When it takes 12-24 hours (or perhaps more) to complete a larger print, are you really going to sit around and watch the thing? No, you're going to go about your life until its finished. That means sleeping, going to work, etc.
This all from hobbyists who have full-time jobs. It would be impossible to sit next to the printer for the entire print time for any big/complex enough print.
Though I also disagree with that.
I made a "better than nothing" auto off switch using an Arduino, a 230V relay, a couple of MQ2 smoke detectors, and a couple of DS18B20 digital thermometers.
The MQ-2 is mounted about 50cm above my printers frame, one for each printer, connected to an arduino which has a relay controlling power to the printers.
If smoke is detected, or the temperature rises above 45C, it cuts the power to all printers.
The arduino defaults to off, requiring manual intervention to turn it on again via a push button. If the arduino loses power, so does the printers.
It probably won't prevent the house from burning down, but in case of an electrical fire it should shut that down pretty good. The problem is the filament itself. It burns like a candle, so if the flames ever make it to the filament, it should have no problems continuing to the spool, setting the house ablaze.
> The problem is the filament itself. It burns like a candle...
While they're maybe not the highest build quality, they're made from quality parts, with safety features enabled in software. Sometimes they're a bit too sensitive, like printing PETG with an open window, which will trigger a thermal runaway 85% of the times because the heater is unable to keep a steady temperature with the draft.
The main "fire prevention" though is i never print while not at home, and i never print while sleeping. That of course limits the time i have for printing, but so be it.
I'm thinking about upgrading to a Prusa i3 Mk3, as this supports pausing/resuming prints and cutting power between it.
You could always mount some of those fire extinguisher balls over the printers - no need for fancy electronics. Might ruin the printer though...
My Macbook developed a "hunchback" and is currently having it's battery replaced, so i can't check the details.
IIRC, i wired the relay to a default off, and there's button wired to the arduino that needs to be pushed before it turns on the relay. It then stays that way until one of the MQ-2 or DS18B20 sensors detect a reading that's outside normal operating parameters, or power is cycled.
I spent quite a few hours fine tuning the MQ-2 with cigarette smoke, vape "smoke", and finally burning filament. The bad news is that the MQ-2 is rather cheap, so they need a long "burn in" period before they start giving even remotely consistent readings, and then they still vary wildly from each other. Once burn in is over though, they're rather consistent with their own readings, just don't try to match them to the neighbor :)
As for the extinguisher balls, i considered it, but they looked like they'd probably destroy more than they would save.
I keep my printers on floor tiles, ~60cm away from any wall, and with 160cm to the ceiling, so any small fire would have trouble spreading.
If the fire was to spread beyond that, i doubt the fire extinguisher balls could save it.
I was looking into CO2 cannisters, but couldn't find any that could be activated by an electrical circuit, and while i could probably design a mechanical part to activate a regular fire extinguisher, i'm not sure i would trust it.
I don't need to iterate on the greatness of them here but they have the potential to radically help teach people how to make stuff which drastically helps in industry.
My main concern with these articles is that there is no relative risk factor presented against. I have no idea if these particulates are something it would be worthy to invest in an enclosure or are there low levels which are permittable.
I know that I personally am much more likely to have health complications from almost anything else but to someone else reading the above article they may draw the conclusion that 3d could be dangerous and should be restricted. If a person shows up to a school board meeting throwing a fit that they are running 3d printers with children in the same room then it looks bad on the printers, possibly having them removed and to generalize I think that that is the last thing anyone wants.
Ninja edit: formating
Just do an image search for "solder ventilation" for ideas on how to do it.
Regardless of this I kinda do understand the motivation to ignore the issue. People are afraid that there will be a panic and it's going to be banned.
> Gosh, this process produces something that is harmful to me. But it's OK, I'll just put it outside.
I bought these:
Make sure you find the right dampers for your motors. Ender 3 uses Nema 17.
There is a big gap between aerosol science and the medical / biological perspective needed to determine the magnitude of the risk. It is great to have the likelihood - but it is frustrating to not have the whole equation.
From this one data point, it seems that ABS is the big emitter.
Though that is just one graph out of many. With modern PLA getting better and better, it's rare people use ABS. Makes me wonder how harmful PLA is.
I want to add an HEPA filter anyway.
And if you print a toy for your kids it's gonna end up in their mouth at some point...
As for toys, I don't see a big problem. Even if you eat PLA it won't really do much harm. It's safer than the ABS most toys are made from.
HEPA filters can still be effective - the study doesn't talk about the charge of the UFPs - and the 0.3 micron DoP particles used in HEPA testing are designed to be uncharged. It is common designing filter media to use charged media to attract small particles.
If you were running a 3D printer and concerned about this risk, I would suggest:
1/ Encapsulate the unit.
2/ Wear a mask when the enclosure is open.
3/ Ensure a steady flow of process air when running to prevent accumulation. You could also run at a negative pressure to keep USPs in the enclosure.
4/ Have a filter bank on the air outlet that you change out regularly. Pair a HEPA element with a highly charged media.
Link to 2013 blog post: https://fredlybrand.com/2013/10/19/filtration-in-the-popular...
We need to quantify these risks, educate builders and make 3D printers as safe as possible, but TFA did give me a slight sense of alarmism.
There are plenty of things labeled "non-toxic" which, when heated, produce toxic fumes. Pretty much every children's toy in existence is toxic to breathe when melted.
It would seem trivial to distill out the dioxane to an unreasonably low impurity level.
As with pharma, people may not like the cost of synthetic pure bespoke molecules, but some will sell.
That's why smoking has almost no risk unless repeated. With enough exposure, those minimal alkynes add up. And they destroy DNA and wreak general havok due to their bond energy.
I know I just reiterated your point. Thank you for making the point - smoke is what is a probabilistic distribution of energetic hydrocarbons -- not the plant!!
Tiny particulates are extremely bad for your lungs when inhaled and it doesn't matter much what they are made of. PLA is not "made of mostly corn" just because the material originates there. If you printed a corn-cob pipe with PLA it would still be plastic.
I've only tried printing with ABS a couple of times, but to me it smells almost exactly like an old photocopier... kind of nostalgic.
PLA has a definite smell but doesn't seem to affect me physically.
A dry atmosphere is full of nano-particles (and yes they are harmful). But natural particles tend to be larger and more benign than most human made ones.
Nature copes with them the same way it copes with ever other long term problem: it affects individuals, and individuals are all dead at the long term anyway.
I'm not sure what you mean by "cope". There's so many things that are nature, and many are entirely unaffected while others are irreparably affected immediately. If you kill off a whole bunch of prey animals all at once you might see a decline in predators, a simultaneous explosion of scavengers, and then a correction as the predators switch to the scavengers as their primary prey. Or you might see a complete ecosystem collapse. Natural systems are so many things from the water cycle to the flora and fauna to the geological systems.
Another case, which I totally overlooked, is pollen and dust, which do result in serious negative reactions in humans, quite regularly. This may be not outright deadly but debilitating nevertheless.
Short answer: we don't. You breath enough smoke, it kills you, you die in part because these nano-particles (soot) are clogging up your lungs (Along with the CO2/lack of O2). Carbon particles in your food are carcinogenic and can accumulate in your body. Everything around you is constantly killing you by inches. Your body is pretty good at just ignoring anything that isn't causing immediate system shocks and allowing you to function.
Which is to say, the fact that toxic particles are being spewed by your 3D printer might not be any worse than working next to a grill. That's not to say that either is good, and you should probably minimize contact to prevent accumulation. We haven't "adapted" to natural chemicals, it's more that different chemicals are different degrees of problematic to the body.
Everything that expires an O2 or a CO2 molecule is producing nanoparticles.
To me that says, the quantities they did measure were too low to publish for this alarmist article.
From the article:
>all tests indicated at least some level of toxic response (though the toxic response varied by filament type).
>The sheer variety of the toxic substances produced by these printers was alarming. No less than 200 different volatile organic compounds (VOCs)
uh huh. The "sheer variety is alarming" line was about where my eyes started to roll, finishing their 135° journey after confirming there are no meaningful stats in this article.
Much like how there are wall paints that have low or no VOCs I imagine we'd want these printers to head in the same direction. Why would anyone say... oh yeah these paints have a variety of VOCs they emit. Sounds alarmist and I don't see enough evidence so we shouldn't explore further and come up with ones that don't potentially harm people.
It also does open the door for someone to come in and make a vent/hood system that works for many types of 3d printers so I guess there's that...
Especially in this case, unless you're working in a 3D printing farm it shouldn't be too difficult to work around these problems. If you have a 3D printer on your desk consider moving it to a more isolated, well ventilated location. Maybe buy a couple more fans and an enclosure.