3D printer, a Sovol 01.

My Sovol 01 3D Printer

A lot of printing groups have joined together to print personal protective equipment (PPE) for emergency personnel around the world. However, these groups weren’t really in my area, nor did they focus on more rural areas who don’t have the liquid funds to enter a price war for the necessary PPE. I knew this is where i needed to focus.

I contacted my dad who runs a local EMS service in a rural area around Atlanta, and asked if they needed any kind of PPE. They needed face shields, and 20 of them.

I started looking through all of the models available, and what was available in out local stores. Unfortunately, there isn’t really any elastic in our area, so that ruled out any designs that required any elastic bands, cords, or straps. This lead me to the 3D Verkstan model. This model was light, required no elastic, and would save on print time and plastic.

3D Verkstan Visor
Credit: https://3dverkstan.se/protective-visor/protective-visor-versions/

Now it was time to pick a material. First, I looked at PLA. PLA would be nice and light, save me in cost, and be flexible enough to go around any size head. However, PLA is not chemical resistant, can be very brittle, and doesn’t do well with UV exposure. I want these to be cleaned and reused, to that material won’t work.

The next material was ABS. ABS is chemical resistant, relatively flexible, and a good bit tougher than PLA. However, ABS requires a higher temperature from both the nozzle and print bed. Our house is being run cold to combat the temperature coming from 2 computers running 2 people telecommuting. I could order an enclosure to keep the heat in, but then I would have to wait several days for delivery. Time is important here, so lets see what can be printed ASAP.

Since we need a lower-temperature but chemical resistant material, the next choice is PETG. This plastic prints at a lower temperature than ABS, but stills has the great qualities of both ABS and PLA. The biggest downside is that it doesn’t do well with UV exposure. However, the time in UV light is minimal for this use application.

Once I got the plastic and the printer together, it was time for a test print in order to dial in the settings. My first print with the PETG is an XYZ cube. Reviewing the manufacturer’s recommended settings on the spool, I used a nozzle temperature of 240°C and a bed temperature of 80°C.

Test Print: XYZ Cube

When printing the inner portions of the cube, the plastic looked like it was leaving strings behind. This means that the nozzle temperature is too high. I lowered the nozzle temperature to 235°C, and that greatly reduced the stringing. Now it was time to print the first model.

3D Printed Face Shield Visor

Even though there is still stringing, it can be easily removed by pulling them off when the part is fully cooled. Now that this test looks good, we can start printing more. For the transparent sheet that makes up the actual shield, you can use either transparency sheets, or clear document covers. I had bought a pack of 100 transparency sheets from our local office supply store.

Completed Face Shield

If you want to join the effort in providing 3D printed PPE, please use the “Get in Touch” button on the About page. At the time I’m writing this article, the Georgia Emergency Management Agency (GEMA) is noting the difficulties of optaining PPE, especially for the more rural areas of Georgia. The help is needed now more than ever. https://www.gwinnettdailypost.com/local/obtaining-ppe-continues-to-be-a-struggle-in-georgia/article_5080975e-8013-11ea-b24e-97662101a1a4.html

If you want to know more about 3D printed PPE and other medical devices, you can use the following link for FDA guidelines: https://www.fda.gov/medical-devices/products-and-medical-procedures/3d-printing-medical-devices

For more information on the 3D Verkstan face shield, please use the following link to their information page: https://3dverkstan.se/protective-visor/protective-visor-versions/

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