Hacker News Reader

Comment by zactato | Hacker News Reader

I just ordered by first 3D printer, I'm not normally sensitive to air quality issues, but my partner is, so I spent some time doing some research on the issue.

It's amazing how many people believe "if you can't smell it, there's no problem" and quite incorrectly assume that things like PLA won't hurt them. Surely minimal exposure is fine, but 3d printers run over many hour periods and those VOCs can build up.

I decided to be safe and bought a basic fabric enclosure with an exhaust fan that vents to the outdoors. It's probably not perfect, but maintaining negative pressure inside the enclosure should remove most particulates. I wouldnt handle bromine in it.

I'm worried about all the folks running print farms in their house with minimal ventilation.

View on HN

And you're talking about an FDM printer but the author talks about resin printers which are hundreds of times more harmful.

That said fabric enclosure with something that goes up to 250 degrees Celsius isn't the best idea. There are fireproof 3D printing enclosures.

I recently learned that now there's some kind of "bio resin" that seems to be less toxic. So maybe that would be ok?

I doubt it's any safer. Things that UV cure tend not to be nice.

Hm, they say it's safe for children's toys, according to some certification:

https://store.anycubic.com/collections/uv-resin/products/bio...

Once it's cured maybe, that doesn't mean it's at all safe until then.

It's similar to 2 component epoxy: The raw materials are highly poisonous, but the reaction end product is safe. It's just that you need to be 100% sure that there are no un-reacted resin leftovers anywhere on your part. And that part is very difficult.

A lot of the so-called "water washable" bio resins need to be diluted down to 1L of resin + 1 million L of clean water before they are considered safe enough that you're allowed to flush them down the toilet. So I would never touch them without gloves.

And while you are correct that some plant-based resins are not a class 3 lung poison anymore, they are still a class 2 eye irritant and can cause burns in your eyes purely through aerial exposure. Which means you need to wear goggles whenever you're in the same room.

The nozzle will hit that temp, but air temp will be much closer to room temp. A porous and poorly insulated fabric enclosure will probably not add more than 10 C temp increase.

Air temperature is not the issue and is not how 3D printers catch on fire, I should have clarified in my previous comment.

Nozzle clogs can happen frequently, and if left unmonitored, can quickly turn into a disaster. If your nozzle is clogged it can essentially destroy your printer and cause an electrical fault that can set the printer on fire.

Printer fires are a lot less frequent in recent years than a decade ago, but it can still definitely happen.

A nozzle clog won't set a 3d printer on fire either. It'll make a good mess of the hot-end. There'll be a bunch of charred filament, and heat creep will clog the nozzle nicely. It won't however magically get any hotter than it does while printing with an unclogged nozzle.

What does cause fires is failed thermistors. These days most firmware will detect unreasonably high or unreasonably low temperature readings and turn off the heaters. You thermistor can still however fail with a reasonable reading if you're very unlucky.

Another factor is MOSFET failure. MOSFETs have a failure mode where they can fail closed. This can turn a heater on permanently. Modern firmwares will detect the temperature going unreasonably high, but most hardware is not set up such that the firmware can do much about it.

Reply on news.ycombinator.com