FAQ
TL;DR: Under £6 per resuscitator filter, plus a 3D‑printed adapter—"It is used to connect an antibacterial/anti‑viral filter"—lets 3M mask users add medical filters at home. [Elektroda, piotr_go, post #18584752]
Why it matters: This FAQ helps makers and medics quickly decide how to print, fit, and safely use adapters for 3M masks.
Quick Facts
- Material: Printed in PLA; varnish improves seal. PET‑G is a viable alternative if available. [Elektroda, piotr_go, post #18584752]
- Cost: “Resuscitator” filters were <£6 each when posted; availability varies. [Elektroda, piotr_go, post #18584752]
- Layout: Single‑filter setup works; second port can be blanked with an epoxy‑filled plug. [Elektroda, piotr_go, post #18584752]
- Safety note: If converting full‑face snorkel/clinical masks, the exhalation outlet must be sealed. [Elektroda, Krzysztof Kamienski, post #18589930]
- Sourcing prints: No retail adapter; ask a local 3D‑printer owner to fabricate your size. [Elektroda, piotr_go, post #18593583]
What is this 3M filter adapter, in one sentence?
A 3D‑printed coupler that lets a 3M mask accept a disposable “resuscitator”/ventilator filter for antibacterial/antiviral use. [Elektroda, piotr_go, post #18584752]
Which filament should I use—PLA, PET‑G, or ABS?
PLA works and can be varnished for better tightness; PET‑G is a suggested, tougher alternative if your printer and supply allow. [Elektroda, LA72, post #18585213]
How do I block the second filter port on a dual‑port 3M mask?
Print a second adapter to 12 mm height and flood its hole with epoxy; use that as a solid blank. [Elektroda, piotr_go, post #18584752]
Is a bent adapter better than a straight one for ergonomics?
A bent DAR‑style adapter can improve ergonomics, but challenging overhangs may exceed some printers’ capabilities. [Elektroda, Mscichu, post #18585176]
How available are these medical filters right now?
Availability fluctuates; one update noted 120 units in stock one day and none the next, so act quickly. [Elektroda, piotr_go, post #18585260]
Does a 3M mask protect others, or just the wearer?
Unmodified exhalation valves vent outward; to protect others, route exhalation through a filter or seal the outlet. [Elektroda, Krzysztof Kamienski, post #18591225]
How do exhalation valves and P‑series filters interact?
P1/P2/P3 filter particulates; exhalation valves bypass them unless blocked, so outbound air needs added filtration or sealing. [Elektroda, Anonymous, post #18593744]
Is a 3M half‑mask with filters the same as a surgical mask?
No. “These 3M’s are sealed” and filtering depends on the cartridge class; surgical masks mainly reduce droplets. [Elektroda, piotr_go, post #18591698]
Should I add an LED timer to remind me to change filters?
It was proposed, but responders warned the cue could trigger stress if no spare is available; keep it simple. [Elektroda, Matheu, post #18587149]
If I convert a full‑face snorkel/clinical mask, what must I seal?
Seal the front exhalation opening completely; “Must be sealed!” Also ensure every connector is air‑tight. [Elektroda, Krzysztof Kamienski, post #18589930]
Will removing internal one‑way valves cause fogging?
Yes. Tests showed removing inner valves led to lens fogging; keep them to preserve visibility. [Elektroda, piotr_go, post #18590304]
What is a DAR/resuscitator filter in this context?
It’s the disposable breathing‑circuit filter medics use on ventilators; the adapter mates a 3M mask to this filter. [Elektroda, Mscichu, post #18585176]
How can I get an adapter printed if I don’t have a printer?
Ask in your local community; the thread suggests contacting nearby 3D‑printer owners and stating your mask model. [Elektroda, piotr_go, post #18593583]
Any printing pitfalls I should expect?
Large overhangs on bent designs may print poorly; tune supports or choose a straight adapter to avoid failures. [Elektroda, piotr_go, post #18585260]
Could moisture clog filters during two‑way breathing?
Sustained inhalation and exhalation through the same filter can raise breathing resistance as media gets wet. [Elektroda, piotr_go, post #18590304]
How do I install the adapter and filter (3 steps)?
- Print the adapter; apply varnish to seal pores.
- Press‑fit the resuscitator filter to the adapter.
- Mount on the 3M mask; blank unused port with an epoxy‑plug. [Elektroda, piotr_go, post #18584752]
Comments
I've been printing a lot of these types of adapters to nearby medics lately. See here is a bent version that supposedly improves ergonomics: https://grabcad.com/library/3m-mask-to-dar-filter-adapter-2 It's... [Read more]
Instead of PLA, you could have used PET-G. [Read more]
Cool, but not for my printer I'm afraid. "Overhang" works out poorly for her. I checked a while ago and they don't have any more. As recently as yesterday there were over 120 in stock. I d... [Read more]
@piotr_go Couldn't you install some kind of small led in this adapter that would start flashing and remind you to change the filter after e.g. 24h? The counter reset would happen automatically when the... [Read more]
I have added a v2 fit from the other side of the filter. Too much luxury, someone else would envy me and steal it. :) [Read more]
Anyone here who has played "Metro" ? :D Clear association :D [Read more]
Let's not, because if this LED started flashing (and you wouldn't have noticed, or just happened not to have the filter with you for the change) you could get a stone in your back (a lot of stones)...... [Read more]
Excellent idea. :idea: So let me, as a , "Super - Coronavirus Carrier" :cry: I will spit, huff and puff at you, via this unmodified exhaust valve. :D Alternatively, this valve should also be... [Read more]
Yes, but probably from UV radiation :) Added after 17 [minutes]: Ok, then you might need to make some kind of small, discreet button. When pressed, the led would light up green or red. The... [Read more]
@piotr_go This now reads..constructor :cry: Based on the Italian experience of using airtight facial diving masks, we have today tried to assess for the first time with us their practical suitability... [Read more]
I happen to have such a mask. 1. Removing the internal valves is not necessary, it is actually harmful. When they are removed, the glass fogs up (I checked). They are only there to prevent the exhaled... [Read more]
Maybe off topic but what's the deal with the valve? I couldn't find anything on the internet about it. I was wondering about a bonnet e.g. M3 7502 with a round P3 filter. There, the exhaust valve is not... [Read more]
@tomek_byd How much can you write !!! The point is. to filter the air exhaled too. If you are infected, you spit up these viruses with every breath. [Read more]
I just couldn't find anywhere what this was about. I understood from this statement that the other way this valve does not protect. As much as I agree that towards the environment there is no protection... [Read more]
@tomek_byd Yes, and then it is the equivalent of a normal surgical mask. [Read more]
A normal surgical mask has problems with tightness and length of use. They can only be worn for 2h although I have read that it is even shorter. In addition, they are almost unavailable and come at extremely... [Read more]
No, a surgical mask is neither airtight nor filtering. It is only there to keep you from spitting on the patient. Alternatively: These 3M's are sealed and the filtering depends on the filter used. There... [Read more]
Hello I am a paramedic . Where can I get such adapters because my colleagues and I have such masks 3m which we bought ourselves but recently the prices of filters have been so exorbitant that it is a pity... [Read more]
Look for someone with a 3D printer in your area, or state what city you are from, maybe someone will come forward. [Read more]