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Scott Shepherd
01-28-2015, 9:16 PM
I pulled up in my driveway as the hourly news update was on the radio. The fire chief was saying the fire started in the garage of a residence and it appeared to have started by a laser cutter the owner operated in his home.

I came in, looked it up on a local news site and realized I have been in the guys garage. I bought a piece of equipment from him.

http://www.nbc12.com/story/27965317/serious-injuries-reported-after-chesterfield-house-fire

Bert Kemp
01-28-2015, 9:49 PM
Yea as much of a------ it is I stand there and watch it cut.I keep a small spray bottle on the laser itself and have a Kiddi extinguisher by the kitchen stove (less then 10 ft away) I'll do computer work if engraving but if its cutting I stand right there drinking coffee. I'm thinking about putting a mirror over head so I can sit at the computer and do design stuff, all I'd have to do is look up to see inside or maybe install a heat sensor inside the case that set off a bell or something.I dunno just thinking out type :p

John Noell
01-28-2015, 10:38 PM
After reading anough fire threads here, I bought a big CO2 extinguisher. If I do have a fire, putting it out with CO2 will not kill the machine. (I remember a car fire when a bare carb and bad spark plug wire caused a BIG problem. As it turns out, spraying fire extinguisher powder down the carb of a running motor is definitely not good for the motor!)

Clark Pace
01-28-2015, 11:59 PM
After reading anough fire threads here, I bought a big CO2 extinguisher. If I do have a fire, putting it out with CO2 will not kill the machine. (I remember a car fire when a bare carb and bad spark plug wire caused a BIG problem. As it turns out, spraying fire extinguisher powder down the carb of a running motor is definitely not good for the motor!)

About 1 year ago laser company about 1/2 away from me caught on fire. They left the room for only a few minutes. I believe it was a total loss.

Rich Harman
01-29-2015, 12:00 AM
I hope he doesn't have problems getting his insurance to cover the damage.

Scott Shepherd
01-29-2015, 8:02 AM
I hope he doesn't have problems getting his insurance to cover the damage.

It should be interesting. When I bought the equipment from him, I saw this "contraption" packed into the corner of the garage. He said "it's a laser cutter" then told me that he built it all himself. He opened the top and it was all stuff he had hacked together to make a machine.

Bill George
01-29-2015, 8:13 AM
It should be interesting. When I bought the equipment from him, I saw this "contraption" packed into the corner of the garage. He said "it's a laser cutter" then told me that he built it all himself. He opened the top and it was all stuff he had hacked together to make a machine.
Hmmm, built it as homemade. I bet his insurance Co will take a long look. The CO2 extinguisher is a good idea. Wonder why a automatic fire protection could not be fitted?

chris szlachetka
01-29-2015, 8:51 AM
If the box is enclosed, how could the fire jump ? We have an Epilog mini 24 and can't see how a fire could exit out of the machine. There's gotta be a better way to extinguish a small fire like that vs using a powder base extinguisher. How about a fireproof blanket or something along those lines to smother the fire ?

Nicolas Silva
01-29-2015, 8:55 AM
If you haven't already done it, make sure you've installed a smoke detector in the laser room.
I keep a fire extinguisher in the corner as well. Cheers!

chris szlachetka
01-29-2015, 9:29 AM
We're in a commercial building that's setup for this kind of thing. One of the first things we purchased was a fire extinguisher (located right near the machine) and smoke detectors. I was just thinking there's gotta be a better way to put it out if the problem was to ever show its ugly face.

Scott Shepherd
01-29-2015, 9:32 AM
If the box is enclosed, how could the fire jump ? We have an Epilog mini 24 and can't see how a fire could exit out of the machine. There's gotta be a better way to extinguish a small fire like that vs using a powder base extinguisher. How about a fireproof blanket or something along those lines to smother the fire ?

If the lid is acrylic, it'll catch the lid on fire and then you've got a serious fire going.

Also, there was nothing said (nor will there be in the news stories) about what caught fire. Was it material? Was it electronics in the machine? It could have been totally outside of the machine, or it could have been inside, while cutting. If my memory is correct, he wasn't engraving anything, only cutting and his machine was running Mach 3, so it was strictly used for cutting. I think he told me that almost everything he cut was plywood.

Mark Ward
01-29-2015, 1:14 PM
Sometimes I'll leave the room when doing the wood that we use in day in day out but never do when it's acrylic.
We have a smoke alarm and a CO2 extinguisher in there with it.

Mike Audleman
01-29-2015, 1:52 PM
Well, given my other hobbies, one of which is reloading (ammo), I have an acute awareness of fire hazards. The last thing I need is a fire eating up 50# of powder and 10's of thousands of primers and getting out of hand and getting to the loaded ammo.

Extinguishing fires is accomplished in one of three ways. Remove the fuel. Remove the oxygen. Remove the heat. Since both of those (powder and primers) contain their own oxidizers, a chemical ABC will not work as it operates by removing oxygen to the fire. I use pressurized water type extinguishers as they remove both the oxygen and the heat from the fire. Also by saturating surrounding surfaces they remove additional fuel as a source. But, if its more than a small fire, there is no surviving it unless I get everyone out of the house toot sweet. With that much powder and primers along with 100's of thousands of loaded rounds of various types (from 22LR to 50BMG) being stored there, well, lets just say you won't want to be around when it starts cooking off.

I do keep a small windex type spray bottle with water near the laser cutter. I know the water extinguishers are very close though as my relaoding room is on the other side of a partition wall (its all in the basement). They are not good with electrical and I can see a serious hazard given the HV on the tube. I think I need to re-think things and seek out a CO2 or Halon extinguisher for around the laser cutter. It should sufficiently take care of any issues inside the cutter as well as not causing a shock risk around the high voltage components of the cutter.

Clark Pace
01-30-2015, 12:44 AM
The company that burnt down near me pretty much only did wood! So wood can be just as dangerous. In my town a fire extinguisher was required before I could open business.

Mike Audleman
01-30-2015, 10:17 AM
The company that burnt down near me pretty much only did wood! So wood can be just as dangerous. In my town a fire extinguisher was required before I could open business.

I am not a business, just a home hobbyist. But its the same risk as far as fire goes.

joe claudio
01-30-2015, 6:46 PM
Greetings all ..
just putting out some stuff I havethought of in the name of "safty".... my main in production machine is a Gen4 FSL 40 watt hobby that has been tweeked. That being said , some of the future pie in the ski improvemts I "want" to make was to abandon the air compressor in favor of an inert gas bottle for the air assist. The current contol board does not have a an "output" to control a solieniod- I only want "bottle gas" to be running when the laser is in operation. now big picture- If I have a 2 stage soliniod, - one low presure for air asist, and then a larger "gas circut" controlled by a heat sensor that will turn on when the heat sensor trips - that ALSO shuts off the laser and floods the machine with inert gas... I have quite figured it out .. but the concept is there. On my Rd350, this woudl be easier to acomplish as the Rdlc320 controler has outputs that can drive "stuff".... Its knocking around in my head ..... Also .. I THINK .. a race car fire supresion system might be able to be modified as a stand alone ....
- J

Dan Hintz
02-02-2015, 6:17 AM
That's a very dangerous concept, Joe. You could flood a room with inert gas and kill someone.

Dave Sheldrake
02-02-2015, 8:49 AM
Like Dan said Joe, the level at which combustion will no longer take place is several orders of magnitude above what would have already killed anybody in the room.

Mike Audleman
02-02-2015, 11:22 AM
Greetings all ..
just putting out some stuff I havethought of in the name of "safty".... my main in production machine is a Gen4 FSL 40 watt hobby that has been tweeked. That being said , some of the future pie in the ski improvemts I "want" to make was to abandon the air compressor in favor of an inert gas bottle for the air assist. The current contol board does not have a an "output" to control a solieniod- I only want "bottle gas" to be running when the laser is in operation. now big picture- If I have a 2 stage soliniod, - one low presure for air asist, and then a larger "gas circut" controlled by a heat sensor that will turn on when the heat sensor trips - that ALSO shuts off the laser and floods the machine with inert gas... I have quite figured it out .. but the concept is there. On my Rd350, this woudl be easier to acomplish as the Rdlc320 controler has outputs that can drive "stuff".... Its knocking around in my head ..... Also .. I THINK .. a race car fire supresion system might be able to be modified as a stand alone ....
- J

Lots of problems with that concept. Well, not in using CO2 as an assist gas, thats easily done, but as a fire suppression system, bad concept.

CO2, yes its heavier than air, diffuses very readily. Nevermind the hazard to humans as mentioned before. The only way you are going to get enough CO2 out of that tank in time to extinguish the fire is to bypass the regulator (no way it can supply sufficient volume of low pressure gas) and go straight to the valve and that means direct tank pressure. Are you prepared and technically savvy enough to work with gas pressures anywhere from 800 to 4000psi? You are not just gonna trot down to Home Depot and buy pipe fittings rated for that, not without blowing yourself up anyway. Those large gas cylinders are hydrostatic tested (thats what the date stamp in the metal on the top of the tank is) to withstand the extreme pressures the tank will endure, are you prepared to have your system pressure tested too? Unless you have sufficient engineering background, um, you are treading into dangerous waters here.

What happens when the CO2 tank is empty and there is a fire? Got a backup?

I used to have a "street" drag (home built 700hp dual supercharged nitrus boosted 11sec in the quarter) back in the late 70's and early 80's. Yes, it had a FSS or fire suppression system. Back then it was hundreds of dollars. Race car FSS are almost always Halon or FE-36 based, at least for gas based systems, others may be foam or other chemicals. Those gasses are expensive so that means you must use it strictly as a fire system, not as a air-assist system. You are looking at $400+ for an automatic FSS just to get started and more likely into $1k or more. And most won't trip until 150+ degrees minimum. Ones designed for fuel area are usually upwards of 250 degrees and engine compartments are 350+. You want to wait until your laser cabinet heats up to the temperature your wife bakes cakes at before it trips? Didn't think so. Yea, they work well for cars. I don't think so much for laser cabinets. They are designed for sudden fuel fires, not smouldering plexiglass. And, they are designed to be used OUTSIDE where the driver can get a supply of fresh air fairly quickly. The FSS discharges quickly to smother the fire but the smothering gas dissipates quickly so it doesn't kill the driver. Outside anyway. Both gasses are VERY heavy gasses. That means they will displace the air in the room and potentially kill everyone inside if the system is discharged un-monitored or even monitored and people don't get out immediately. I am dubious in converting them to CO2 as well. Pressurized CO2 causes an extreme temperature drop when released (well, most any high pressure gas will I guess). Halon and FE-36 are not stored at nearly as high a tank pressure as CO2 is and therefore do not pose the threat of freezing the discharge valve. I would be worried that the modified FSS valve might freeze up during a release and fail to release CO2 properly.

Every aspect of the concept is wrought with extreme complications that make it impractical to implement.

Robert Tepper
02-04-2015, 12:17 AM
I mostly vector cut mylar at low power, about 16 watts. I am always in the room and have a very large CO2 extinguisher right next to the machine. I have excellent ventilation flow but I am always never more than a few steps away.

When I make rubber stamps I never leave the laser.

I do not do any wood or acrylic cutting.

Robert

Steve Morris
02-04-2015, 5:28 AM
yep the best fire warning system is the mk1 eyeball in these situations. NEVER leave the machine running unattended is the best policy.
Keep a fire extinguisher to hand and make sure you have clear exit paths.