I loaded up the Prusa face shield .dxf file into the laser cutter, and cut one from acrylic.
The slots are the trouble. There’s one round hole, 5.5mm, at the bottom center. That’s very close to 7/32", and we have a pin punch that size. All the rest are slots. But since the vinyl is a bit stretchy, maybe we can get away with just a round hole, possibly a bit larger than 7/32". Or a hole in the center followed by a slit down the length of the slot from a chisel-like punch. I think just a hole would work in vinyl.
We could make a die by drilling 7/32" or 1/4" holes in a piece of 1/4" thick metal plate (wouldn’t even need CNC for that). Then a vinyl blank goes over the die, the acrylic guide goes on top, add a clamp, then punch punch punch. And trim around the edge with a razor blade or fabric cutter (like a pizza cutter but sharp as all hell). The outside edge isn’t critical; a little slop there won’t hurt.
I also hand cut one from what I think is dura-lar. The good news on that is it is laser cuttable , you can even cut stacks of it at once. Brian is trying to locate some locally. I initially thought I had .002 i based on my Amazon order history but a caliper says it’s much thinner. .002 is on the low end of what prusa recommends.
The one I cut is a bit weak and the bottom reinforcement piece doesn’t stay attached.
The one Jody dropped off is pretty good, maybe heavier than someone would like up wear for many hours of a day. Also the vinyl one from Jody does have a bit of memory to it from the roll initially and now from how it was sitting on my counter over night.
Jody also mentioned something about people laser cutting the head band part too and I think that would be a great idea if someone can work out a design.
I realized I have 150+ sheets of 8.5" x 11" overhead transparencies. I measured them at 0.09mm = 0.0035in thick. The Prusa design is 240mm x 240mm, and these are 215mm x 279mm. But this could be close enough. A short shield is better than none.
If we find that anything made isn’t usable by healthcare workers, I think we could make our donations to homeless shelters and food banks. The recent videos from these nonprofits show folks working together without masks and I think they could benefit greatly from them.
I talked with Brian Smith up at MSU EHS. He sounded slightly overwhelmed but got me in touch with Nathan Tykocki. Here’s the response I got about 3d printing the Prusa shields:
---------- Forwarded message ---------
From: Nathan Tykockinathantykocki@gmail.com
Date: Fri, Mar 27, 2020 at 2:44 PM
Subject: Re: 3D printed shields
Jody, I’d be excited if you had 2. (c:
Ive been using the Prusa shield design (RC2 and RC3) to print stacks in my home, too. So far Ive made 27 in 3 days. I’ll keep at it until I run out of PETG. We’ve a lot more plastic shielding than frames right now, believe it or not. We’re using the resources of MSU to get them made. So if you can make the frames, we can fill them with the actual shield part. We were using the shield design that went with Prusa’s shield too. I have sheeting cut for at least 100 or more shields, with more on the way.
The frames should be wiped with a Clorox wipe or something similar, bagged, and dated. Handling with gloves and dating the bass is awesome.
People have been dropping off frames in a disinfected bin on my porch, where I’ve cleaned them again, assembled them, and gotten them ready to be donated. I will wipe them down again before taking them to the donation site. If you or your people would like to add to this, we’d be ever so grateful. I could also get you some pre-cut plastic sheets if you want to give some out to assemble on your own. What do you think?
Awesome. Thanks James! Haven’t got an email back with his address.
As for PETG filament, @jmccurry is right. It’s the flexibility that SLA doesn’t have. He says TinkerLabs might have some in stock. You’d have to call them directly. Otherwise it’s mail order all the way.
We have two spools of TPU filament that were donated to LMN. Is that suitable for printing the headband part? If so I can use our printer to get some going.
I’m actually at the space now (alone, socially distant), using the laser cutter to cut overhead transparencies. It’s working, but they need some cleaning when they come out of the machine. It’s about two minutes per.
But if MSU is mass producing something better, and cleaner, that’s the way to go.
Thought I would give an update. Nathan R. Tykocki messaged to update that he sterilized everything and assembled them this morning. Most of what I gave was the rc2 version, most of them petg (running low)
I wanted to announce that I did make some with a higher temperature pla filament. And he said it Seems like it has enough flex to not shatter. And they might be worth producing.
“I’m a scientist with proper PPE in my home, so I can clean and disinfect all relatively quickly without exposure to me or my family”, and thinks that the pla will clean well enough from my understanding.
The pla I have prints around 230 c. And has had early decent results.
I’m being funded by my company to produce these masks and now face sheilds. However since you guys have already been building the prusia shields I have some questions.
Where could I get the laminate if I wanted to buy mass quantities.
I’ve been printing prusa rc2 and rc3 shields no problem. both in petg and higher temp pla. Im now attempting this design in high temp PLA. i can let you know how this goes. https://www.prusaprinters.org/prints/27477-covid-onx-protective-shield-1620-shields-per-day-o
I’m trying a stack of 8. Nathan would be a good contact to see what he’s using. He gave me a few for masks I’m donating to extended family . I’m impressed with the feel
So I would like to update all on the “3d printing face masks” front.
First of all,
Supplies
If anyone needs filament 3dxtech out of Grand Rapids is staying open as an essential business. They make the filament, so supplies in that realm are good.
Mcmaster-Carr is completely sold out of elastic bands, Walmart, Michael’s, Joanna’s, and Amazon are oversold or out of stock. Printing TPU or Ninjaflex may be an option.
Filter media can be purchased from just about anywhere. Using the filter paper from furnace filters with a MERV 12 or greater is preferred.
Designs
Many different mask designs have surfaced and so far I’ve attempted to print them all. Keep in mind these are my opinion and printing times are based on a Lulzbot Taz6 with a 0.5mm head. From worst to best…
Sparc Mask - Must be supported and failed horribly.
Recommendation: Dont print!
It will not lay flat in any orientation so you must print with supports. There is a lot of wasted material and the time is extensive.
Copper3d V2 Mask - Very brittle with PLA and must be printed in a high resolution. Fitment issue.
Recommendation: Dont print! https://copper3d.com/hackthepandemic/
Fits like a jockstrap for your face. Extremely narrow, would require extensive modeling changes to be feasible. Low-resolution prints fail and high-resolution prints are between 8-10 hours per mask.
Copper3d V1 Mask - Must be molded and does not seal very well.
Recommendation: Modifications to the taps resolve this however there are better designs.
Creality Mask - The C-lock buckles on this page are awesome.
Recommendation: Have yet to slice or try as better designs were found. Printed a plate of the c-lock buckle and they work great.
Nurse Mask - Mind the names I need something to identify these types
Recommendation: This mask is an alright design, however, better designs include more strap tie-offs. I’ve printed a lot of these masks, in various sizes.
Tinkrlab Mask - Print Force?
Recommendation: Good mask, heavy design, no alternate sizes, 5-6 hour print
Low Poly Mask Super fast print Current Winner
Recommendation: Fast Printing 2hr, super light design, multiple sizes. This is the one I’m filling my plate with.
If anyone knows of a good location to get elastic I’ll place an order. So far all the orders I’ve placed have been canceled.
Good Luck. Stay Safe.
My wife has been wearing one of those masks with elastic behind the ears. These ear savers are nice for keeping ears from going raw. The designs are for 3d printing, but are better suited for cutting a 100 at a time on the laser.
