[ARCHIVED THREAD] - 3D Printed N95/surgical mask emergency substitute. Now: purchase through the EE! (Page 2 of 7)
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Updates of what I have is uploaded to: https://www.prusaprinters.org/prints/26740-3d-printable-n95surgicalrespirator-mask-substitute https://www.thingiverse.com/thing:4236172 |
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Awesome work sir. Printing up some for test right now. 
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Quoted: Extruder mods make TPU easier on the Ender 3, mainly you want to constrain the filament path leaving the drive gear & entering into the bowden tube. There are a few that make use of the existing drive gear, but after running one for a while I switched to a build that uses the E3D Hobb-Goblin - 5mm ID Drive Gear presssing against a 608zz bearing. You need the drive gear, one bearing & some nuts and cap head screws for assembly. It uses screws to set the tension on the filament squeeze between gear & bearing rather than a spring loaded arm. A short piece of bowden tube material on the input side prevents erosion from filament movement. The original version of what I used is the "Neustruder" https://www.thingiverse.com/thing:2422803 and I did a small remix of one part to work better with the Ender 3 by flipping the tensioning screws & nuts orientation by 180 https://www.thingiverse.com/thing:3897798. There is an amazon listing for the gear itself: www.amazon.com/dp/B071LDTFK4 If you want to try semi-flex TPU, I really like the way the Tianse brand TPU prints. www.amazon.com/dp/B07848C1DZ Quoted: Quoted: Hmmmm, might have to try this but I only have pla. Not sure i could even get TPU or print on my ender3. Extruder mods make TPU easier on the Ender 3, mainly you want to constrain the filament path leaving the drive gear & entering into the bowden tube. There are a few that make use of the existing drive gear, but after running one for a while I switched to a build that uses the E3D Hobb-Goblin - 5mm ID Drive Gear presssing against a 608zz bearing. You need the drive gear, one bearing & some nuts and cap head screws for assembly. It uses screws to set the tension on the filament squeeze between gear & bearing rather than a spring loaded arm. A short piece of bowden tube material on the input side prevents erosion from filament movement. The original version of what I used is the "Neustruder" https://www.thingiverse.com/thing:2422803 and I did a small remix of one part to work better with the Ender 3 by flipping the tensioning screws & nuts orientation by 180 https://www.thingiverse.com/thing:3897798. There is an amazon listing for the gear itself: www.amazon.com/dp/B071LDTFK4 If you want to try semi-flex TPU, I really like the way the Tianse brand TPU prints. www.amazon.com/dp/B07848C1DZ Are these directions in crayon anywhere, hopefully with pictures? 
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| Tagscribe like a mofo. I have a modded anet a8 and 2 weeks of home lockdown. Only have pla and petg right now though. Worth trying with these materials? Even if I have to sterilize with alcohol or UV? Though I could see the face/sealing part being fucky because of the rigidity. |
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Quoted: We have an Ender 3 that is sitting idle. I'm not sure what you wrote because I haven't used it, it's my son's but I'd really like to give this a whirl. Are these directions in crayon anywhere, hopefully with pictures? You can try semi-flexible TPU (shore 95A) with the stock Ender 3 extruder, some folks have had reasonable success with it. You would probably need to print slowly (15 - 20 mm/sec) to avoid trying to move too much filament at a time (i.e. building up pressure on the filament). You can try to ramp up your print speed (via the "FR" or feed rate adjustment on the control panel - i.e. when you turn the control knob during a print) to see how fast you can print before the filament starts escaping prior to entering the bowden tube. A good quality bowden tube (like Capricorn) has less friction & keeps the filament inside straighter, which also helps with TPU printing, which would also improve the odds for successful TPU printing with the stock extruder. With an extruder optimized for flexible filament you can easily print 50mm/sec with no issues. If you aren't handy with DIY printer mods you might be better off buying an upgrade if you want to do a lot of TPU printing. Look for one that references printing with flexible materials. The main thing for a flexible filament friendly extruder is not having any significant gap/open space between where the filament leaves the drive gear & where the filament enters the bowden tube. When under pressure it can become easier for the filament to push through such a gap than to get pushed into the bowden tube. (The bowden tube is the teflon plastic tube that guides filament from the extruder to the hot end.) |
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@rat_patrol The zip file (@ download all files) still has only the original files, not the updates. You have to go to the "thing files" tab & download each individual file to get the new ones. A thingiverse automated screwup, I guess. You might want to note this at the top of the description to give folks a heads-up. |
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Quoted: The zip file (@ download all files) still has only the original files, not the updates. You have to go to the "thing files" tab & download each individual file to get the new ones. A thingiverse automated screwup, I guess. You might want to note this at the top of the description to give folks a heads-up. I'll have the files on the Prusa platform shortly. |
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Quoted: I just upgraded my Ender 3, it should be able to handle TPU. So ABS for the main body, and TPU for the interface/gasket? With the new snap action system, TPU is not tested, going to run a test this morning. I'll make the base where the retainer snaps on solid, should work fine then. The body could be TPU, the retainer should be abs or petg. Pla may not like the flexing. |
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Quoted: With the new snap action system, TPU is not tested, going to run a test this morning. I'll make the base where the retainer snaps on solid, should work fine then. The body could be TPU, the retainer should be abs or petg. Pla may not like the flexing. Quoted: Quoted: I just upgraded my Ender 3, it should be able to handle TPU. So ABS for the main body, and TPU for the interface/gasket? With the new snap action system, TPU is not tested, going to run a test this morning. I'll make the base where the retainer snaps on solid, should work fine then. The body could be TPU, the retainer should be abs or petg. Pla may not like the flexing. I'm going to try a print with PETG once it comes in, I like it better as a material than ABS. |
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Quoted: If you use PLA or PETG you'll probably want to soak that part in a bleach or hydrogen peroxide solution. Quoted: Quoted: Abs and TPU can survive boiling water bath to sanitize. If you use PLA or PETG you'll probably want to soak that part in a bleach or hydrogen peroxide solution. |
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Quoted: Please upload somewhere else, Thingiverse is absolute GARBAGE. I can't even get it to load, let alone download. now also on Prusa's website: https://www.prusaprinters.org/prints/26740-3d-printable-n95surgicalrespirator-mask-substitute |
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Been doing some research on sterilization. PLA and other "low" glass transition materials may be able to withstand a few autoclave cycles before structural integrity becomes an issue, it may be worth some experiments. On another note, the purpose of these masks is to protect the wearer rather than prevent transmission, with a really low cost to print these masks, approximately $1 in materials, maybe a 2 or 3 part shell design. The wearer doesn't have to protect from auto exposure, just external exposure. So the parts that interface with the user's face won't need extensive sterilization. |
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Quoted: Been doing some research on sterilization. PLA and other "low" glass transition materials may be able to withstand a few autoclave cycles before structural integrity becomes an issue, it may be worth some experiments. On another note, the purpose of these masks is to protect the wearer rather than prevent transmission, with a really low cost to print these masks, approximately $1 in materials, maybe a 2 or 3 part shell design. The wearer doesn't have to protect from auto exposure, just external exposure. So the parts that interface with the user's face won't need extensive sterilization. I'm testing a mask print with TPU right now. Provided the snap retention system still works, and it should, it would be the ideal material as it would conform to the wearer for a better seal and much better comfort. Even PETG could take 60-70c, which will take longer in a hot water bath, and the water temp would have to be regulated, but PLA is just not the material for the job if other options are available to you. |
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Quoted: Quite honestly, just put a carboard box over your 3D printer and print with ABS. Or leave your printer as is, and print with 95A TPU (most printers, even Bowden systems, can print this stiffer TPU). I'm testing a mask print with TPU right now. Provided the snap retention system still works, and it should, it would be the ideal material as it would conform to the wearer for a better seal and much better comfort. Even PETG could take 60-70c, which will take longer in a hot water bath, and the water temp would have to be regulated, but PLA is just not the material for the job if other options are available to you. Quoted: Quoted: Been doing some research on sterilization. PLA and other "low" glass transition materials may be able to withstand a few autoclave cycles before structural integrity becomes an issue, it may be worth some experiments. On another note, the purpose of these masks is to protect the wearer rather than prevent transmission, with a really low cost to print these masks, approximately $1 in materials, maybe a 2 or 3 part shell design. The wearer doesn't have to protect from auto exposure, just external exposure. So the parts that interface with the user's face won't need extensive sterilization. I'm testing a mask print with TPU right now. Provided the snap retention system still works, and it should, it would be the ideal material as it would conform to the wearer for a better seal and much better comfort. Even PETG could take 60-70c, which will take longer in a hot water bath, and the water temp would have to be regulated, but PLA is just not the material for the job if other options are available to you. I have TPU and PETG on the way. |
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For all those who are looking to buy TPU, looks like Amazon won't be delivering until the end of April of the type I normally get. Put in your orders! For ABS, I REALLY like the offerings from Atomic Filament. It prints well, lower warp than many, USA made, just nice stuff. Always order 2+ spools from Atomic at a time so you get a hard shipping box. Single spools are shipped in a soft package, they occasionally arrive damaged. |
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Quoted: For all those who are looking to buy TPU, looks like Amazon won't be delivering until the end of April of the type I normally get. Put in your orders! For ABS, I REALLY like the offerings from Atomic Filament. It prints well, lower warp than many, USA made, just nice stuff. Always order 2+ spools from Atomic at a time so you get a hard shipping box. Single spools are shipped in a soft package, they occasionally arrive damaged. Walmart still has stuff available to be shipped to your house within 2 days, but it is going fast and it isn't the stuff I normally use (hatchbox, etc). |
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Quoted: Printing one in PLA right now to try out. Is this is viable, I will crank some out at work for all us poor suckers having to come in during the apocalypse. For PLA, I'm thinking alcohol, bleach solution, UV, and ozone would all be viable disinfecting methods. Same thing with anything containing water, the PLA will get pretty brittle. |
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Decided to try it with PETG because I have it on hand. Almost done, then I gotta print the retainer. So far, the print looks GREAT. No supports, printed at 50 mm/sec and 0.2 layer height with a 0.4 nozzle. Do we have a preferred filter media yet? Progress pic from earlier Attached File |
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It's possible, on the Ender 3 build plate to get both printed in the same print. Doing a PLA just for testing purposes right now; Cura estimates just under 6 hours for this print. Attached File |
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Finishing up a mask & retainer in white TPU on the Ender 3. About 7 hours print time? Attached File Large brims as I had a bit of edge lift on an earlier mask print on an unheated bed, also went to 60° bed. Retainer in TPU probably won't do well, but thought I'd give it a try & see. |
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Quoted: It's possible, on the Ender 3 build plate to get both printed in the same print. Doing a PLA just for testing purposes right now; Cura estimates just under 6 hours for this print. https://www.AR15.Com/media/mediaFiles/228109/20200324_162911_jpg-1331393.JPG |
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Quoted: You should not need any supports. There is only minute overhangs on the string/elastic attachment points, but even TPU printed it just fine for me. Quoted: Quoted: It's possible, on the Ender 3 build plate to get both printed in the same print. Doing a PLA just for testing purposes right now; Cura estimates just under 6 hours for this print. https://www.AR15.Com/media/mediaFiles/228109/20200324_162911_jpg-1331393.JPG |
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Switching over to .6 nozzle and .3mm layer heights is giving me a dramatic reduction in print time. ABS retainer is 44 minutes TPU mas is 2 hours, 18 min ABS mask is 1 hour, 36 minutes. Those specs are for 2 perimeters, but each perimeter is .72mm wide. I'm printing ABS at 70mm/sec nominal, TPU at 30mm/sec for everything. I switched to the .6mm nozzle, running a TPU mask right now. |
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TPU for both parts with a 0.4mm nozzle was 7hrs 50min real time using a 0.28 layer height & nominal 50mm/sec print speed. 99% infill on media retention layers, 20% on remainder 3 layer (1.2mm) shell. Printed fine with no supports Attached File The TPU clip ring (1mm) actually worked fine with 1 layer hobby felt as filter media. Would need to use the 2mm for 2 layers. PLA+ would probably be more secure, though. Shown with the original minnesota mask, using 2 layers felt media for trial fitting. Attached File |
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Got mine all done. I'm worried about the tabs possibly breaking during install and removal, it's pretty darn tight. Printed both in PETG. I have PLA and PLA+ available to play with as well. About 4.5 hours total print time. Paper towel in for visual effect only Attached File Attached File |
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Quoted: Got mine all done. I'm worried about the tabs possibly breaking during install and removal, it's pretty darn tight. Printed both in PETG. I have PLA and PLA+ available to play with as well. About 4.5 hours total print time. Paper towel in for visual effect only https://www.AR15.Com/media/mediaFiles/331964/1585086656316_copy_784x522_jpg-1331586.JPG https://www.AR15.Com/media/mediaFiles/331964/1585086969354_copy_784x522_jpg-1331587.JPG |
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Quoted: Yeah, they are semi-disposable. I'd be curious to see if you have breakage fairly early on. I played with my ABS version quite a bit last couple days, still hasn't broke. It is definitely way tighter than your example in the video (if that's you). I may try doing a retaining ring 1 or 2% bigger or under-extruding a hair. |
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Quoted: It is definitely way tighter than your example in the video (if that's you). I may try doing a retaining ring 1 or 2% bigger or under-extruding a hair. There are 2 retainer rings; 1mm and 2mm gap. The 1mm gap IS tight, the 2mm much looser. Of course, who is to say the actual tolerances that your printer or my printer are the same as the CAD file, or even close? |
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Quoted: Yup, its me. There are 2 retainer rings; 1mm and 2mm gap. The 1mm gap IS tight, the 2mm much looser. Of course, who is to say the actual tolerances that your printer or my printer are the same as the CAD file, or even close? That may make sense, I printed the 1mm. That and my printer is a $200 anet with a bunch of mods. I'll bust out a 2mm next. My 6 year old wanted one, so I got one going for him right now. I downsized to 90% I expect to have to mess around with scale on retaining ring for a good fit on his. Thank you for sharing this! |
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So just under 6 hours to print both at .28mm layer height, with supports (I agree they aren't needed, removing them will probably save 30 minutes), and 20% infil with PLA. I'll may try 10% infil, to be honest I think this could get away with 0% infil, it is very sturdy with some very minor flex. Fits well on my face, and I can pull a vacuum with some minor pressure placed on the front piece. Paper towel as a filter right now just for mockup. Attached File |
New video with some more info. Failed To Load Title |
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Quoted: Just saw a FB post from my dentist. He is using his resin printers to knock some of these out. His solution to get the best form fitting mask is to incorporate dental impression type stuff. Thought that was cool. He did a follow up video tonight. One thing he mentioned is with the MT mask is with the smaller opening it's harder to breathe. He had another mask that had a larger opening but the filter was held on with a rubber band. I sent him over your file Rat to see what he thinks. 
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