Opinions: Safe to cut or fire hazard


#1

I have a large number of dualply cardboard sheets. Wondering if this is likely to catch fire during cutting. I’d like to use it for prototypes and, more importantly let my son use it to prototype (more worried about how he reacts to a fire). Opinions wanted.


#2

Corrugated box board requires you to stand over it. It is fine to use as long as you know the risk, it is not going to instantly cause a conflagration but it may flare up. Avoid sharp corners and points. Rounded corners and organic shapes tend to work well.

Have a damp cloth ready for if it does flare and doesn’t immediately self-extinguish.

Edit: I forgot to ask how old and mature your son is? If he is old enough to be running it without you right there, do some drills on having a fire so he does not panic and just reacts to the situation.


#3

I have been cutting a bunch of that, 250 speed and full power. The only time I get a flare up is if two cuts are really close to each other.


#4

I would not leave it unattended, but it is not unsafe. I use 190 speed and 90 power and it has never caught fire. I did start a campfire in my glowforge using the engrave (I wasn’t trying to engrave, it was my first day and was clueless.) You can see from this post the cardboard once it was extinguished.


If an ember does get caught inside it, just open the lid and press down on it with a damp wash cloth. As the Hitchhikers Guide to the Galaxy reminds us, Don’t Panic. Lift the lid and tap it out before it can spread much.


#5

Cardboard is safe with the Proper Power and Speed settings.

Going too slow will create a fire issue. Run multiple tests with the different types of cardboard BEFORE letting him go on his own AND never leave cardboard cuts without supervisor.


#6

Double corrugations offer more folds to catch fire and hide from the air assist. Needs some more supervision. On my Basic I prefer to cut cardboard at a lower power, or at least not Full power. Generally around 80%.

I’d suggest doing a series of 1/8" by 2" rectangles spaced right next to each other. Every two rectangles change one parameter and see what works.

Start by doing the first two (black) at 500 speed and 70% power. Then decrease speed by 50 magical speed units each operation but keeping 70% power. You’ll get down to 150 speed. Doing it with increased laserness (in this case by slowing it down) will allow you to watch an cancel the print if something gets nasty by the end of the operation.

Then do another set of tests, this time with 80% power. By then you may opt to try it at 90" power, for the good of the order but you will need to be doubly vigilant from the start because likelihood of area char taking place will be great. Using a tight grid like this gives a good indication of how char and burnout developes with cardboard. Isolated paths aren’t too much of a problem, but tight radii and close lines can be problematic.

TightRectangleTests

There are other ways to do this, but that’s I how proceed and can to what I can live with.


#7

Thanks for the comments and advice. Cuts perfectly at 250 speed full power on pro. No signs of flare up but I’ll make sure it’s watched closely.


#8

I’ve never had dualply catch fire, but I’d babysit constantly.


#9

I believe Hitchhiker’s Guide also mentions towels*. So Don’t Panic, carry a towel - so you can put out the fire in the GF. Douglas Adams was way ahead of his time.

*“A towel, it says, is about the most massively useful thing an interstellar hitch hiker can have.”


#10

Cut it up, just keep an eye on it. Catching something on fire is like losing your laser virginity.


#11

that makes my laser a tramp :rofl:


#12

With attitude like that, it’s not that great a Lady.