Small fire procedure - How to move laser head away FAST?

Does anyone have any tips for dealing with small fires?

Small flames tend to go away when I’m cutting acrylic, and for big serious fires I assume I’ll just blast it with an extinguisher.

But what about smaller fires that I could put out by hand? Will the laser head still be hanging around getting torched and getting in the way?

I suspect I want a way to move the laser head away to safety (via a hotkey/hardware button) at high speed. Is this possible via Saved Positions or something?

Any thoughts welcome.

Well not sure about what controller you have but my rudia allows me to move the head and it isn’t slow, not screaming fast.

I am more curious why you have fire issue. Are you using too much power? Got air flow?

I have a Ruida RDC6445, but at any given time I might have the speed set to something really slow, and fiddling with the controller seems a bit suboptimal in an emergency.

I’m not currently experiencing fires, but I keep reading “don’t leave it unattended, have an extinguisher, you will get a fire” etc. So I’m trying to be prepared. Unless I’m overthinking it?

I don’t think I can do anything with the head while it’s running a job on my Ruida. Seems that the console is locked out during a pause.

If you have flames large enough to endanger the cutting head, I think you need to look back at the speeds and feeds you’re using. What kind of bed do you have? This can aggravate burning. Mine is rolled steel and although residue collects it’s easy to clean.

I keep a CO2 extinguisher for emergency. Hope your extinguisher is gas and not powder based.

:slight_smile:

I haven’t had any fires yet, but since I’m new and still figuring out material settings, I assume it’s only a matter of time. I’ll know something is wrong with the feeds and speeds if I do get a fire, but I’ll still need to deal with the fire :slight_smile:

If a macro/hotkey isn’t possible, what about manual moving? If I hit emergency stop, does it kill power to the motors so I can just physically push the laser head away?

I’ve got one of those black aluminium knife tables and a CO2 extinguisher.

Usually air pressure will do the trick as fires seem to occur when cutting. Glad you have a gas extinguisher for the issue if it arises.

When you press the emergency stop switch most of these machine kill the mains voltage to the whole device, so you should be able to hit the emergency switch and move the head by hand. Personally my hand is worth more than the head… but I can see your point.

Most of the fires you hear about are where the operator has left it running and it got out of hand before anyone knew it was an issue.

Your worry is justified, but I think you have it handled about the best you can do. One of the users has his compressor for the shop as air, he has an air attachment to blow fires out. He claims it works well…

:slight_smile:

Thanks, that’s good to know. I feel I can relax a little now :slight_smile:

Interesting, I might have to look into the air attachment idea. Sounds like a fun experiment.

Hmm. I like that. I think I’ll stick a tee in my air line right next to the laser and keep a short hose and nozzle permanently attached for that purpose.

Make sure your air supply is at high enough pressure to blow out the fire, not just fan the flames. If you have access to shop air pressure (75-100 psi or so) that should do it, 3 or 4 psi will make it worse.

That air line is backed by a Ingersoll Rand 2340 so I’m probably all set there.

I’m not sure why you are worried so much about fire and moving the head. If you hit the emergency off switch you can grab the gantry and push it backwards or pull it forwards. As for air supply to the laser head it’s more about airflow than pressure. I have an aquarium pair pump that push’s 115 liters per minute and that’s enough.

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I was going to say the same, shut the machine off. It will release the hold on the motors. The gantry will move with ease.

CO2 Extinguishers are suited for Class B fires (such as flammable liquids, and electrical) NOT Class A fires involving paper and wood.

You would be much better off with a dry chemical extinguisher loaded with PKP (aka: ‘Purple K’). DO NOT confuse this with a Sodium Bicarbonate ‘dry chemical’ extinguisher found in most RV’s in North America PKP has over four (4) times the knock-down of CO2 against a Class B fire (flammable liquid), but you are dealing with a laser, not a Class B event.

Any fire you are likely to encounter with your laser will MOST likely be a Class A fire.

You can set fire to the Christmas Turkey, put it out with your CO2, and continue cooking it. But it will NOT effectively put out a fire that’s likey on you laser bed.

Q: what ‘fires’ are you “putting out by hand”?

Thanks for the information. It seems there’s a lot of confusion around CO2 fire extinguishers; indeed Trotec and HPC both recommend using them for their laser machines. It would be interesting to know their thoughts.

I think I mentioned a couple of times I’m not experiencing fires, but when I say “by hand” I refer to fires small enough to not require an extinguisher, which I believe is also the case for the people talking about using an air hose to blow fires out.

My thoughts on that would be the dry chemicals can really mess with machines. CO2 removes the O2. When I was messing with turbines we were warned no dry chemical extinguisher as it will cause damage to the turbine.

A fire on a turbine is most likely to be an oil leak, soaking into the insulation, and therefore a CO2 is not the best choice for ‘knock-down’. If the turbine is on an aircraft, a sideslip is a valid option, or deploying the extinguisher bottles, which used to be Halon, but have been replaced with HFC’s in the '90’s.

But getting back to his concerns… I would strongly urge a Purple K extinguisher be alongside, and be familiar with how to deploy it. OR … since it is a laser, burning material … don’t leave it unattended.

Just remember: the fire is a tetrahedron … not a ‘triangle’ like most of us were taught as children.

CO2 only reduces the O2, and cools the environment, and yes Dry Chemical can cause corrosive effects to hot bus bars, and contacts in an electrical fire event … but damaging a turbine?

Most fires in these lasers are small and not a large engulfed fire… Filling the case with CO2 smothers the fire. It has to be really hot to start up again which is not usually the case with CO2 machine fires. If it goes up big time, I doubt anything useful will be left anyway.

This is from the wiki

"Cleanup of spent agent can be difficult, as it forms a residue when discharged. If the spent agent is dry it can be removed by suction, but when combined with water, hydrocarbons and other liquids, it forms a thick crusty scum that can be challenging to remove. "

Anything that has any kind of lubrication, such as the rails and bearings will be crusted. This is the exact reason I went with a gas.

Not to mention a 5 lb CO2 is 100 bucks, Purple K appears to be twice to three times the price.

Thanks, but I’ll stick with my CO2…

You could always consider Halon 1301 suppression. :smirk:

Halon makes the Purple K seem low cost. And you can’t get Halon anymore, there’s some new variant that is supposedly safer, of course more money…

I’ll stick with the CO2. Been though this a year or more ago when I was looking for controlling a fire. Haven’t seen anything yet that as low cost and effective as CO2. :slight_smile: