Hi, I just read @Alex_Anderson printed a awesome print in 22 Hrs. Can I ask a stupid question and I am new to 3D. If you printing for 22 hours , is there a chance of a fire. I read that printers catching on fire. Whats you take on not watching your print, leaving your printer alone. Thanks
I worry about that too.
Its not time period , its leaving your printer alone or going to sleep while it prints. Wake up and the house is burning down.
The principal fire risks come from the hot end overheating and possible electrical shorting. Both of these can be isolated or controlled. In the case of shorts, make sure you use the right gauge of wire for you 12v, particularly the heated bed and ensure everything is screwed down correctly, no exposed copper etc. You can also then enclose the electronics in a fire retardant enclosure - if something does catch fire, there’s not much to burn on the electronics board so you just need to prevent it spreading. For the hot end, you can use 2 thermistors: if there is, a significant delta in their readings (as you might experience with a thermistor failure) the printer shuts down.
My print cave also has a powder fire extinguisher and dedicated smoke alarm.
Last night I sent a rantmail to our printer manufacturer about that subject. After finding, on a new machine, actual circular burn marks on one of the connectors, wires not connected and very short wire that doesn’t reach. Terrifies me that we’ve had this machine running at all, not while asleep. Thank goodness its not working in some ways!
@Tim_Rastall Thank you Tim for super advice and oh my goodness, we have lots of exposed copper too. Have insisted that, when their engineer comes over to fix it (they have to fly one over) that we have a UK electrician here too. Wonder where I can get a fire box, do you have any example links at all please? Will also ask some technical questions based on your good advice regarding wire and so on. Thank you x
@Jo_Bigger no problem Jo. Any large electrical junction box or enclosure should do you, I’m from the UK originally and the electrical standards there are very prescriptive. The box might melt but it should be lszh (low smoke zero halogen (no nasty fumes)) and won’t burn. Failing that an aluminium or dibond enclosure would do it, hardware stores or electrical suppliers will stock them. Out of interest, what’s your printer?
Thank you for the advice and help guys. Really appreciate it. When I start building my Mendel90, I take all this into consideration. Thanks again. @Jo_Bigger @Tim_Rastall @Matt_Kraemer1
Hello guys,
Preventing fire is crucial. Just in case something goes wrong anyway, detecting smoke/fire is important too. But being alerted if your out is also something to consider.
I use Nest + Camera feed + internet connectivity test when I’m out of office.
Maybe it can gives you some idea too.
The biggest risk of fires, in my opinion, is the wiring, especially when in constant movement. One part of that is what connectors are used - if you look closely, you’ll find that many of the common connectors are run close to or even beyond their maximum rating. Always keep a safety margin to those ratings, since a connector can deteriorate over time or simply not reach its full spec because of user errors.
Then there’s wear from the constant bending that occurs when the axis move around - every time i see that spiral wrap on a bunch of wires it makes me cringe. While that keeps the wires from tangling around, it introduces a weak point right where the wrap ends. Using proper wiring (ribbon cable) and/or drag chains is the right way to do it.
The electronics themselves are really not that prone to buring up (as in with fire). Both the PCB and the parts are flame retardant and usually engineered in a way that if something fails, it’ll just emit a whole bunch of smoke, but not ignite everything around it.
Now, for the hotend and heated bed, there are some basic safety features available in the common firmwares - all you need to do is enable them. They do, however, not prevent every possible failure mode, so a bit of common sense is required either way. It is still a powerful heating element that, when failing for whatever reason, can easily ignite wood and plastic.
@Matt_Kraemer1 , @nop_head uses ribbon cable on the official Mendel90 for everything, including the bed. If you use enough wires in parallel, you can run any amount of current through them.
Don’t forget there are other 3d printing designs that don’t require high temperature components. Powder printers and photo resin dlp for example. All electrical circuits have the potential to short and cause fires, but lower temps, lower voltage, and lower current designs help reduce risk.
I’m another one of those whose printer caught on fire. It was caused by poorly spec’d wires and connectors.
use a higher end electronics and more wires (or thicker) for the high current components like the hotend and heated platform.
Have a smoke detector in the room, nearby. Spend the 10$ for one, it can save your life and your home.
If you notice your wires or connectors melting, deforming, getting brittle, or browning, replace them ASAP. That means they are under rated, so get wires and cables with a higher currect rating.
Owning a 3D printer could void your home insurance due to possible fire hazard, (someone posted about this in the reprap forums).
I’m with most everyone here and don’t like leaving the printer unattended. I’ve had some projects take 8 hours, but I make it a point to keep visiting the room to see how it’s doing. I thought I’d read somewhere how the latest Marlin code now shuts down the hot end if it gets an unusually low reading from the thermister versus trying to keep cranking up the temp based on the low reading. Still, I don’t like having the dependency on what I think it should be doing.
I like what @Tim_Rastall mentioned about using dual thermisters.
@Tim_Rastall Thank you, going to read this all again tomorrow and digest info/research/order products. Feel that I can’t say which printer because I still love the company that makes them. The people. Still willing them to get through this and do well. Think they are better than this and reckon they do too. They will do the right thing, I’m certain of it. I don’t want to damage them, they are new.
Thanks again to everyone that contributed, much appreciate it. Excellent advice.