Some one will need to monitor the pressures closely. I will be in the boondocks this weekend with no cell reception, so I will not be able to do that. If the pressures get too low, it will need to be shutdown again unless you come up with another suppression source.
I’ve pulled the signs off Donner and Blitzen, but left them on Big Thunder - not sure what, if anything, still needs to be done to it.
Edit: Looks like power is off.
Edit 2: Emergency stop was pulled. Working now.
If anyone does need to shut this off the main shutoff is on the exterior wall in metal shop behind a red tank marked argon. For lasers it’s the bottom valve in this picture secured by a pipe clamp in the open position.
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And, as you can see by the gauges in the center there (more obviously the center when viewing in the Metal Shop), the gas is currently at full pressure.
Just adding a quick note to say the diligence and care is appreciated (despite any comments you could receive to the contrary). The extra care and downtime that happens sometimes in the immediate can be inconvenient but keeps us from potentially losing out in the long term, especially when this equipment is such a great resource for so many.
Thanks for all you (all!) do as volunteers!
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Pressure reading outside as of this morning. Barely moved from yesterday.
Note: This line is shared with some welding equipment, something to keep in mind.
This
To this
Looks like a hundred or so PSI, given each hash mark is 200. Probably no biggie if the tank is being used for welding, but seems excessive for bleed down of a closed system. Not sure which we have…
Ok, despite what went on with the tanks - what was the root cause of the fire? what was the material? what was the power level and speed for that material. was air assist on?
Just because it is a 100watt machine does not mean it should be run at 100 watts everytime for everthing. The idea of less power and more passes definately seems to be lost on people. More importantly - if it doesn’t cut thru the first time, you just don’t run a 2nd pass at the same level. Why? Because the focal point is at the same spot! it is important to raise a bed a smidge (technical term for .003 to .01 inches). I have seen someone try to cut 3/4" oak by running the same location and full power over and over because it didn’t cut thru. Yes - the result was it caught fire since all you’re doing is heating the sides of the kerf.
the material setting guide is just that. but it doesn’t take into account thicknesses or density. Using foam as an example - it will state only one power/speed setting. but you have to ask - was it 1/8" or 3/4". Closed cell or open cell. Dense or soft? All of those require a modification from the baseline. The same for wood and for plastics, etc, etc. This little tidbit needs to be taught as part of the check out class. basically - to run a materials test on a scrap BEFORE running the big job. Just 2 pennies worth of malarchy from someone who’s run his machine for 21 years and never caught it on fire.
I’m not sure if this relates to this current problem
But I was using Donner this morning. It was working perfectly then just started not cutting or etching at all…even at 85% power.
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The material in question was apparently EVA foam.
@cvrana The material I was using was 10mm thick EVA foam, and I had confirmed it to be safe to use on wiki.
Here is the amazon link to it: Amazon.com
I still have it kept there.
I was cutting it at 90% power and around 13 mm/sec speed.
It was cutting perfectly fine for about 45 - 50 mins:
I’ve cut multiple sheets like these, and some smaller ones for testing too.
After about 45-50 mins, it started a minor at which point I realized that the air nozzle is not working.
I definitely should have checked the air nozzle beforehand, which was a major mistake from my side. I will check it for all my projects next time onwards.
Could you please confirm if the material is safe to use in laser cutter again and if yes, what should the speed/power settings be to not put it on fire again?
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I’m honestly inclined to chalk this up to a freak accident. So far the only issue that I’ve been able to determine as a problem was as you mentioned not checking the air nozzle before beginning, which is something that I’ll be sure to stress more to people to actually do before prints of flammable materials.
The only other issue I see is that you should limit your power to 70%. That’s for any material and any job, not just things like EVA foam.
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Team, I was advised that I should have left all the empty argon tank valves in the open position when I opened the spare tank. I’ve now done so which reduces the overall high side system pressure because the other tanks were empty. I.e. the tank with 2000 PSI spread itself across it’s tank and 5 other empty tanks reducing the overall system pressure as a result and anyone monitoring the hi pressure in the tanks will notice this large drop.
This is OK; The system is working normally. I wanted any members monitoring pressures to be aware of the reason for the drop on the high side.
Thanks!
Not sure how much temperature swings affect pressure, especially high day time temps and sunlight on the tanks, could be 100psi swings. Think how hot the surface of a parked car can get.
By shutting the tank down, you’ll see how fast the HP line pressure drops and the LP line. If you set LP to zero and the HP doesn’t drop then you know it’s not in the LP side of the gauge. Shut off between above HP and then turn back on, if no loss, then in gauge. Otherwise some where in other lines connecting tanks into a gang.
Guys I got notification that the argon is now below 300. May be time to shut it down again. That was a lot of argon lost quickly
isn’t this the large drop that was mentioned by opening the other tanks? In theory it should have gone from 2000psi to just over 300psi because the total volume was effectively being multiplied by 6. I feel like this is the expected thing.
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Tim, see my previous post; A big drop was expected. I also believe @rlisbona has replacements on order and we’ll see them hopefully on Monday.
My apologies, 680 miles over 2 days, as well as being out in the heat all day apparently effects my reading comprehension. Just happened to get the alert & check on it
The pressure monitoring system was estimating 22 days of Argon yesterday afternoon. It shows the peak pressure when Jay opened the spare bottle, and after reopening the 5 mostly empty tanks it dropped dramatically but was close to 500 which makes sense if the newly opened tank filled the remaining 5. Its not showing me an estimated time left today. I’ll order a new 6 pack monday morning.
There was larger than typical usage or leaks just prior to opening the 6th bottle.
-Randy
