Fire :(

[Lightnin]

I don't cut acrylic ... but I guess improved extraction (and maybe air assist) would reduce the risk ?
Take the fumes out .. then they cant ignite

[Tom]

You should treat all materials the same
It's not just acrylic that gives off resigns/fumes that can ignite

[Lightnin]

You should treat all materials the same
It's not just acrylic that gives off resigns/fumes that can ignite

not quite true .. some are MUCH worse than others !
you'd have to try hard to ignite MDF fumes

I've spent the last hours of today with a blow torch and scraper cleaning off the MDF residue of the bed .. no fires or anything !

[Tom]

Thats quite funny

[Lightnin]

I thought so too, as I was doing it ! lol

once a year it gets a good going over
new honeycombe too ...

[Tom]

Once a year that's terrible

[Daven]

I don't cut acrylic ... but I guess improved extraction (and maybe air assist) would reduce the risk ?
Take the fumes out .. then they cant ignite

More air = more oxygen. Tried it

The acrylic is basically getting too hot and becoming more volatile at the hot spot, I doubt we would be able to increase the extraction enough to the system (I have quite a good setup already) - inert gas would be a possibility.

All materials we use in the lasers carry a risk - airborne particles become explosive even. MDF, once alight burns quite fiercely - given the right circumstances I suspect it could be as good (bad!?) as acrylic. Wood fumes are flammable - do the school experiment of heating sawdust in a test tube and ignite the fumes - think someone made an engine to work off the fumes too!

The sticky residue MDF excretes when cut in the laser (I assume the bonding agent) help to suppress a flame so the risk is lower but still present.

At the end of the day the 'never leave unattended' is the final solution

Cheers
Dave

[llamalasers]

Aye from now on I'm physically checking the machine every minute or so when doing a cut.. it's only a matter of standing up and looking over.

[Daven]

I have wondered about rigging up some sort of adjustable heat detector that sits in the machine - phillydee - one for you matey

[TimBobTastic]

is fire a higher risk on machined with honeycomb beds that sit in a pretty much enclosed tray?

If so... could the enclosed tray be modified so it was more open allowing for a better flow of flammable gasses...

Just thinking aloud really... probably a bad idea for reasons I have not thought of... But I have access to a friendly bunch of sheet metal workers and industry standard 3D CAD... so was wondering if a little design effort could reduce the risk of fire without making big changes to the machine (apart from swapping the honeycomb tray)