Nothing shiny like chrome. I believe they had a note about it somewhere in either the user manual or something that they sent out at around that time.
My gut feeling is that a 4" fan, similar to the one the GF uses for venting (under the assumption of a properly sealing vent tube) will pull more than enough air to remove any HCN or other fumes. A quick average of the CFM ratings of three different 100mm computer case fans (which the one in the GF certainly isn’t based on the noise alone) comes to 39 CFM, which works out to a box 3.3’ (essentially a meter) per side. This also works out to be 2/3 of a cubic foot of air PER SECOND.
Using a rough internal volume of 18x20x9" the entire internal volume of the GF is getting 100% fresh air every 2.8 seconds (again assuming what I feel are conservative CFM ratings for computer case fans of approximately the same size).
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Tangential question:
Is there any difference (in human safety) in the smoke produced from lasing wood vs the smoke from a campfire? Same thing? Or if not, why and how…
I can think of one difference. With a camp fire, you usually have fresh air with occasional breaths of smoke. With a laser in a confined space you would have constant low level smoke inhalation that you willingly breath, so perhaps it could be more harmful
I havent run any cuts on Polyurethane yet but I have run about 90 minutes continuous engraves. My ventilation is buttoned up tight though, I don’t have any odors or vapors during projects, except what’s left lingering in the GF after a job.
You’ll know right away if you have an HCN leak though. The gas displaces oxygen so the first signs will be shortness of breath then dizziness/confusion.
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Taking a look now, That bottom sheet is fairly reflective! I can see the LEDs clearly in it, despite the anisotropic metal texture…
The goal on this site is safety of final product, but handling of the wood, avoidance of fumes//dust, etc, can be derived from this list.
Some information explaining the terms (like Sensitizer) on the bottom of the page.
Some, like YEW, are pretty straight forward, (DIRECT TOXIN), and Oleander goes even further since every aspect is Toxic.
http://www.wood-database.com/wood-articles/wood-allergies-and-toxicity/
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The heat conditions are a bit different. For example, many combustion byproducts are also combustible so burn in the context of oxygen and heat. Some more of those could stay uncombusted in a laser cutter because you’re actively cooling the area.
On the other hand you’re trying to transmit the 40W of heat to as finely focused spot as you can manage which directly vaporizes the material rather than oxidizing it to generate heat in a normal combustion chain reaction. So the initial fume composition may be different as well.
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I HATE this plant with a passion.
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Ugh
Stainless, it seems. Magnets love it. The owner manual is extremely explicit, as is support, about not letting the laser hit the base of the unit, so I choose to avoid the risk. Maybe I will do some testing with some paper on a backstop and see what power hits .3 above the bottom.
I went to ReStore and bought a LARGE floor tile for $0.25 for my backstop. The laser can’t get through it without a LOT of effort, if at all.
In my time at TechShop we learned that we were never to do any “uncoated” metals due to the possibility of a reflection. Another one to avoid is Polycarbonate materials as they will burn severely and that is not good for the machine, not sure what the combustion products are but I would not want to breath even the tiniest amount.
So, I did install my backstop. Then I taped a paper to it. Told it to do full power with a .5" focus for an engrave.
Ready for the Go button! So go!
I stopped it early with a hole burned through the paper and marking the tile beneath. I’m pretty sure the laser does NOT defocus enough to avoid reflection for potential damage. It’s hella bright.
So the manual and support are quite adamant about this, and I’m certainly not going to ignore them.
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WOW, I’d put that in the “Avoid at all costs” category. That’s bright even on my screen!
It was VERY bright, brighter than hitting slate with full power. That’s hitting a tile (laser resistant) around .3" from the bottom. I’d hate to think what it could do hitting the reflective bottom and bouncing back.
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Good point, could have used a lot better word for my intent.
Using my harbor freight stainless steel ruler. I coated with CRC Dry Molybdenum Lube (spray). Lasered it at 100power and 100 speed… then wiped off the moly.
It seems to have etched the metal… rather than marked… Seems to have pits in the metal now. You can see depending on the light angle, it’s dark or reflective - I think because of the raw unpolished metal underneath…
To test this idea, above the (R) you see a “k” rotated 90deg… That’s been lasered without any moly at all…
Maybe harbor freight uses a special stainless that is meant for laser marking… Or maybe coats these in a very thin stainless layer to save costs, and my laser obliterates that. Is all I can think of.
My laser is still good. Done many projects since this test.
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Here is my experiment with Aluminum marking, using CRC Dry Moly Lube (spray).
Lasered at 100power and 100 speed, 3 passes.
As you can see, the result is faint. And the laser needed the extra passes to get this dark. The metal appears to be very slightly raised where the moly was (the metal wasn’t pitted like the stainless was.).
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With dry moly lube, I’m always doing multiple coats with dry time between, then multiple full power passes. I’ve been able to get some ok marking, though fades a bit when seen at an angle.
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Yeah, I didn’t mention that that was with 2 coats and drying time.