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?
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.
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
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…
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.
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.
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.
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.
"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.
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.
Only with hobbyists it isn’t going to be a 3 alarm fire. Maybe some ply or acrylic. I can flood the whole cabinet multiple times with a co2 reaching areas not covered by a powder type, such as in the holes on the underside of a honeycomb bed, where many of these fires start. The work will usually be a write off.
ANY powder you spray into a greasy go-round machine is going to be a major clean up problem and may end up costing you the whole machine.
It would be much better to take steps to eliminate or reduce the possibility of a fire. Many of the fires I see are due to dirty machines or machines with honeycomb in them that have a build up. Keep them clean, air assist and proper ventilation will deals with this issue, as it does in industry.
Until I burn my house down, I’ll stick with the CO2
I keep a bucket of water near and a microfiber towel…If I think I am going to have a problem, I soak the towel in the water and just have it sitting on the edge of the bucket…My plan is to smother the fire quickly with the wet towel to put of the fire…Plan to place the towels over the work, not the laser head….
Also have a 5lb extinguisher next to the machine……
Improve your air assist to prevent fires starting in the first place. The air pumps provided on most lasers are grossly inadequate, aquarium pumps will provide enough air to keep the lens clean and little else. Not a problem if you are cutting acrylic which is self extinguishing but useless if you are cutting flammable materials such as paper, card or wood. I have a 3HP shop compressor connected to my air assist and used to cut paper, card and wood commercially (up to 14 hours per day). Never had a fire and was happy to leave the laser to work unattended - did stay in the same part of the house but often in a different room.
