Newb to all things lasers Fiber, CO2 and the little guys on ebay

Hi all, one of the gents that is a member of this forum was kind enough to provide me the link and said I should ask around and get familiar with this site. I am currently looking at building my own cnc laser for stippling Polymer frames and hopefully using the same setup to do engraving and design work on anodized and non anodized 80% aluminum. Any directions or pointers you guys have I would be grateful. Or even if you just say hey stupid its already been discussed over here or hey your barking up the wrong tree. I don’t mind. If you dont ask you dont learn Is how I see things and there is so many folks out there that have the same ideas as me and have either tried and failed or tried and made it and why not use their notebooks. Thanks in advance for your assistance.

Jake

Metal needs a YAG laser; the CO2 lasers are the wrong wavelength for metal. When you look up the prices for YAG lasers you’ll understand why hobbyists are rather more likely to have CO2 lasers than YAG lasers.

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20W Fiber lasers have now dropped into the $3-5K range now, so they have become somewhat affordable.

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One question… the reason why I until now avoided to buy a laser is the fumes. How do you deal with this problem. At my previous job we wanted to laser engrave halogenized polyamide. We had to check the emissions and from that time that technology was never touched again. One of the emitted residuals I was told about was Carbonyl Dichloride… other / better known name is Phosgene

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CO2 lasers in general are in a closed case with an exhaust fan that is directed to the great outdoors, or into a fume filter like a BOFA unit.

So you use filters? I was told that the reliable ones are pretty expensive. I have a small flat but no garage with a direct way out… perhaps I could use it on the balcony

My shop has no window, and I would have to cut a hole in the wall to ventilate. I’ve been wondering the same. How effective are the carbon filters? At least some people I’ve talked to with experience do both…

There are good explanations regarding different filter classes by manufacturer Draeger available, but dependent on the chemicals resulting from melting vapourizing or pulse eroding materials I can’ t believe that one filter class is able to do bind all different components… as there is even a filter change necessary for organic chemicals vapourizing below 65degree Celsius and over 65degree Celsius.
https://www.berner-safety.de/filter_selection_guide_for_draeger_respiratory_masks_en_1078.html

Those are for respiratory filters but I think for static filter units its the same…

And for example our marking units filter at the job has to be serviced. You are not able to either buy such a filter or allowed to service it yourself… they always send a maintenance guy…

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Filters = Expensive, the media clogs up very quickly and is expensive to replace. It is a method of last resort in my opinion, being able to vent outside is my preferred way.

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The biggest thing we recommend not to laser cut/engrave are halogenated materials like PVC. Typically these type materials generate toxic / corrosive by products.

I’ve seen examples of people making DIY fume filters with particulate prefilters followed by activated carbon chemical absorbing medium. A good high efficiency particulate prefilter would be key to keep the activated carbon from plugging up to quickly

You can use a co2 laser to laser off the coloring from colored / dyed anodized aluminum but you would need a fiber laser, as mentioned above, to engrave into metal. At least at common CO2 wattages.

Interesting

https://www.ebay.com/i/163256843314

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I considered to build a filter from filter fabric plates from vapor absorbing devices in the kitchen , but when my father died from sclc in 2012 and they had asbestos under suspiction I promised myself I never will do things I cannot approve in function when its going to be health related.
Halogenated (anti burn additives) plastics, -when burned- generate -as I learned- gases like Phosgene, which you don’t smell but with the humidity in your loungs react to hydrochloric acid… noting I would like to have, as Its chemical warfare at its finest (see reports of WWI - its more toxic then Chloric gas).
Burning PVC around 770 deg Celsius generates another well known substance called TCDD… yes DIOXIN which is considered to be one of the - by dose- poisonest substances made by man. Its cancerogenous and the LD50 for a mouse is about 0.000005g/kg bodyweight. A human needs more then 10 years to halve the ingested dose without ingesting new one… not to blame anyone, but keep yourself safe guys.

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In our fablab we have built a filter system with 3 stages. 1st stage is high voltage ionizing, 2nd stage is a industrial fleece mat filter and the 3rd stage is a large activated carbon filter flanged to an industrial blower. The output is still vented outside.

The high voltage ionizing helps to build up bigger clusters of small vapor, which then can be captured in the fleece filter, instead of clogging the activated carbon.

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Sounds interesting, but how to check if it works efficient enough and keeps the unwanted from the inside air if the final vent out is not possible. And how do you plan the maintenance cycle.
That sounds a bit difficult to me. I’m living in a house together with others and so would share the risk… I think I’ll stay wih my router bits… even, if it would be a bit slower!

I would not recomend blowing the output into the room. After a year of operation, we can see at the fins of our blower that there is still unwanted dust in the output (that I wouldn’t want to breath).

For early maintenance indication we have added pressure sensors between the 3 stages so we can predict when the filters need maintenance. Whithout this, it’s impossible to predict how long the filters will last, because it’s depending on the material you cut or engrave.

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I like the strategy to have an idicator for the airflow but thats showing only particle related. Molecular structures like the hazardous gases are hopefully reacted to non hazardous ones by the active carbon structure but the saturation / wear of that filter is not that easy to watch. In my past I did also some painting for which I got an on face respirator mask + filter from an uncle… the filters were new at the beginning and I extended the use until I was able to smell solving agent. Put from position “now” I should have changed them earlier. (For my luck the paint and solvent were not that hazardous). But what I wanted to say… the fumes were smellable altough I was - all the time- able to breath freely through the filter… which I would think means a rather low pressure drop by clogging.

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